Collected Evidence: Collected Evidence: Soil: Grow cover crops in arable fieldsOrganic matter (12 studies): One meta-analysis of studies from Mediterranean-type climates and ten replicated, controlled studies (nine randomized, two before-and-after) from Italy, Spain, and the USA found more organic matter (mostly measured as carbon) in soils with winter cover crops, compared to soils without them, in some or all comparisons. One replicated, randomized, controlled, before-and-after study from Italy found inconsistent differences in organic matter in soils with or without winter cover crops (sometimes more, sometimes less). Nutrients (22 studies) Nitrogen (21 studies): Ten replicated, randomized, controlled studies (two before-and-after) from Italy, Spain, and the USA found more nitrogen in soils with winter cover crops, compared to soils without them, in some comparisons. One replicated, randomized, controlled study from the USA found less nitrogen in soils with winter cover crops, compared to soils without them. Ten replicated, controlled studies (nine randomized, two before-and-after) from Italy, Spain, and the USA found inconsistent differences in nitrogen (sometimes more, sometimes less) between soils with or without winter cover crops (but see the paragraphs, below, for distinctions between different forms of nitrogen). Phosphorus (1 study): One replicated, randomized, controlled study from the USA found similar amounts of phosphorus in soils with or without winter cover crops. Potassium (1 study): One replicated, randomized, controlled, before-and-after study from the USA found an increase in potassium in soils with winter cover crops, and no increase in soils without them. Soil organisms (12 studies) Microbial biomass (6 studies): Five replicated, randomized, controlled studies from the USA found more microbial biomass in soils with cover crops, compared to soils without them, in some or all comparisons. One replicated, randomized, controlled, before-and-after study from Italy found inconsistent differences in microbial biomass (sometimes more, sometimes less) between soils with or without winter cover crops. Nematodes (2 studies): Two replicated, randomized, controlled studies from the USA found more nematodes in soils with cover crops, compared to soils without them, in some comparisons. One of these studies also found a higher ratio of bacteria-feeding nematodes to fungus-feeding nematodes in soils with cover crops, compared to soils without them. Earthworms (2 studies): One replicated, controlled study from the USA found more earthworms in soils with winter cover crops, compared to soils without them. One replicated site comparison from the USA found similar numbers of earthworms in soils with or without winter cover crops. Bacteria and fungi (2 studies): One replicated, randomized, controlled study from Spain found more bacteria and fungi in soils with winter cover crops, compared to soils without them, in some comparisons. One replicated, controlled study from Italy found more spores and species of beneficial fungi (mycorrhizae) in soils with winter cover crops, compared to soils without them, in some comparisons. Soil erosion and aggregation (4 studies) Soil erosion (2 studies): Two controlled studies (one replicated and randomized) from Israel and the USA found less erosion of soils with cover crops, compared to soils with fallows or bare soils. Soil aggregation (2 studies): Two replicated, randomized, controlled studies from Spain and the USA found more water-stable soil aggregates in plots with winter cover crops, compared to plots without them, in some or all comparisons. Greenhouse gases (5 studies) Carbon dioxide (5 studies): Three controlled studies (two replicated and randomized) from Italy and the USA found similar amounts of carbon dioxide in soils with or without cover crops. Two replicated, randomized, controlled studies from the USA found more carbon dioxide in soils with cover crops, compared to soils without them, in some comparisons. Carbon storage (1 study): One replicated, randomized, controlled study from Italy found more carbon accumulation in soils with cover crops, compared to soils without them, in some comparisons. Nitrous oxide (2 studies): One replicated, randomized, controlled study from the USA found more nitrous oxide in soils with cover crops, compared to soils without them, in some comparisons. One controlled study from the USA found similar amounts of nitrous oxide in soils with cover crops or fallows. Implementation options (9 studies): Five studies from Italy, Spain, and the USA found more nitrogen in soils that were cover cropped with legumes, compared to non-legumes. One study from the USA found inconsistent differences in nitrogen (sometimes more, sometimes less) between soils with different cover crops. One study from the USA found no differences in phosphorus or microbial biomass between soils with different cover crops. One study from Italy found differences in beneficial fungi (mycorrhizae) between plots with different cover crops. One study from Spain found higher soil quality in plots with long-term cover crops, compared to short-term. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1345https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1345Wed, 08 Mar 2017 15:10:16 +0000Collected Evidence: Collected Evidence: Crop production: Add compost to the soilCrop yield (8 studies): Three replicated, controlled studies (two randomized) from Italy, Spain, and the USA found higher crop yields in plots with added compost, compared to plots without added compost, in some comparisons or all comparisons. Two replicated, randomized, controlled studies from Italy and the USA found inconsistent differences in crop yields (sometimes higher, sometimes lower) between plots with or without added compost. Three replicated, randomized, controlled studies from Spain and the USA found similar crop yields in plots with or without added compost. Of two replicated, randomized, controlled studies from Spain, one study found higher yields of barley straw in plots with added compost, compared to plots without added compost, and one study did not. Crop quality (0 studies) Implementation options (1 study): One replicated, randomized, controlled study from the USA found similar crop yields in plots with added compost that did or did not also have added fertilizer.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1346https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1346Thu, 09 Mar 2017 17:05:03 +0000Collected Evidence: Collected Evidence: Crop production: Add manure to the soilCrop yield (2 studies): One replicated, randomized, controlled study from Greece found higher maize yields in plots with added manure, compared to plots without added manure, in two of three comparisons. One replicated, randomized, controlled study from Italy found similar nectarine yields in plots with or without added manure. Crop quality (0 studies)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1347https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1347Mon, 20 Mar 2017 10:57:28 +0000Collected Evidence: Collected Evidence: Crop production: Add sewage sludge to the soilCrop yield (1 study): One replicated, randomized, controlled study from Spain found higher barley yields in plots with added sewage sludge, compared to plots without it. Crop quality (0 studies) Implementation options (1 study): One replicated, randomized, controlled study from Spain found higher barley yields in plots with low amounts of added sewage sludge, but not high amounts, compared to plots without added sewage sludge.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1348https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1348Mon, 20 Mar 2017 11:58:57 +0000Collected Evidence: Collected Evidence: Crop production: Add slurry to the soilCrop yield (6 studies): Six replicated, randomized, controlled studies from Spain found higher crop yields in plots with added pig slurry, compared to plots without it, in some comparisons. Crop quality (0 studies) Implementation options (4 studies): Two replicated, randomized, controlled studies from Spain found similar crop yields in plots with digested pig slurry, compared to untreated pig slurry. One replicated, randomized, controlled study from Spain found lower crop yields in plots with less pig slurry, compared to more, but another found similar crop yields with different amounts of pig slurry.