Green manure crops and n rates influence on variability of dry matter and N content at anthesis and maturity in wheat (Triticum aestivum L.)

F. Gerami, E. Fateh, A. Aynehband

Abstract: Efficient and economic utilization of green manure crops is crucial in sustainable agriculture. Field experiments were conducted to study the effect of nitrogen supply through chemical N fertilizer and green manures on grain yield and nitrogen loss and gain of wheat as subsequent crop. The experimental design was split plots, arranged in randomized complete block with three replications. Results showed that, green manure differences in dry matter and nitrogen translocation efficiencies were related to nitrogen and biomass accumulated in plant reserve parts at both anthesis and maturity. Green manure dry matter translocation efficiencies ranged from 18.7 in cowpea to 22.5% in amaranth, nitrogen translocation efficiencies from 73.9 in sesbania to 76.6% in amaranth and contribution of pre-anthesis assimilates to grains from 32.8 in millet to 43.5% in amaranth. It has to indicate that all of them were greatest in the non-legume green manures. Increase in N application, decreased the contribution of pre-anthesis assimilates to grains, but had various effect on N gain and losses. At the highest N application rates dry matter translocation efficiency, contribution of pre-anthesis assimilates to grain, nitrogen translocation efficiency, harvest index and nitrogen harvest index were greatest in amaranth (non-legume) green manure crops. But, at the optimum and lower N application rates (100 and 50 kg N ha-1) this parameters were greatest in all legume green manure crops. In addition, greatest N losses also occurred at the highest N rates. Consequently, high amounts of N accumulated at anthesis led to worst N loss at maturity.

Keywords: dry matter; efficiency; Green manure; nitrogen; wheat

Date published: 2019-03-25