An assessment of symbiotic nitrogen fixation by leguminous cover crops and its contribution to the nitrogen balance in a vineyard cover crop system
Van Schalkwyk, D
To evaluate different legume cover crops for their ability to enhance the nitrogen nutrition of the vine on a sandy soil and to determine the nitrogen contribution made by legume cover crops as measured by 15N natural abundance methodologies.
Throughout this study it has become evident that, among the legumes, grazing vetch has the greatest potential to improve the soil nitrogen status of the vine in the Olifants River region as it supplies the highest above ground nitrogen. Nitrogen supply from legume cover crops are synchronized with vine nitrogen demand, yet adequate moisture has to be supplied in order to gain the full benefit of legumes with regard to nitrogen supply. This research has shown that cover cropping is beneficial to the nitrogen economy of the vine.
Potential to promote cost-effective, environmentally friendly and sustainable viticultural practices for resource limited producers. Legume cover crops could supplement nitrogen fertilization and thereby reduce the application of chemical fertilizers and input costs.