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Individual study: Soil quality, microbial functions and tomato yield under cover crop mulching in the Mediterranean environment

Published source details

Marinari S., Mancinelli R., Brunetti P. & Campiglia E. (2015) Soil quality, microbial functions and tomato yield under cover crop mulching in the Mediterranean environment. Soil and Tillage Research, 145, 20-28


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

Crop production: Grow cover crops in arable fields Mediterranean Farmland

A replicated, randomized, controlled study in 2012–2013 in two irrigated tomato fields in central Italy (same study as (22)) found that cover crops had inconsistent effects on tomato yields. Crop yield: Higher tomato yields were found in plots that had been cover cropped and mulched with hairy vetch, compared to plots that had not (6.4–7 vs 3.2–5.3 kg/m2). Lower tomato yields were found in plots that had been cover cropped and mulched with lacy phacelia (in one of two comparisons: 4.2 kg/m2) or white mustard (2.1–3.5), compared to plots that had not (3.2–5.3). Implementation options: The highest tomato yields were found in plots with hairy vetch (6.4–7 kg/m2) and the lowest were found in plots with white mustard (2.1 kg/m2). Methods: Three species of winter cover crops (Vicia villosa hairy vetch, Phacelia tanacetifolia lacy phacelia, or Sinapis alba white mustard) were sown on three plots each, but not on three control plots (plot size not reported), in September. The cover crops were mulched in May, and the control plots were tilled (depth not reported). Tomato seedlings were transplanted in May (transplanted into the mulch) and harvested in August. All plots were tilled in September. It was not clear whether these results were a direct effect of cover cropping, mulching, or tillage.

 

Soil: Grow cover crops in arable fields Mediterranean Farmland

A replicated, randomized, controlled before-and-after study in 2012–2013 in two irrigated tomato fields in central Italy found more organic matter, nitrogen, and soil organisms in soils with cover crops (and no tillage), compared to soils without cover crops (with tillage), in spring. By the end of summer, less organic matter, but more nitrogen, had accumulated in soils with cover crops, and there were inconsistent effects on soil organisms. Organic matter: In May, more organic carbon was found in soils that had been cover cropped and mulched, compared to soils that had not, in two of six comparisons (lacy phacelia or white mustard, in 2013: 16 vs 12 mg C/g soil). By August, less organic carbon had accumulated in soils with mulch, compared to soils without mulch, in two of six comparisons (lacy phacelia or white mustard, in 2013: –1% to 4% vs 28% increase in organic carbon). Nutrients: In May, more nitrogen was found in soils that had been cover cropped and mulched, compared to soils that had not, in one of two years (all cover crops, in 2013: 1.3–1.5 vs 1.1 mg N/g soil). By August, more nitrogen had accumulated in soils with mulch, compared to soils without mulch, in one of six comparisons (white mustard, in 2013: 44% vs 2% increase in nitrogen). Soil organisms: In May, more microbial biomass (measured as carbon) was found in soils that had been cover cropped and mulched, compared to soils that had not (140–330 vs 100–150 µg C/g soil), and more microbial biomass was also found in two of three comparisons in August 2012 (175 vs 135 µg C/g soil), but less was found in two of three comparisons in August 2013 (175–210 vs 270 µg; 2012 was hotter and drier than 2013). Methods: Three species of winter cover crops (Vicia villosa hairy vetch, Phacelia tanacetifolia lacy phacelia, or Sinapis alba white mustard) were sown on three plots each, but not on three control plots (plot size not reported), in September. The cover crops were mulched in May, and the control plots were tilled (depth not reported). Tomato seedlings were transplanted in May (transplanted into the mulch) and harvested in August. All plots were tilled in September. Soil samples were collected at the beginning (May) and end (August) of the tomato-growing season (0–20 cm depth). It was not clear whether these results were a direct effect of cover cropping, mulching, or tillage.