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1349https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1349Mon, 20 Mar 2017 12:04:53 +0000Collected Evidence: Collected Evidence: Crop production: Use organic fertilizer instead of inorganicCrop yield (11 studies) Food crops (10 studies): Four replicated studies (three controlled, two randomized; one site comparison) from Italy and Spain found higher yields in plots with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Three replicated, randomized, controlled studies from Spain and the USA found lower yields in plots with organic fertilizer, compared to inorganic fertilizer, in some or all comparisons. Three replicated, randomized, controlled studies from Greece and Spain found similar yields in plots with organic or inorganic fertilizer. Forage crops (1 study): One replicated, randomized, controlled study from Spain found higher alfalfa yields in plots with organic fertilizer, compared to inorganic, in one of two comparisons. Crop quality (0 studies)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1350https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1350Mon, 20 Mar 2017 16:57:26 +0000Collected Evidence: Collected Evidence: Crop production: Grow cover crops in arable fieldsCrop yield (24 studies): Six replicated, controlled studies (five randomized) from Spain and the USA found lower cash crop yields in plots with winter cover crops, compared to plots without them, in some comparisons. Three replicated, randomized, controlled studies from Italy and the USA found higher cash crop yields in plots with winter cover crops, compared to plots without them, in some comparisons. Eight replicated, randomized, controlled studies from Italy and the USA found inconsistent differences in cash crop yields (sometimes higher, sometimes lower) between plots with or without cover crops. Seven controlled studies (six replicated, four randomized) from France, Israel, Spain, and the USA found no differences in cash crop yields between plots with or without cover crops. One replicated, randomized, controlled study from the USA found inconsistent differences in cash crop yields between plots with or without summer cover crops. Crop quality (6 studies): Three replicated, controlled studies (two randomized) from Italy, Spain, and the USA found no differences in cash crop quality between plots with or without winter cover crops. Two controlled studies (one replicated and randomized) from the USA found some differences in tomato quality between plots with winter cover crops or fallows. One replicated, randomized, controlled study from the USA found inconsistent differences in cash crop quality between plots with or without winter cover crops. Implementation options (9 studies): Eight studies from Italy, Spain, and the USA found higher cash crop yields in plots that had legumes as winter cover crops, compared to non-legumes. One study from the USA found higher cash crop yields in plots that had a mixture of legumes and grasses, compared to legumes alone.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1351https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1351Tue, 21 Mar 2017 11:54:49 +0000Collected Evidence: Collected Evidence: Crop production: Plant or maintain ground cover in orchards or vineyardsCrop yield (11 studies) Grapes (8 studies): Two replicated, randomized, controlled studies from France and the USA found lower grape yields in plots that were seeded with grass between the vine rows, compared to plots with bare soil between the vine rows, in some or all comparisons. Six replicated, randomized, controlled studies from Italy, Portugal, Spain, and the USA found similar grape yields in plots with or without ground cover between the vine rows. Other crops (3 studies): Two replicated, randomized, controlled studies from Portugal found higher chestnut yields in plots with resident vegetation, compared to plots without ground cover, but found no difference in chestnut yields between plots with seeded cover crops and plots without ground cover. One of these studies also found higher mushroom yields in plots with resident vegetation, compared to plots without ground cover. One replicated, randomized, controlled study from Chile found lower avocado yields in plots that were seeded with grasses and legumes, compared to plots with bare soil.   Crop quality (8 studies) Grapes (6 studies): Five replicated, randomized, controlled studies from Italy, Portugal, and the USA found similar sugar contents in grapes with or without ground cover between the vine rows. Three of these studies found similar pH levels, and two of these studies found no differences in titratable acidity, but two of these studies found lower titratable acidity in grapes with ground cover between the vine rows. One replicated, randomized, controlled study from the USA found heavier grapes with ground cover between the vine rows, but two replicated, randomized, controlled studies from Italy and Spain did not. Two replicated, randomized, controlled studies from Portugal and Spain found other differences in grape quality with ground cover between the vine rows. Other crops (2 studies): One replicated, randomized, controlled study from Portugal found larger chestnuts in plots with ground cover, compared to plots without ground cover. One replicated, randomized, controlled study from Chile found no difference in avocado quality in plots with or without ground cover.   Implementation options (6 studies) Ground cover (5 studies) Grapes (3 studies): One replicated, randomized, controlled study from the USA found similar grape yields in plots with different types of ground cover. However, this study found lighter-weight clusters of grapes in plots with seeded cover crops, compared to resident vegetation, in one of three years, and found inconsistent differences in cluster weights between plots with different types of seeded cover crops. Two replicated, randomized, controlled studies from Spain and the USA found other differences in grape quality between plots with different types of ground cover. Other crops (2 studies): Two replicated, randomized, controlled studies from Portugal found lower chestnut yields in plots with seeded cover crops, compared to resident vegetation. One of these studies also found smaller chestnuts and lower mushroom yields. Tillage (2 studies): One replicated, randomized, controlled study from the USA found higher grape yields, and heavier grape clusters, in plots without tillage between the vine rows, in one of six comparisons. Another replicated, randomized, controlled study from the USA found similar grape yields, with or without tillage between the vine rows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1352https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1352Thu, 23 Mar 2017 09:24:58 +0000Collected Evidence: Collected Evidence: Crop production: Use crop rotationsCrop yield (8 studies): Four replicated, controlled studies (three randomized) from Italy, Spain, and Turkey found higher crop yields in plots with rotations, compared to monocultures, in some comparisons. Four replicated, randomized, controlled studies from Australia, Portugal, and Spain found similar crop yields in plots with or without rotations. Crop quality (1 study): One replicated, controlled study from Italy found more protein in wheat that was grown in rotation, compared to continuously-grown wheat. Implementation options (2 studies): One study from the USA found higher tomato yields in four-year rotations, compared to two-year rotations. One study from Italy found higher wheat yields in rotations with beans, compared to clover.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1354https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1354Tue, 18 Apr 2017 13:02:25 +0100Collected Evidence: Collected Evidence: Crop production: Use no tillage in arable fieldsCrop yield (23 studies) Crops (22 studies): Eight replicated, controlled studies (seven randomized) from Italy and Spain found higher crop yields in plots with no tillage, compared to conventional tillage, in some or all comparisons. Seven replicated, controlled studies (six randomized) from Italy, Lebanon, Spain, and the USA found lower crop yields in plots with no tillage, compared to conventional tillage, in some or all comparisons. Four replicated, randomized controlled studies from Italy and Spain found inconsistent differences in crop yields (sometimes higher with no tillage, sometimes lower). Three replicated, controlled studies (two randomized) from Italy, Portugal, and Spain found similar crop yields in plots with or without tillage. Crop residues (5 studies): Two replicated, randomized, controlled studies from Lebanon and Spain found higher straw yields in plots with no tillage, compared to conventional tillage, in some comparisons. One replicated, randomized, controlled study from Spain found inconsistent straw yields (sometimes higher with no tillage, sometimes lower). Two replicated, controlled studies (one randomized) from Italy and Spain found similar straw yields in plots with or without tillage. Crop quality (6 studies): One replicated, controlled study from Italy found less protein in wheat grains from plots with no tillage, compared to conventional tillage. One replicated, randomized, controlled study from Spain found heavier cereal grains in plots with no tillage, compared to conventional tillage. Two replicated, randomized, controlled studies from Spain found other differences in crop quality, but two replicated, controlled studies from Italy and the USA did not.