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

Abstract

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