Inclusion of Cover Crops in Cropping Sequences with Soybean Predominance in the Southeast of the Humid Argentine Pampa
RESEARCH ARTICLE

Inclusion of Cover Crops in Cropping Sequences with Soybean Predominance in the Southeast of the Humid Argentine Pampa

The Open Agriculture Journal 08 Feb 2013 RESEARCH ARTICLE DOI: 10.2174/1874331501307010003

Abstract

The incorporation of a cover crop (CC) may be an alternative to increase soil carbon (C) and nitrogen (N) supply in crop sequences with a high frequency of soybean. The aims of this study were (i) to determine shoot biomass production, C and N contents in the CC under two N additions, (ii) to evaluate the effect on soybean grain yield of including a CC, and (iii) to evaluate the water productivity of the crop sequences. Crops were evaluated during three growing seasons of a long-term field trial under no tillage on Typic Argiudoll in Balcarce, Buenos Aires, Argentina. Mean CC shoot biomass was 6.6 Mg ha-1 yr-1 for N-fertilized and 5.2 Mg ha-1 yr-1 for non-fertilized treatments. Mean C and N accumulation in the CC shoot biomass were 2.8 Mg C ha-1 yr-1 and 131 kg N ha-1 yr-1 in N-fertilized treatments, and 2.3 Mg C ha-1 yr-1 and 67 kg N ha-1 yr-1 in nonfertilized treatments. Soybean grain yield ranged from 2.4 to 4.3 Mg ha-1. In two out of the three growing seasons, soybean grain yield was greater (p<0.05) for crop sequences that included a CC. Water productivity was higher (p<0.05) in crop sequences with a CC and even higher when they were N-fertilized. The inclusion of a CC preceding soybean in crop sequences is an alternative to improve soil C and N budgets and would be a promising strategy to increase productivity and cropping system sustainability in this region.

Keywords: Yield, sustainability, carbon, nitrogen.