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1355https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1355Tue, 18 Apr 2017 14:10:16 +0100Collected Evidence: Collected Evidence: Water: Grow cover crops in arable fieldsWater use (2 studies): Of two replicated, randomized, controlled studies from Spain, one found that cover crops used more water than bare fallows, and one found no difference in water use. Water availability (16 studies) Water content (9 studies): Seven replicated, randomized, controlled studies from the USA found less water in soils with winter cover crops, compared to soils without them, in some or all comparisons. Two replicated, randomized, controlled studies from the USA found more water in soils with winter cover crops, compared to soils without them, in some comparisons. Water loss (6 studies): Five controlled studies (four replicated, three randomized) from France, Israel, Spain, and the USA found that less water was lost (through drainage, runoff, or evaporation) from plots with cover crops, compared to plots without them, in some or all comparisons. One replicated, randomized, controlled study from Spain found that more water was lost through drainage from plots with winter cover crops, compared to plots without them, in some comparisons. Water infiltration (3 studies): Of two replicated, controlled studies from the USA, one found that more water filtered into soils with cover crops, and one found no difference in infiltration between plots with or without winter cover crops. One controlled study from the USA found that more water percolated deep into the soil in part of a field with a winter cover crop, compared to part with a winter fallow. Pathogens and pesticides (1 study): One replicated, controlled study from France found that less herbicide was leached from soils with winter cover crops, compared to soils without them. Nutrients (5 studies): Four replicated, randomized, controlled studies from Spain and the USA found that less nitrate was leached from soils with winter cover crops, compared to soils without them, in some or all comparisons. One controlled study from the USA found that similar amounts of nitrate were leached from part of a field with a winter cover crop and part with a winter fallow. This study also found less ammonium and dissolved carbon, but more phosphorus, in runoff from the part with the winter cover crop, in some comparisons. Sediments (1 study): One controlled study from the USA found less suspended sediment in runoff from part of a field with a winter cover crop, compared to a winter fallow, in some comparisons. Implementation options (5 studies): One study from Spain found more water in soils with long-term cover crops, compared to short-term, in some comparisons. Two studies from Spain and the USA found differences in water availability between plots with different cover crops. One study from Spain found differences in nitrate leaching between plots with different cover crops. One study from the USA found similar infiltration rates under different cover crops.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1357https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1357Thu, 04 May 2017 13:33:53 +0100Collected Evidence: Collected Evidence: Crop production: Use no tillage instead of reduced tillageCrop yield (15 studies) Cereals (7 studies): Three replicated, randomized, controlled studies from Spain found higher cereal yields in plots with no tillage, compared to reduced tillage. One of these studies also found lower cereal yields in some comparisons. One replicated, randomized, controlled study from Spain found lower cereal yields in plots with no tillage, compared to reduced tillage, in some comparisons. Three replicated, randomized, controlled studies from Australia, Lebanon, and Spain found similar cereal yields in plots with no tillage or reduced tillage, in all comparisons. Fruits and vegetables (3 studies): Three replicated, randomized, controlled studies from Italy found lower fruit or vegetable yields in plots with no tillage, compared to reduced tillage, in some comparisons. Two of these studies also found higher yields, in some comparisons. Legumes (3 studies): Two replicated, controlled studies from Italy and Spain found higher legume yields in plots with no tillage, compared to reduced tillage, in some or all comparisons. One replicated, controlled study from Lebanon found similar legume yields in plots with no tillage, compared to reduced tillage. Oilseeds (1 study): One replicated, randomized, controlled study from Spain found lower sunflower seed yields in plots with no tillage, compared to reduced tillage, in some comparisons. Crop residues (6 studies): Three replicated, controlled studies from Lebanon and Spain found higher straw yields in plots with no tillage, compared to reduced tillage, in some or all comparisons. One replicated, randomized, controlled study from Spain found lower straw yields in plots with no tillage, compared to reduced tillage. Two replicated, controlled studies from Italy and Spain found similar straw yields in plots with no tillage or reduced tillage. Crop quality (3 studies): One replicated, randomized, controlled study from Spain found larger peas, and more peas in a pod, in plots with no tillage, compared to reduced tillage, in one of four comparisons. One replicated, controlled study from Italy found similarly sized faba beans, and similar numbers of beans in a pod, in plots with no tillage, compared to reduced tillage. One replicated, randomized, controlled study from Spain found differences in the nutritional values of sunflower seeds in plots with no tillage, compared to reduced tillage. · Crop yield (15 studies) o Cereals (7 studies): Three replicated, randomized, controlled studies from Spain2,4,13 found higher cereal yields in plots with no tillage, compared to reduced tillage. One of these studies10410417Angás, P.Lampurlanés, J.Cantero-Martínez, C.Tillage and N fertilization: Effects on N dynamics and Barley yield under semiarid Mediterranean conditionsSoil and Tillage ResearchSoil and Tillage Research59-71871Conservation tillageNitrogen fertilizationN fertilizer efficiencyPhysiological N use efficiency20065//0167-1987http://www.sciencedirect.com/science/article/pii/S0167198705000991http://dx.doi.org/10.1016/j.still.2005.02.0362 also found lower cereal yields in some comparisons. One replicated, randomized, controlled study from Spain868617López-Garrido, R.Madejón, E.León-Camacho, M.Girón, I.Moreno, F.Murillo, J. M.Reduced tillage as an alternative to no-tillage under Mediterranean conditions: A case studySoil and Tillage ResearchSoil and Tillage Research40-47140Tillage systemsSoil conditionsCrop performanceSeed qualitySunflower20147//0167-1987http://www.sciencedirect.com/science/article/pii/S0167198714000300http://dx.doi.org/10.1016/j.still.2014.02.00811 found lower cereal yields in plots with no tillage, compared to reduced tillage, in some comparisons. Three replicated, randomized, controlled studies from Australia19119117Manalil, SudheeshFlower, KenSoil water conservation and nitrous oxide emissions from different crop sequences and fallow under Mediterranean conditionsSoil and Tillage ResearchSoil and Tillage Research123-129143AustraliaDroughtFallowNitrous oxide201411//0167-1987http://www.sciencedirect.com/science/article/pii/S0167198714001214http://dx.doi.org/10.1016/j.still.2014.06.00612, Lebanon777717Yau, S. K.Sidahmed, M.Haidar, M.Conservation versus Conventional Tillage on Performance of Three Different CropsAgronomy JournalAgronomy Journal269-2761022010Madison, WIAmerican Society of Agronomyhttp://dx.doi.org/10.2134/agronj2009.024210.2134/agronj2009.0242English3, and Spain848417Hernanz, J. L.López, R.Navarrete, L.Sánchez-Girón, V.Long-term effects of tillage systems and rotations on soil structural stability and organic carbon stratification in semiarid central SpainSoil and Tillage ResearchSoil and Tillage Research129-141662Long-term effectTillageCrop rotationAggregate stabilitySoil organic carbonSemiarid conditions20027//0167-1987http://www.sciencedirect.com/science/article/pii/S0167198702000211http://dx.doi.org/10.1016/S0167-1987(02)00021-11 found similar cereal yields in plots with no tillage or reduced tillage, in all comparisons. o Fruits and vegetables (3 studies): Three replicated, randomized, controlled studies from Italy9,10,15 found lower fruit or vegetable yields in plots with no tillage, compared to reduced tillage, in some comparisons. Two of these studies9,15 also found higher yields, in some comparisons. o Legumes (3 studies): Two replicated, controlled studies from Italy10710717Giambalvo, DarioRuisi, PaoloSaia, SergioDi Miceli, GiuseppeFrenda, Alfonso SalvatoreAmato, GaetanoFaba bean grain yield, N2 fixation, and weed infestation in a long-term tillage experiment under rainfed Mediterranean conditionsPlant and SoilPlant and Soil215-227360120122012//1573-5036http://dx.doi.org/10.1007/s11104-012-1224-510.1007/s11104-012-1224-57 and Spain838317Santín-Montanyá, M. I.Zambrana, E.Fernández-Getino, A. P.Tenorio, J. L.Dry pea (Pisum sativum L.) yielding and weed infestation response, under different tillage conditionsCrop ProtectionCrop Protection122-12865DiversityLegume-cropsSemi-arid conditionsYieldWeeds201411//0261-2194http://www.sciencedirect.com/science/article/pii/S0261219414002373http://dx.doi.org/10.1016/j.cropro.2014.07.017 Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1358https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1358Fri, 05 May 2017 11:33:13 +0100Collected Evidence: Collected Evidence: Crop production: Use reduced tillage in arable fieldsCrop yield (25 studies) Cereals (16 studies): Nine replicated, controlled studies from Egypt, France, Spain, and Turkey found higher cereal yields in plots with reduced tillage, compared to conventional tillage, in some or all comparisons. Three of these studies also found lower cereal yields in plots with reduced tillage, compared to conventional tillage, in some comparisons. Three replicated, randomized, controlled studies from Lebanon and Spain found lower cereal yields in plots with reduced tillage, compared to conventional tillage. Four replicated, controlled studies from Italy, Spain, and the USA found similar cereal yields in plots with reduced tillage or conventional tillage, in all comparisons. One replicated, randomized, controlled study from Spain found that crops failed in plots with conventional tillage, but not in plots with reduced tillage, in one of three comparisons. Fruits and vegetables (7 studies): Five replicated, randomized, controlled studies from Italy and the USA found higher fruit or vegetable yields in plots with reduced tillage, compared to conventional tillage, in some comparisons. Two of these studies also found lower fruit or vegetable yields in plots with reduced tillage, compared to conventional tillage, in some comparisons. Two replicated, controlled studies from Italy and the USA found