Abstract:
This study was conducted for three consecutive seasons 2014/15 (direct effect), 2015/16 (direct and residual effects ) and 2016/17 (residual effect) on a desert soil with the aim to investigate direct and residual effects of green manure with three levels on soil fertility of desert soil and grain yield of wheat in the Northern State of Sudan. Four types of green manure Vigna radiate (Green gram), Vigna sinensis (Cowpea), Dolichos Lablab (Lablab bean) and Sesbania canabina (Sesbania pea) were selected as green manure corps with three levels. The first level was a seed rate of 12 kg ha-1, 18 kg ha-1, 24 kg ha-1 , 12 kg ha-1 respectively. The second level was two times of the first level and third level was three times of the first level. The treatments were arranged in a randomized complete block design with three replications. Land preparation was done manually for the residual effects of green manure so as not to disturb the treatments which were fixed in the same plots of the first application of the manures. The results showed that the direct and residual effects of green manure were effective in improving the nitrogen and phosphorus uptake by plant and the chemical properties of the soil under investigation. The results showed that the green manure and its residues increased the organic carbon, nitrogen, available phosphorus, potassium, CEC and improved nitrogen and phosphorus uptake by wheat plant. The result also showed that the direct and residual effects of green manure obtained very high significant increase (P≤0.001) in the grain yield of wheat on the desert plain soils.
