Contribution of Roots and Shoots of Three Summer Cover Crops to Soil C and N Cycling Post-Termination

Summary

Although summer cover crops (CCs) have relatively short growing periods, they can significantly enhance soil health by contributing to carbon (C) and nitrogen (N) cycling. Three summer CCs—including oat, buckwheat, and pea—were planted in June–July and evaluated for their biomass, allocation of assimilates to roots, C and N yield, and residue decomposition patterns after termination in a 14-week period. Total biomass (roots + shoots) was highest in buckwheat (5822 kg ha−1), followed by oat (4836 kg ha−1) and then pea (20 22 kg ha−1). Across species, the allocation of assimilates to roots decreased from 34% at 30 days after planting to 18% at termination. Total C yield was 2409, 1941, and 808 kg ha−1 for buckwheat, oat, and pea, respectively, with root C content considerably lower than shoo