similar fruit yields in plots with reduced tillage or conventional tillage, in all comparisons. All fruit or vegetable plots were irrigated, in contrast to most cereal or legume plots. Legumes (3 studies): One replicated, randomized, controlled study from Spain found lower legume yields in plots with reduced tillage, compared to conventional tillage, in one of four comparisons. Two replicated, controlled studies from Italy and Lebanon found similar legume yields in plots with reduced tillage or conventional tillage, in all comparisons. No studies found higher legume yields in plots with reduced tillage, compared to conventional tillage. Oilseeds (1 study): One replicated, randomized, controlled study from Spain found higher rapeseed yields in plots with reduced tillage, compared to conventional tillage. Crop residues (6 studies): Two replicated, randomized, controlled studies from Lebanon and Spain found lower straw yields in plots with reduced tillage, compared to conventional tillage, in some comparisons. One replicated, randomized, controlled study from Spain found higher straw yields in plots with reduced tillage, compared to conventional tillage, in some comparisons. Two replicated, controlled studies from Italy and Spain found similar straw yields in plots with reduced tillage or conventional tillage, in all comparisons. One replicated, randomized, controlled study from the USA found higher cover crop biomass in plots with reduced tillage, compared to conventional tillage. Crop quality (7 studies): One replicated, randomized, controlled study from Spain found that sunflower seeds had more oil, more monounsaturated fatty acid, and less polyunsaturated fatty acid in plots with reduced tillage, compared to conventional tillage. One replicated, controlled study from Italy found that wheat had a lower protein content in plots with reduced tillage, compared to conventional tillage. Two replicated, controlled studies from Italy and Turkey found similar seed weights in plots with reduced tillage, compared to conventional tillage. One replicated, randomized, controlled study from the USA found that lettuce or broccoli plants were larger in plots with reduced tillage, compared to conventional tillage, in some comparisons, but they were smaller in other comparisons. Implementation options (2 studies): One replicated, randomized, controlled study from Egypt found higher wheat yields in plots that were tilled at slower speeds. One replicated, randomized, controlled study from Turkey found higher wheat yields, but lower vetch yields, in plots with one type of reduced tillage (rototilling and disking), compared to another type (double disking).Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1359https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1359Fri, 05 May 2017 12:03:43 +0100Collected Evidence: Collected Evidence: Crop production: Plant flowersCrop yield (2 studies): One replicated, controlled study from Spain found higher crop yields in coriander plants next to planted flower strips, compared to coriander plants next to unplanted field margins. One replicated, randomized, controlled study from Italy found higher crop yields in tomatoes next to planted flower strips, compared to tomatoes next to bare ground, in some comparisons. Crop quality (0 studies) Implementation options (3 studies): One replicated, randomized, controlled study from the USA found smaller lettuces in fields planted with flowers, in five out of six configurations. One replicated, controlled study from Spain found higher coriander yields next to field margins planted with more flower species, compared to fewer flower species. One replicated, randomized, controlled study from Italy found lower crop yields in tomatoes next to field margins planted with more flower species, compared to fewer flower species, in some comparisons.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1360https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1360Fri, 05 May 2017 15:10:52 +0100Collected Evidence: Collected Evidence: Crop production: Plant hedgerowsCrop yield (1 study): One replicated, paired site comparison from the USA found similar crop yields in fields with hedgerows and fields with bare/weedy edges. Crop quality (0 studies)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1361https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1361Fri, 05 May 2017 15:41:01 +0100Collected Evidence: Collected Evidence: Soil: Add compost to the soilOrganic matter (12 studies): Twelve replicated, controlled studies (ten randomized) from Italy, Spain, Syria, Turkey, and the USA found more organic matter in soils with added compost, compared to soils without added compost, in some or all comparisons. Nutrients (10 studies): Six replicated, controlled studies (five randomized) from Italy, Portugal, Spain, and Syria found more nutrients in soils with added compost, compared to soils without added compost, in some or all comparisons. Three replicated, randomized, controlled studies from Italy and the USA found inconsistent differences in nitrogen between soils with or without added compost. One replicated, randomized, controlled study from the USA found no differences in phosphorus between soils with or without added compost. Three replicated, randomized, controlled studies from Italy and Spain found similar pH levels in soils with or without added compost. Soil organisms (10 studies): Six replicated, controlled studies (five randomized) from Italy, Spain, and the USA found more microbial biomass in soils with added compost, compared to soils without added compost, in some or all comparisons. Two replicated, controlled studies from Italy and the USA found similar amounts of microbial biomass in soils with or without added compost. One replicated, randomized, controlled study from Italy found inconsistent differences in bacterial abundance between plots with or without added compost. Two replicated, randomized, controlled studies from Italy and Spain found differences in bacteria communities, in some comparisons. Soil erosion and aggregation (5 studies): Two replicated, controlled studies (one randomized) from Spain found less erosion of soils with added compost, compared to soils without added compost, in some or all comparisons. Four replicated, randomized, controlled studies from Spain and Turkey found that soils with added compost were more stable than soils without added compost, in some or all comparisons. Greenhouse gases (10 studies): Six replicated, controlled studies (five randomized) from Italy, Spain, and the USA found more greenhouse gas in soils with added compost, compared to soils without added compost, in some or all comparisons. Four replicated, randomized, controlled studies from Spain found no differences in greenhouse gas between soils with or without added compost. Implementation options (2 studies): One replicated, randomized, controlled study from Syria found more nitrogen in soils with compost added every two years, compared to soils with compost added every four years. One replicated, randomized, controlled study from Italy found inconsistent differences in bacteria abundance between soils with different amounts of added compost.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1362https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1362Mon, 08 May 2017 13:08:46 +0100Collected Evidence: Collected Evidence: Soil: Add manure to the soilOrganic matter (8 studies): Five replicated, controlled studies (two randomized) from Italy, Tunisia, Turkey, and the USA found more organic matter in soils with added manure, compared to soils without it. Three replicated, randomized, controlled studies from Italy, Spain, and Greece found similar amounts of organic matter in plots with or without added manure. Nutrients (5 studies) Nitrogen (5 studies): Three replicated, controlled, studies (one randomized) from Italy and Tunisia found more nitrogen in soils with added manure, compared to soils without it, in some comparisons. Two replicated, randomized, controlled studies from Greece and Italy found similar amounts of nitrogen in soils with or without added manure. Phosphorus (3 studies): One replicated, randomized, controlled study from Greece found more phosphorus in soils with added manure, compared to soils without it. One replicated, randomized, controlled study from Italy found similar amounts of phosphorus in soils with or without added manure. One replicated, controlled study from Italy found inconsistent differences in phosphorus between soils with or without added manure. Potassium (2 studies): Two replicated, randomized, controlled studies from Italy and Greece found more potassium in soils with added manure, compared to soils without it. pH (3 studies): One replicated, randomized, controlled study from Tunisia found lower pH levels in soils with added manure, compared to soils without it. One replicated, controlled study from Italy found higher pH levels in soils with added manure. One replicated, randomized, controlled study from Italy found similar pH level in soils with or without added manure. Soil organisms (3 studies) Microbial biomass (2 studies): Two replicated, randomized, controlled studies from Italy and Spain found similar amounts of microbial biomass in soils with or without added manure. Nematodes (1 study): One replicated, randomized, controlled study from Greece found similar numbers of nematodes in soils with or without added manure. Soil erosion and aggregation (4 studies): One replicated, randomized, controlled study from Spain found less erosion in plots with added manure, compared to plots without added manure. Three replicated, randomized, controlled studies from Spain and Turkey found higher soil stability in plots with added manure, compared to plots without added manure, in some or all comparisons. One replicated, controlled study from the USA found similar soil stability in plots with or without added manure. Greenhouse gases (2 studies): One replicated, controlled study from the USA found higher carbon dioxide emissions in plots with added manure, compared to plots without added manure. One replicated, randomized, controlled study from Spain found higher nitrous oxide emissions in plots with added manure, compared to plots without added manure. Implementation options (1 study): One study from Tunisia found no differences in organic matter or pH between soils with different amounts of added manure, but found less nitrate in soils with less added fertilizer.