Collected Evidence: Collected Evidence: Change the timing of ploughingTwo replicated site comparison studies from Denmark and Norway (one also randomized) found reduced soil loss and nitrate leaching when ploughing was delayed until spring. SOIL TYPES COVERED: sandy, sandy-loam, silty-clay loam.  Collected, 29 May 2013 10:39:46 +0100Collected Evidence: Collected Evidence: Plant new hedgesFive studies in Slovakia, Kenya and Thailand measured the effects of planting grass or shrub hedgerows on soil animals and soil fertility. All five found hedgerows to maintain or improve soil fertility and soil animal activity. Of these, three replicated studies found reduced soil erosion and higher soil organic matter levels. Another replicated trial found a higher diversity of soil animals near to the hedgerows. One of the replicated studies and one review found that adding woody species to the hedgerows improved many factors contributing to soil fertility. SOIL TYPES COVERED: Alluvial, clay, sandy-loam.  Collected, 04 Jun 2013 16:25:36 +0100Collected Evidence: Collected Evidence: Convert to organic farmingBiodiversity: Four studies in Asia, Europe, and the USA (including two site comparison studies and three replicated trials) found higher numbers, diversity, functional diversity (see background) or activity of soil organisms under organic management. Soil organic carbon: Two replicated trials in Italy and the USA showed that organically managed orchards had higher soil carbon levels compared to conventionally managed orchards. One randomized, replicated trial in the USA found soil carbon was lower under organic management compared to alley cropping. Soil organic matter: One replicated trial in Canada found that soil nutrients were lower in organically managed soils. Yields: One replicated trial in Canada found lower yields in organically managed soils. Two replicated trials in the USA (one also randomized) found that fruit was of a higher quality and more resistant to disease, though smaller or that organic management had mixed effects on yield. SOIL TYPES COVERED: clay, clay loam, fine sandy-loam, loam, sandy loam, sandy-clay loam, silt, silty-clay, silt-loam.  Collected, 30 Sep 2013 11:31:06 +0100Collected Evidence: Collected Evidence: Control traffic and traffic timingBiodiversity: One randomized, replicated study from Poland found higher numbers and bacterial activity under controlled traffic. One replicated site comparison study from Denmark found higher microbial biomass when farm traffic was not controlled Erosion: Five trials from Europe and Australia (including three replicated trials, one controlled before-and after-trial, and one review) found a higher number of pores in the soil, less compaction, reduced runoff and increased water filtration into the soil under controlled traffic. One controlled, replicated trial from India found increased soil crack width when traffic was not controlled. Yield: Two replicated trials from Australia and the USA found increased yield under controlled traffic. SOIL TYPES COVERED: clay, loamy-sand, loamy-silt, sandy loam, silty, silty-clay, silt loam.  Collected, 01 Oct 2013 10:25:04 +0100Collected Evidence: Collected Evidence: Change tillage practicesBiodiversity loss: Eleven studies from Canada, Europe, Mexico, or the USA measured effects of reduced tillage on soil animals or microbes. Of these, four (including three replicated trials (three also randomized and one also controlled)) found more microbes, more species of earthworm, or higher microbe activity under reduced tillage. One replicated trial found increased numbers of soil animals and earthworms under reduced tillage. One controlled, replicated trial found mixed effects on microbe diversity depending on time of sampling. Two, (including one controlled, replicated trial) found no effect of reduced tillage on earthworm activity or microbe activity. Compaction: Five studies from Australia, Canada, and Europe measured the effect of controlled traffic and reduced tillage on compacted soils. Of these, two (including one before-and-after trial and one replicated trial) found reduced compaction and subsequent effects (reduced water runoff, for example) under controlled traffic, and one also found that crop yields increased under no-tillage. Three replicated trials, including one site comparison study, found higher compaction under reduced tillage. Drought: Three replicated trials from Europe and India (one also randomized) found the size of soil cracks decreased, and ability of soil to absorb water and soil water content increased with conventional ploughing and sub-soiling. Erosion: Nine replicated trials from Brazil, Europe, India, Nigeria and the USA, and one review showed mixed results of tillage on soil erosion. Seven trials (one also controlled and randomized) showed reduced soil loss and runoff under reduced tillage compared to conventional ploughing. One trial showed no differences between tillage systems, but demonstrated that across-slope cultivation reduced soil loss compared to up-and-downslope cultivation. Two trials showed that no-tillage increased soil loss in the absence of crop cover. Soil organic carbon: Twelve studies from Australia, Canada, China, Europe, Japan and the USA compared the effect of no-tillage and conventionally tilled systems on soil organic carbon. All (including two randomized, five replicated, two randomized, replicated, and one controlled, randomized, replicated) found higher soil organic carbon in soils under a no-tillage or reduced tillage system compared to conventionally tilled soil. One review showed that no-tillage with cover cropping and manure application increases soil organic carbon. One randomized, replicated trial from Spain found greater soil organic carbon in conventionally tilled soil. One replicated trial from Canada found no effect of tillage on soil carbon. Soil organic matter: Fifteen studies from Canada, China, Europe, Morocco, and the USA measured effects of reduced tillage on soil organic matter content and nutrient retention. Of these, eight studies (including four replicated (two also randomized), two site comparisons (one also replicated) and one controlled) found maintained or increased soil organic matter and improved soil structure under reduced tillage. Four trials (including two replicated and two site comparison studies) found higher nutrient retention under reduced tillage. One controlled, replicated trial found less carbon and nitrate in no-till compared to conventionally tilled soil, but conventionally tilled soil lost more carbon and nitrate. One controlled, randomized, replicated trial and one replicated trial found mixed effects of reduced tillage on soil nitrogen levels. Yield: One replicated study from Canada found lower yields under minimum or no-tillage compared to conventional tillage, and one controlled, randomized, replicated study from the USA found higher yields when subsoiling was done. One randomized, replicated study from Portugal found no effect of tillage treatment on yield.   SOIL TYPES COVERED: anthrosol, calcareous silt loam, chalky, clay, clay loam, fine sandy loam, loam, loamy-clay, loam - sandy loam, loam – silt-loam, loamy sand, loamy silt, non-chalky clay, sandy, sandy clay loam, sandy loam, sandy silt-loam, silt loam, silty, silty-clay, silty clay loam, silty loam.Collected, 02 Oct 2013 11:37:18 +0100
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