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 of bio-fertilizer on dynamic of nitrogen in the soil and sweet maize yield. Also, we evaluated the effect of fall-winter species (common vetch, field pea, winter oats, fodder kale) and a mixture of vetch and field pea with oats used as cover crops, as such as dead organic mulch and traditional variant, without coverage on biomass, chlorophyll and protein content in leaves and grain of main crop. Biomass production and N uptake by cover crops ranged from 4.25 to 90.20 kg ha(-1) and from 0.34 to 133.80 kg ha(-1) N, respectively, depending on cover crop type. At harvest 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 of microbiological fertilizer. The chlorophyll content of the main crop was significantly lower in treatments without cover crops. Consequently, sweet maize yield was the highest in fodder kale and field pea (7263.83 and 7177.27 kg ha(-1)) treatments, but the smallest in winter oat and common vetch (6802.47 and 6184.14 kg ha(-1)). In terms of all investigated traits, particularly grain 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 after planting of cover crops in biological farming systems in a semiarid region