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1363https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1363Tue, 09 May 2017 10:32:58 +0100Collected Evidence: Collected Evidence: Soil: Add sewage sludge to the soilOrganic matter (1 study): One replicated, controlled study from the USA found more organic matter in soils with added sewage sludge, compared to soils without it. Nutrients (2 studies): One replicated, controlled study from Spain found more nitrate in soils with added sewage sludge, compared to soils without it. One replicated, randomized, controlled study from Portugal found similar amounts of nitrate in soils with or without added sewage sludge. Soil organisms (2 studies): Two replicated, controlled studies (one randomized) from Spain found similar amounts of microbial biomass in soils with or without added sewage sludge. Soil erosion and aggregation (2 studies): One replicated, controlled study from Spain found less erosion in plots with added sewage sludge, compared to plots without it. One replicated, controlled study from the USA found no difference in stability between soils with or without added sewage sludge. Greenhouse gases (2 studies): Two replicated, controlled studies from Spain and the USA found higher carbon dioxide emissions from soils with added sewage sludge, compared to soils without it. Implementation options (1 study): One replicated, controlled study from Spain found more nitrate in soils with digested sewage sludge, compared to composted or thermally dried sewage sludge.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1364https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1364Tue, 09 May 2017 14:12:57 +0100Collected Evidence: Collected Evidence: Soil: Add slurry to the soilOrganic matter (4 studies): Three studies (two replicated, randomized, controlled; one meta-analysis) from Spain and multiple Mediterranean countries found similar amounts of organic matter in soils with or without added slurry. One replicated, randomized, controlled study from Spain found more organic matter in soils with added slurry, compared to soils without it, in some comparisons. Nutrients (4 studies): Two replicated, randomized, controlled studies from Spain found more nitrate in soils with added slurry, compared to soils without it. Two replicated, randomized, controlled studies from Portugal and Spain found similar amounts of nitrate in soils with or without added slurry. One of these studies also found more ammonium, but another one did not. Soil organisms (2 studies): One replicated, randomized, controlled study from Spain found more microbial biomass in soils with added slurry, compared to soils without it, but another one did not. Soil erosion and aggregation (1 study): One replicated, randomized, controlled study from Spain found more stable soils in plots with added slurry, compared to plots without it, in some comparisons. Greenhouse gases (8 studies) Carbon dioxide (3 studies): Of three replicated, randomized, controlled studies from Spain, two studies found higher carbon dioxide emissions in soils with added slurry, compared to soils without it, but one study did not. Methane (4 studies): One replicated, randomized, controlled study from Spain found that less methane was absorbed by soils with added slurry, compared to soils without it. Three replicated, randomized, controlled studies from Spain found similar methane fluxes in soils with or without added slurry. Nitrous oxide (6 studies): Five replicated, randomized, controlled studies from Spain found higher nitrous oxide emissions in soils with added slurry, compared to soils without it, in some or all comparisons. One replicated, randomized, controlled study from Spain found similar nitrous oxide emissions in soils with or without added slurry. Implementation options (3 studies): One replicated, randomized, controlled study from Spain found no differences in organic matter or greenhouse-gas emissions between plots with different amounts of slurry. One replicated, randomized, controlled study from Spain found similar amounts of nitrogen in soils with or without added slurry. One replicated, randomized, controlled study from Spain found similar nitrous oxide emissions in soils with digested or untreated pig slurry. One replicated, randomized, controlled study from Spain found similar carbon dioxide and methane emissions in soils with digested or untreated slurry.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1365https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1365Tue, 09 May 2017 14:27:06 +0100Collected Evidence: Collected Evidence: Soil: Use organic fertilizer instead of inorganicOrganic matter (13 studies): Eight replicated studies (including one meta-analysis) from France, Italy, Spain, Turkey, and Mediterranean countries found more organic matter in soils with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Five replicated, randomized, controlled studies from Greece, Spain, and the USA found similar amounts of organic matter in soils with organic or inorganic fertilizer. Nutrients (14 studies) Nitrogen (9 studies): Four replicated studies (three controlled, two randomized; one site comparison) from France, Italy, and Spain found more nitrogen in soils with organic fertilizers, compared to inorganic fertilizer, in some comparisons. Five replicated, randomized, controlled studies from Greece, Spain, and the USA found similar amounts of nitrogen in soils with organic or inorganic fertilizer. Ammonium (3 studies): Two replicated, randomized, controlled studies from Italy and Spain found more ammonium in soils with organic fertilizer, compared inorganic fertilizer, in some comparisons. One replicated, randomized, controlled study from Spain found similar amounts of ammonium in soils with organic or inorganic fertilizer. Nitrate (3 studies): One replicated, randomized, controlled study from Spain found less nitrate in soils with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Two replicated, randomized, controlled studies from Portugal and Spain found similar amounts of nitrate in soils with organic or inorganic fertilizer. Phosphorus (5 studies): Three replicated, randomized, controlled studies from Italy and Spain found more phosphorus in soils with organic fertilizer, compared to inorganic fertilizer, in some or all comparisons. One replicated site comparison from France found less phosphorous in soils with organic fertilizer, in some comparisons. One replicated, randomized, controlled study from Spain found similar amounts of phosphorous in soils with organic or inorganic fertilizer. Potassium (6 studies): Three replicated, randomized, controlled studies from Italy and Spain found more potassium in soils with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Three replicated studies (two controlled, one site comparison) from France and Spain found similar amounts of potassium in soils with organic or inorganic fertilizer. pH (6 studies): Four replicated studies (three randomized and controlled, one site comparison) from France, Italy, and Spain found similar pH levels in soils with organic or inorganic fertilizer. One replicated, controlled study from Italy found higher pH levels in soils with organic fertilizer, in some comparisons. One replicated, randomized, controlled study from Spain found lower pH levels in soils with organic fertilizer, in some comparisons. Soil organisms (7 studies) Microbial biomass (4 studies): Four replicated studies (three randomized and controlled, one site comparison) from France, Italy, and Spain found more microbial biomass in soils with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Other soil organisms (4 studies): One replicated, randomized, controlled study from Spain found fewer bacteria in soils with organic fertilizer, compared to inorganic fertilizer, in one comparison. One replicated site comparison from France found fewer nematodes in plots with organic fertilizer, compared to inorganic fertilizer, in some comparisons. One replicated, randomized, controlled study from Spain found fewer mites in plots with organic fertilizer, compared to inorganic fertilizer. One replicated, randomized, controlled study from Italy found inconsistent differences in microbes between plots with organic or inorganic fertilizer. Soil erosion and aggregation (5 studies): Three replicated, randomized, controlled studies from Turkey and Spain found greater aggregation in soils with organic fertilizer, compared to inorganic fertilizer, in some or all comparisons. Two replicated, randomized, controlled studies from Spain and the USA found no difference in aggregation between soils with organic or inorganic fertilizer. Greenhouse gases (11 studies) Carbon dioxide (5 studies): Four replicated, randomized, controlled studies from Italy and Spain found higher carbon dioxide emissions