Cover crops and cultivation: Impacts on soil N dynamics and microbiological function in a Mediterranean vineyard agroecosystem

Published source details Steenwerth K. & Belina K.M. (2008) Cover crops and cultivation: Impacts on soil N dynamics and microbiological function in a Mediterranean vineyard agroecosystem. Applied Soil Ecology, 40, 370-380.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Soil: Plant or maintain ground cover in orchards or vineyards Action Link
	Water: Plant or maintain ground cover in orchards or vineyards Action Link

Soil: Plant or maintain ground cover in orchards or vineyards

A replicated, randomized, controlled study in 2001–2006 in a vineyard in the Central Coast, California, USA (same study as (7)), found more soil organisms and higher greenhouse-gas emissions in plots with cover crops between the vine rows, compared to tilled soils without cover crops, but found inconsistent effects on nitrogen. Nutrients: Less nitrate was found in soils with cover crops, compared to tilled soils, between vine rows, in 12 of 19 comparisons (0–1 vs 1.4–5.7 µg NO₃-N/g dry soil). In contrast, more ammonium was found in soils with cover crops, in six of 19 comparisons (during the spring rains: 1.3–3 vs 0.7–1.7 µg NH₄-N/g dry soil), and more available nitrogen was found in 18 of 19 comparisons (potentially mineralizable nitrogen: 21–55 vs 2–15 µg NH₄-N/g dry soil). Soil organisms: More microbial biomass (measured as nitrogen) was found in soils with cover crops, compared to tilled soils, in 15 of 38 comparisons (during the spring and autumn rains: 21–61 vs 4–39 µg N/g dry soil). Greenhouse gases: Higher nitrous oxide emissions were found in soils with cover crops, compared to tilled soils (1.9–2.3 vs 1.6 g N₂O-N/ha/day). Methods: There were six plots (84.3 x 2.4 m interrows between vines) for each of two cover crops, and there were six control plots (cultivated every two months to control weeds). The cover crops (1.8 m width) were Triticale x Triticosecale Trios or Secale cereale rye, seeded in November 2001–2005 (interrows disked before seeding), and mown in April 2002–2006. Soil samples were collected every 2–3 weeks in December 2005–November 2006 (19 samples/plot, two cores/sample, 0–15 cm depth). Nitrous oxide was measured in 5.2 litre chambers (13 mL samples, every 30 minutes from solar noon, for 1.5 hours). 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

A replicated, randomized, controlled study in 2001–2006 in a vineyard in the Central Coast, California, USA (same study as (12)), found more water in soils with cover crops between the vine rows, compared to tilled soils without cover crops. Water availability: More water was found in soils with cover crops, compared to tilled soils, in some comparisons (e.g., in spring: 19–21% vs 17% water), but similar amounts of water were found in most comparisons. Methods: There were six plots (84.3 x 2.4 m interrows between vines) for each of two cover crops, and there were six control plots (cultivated every two months to control weeds). The cover crops (1.8 m width) were Triticale x Triticosecale Trios or Secale cereale rye, seeded in November 2001–2005 (interrows disked before seeding), and mown in April 2002–2006. Soil samples were collected every 2–3 weeks in December 2005–November 2006 (19 samples/plot, two cores/sample, 0–15 cm depth).