THE EFFECTS OF DIFFERENT COVER CROPS ON GRAIN YIELD OF POPCORN (ZEA MAYS L. SSP. EVERTA STURT)

Abstract

Cover crops are specific system of growing and mainly cover the surface of the soil during the winter, improve the physical and mechanical properties of the soil, water regime, increase the content of nutrients, reduce weed control and contribute to the achievement of higher yields of the main crops. The positive impact on the higher yields in the main crop is the result of lower infestation and increased competition for the main factors of growth and development and through secretion allelopathic compounds.
The experiments were performed in 2014 on experimental field of the Maize Research Institute in ZemunPolje (Belgrade, Serbia). We have includedthe following types of individual winter cover crops: common vetch, oat, fodder kale and field pea; Mixtures: common vetch + oats, field pea + oats; and two controltreatments:deadorganicmulch- soilcovered with strawin autumnand winter time, andconventional (traditional) variant– bare soiluncoveredduring fall andwinter time. Sowing cover crops is carried out in the autumn, the elemental plots of 35 m-2. Mowing and soil incorporation of cover crops was carried out in late April or early May, when the crops were most abundant. Sowing popcorn (ZP 611k) was done manually in mid-May at a density of 65 000 plants ha-1. In both years, in the phase of intensive growth of the main crop, is determined total number of weed species, total number of plants per species and fresh biomass per m-2.
In a year that was rich precipitation (2014), the highest grain yield obtained with legumes cover crops and the lowest in traditional variant, classical plowing in the fall and keeping bare land uncovered during the winter. We can be concluded that higher yields of popcorn by sowing cover crops in sustainable farming systems in a semi - arid regions.