from plots with organic fertilizer, compared to inorganic fertilizer, in some comparisons. One replicated, randomized, controlled study from Spain found similar carbon dioxide emissions from plots with organic or inorganic fertilizer. Methane (4 studies): Two replicated, randomized, controlled studies from Spain found that more methane was absorbed by soils with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Two replicated, randomized, controlled studies from Spain found that similar amounts of methane were absorbed by soils with organic or inorganic fertilizer. Nitrous oxide (8 studies): Five replicated, randomized, controlled studies from Spain found similar nitrous oxide emissions from plots with organic or inorganic fertilizer. Three studies (including one meta-analysis and two replicated, randomized, controlled studies) from Spain, the USA, and Mediterranean countries found lower nitrous oxide emissions from plots with organic fertilizer, compared to inorganic fertilizer, in some comparisons. Implementation options (4 studies): One study from Spain found that plots with slurry absorbed methane, but plots with manure emitted methane. One study from Italy found more organic matter, nutrients, and microbial biomass in plots fertilized with compost, compared to manure. One meta-analysis found lower nitrous oxide emissions after adding solid organic fertilizer, but not liquid organic fertilizer, compared to inorganic fertilizer. One study found inconsistent differences in soil bacteria with a single or double application of organic fertilizer.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1366https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1366Tue, 09 May 2017 15:33:46 +0100Collected Evidence: Collected Evidence: Soil: Plant or maintain ground cover in orchards or vineyardsOrganic matter (12 studies): Ten studies (eight replicated, randomized, and controlled, and two site comparisons) from Chile, France, Spain, and the USA found more organic matter in soils with ground cover, compared to soils without ground cover, in some or all comparisons. Two meta-analyses of studies from Mediterranean climates also found more organic matter in plots with ground cover. Implementation options (4 studies): One study from France found more organic matter in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. Two studies from the USA found similar amounts of organic matter in soils with resident vegetation or seeded cover crops. One study from Spain found more organic matter where cover crops were incorporated into the soil. Nutrients (12 studies) Nitrogen (9 studies): Five studies (four replicated, randomized, and controlled, and one site comparison) from Chile and Spain found more nitrogen in soils with ground cover, compared to soils without ground cover, in some or all comparisons. One replicated, randomized, controlled study from the USA found less nitrogen in soils with ground cover, in some comparisons. Two replicated, randomized, controlled studies from Spain and the USA found inconsistent differences in nitrogen between soils with or without ground cover. One replicated site comparison from France found similar amounts of nitrogen in soils with or without ground cover. Implementation options (5 studies): Two studies from Spain and the USA found more nitrogen in soils that were cover cropped with legumes, compared to non-legumes, in some or all comparisons. Two studies from vineyards in the USA found similar amounts of nitrogen in soils with resident vegetation or seeded cover crops. One of these studies also found similar amounts of nitrogen in soils with different types of seeded cover crops, and in soils with or without tillage (both with ground cover). One study from Spain found more nitrogen where cover crops were incorporated into the soil. Phosphorus (4 studies): One replicated site comparison from France found more phosphorus in soils with ground cover, compared to bare soils, in one of six comparisons. Two studies (one replicated, randomized, and controlled, and one site comparison) from Spain and the USA found less phosphorus in soils with seeded cover crops, compared to tilled soils, in some comparisons. One replicated, randomized, controlled study from Chile found similar amounts of phosphorus in soils with seeded cover crops and bare soils. Implementation options (3 studies): One study from France found more phosphorus in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. One study from the USA found similar amounts of phosphorus in soils with resident vegetation or seeded cover crops. One study from Spain found different amounts of phosphorus in soils with different types of seeded cover crops. Potassium (3 studies): One replicated, randomized, controlled study from Chile found more potassium in soils with seeded cover crops, compared to bare soils. Two site comparisons (one replicated) from France and Spain found similar amounts of potassium in soils with ground cover, compared to tilled or bare soil. Implementation options (1 study): One study from the USA found similar amounts of potassium in soils with resident vegetation or seeded cover crops. pH (4 studies): Two studies (one replicated, randomized, and controlled, and one site comparison) from Spain and the USA found lower pH levels in soils with ground cover, compared to soils without ground cover. One replicated, randomized, controlled study from Chile found higher pH levels in soils with ground cover. One replicated site comparison from France found similar pH levels in soils with or without ground cover. Soil organisms (6 studies) Microbial biomass (4 studies): Four replicated studies (three randomized and controlled, one site comparison) from France and the USA found more microbial biomass in soils with ground cover, compared to bare or tilled soils, in some or all comparisons. Implementation options (1 study): One study from France found more microbial biomass in soils with permanent ground cover, compared to temporary ground cover, in some comparisons. Fungi (2 studies): One replicated, controlled study from the USA found more symbiotic fungi (mycorrhizae) in soils with seeded cover crops, compared to tilled soils, in some comparisons, but found similar numbers of roots that were colonized by mycorrhizae. One replicated, randomized, controlled study from the USA found inconsistent differences in mycorrhizae in soils with seeded cover crops or tilled soils. Bacteria (1 study): One replicated, randomized, controlled study from Spain found more bacteria, but similar levels of bacterial diversity, in soils with ground cover, compared to bare soils. Nematodes (1 study): One replicated site comparison from France found more nematodes in soils with ground cover, compared to bare soils. Implementation options (1 study): One study from France found more nematodes in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. Soil erosion and aggregation (10 studies) Soil erosion (7 studies): Six replicated, randomized, controlled studies from Chile, Italy, Spain, and the USA found less erosion of soils with ground cover, compared to bare or tilled soils, in some comparisons or all comparisons. One replicated, controlled study from France found similar amounts of erosion in plots with or without ground cover. Implementation options (1 study): One study from Italy found the least erosion with permanent cover crops, and the most erosion with temporary cover crops. Soil aggregation (5 studies): Four replicated, randomized, controlled studies from Chile and Spain found that soil aggregates were more water-stable in plots with seeded cover crops, compared to tilled or bare soils, in some or all comparisons. One site comparison from Spain found inconsistent differences in water stability between soils with seeded cover crops and bare soils. Greenhouse gases (3 studies): Two replicated, randomized, controlled studies from a vineyard in the USA found more carbon dioxide or nitrous oxide in soils with cover crops, compared to tilled soils. One replicated, randomized, controlled study from an olive orchard in Spain found similar amounts of carbon dioxide in soils with cover crops, compared to tilled soils. Implementation options (1 study): One study from the USA found similar amounts of carbon dioxide in soils with different types of ground cover.