Nitrogen and Sulfur Recycling and Diagnostic in Cover Crop-Maize Systems

CARCIOCHI, WALTER; CRESPO, CECILIA; ELICECHE, MARTÍN; BARBIERI PABLO ANDRÉS

Journal of Soil Science and Plant Nutrition

Springer Nature Switzerland AG

Año: 2021

0718-9508

It remains uncertain how oat (Avena sativa L.) and hairy vetch (Vicia villosa Roth.) impact both nitrogen (N) and sulfur (S) recycling in cover crop-maize (Zea mays L.) systems as well as N and S diagnostic methods in maize. Field trials were conducted at three sites in the southeastern Argentinean Pampas to evaluate the effect of oat, hairy vetch, and bare fallow combined with fourN and S fertilization treatments (unfertilized, N-, S-, and NS-fertilized) on maize. Soil N and S content at maize sowing, chlorophyll meter reading (CMR) at silking, and grain yield were determined. Overall, soil NO3−-N content (0?60 cm) at maize sowing was hairy vetch > bare fallow > oat, while SO4−2-S content was hairy vetch > bare fallow = oat. Maize yield response to N was predicted from soil NO3−-N content (R2 = 0.80). The CMR was negatively correlated with cover crop residue quality (carbon (C)/N and C/S ratios). Also, CMR accurately predicted variations in maize grain yield. In the unfertilized treatment, maize yield was hairy vetch > bare fallow > oat, in two of the three sites. There was no yield response to N or S with hairy vetch. Oat and hairy vetch differentially affected N and S recycling in cover crop-maize cropping systems. Soil NO3−-N and SO4−2-S content at maizesowing combined with CMR are reliable diagnostic tools to assess maize N and S, allowing for sustainable fertilization management