Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Vineyard floor management affects soil, plant nutrition, and grape yield and quality

Published source details

Smith R., Bettiga L.J. & Cahn P.D.M.D. (2008) Vineyard floor management affects soil, plant nutrition, and grape yield and quality. California Agriculture, 62, 184-190


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 2000–2005 in an irrigated vineyard in the Salinas Valley, California, USA (same study as (2)), found more organic matter and microbial biomass, less nitrate, phosphorus, and soil erosion, and lower pH levels in soils with cover crops, compared to bare soils, between vine rows. Organic matter: More organic matter was found in soils with cover crops, compared to bare soils (1.15–1.55% vs 0.95–1.10%). Nutrients: Less nitrate and phosphorus was found in soils with cover crops, compared to bare soils, in five of six comparisons (3–11 vs 17–28 ppm nitrate-N; 20–22 vs 24–25 ppm Olsen-P). Lower pH was found in soils with cover crops, compared to bare soils (data not reported). Soil organisms: More microbial biomass (measured as carbon) was found in soils with cover crops, compared to bare soils, in one of two comparisons (plots that were cover cropped with rye: 105 vs 83 µg C, in vine rows; 190 vs 100 µg C, between vine rows; 0–12 inches depth). More beneficial fungus colonies (mycorrhizae) were found on vine roots in plots with cover crops, compared to bare soils, in two of six comparisons (with rye as the cover crop, and with pre-emergence herbicide or cultivation under the vines: 26–27% vs 21–21% of root length was colonized), but fewer colonies were found in one of six comparisons (with rye, and with post-emergence herbicide under the vines: 17% vs 26%). Soil erosion and aggregation: In winter, less sediment was lost in runoff from plots with cover crops, compared to bare soils, in one of two comparisons (with triticale as the cover crop: 508 vs 1,735 mg/litre). Methods: There were nine plots for each of two treatments and one control. The treatments were triticale (X Triticosecale) or Secale cereale Merced rye, planted in November 2000–2004 as cover crops (32 inches width) between the vine rows (8 feet width), mown in spring, and disked into the soil in the following November. Bare soils were maintained in the controls through disking in spring and summer (depth not reported). Each plot had 100 vines and the adjacent areas between the vine rows. All plots were drip-irrigated in April–October. Soil samples were collected when the vines were flowering (May 2003–2005, 10 samples/plot, 0–12 inches depth, between the vine rows). Vine roots were collected in April 2003, May 2004, and June 2005 (for mycorrhiza measurements). Runoff was measured with sumps (16 inches diameter, 5 feet depth) at the lower end of each plot. It was not clear whether these results were a direct effect of cover crops or tillage.

 

Crop production: Plant or maintain ground cover in orchards or vineyards Mediterranean Farmland

A replicated, randomized, controlled study in 2000–2005 in an irrigated vineyard in the Salinas Valley, California, USA, found similar crop yields and qualities in plots with or without cover crops, except for lower acidity in plots with cover crops. Crop yield: Similar grape yields were found in plots with or without cover crops (6–6.5 vs 6.1 kg/vine; 46–48 vs 47 cluster/vine, 130–139 vs 132 g/cluster). Crop quality: Similar sugar content and pH levels were found in grapes from plots with or without cover crops (24 oBrix, 3.4 pH), but lower titratable acidity was found in plots with cover crops, in one of two comparisons (7.0 vs 7.3 g/litre). Methods: There were nine plots for each of two treatments, and there were nine control plots. The treatments were triticale (X Triticosecale) or Secale cereale Merced rye, planted in November 2000–2004 as cover crops (32 inches width) between the vine rows (8 feet width), mown in spring, and disked into the soil in the following November. Bare soils were maintained in the controls through disking in spring and summer (depth not reported). Each plot had 100 vines and the adjacent areas between the vine rows. All plots were drip-irrigated in April–October. Grapes were harvested from 20 vines/plot (for crop yield), and 200 grapes/plot (for crop quality). It was not clear whether these results were a direct effect of cover crops or tillage.

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

A replicated, randomized, controlled study in 2000–2005 in an irrigated vineyard in the Salinas Valley, California, USA, found less water in soils with cover crops compared to bare soils, but also found that less water was lost as runoff, and runoff water had less sediment, in plots with cover crops. Water availability: In winter, less water was lost as runoff from plots with cover crops, compared to bare soils (38–96 vs 177 gallons/plot). However, less water was found in plots with cover crops, compared to bare soils, in one of two comparisons (in plots that were cover cropped with rye: 21.5% vs 23.5% soil moisture in mid-February 2003, for example, when measured between vine rows; number of significantly different comparisons not clearly reported). In the growing season, less water was found in soils with cover crops, compared to bare soils (in all years, when measured between vine rows: 17% vs 15% soil moisture in mid-May 2004, for example; or, in two of three years, when measured in vine rows: 19% vs 18% in mid-July 2004, for example; number of significantly different comparisons not clearly reported). Nutrients: In winter, similar amounts of nutrients were found in runoff from plots with cover crops or bare soils (nitrate: 1.2–2 vs 1.7 ppm; total nitrogen: 4.5–6.4 vs 5.6 ppm; total phosphorus: 1.6–2.5 vs 2.6 ppm). Sediments: In winter, less sediment was found in runoff from plots with cover crops, compared to bare soils, in one of two comparisons (with triticale as the cover crop: 508 vs 1,735 mg/litre). Implementation options: In winter, more water was found in plots that were cover cropped with triticale, compared to rye (23% vs 21.5% soil moisture, for example, in mid-February 2003; number of significantly different comparisons not clearly reported). Methods: There were nine plots for each of two treatments and one control. The treatments were triticale (X Triticosecale) or Secale cereale Merced rye, planted in November 2000–2004 as cover crops (32 inches width) between the vine rows (8 feet width), mown in spring, and disked into the soil in the following November. Bare soils were maintained in the controls through disking in spring and summer (depth not reported). Each plot had 100 vines and the adjacent areas between the vine rows. All plots were drip-irrigated in April–October. Runoff was measured with sumps (16 inches diameter, 5 feet depth) at the lower end of each plot. Soil moisture was measured with a neutron probe (3.5 feet depth). It was not clear whether these results were a direct effect of cover crops or tillage.