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1367https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1367Mon, 15 May 2017 14:10:27 +0100Collected Evidence: Collected Evidence: Soil: Use crop rotationsOrganic matter (9 studies): Five replicated, controlled studies (two randomized) from Italy, Portugal, and Spain found less organic matter in soils with crop rotations, compared to continuous crops, in some comparisons. One replicated, controlled study from Syria found more organic matter in soils with crop rotations, compared to continuous crops, in some comparisons. Three replicated, controlled studies from Spain found similar amounts of organic matter in soils with or without crop rotations. Nutrients (5 studies) Nitrogen (5 studies): One replicated, randomized, controlled study from Australia found more nitrogen in soils with crop rotations, compared to continuous crops, in one of four comparisons. One replicated, controlled study from Italy found less nitrogen in soils with crop rotations, compared to continuous crops, in some comparisons. One replicated, randomized, controlled study from Spain found inconsistent differences in nitrogen in soils with or without crop rotations. Two replicated, randomized, controlled studies from Portugal and Spain found similar amounts of nitrogen in soils with or without crop rotations. Phosphorus (2 studies): Two replicated, randomized, controlled studies from Portugal and Spain found less phosphorus in soils with crop rotations, compared to continuous crops, in some comparisons. pH (2 studies): Two replicated, randomized, controlled studies from Portugal and Spain found similar pH levels in soils with or without crop rotations. Soil organisms (3 studies) Microbial biomass (2 studies): One replicated, controlled study from Italy found more microbial biomass in soils with crop rotations, compared to continuous crops, in some comparisons. One replicated, randomized, controlled study from Spain found less microbial biomass in soils with crop rotations, compared to continuous crops, in some comparisons. Bacteria and fungi (1 study): One replicated, randomized, controlled study from Portugal found more fungi, but similar amounts of bacteria, in soils with crop rotations, compared to continuous crops. Soil erosion and aggregation (4 studies): One replicated, controlled study from Syria found higher water-stability in soils with crop rotations, compared to continuous crops. One replicated, randomized, controlled study from Spain found lower water-stability in soils with crop rotations, compared to continuous crops, in some comparisons. One replicated, randomized, controlled study from Spain found inconsistent differences in water-stability in soils with or without crop rotations. One replicated, randomized, controlled study from Spain found no differences in water-stability. Greenhouse gases (4 studies): One replicated, controlled study from Italy found higher carbon dioxide emissions from soils with crop rotations, compared to continuous crops, in some comparisons. One replicated, randomized, controlled study from Spain found similar carbon dioxide emissions from soils with or without crop rotations. One replicated, randomized, controlled study from Australia found lower nitrous oxide and methane emissions from soils with crop rotations, compared to continuous crops, but another one found no differences in nitrous oxide emissions. Implementation options (2 studies): Two studies from Syria and the USA found similar amounts of nitrogen in soils with two-year or four-year rotations. One of these studies also found similar amounts of organic matter.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1368https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1368Mon, 15 May 2017 14:21:47 +0100Collected Evidence: Collected Evidence: Soil: Use no tillage in arable fieldsOrganic matter (20 studies): One meta-analysis of studies from Mediterranean countries found more organic matter in soils without tillage, compared to soils with tillage. Fourteen replicated studies (eleven randomized and controlled, one controlled, one site comparison) from Italy, Spain, and the USA found more organic matter in soils without tillage, compared to soils with tillage, in some or all comparisons. One replicated, randomized, controlled study from Portugal found less organic matter in soils without tillage, compared to soils with tillage, in some comparisons. One replicated, randomized, controlled study from Spain sometimes found more organic matter, and sometimes found less, in soils without tillage, compared to soils with tillage. Three replicated, controlled studies (two randomized) from Italy and Spain found similar amounts of organic matter in soils with or without tillage. Nutrients (19 studies) Nitrogen (18 studies): Six replicated studies (five randomized and controlled, one site comparison) from Italy, Spain, and the USA found more nitrogen in soils without tillage, compared soil with tillage, in some or all comparisons. Six replicated, randomized, controlled studies from Spain found less nitrogen in soils without tillage, in some or all comparisons. Two replicated, controlled studies from Spain and the USA sometimes found more nitrogen and sometimes found less nitrogen in soils without tillage, compared to soils with tillage. Four replicated, controlled studies (three randomized) from Italy, Portugal, Spain, and the USA found similar amounts of nitrogen in soils with or without tillage. Phosphorus (5 studies): Three replicated, randomized, controlled studies from Spain and the USA found more phosphorus in soils without tillage, compared to soils with tillage, in some or all comparisons. One replicated, randomized, controlled study from Portugal found less phosphorus in soils without tillage, compared to soils with tillage, in some comparisons. One replicated, randomized, controlled study from Spain found similar amounts of phosphorus in soils with or without tillage. Potassium (3 studies): One replicated, randomized, controlled study from Spain found more potassium in soils without tillage, compared to soils with tillage, in some comparisons. One replicated, randomized, controlled study from the USA sometimes found more potassium and sometimes found less potassium in soils without tillage, compared to soils with tillage. One replicated, randomized, controlled study from Spain found similar amounts of potassium in soils with or without tillage. pH (2 studies): One replicated, randomized, controlled study from Portugal found lower pH levels in soils without tillage, compared to soils with tillage, in some comparisons. One replicated, randomized, controlled study from the USA found similar pH levels in soils with or without tillage. Soil organisms (18 studies) Microbial biomass (13 studies): Five replicated, controlled studies (four randomized) from Italy and Spain found more microbial biomass in soils without tillage, compared to soils with tillage, in some or all comparisons. Two replicated, randomized, controlled studies from Spain sometimes found more microbial biomass, and sometimes found less, in soils without tillage, compared to soils with tillage. Six replicated, randomized, controlled studies from Spain and the USA found similar amounts of microbial biomass in soils with or without tillage. Earthworms (2 studies): Two replicated studies (one controlled, one site comparison) from the USA found more earthworms in soils without tillage, compared to soils with tillage. Nematodes (2 studies): Two replicated, controlled studies (one randomized) from the USA found similar numbers of nematodes in soils with or without tillage. However, one of these studies found different communities of nematodes in soils with or without tillage. Mites (1 study): One replicated, controlled study from the USA found different communities of mites, but similar numbers of mites, in soils with or without tillage. Other soil organisms (1 study): One replicated, randomized, controlled study from Spain found similar amounts of denitrifying bacteria in soils with or without tillage. Another replicated, randomized, controlled study from Spain found more microorganisms in soils without tillage, compared to soils with tillage, in some comparisons. One replicated, randomized, controlled study from Portugal found more fungus in soils without tillage, compared to soils with tillage. Soil erosion and aggregation (9 studies): Seven replicated studies (six randomized and controlled, one site comparison) from Spain and the USA found that soils without tillage were more stable than tilled soils, in some or all comparisons. Two replicated, randomized, controlled studies from Spain found that soils without tillage were sometimes more stable, and were sometimes less stable, than tilled soils. Greenhouse gases (10 studies) Carbon dioxide (7 studies): Three replicated, controlled studies (two randomized) from Italy and Spain found more carbon dioxide in soils without tillage, compared to soils with tillage. Two replicated, randomized, controlled studies from Spain found less carbon dioxide in soils without tillage, compared to soils with tillage, in some comparisons. Two replicated, randomized, controlled studies from Spain sometimes found more carbon dioxide, and sometimes found less, in soils without tillage, compared to soils with tillage. One replicated, randomized, controlled study from Spain found similar amounts of carbon dioxide in soils with or without tillage. Nitrous oxide (3 studies): One replicated, randomized, controlled study from Spain sometimes found more nitrous oxide, and sometimes found less, in soils without tillage, compared to soils with tillage. Two replicated, randomized, controlled studies from Spain found similar amounts of nitrous oxide in soils with or without tillage. Methane (3 studies): One replicated, randomized, controlled study from Spain found less methane in soils without tillage, compared to soils with tillage. One replicated, randomized, controlled study from Spain sometimes found more methane, and sometimes found less, in soils without tillage, compared to soils with tillage. One replicated, randomized, controlled study from Spain found similar amounts of methane in soils with or without tillage. Implementation options (1 study): One replicated, randomized, controlled study from Spain found more organic matter in soils that had not been tilled for a long time, compared to a short time, in one comparison. This study also found greater stability in soils that had not been tilled for a long time, in some comparisons.