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Individual study: Soil management effects on runoff, erosion and soil properties in an olive grove of Southern Spain

Published source details

Gómez J.A., Sobrinho T.A., Giráldez J.V. & Fereres E. (2009) Soil management effects on runoff, erosion and soil properties in an olive grove of Southern Spain. Soil and Tillage Research, 102, 5-13


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Soil: Plant or maintain ground cover in orchards or vineyards Mediterranean Farmland

A replicated, randomized, controlled study in 2000–2006 in a rainfed olive orchard near Cordoba, Spain (partly the same study as (1)), found more organic matter and nitrogen, less erosion, and higher soil stability in plots with cover crops, compared to soils with no tillage or conventional tillage. Organic matter: More organic matter was found in soils with cover crops, compared to bare fallows (1.2–2% vs 0.8–1%). Nutrients: More nitrogen was found in soils with cover crops, compared to bare fallows (0.08–0.11% vs 0.06–0.08% organic nitrogen). Soil erosion and aggregation: Less soil was lost in runoff from plots with cover crops, compared to bare fallows, in five of seven years (0–5 vs 1–19 t/ha/year), or compared to plots with conventional tillage, in two of seven years (0.1–5 vs 0.4–14). Higher stability was found in soils with cover crops, compared to bare fallows, in one of two comparisons (macroaggregates: 452–524 vs 258–333 g water-stable macroaggregates/g soil). Greenhouse gases: Similar amounts of carbon dioxide were found in soils with cover crops, bare fallows, or conventional tillage (soil respiration: 0.5–1.1 kg CO2/kg soil). Methods: There were three plots (6 x 12 m plots, with two olive trees each, on a 13% slope) for each of three treatments: cover crops (2 x 12 m barley strips, sown in October), conventional tillage (15 cm depth, 3–4 passes from September), or bare fallows (no tillage, with herbicide). Plots with cover crops were tilled before the barley was sown (10 cm depth). Runoff was collected with tipping-bucket gauges, and sediment was collected in barrels, from autumn 2000. Soil samples were collected in summer 2006 (0–10 cm depth, two samples/plot).

 

Water: Plant or maintain ground cover in orchards or vineyards Mediterranean Farmland

A replicated, randomized, controlled study in 2000–2006 in a rainfed olive orchard near Cordoba, Spain (partly the same study as (4)), found less runoff from plots with cover crops, compared to bare fallows or conventional tillage. Water availability: Less water was lost as runoff from plots with cover crops, compared to bare fallows, in six of seven years (0.1–6% vs 3–36% of rainfall), and compared to conventional tillage, in three of seven years (0.1–0.2% vs 0.5–2.1%). Methods: There were three plots (6 x 12 m plots, with two olive trees each, on a 13% slope) for each of three treatments: cover crops (2 x 12 m barley strips, sown in October), conventional tillage (15 cm depth, 3–4 passes from September), or no tillage (with herbicide, bare fallows). Plots with cover crops were tilled before the barley was sown (10 cm depth). Runoff was collected with tipping-bucket gauges, and sediment was collected in barrels, from autumn 2000.