MAIZE YIELD AND ITS STABILITY AS AFFECTED BY TILLAGE AND CROP RESIDUE MANAGEMENT IN THE EASTERN ROMANIAN DANUBE PLAIN

Rainfed crop management systems need to be optimized to provide more resilient options in order to cope with projected climatic scenarios, which forecast a decrease in mean precipitation and more frequent extreme drought periods in the Eastern Romanian Danube Plain. This research, carried out in the period of 2011-2014, had as main purpose the determination of influence of tillage practices and residue management on rainfall use efficiency, maize yield and its stability, in order to evaluate the advantages of conservation agriculture (CA) in the time of stabilization of direct seeding effects, in comparison with traditional chisel tillage. The maize grain yields are presented for each crop management practices, as follows: (1) chisel tillage, retained crop residues being chopped and incorporated (ciz); (2) zero tillage, retained crop residue chopped and kept on the field in short flat condition (rvt); (3) zero tillage, crop residues kept on the field in short root-anchored condition (1/2rva), and (4) zero tillage, crop residues kept on the field in tall root-anchored condition (1/1rva). In 2012, a year with prolonged drought during vegetative growth, yield differences between zero tillage with short root-anchored residue retention (1/2rva) and chisel tillage with residue incorporation (ciz) were positive, up to 840 kg ha(-1). On average over 2011-2014, conservation agriculture (CA) practices had a yield advantage over traditional chisel tillage practice. Zero tillage with residue retention used rainfall more efficiently, suggesting that it is a more resilient agronomic system than traditional (conventional) practices involving chisel tillage with residue incorporation.