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1369https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1369Mon, 15 May 2017 14:26:17 +0100Collected Evidence: Collected Evidence: Soil: Use no tillage instead of reduced tillageOrganic matter (6 studies): Three replicated, randomized, controlled studies from Spain found more organic matter in soils with no tillage, compared to reduced tillage, in some or all comparisons. Three replicated, randomized, controlled studies from Spain found similar amounts of organic matter in soils with no tillage, compared to reduced tillage. No studies found less organic matter in soils with no tillage, compared to reduced tillage. Nutrients (7 studies) Nitrogen (6 studies): Three replicated, randomized, controlled studies from Italy and Spain found more nitrogen in soils with no tillage, compared to reduced tillage, in some comparisons. Two of these studies also found less nitrogen in some comparisons. One replicated, randomized, controlled study from Spain found less nitrogen in soils with no tillage, compared to reduced tillage, in some comparisons. Two replicated, randomized, controlled studies from Spain found similar amounts of nitrogen in soils with no tillage, compared to reduced tillage. Phosphorus (2 studies): One replicated, randomized, controlled study from Spain found more phosphorus in soils with no tillage, compared to reduced tillage. One replicated, randomized, controlled study from Spain found similar amounts of phosphorus in soils with no tillage or reduced tillage. No studies found less phosphorus in soils with no tillage, compared to reduced tillage. Potassium (1 study): One replicated, randomized, controlled study from Spain found similar amounts of potassium in soils with no tillage or reduced tillage. No studies found less potassium in soils with no tillage, compared to reduced tillage. Soil organisms (8 studies) Microbial biomass (6 studies): Five replicated, randomized, controlled studies from Spain found similar amounts of microbial biomass in soils with no tillage or reduced tillage. One replicated, randomized, controlled study from Spain found more microbial biomass in soils with no tillage, compared to reduced tillage, in some comparisons, but found less in some comparisons. Bacteria (1 study): One replicated, randomized, controlled study from Spain found fewer denitrifying bacteria in soils with no tillage, compared to reduced tillage. Other soil organisms (2 studies): One replicated, controlled study from the USA found similar numbers of mites and nematodes, but different communities of mites and nematodes, in soils with no tillage, compared to reduced tillage. One replicated, randomized, controlled study from Spain found more mites in soils with no tillage, compared to reduced tillage. Soil erosion and aggregation (4 studies): One replicated, randomized, controlled study from Spain found more large aggregates in soils with no tillage, compared to reduced tillage, in some comparisons. One replicated, randomized, controlled study from Italy found similar aggregates in soils with no tillage or reduced tillage. One replicated, randomized, controlled study from Spain found higher water-stability in soils with no tillage, compared to reduced tillage, in some comparisons, but found lower water-stability in some comparisons. One replicated, randomized, controlled study from Spain found similar water-stability in soils with no tillage or reduced tillage. Greenhouse gases (4 studies): Two replicated, randomized, controlled studies from Spain found less greenhouse gas in soils with no tillage, compared to reduced tillage, in some comparisons. Two replicated, randomized, controlled studies from Australia and Spain found similar amounts of greenhouse gas in soils with no tillage or reduced tillage.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1370https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1370Mon, 15 May 2017 14:40:52 +0100Collected Evidence: Collected Evidence: Soil: Use reduced tillage in arable fieldsOrganic matter (14 studies): One meta-analysis from multiple Mediterranean countries found more organic matter in soils with reduced tillage, compared to conventional tillage. Eleven replicated studies (ten randomized and controlled, one site comparison) from Italy, Spain, Syria, and the USA found more organic matter in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. Two replicated, randomized, controlled studies from Spain and the USA found similar amounts of organic matter in soils with reduced tillage or conventional tillage, in all comparisons. No studies found less organic matter in soils with reduced tillage, compared to conventional tillage. Nutrients (15 studies) Nitrogen (14 studies): Seven replicated studies (five randomized and controlled, one site comparison) from Italy, Spain, and the USA found more nitrogen in soils with reduced tillage, compared to conventional tillage, in some comparisons. Three of these studies also found less nitrogen in some comparisons. Two replicated, randomized, controlled studies from Spain found less nitrogen in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. Five replicated, randomized, controlled studies from Spain, Syria, and the USA found similar amounts of nitrogen in soils with reduced tillage or conventional tillage, in all comparisons. Phosphorus (6 studies): Five replicated, randomized, controlled studies from Italy, Spain, and the USA found more phosphorus in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. One replicated, randomized, controlled study from Spain found similar amounts of phosphorus in soils with reduced tillage, compared to conventional tillage, in all comparisons. Potassium (3 studies): Two replicated, randomized, controlled studies from Spain found more potassium in soils with reduced tillage, compared to conventional tillage, in some comparisons. One replicated, randomized, controlled study from Spain found similar amounts of potassium in soils with reduced tillage, compared to conventional tillage, in all comparisons. pH (1 study): One replicated, randomized, controlled study from Spain found similar pH levels in soils with reduced tillage or conventional tillage. Soil organisms (16 studies) Microbial biomass (15 studies): Eleven replicated, randomized, controlled studies from Italy, Spain, and the USA found more microbial biomass in soils with reduced tillage, compared to conventional tillage, in some comparisons. Two replicated, randomized, controlled studies from Spain and Syria found less microbial biomass in soils with reduced tillage, compared to conventional tillage, in some comparisons. Two replicated, randomized, controlled studies from Spain found similar amounts of microbial biomass in soils with reduced tillage or conventional tillage, in all comparisons. Bacteria (1 study): One replicated, randomized, controlled study from Spain found more denitrifying bacteria in soils with reduced tillage, compared to conventional tillage. Other soil organisms (2 studies): One replicated, controlled study from the USA found similar numbers of mites and nematodes, but differences in mite and nematode communities, in soils with reduced tillage, compared to conventional tillage. One replicated site comparison from the USA found more earthworms in fields with fewer passes of the plough, in one of three comparisons. Soil erosion and aggregation (9 studies) Soil aggregation (8 studies): Three replicated, randomized, controlled studies from Spain found that soil aggregates had higher water-stability in plots with reduced tillage, compared to conventional tillage, in some comparisons. One of these studies also found that soil aggregates had lower water-stability in some comparisons. One replicated, randomized, controlled study from Spain found that water-stability was similar in plots with reduced tillage or conventional tillage. One replicated, randomized, controlled study from Spain found more large aggregates in soils with reduced tillage, compared to conventional tillage, in one of two comparisons. One replicated, randomized, controlled study from Spain found smaller aggregates in soils with reduced tillage, compared to conventional tillage. Three replicated, randomized, controlled studies from Spain and the USA found similar amounts of aggregation in soils with reduced tillage or conventional tillage. Soil erosion (1 study): One replicated, randomized, controlled study from Egypt found less erosion with less tillage (one pass with the tractor, compared to two), but found more erosion with shallower tillage, compared to deeper. Greenhouse gases (11 studies) Carbon dioxide (9 studies): Three replicated, randomized, controlled studies from Spain found more carbon dioxide in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. Three replicated, randomized, controlled studies from Spain and the USA found less carbon dioxide in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. Three controlled studies from Italy, Spain, and the USA found similar amounts of carbon dioxide in soils with reduced tillage or conventional tillage, in all comparisons. Nitrous oxide (3 studies): Two replicated, randomized, controlled studies from Spain and the USA found more nitrous oxide in soils with reduced tillage, compared to conventional tillage, in some or all comparisons. One controlled study from the USA found similar amounts of nitrous oxide in soils with reduced tillage or conventional tillage, in all comparisons. Methane (1 study): One replicated, randomized, controlled study from Spain found similar amounts of methane in soils with reduced tillage or conventional tillage. Implementation options (1 study): One replicated, randomized, controlled study from Egypt found that less soil was lost in runoff water from plots that were tilled at slower tractor speeds. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1371https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1371Mon, 15 May 2017 14:50:31 +0100
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What Works in Conservation

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