Cover crop effects on the fate of N in sweet maize (Zea mays L. saccharata Sturt.) production in a semiarid region

This research aimed to determine the effects of different cover crops and application ofbio-fertilizer on dynamic of nitrogen in the soil and sweet maize yield. Also, we evaluated theeffect of fall–winter species (common vetch, field pea, winter oats, fodder kale) and a mixtureof vetch and field pea with oats used as cover crops, as such as dead organic mulch andtraditional variant, without coverage on biomass, chlorophyll and protein content in leaves andgrain of main crop. Biomass production and N uptake by cover crops ranged from 4.25 to 90.20kg ha-1 and from 0.34 to 133.80 kg ha-1 N, respectively, depending on cover crop type. Atharvest soil nitrate content in treatments with cover crops was 50-90% lower than in the control,reducing spring N leaching risk. Residual mineral N significantly increased with application ofmicrobiological fertilizer. The chlorophyll content of the main crop was significantly lower intreatments without cover crops. Consequently, sweet maize yield was the highest in fodder kaleand field pea (7263.83 and 7177.27 kg ha-1) treatments, but the smallest in winter oat andcommon vetch (6802.47 and 6184.14 kg ha-1). In terms of all investigated traits, particularlygrain yield, cover crops and microbiological fertilizer expressed more efficiency in the dry year.It could be concluded that N content should be controlled effectively by sowing main crops afterplanting of cover crops in biological farming systems in a semiarid region.