Residual effects of summer green manure crops and zinc applied to rice (Oryza sativa) on succeeding durum wheat (Triticum durum) under basmati ricewheat cropping sequence

Abstract

Field experiments were conducted for two consecutive years (2009-11) at the research farm of Indian Agricul- tural Research Institute, New Delhi, to determine the direct and residual effects of summer green manuring crops [Sesbania aculeata (Dhaincha), Crotalaria juncea (Sunhemp) and Vigna unguiculata (Cowpea)] and zinc fertilizer sources [EDTA-chelated Zn (12% Zn), ZnSO .7H O (21% Zn), ZnSO .H O (33% Zn), ZnO (82% Zn) and 4 2 4 2 ZnSO .7H O + ZnO (50% + 50%)] on productivity, Zn uptake and economics of basmati rice (Oryza sativa L.)du- 4 2 rum wheat (Triticum durum Desf.) cropping sequence. In this paper information pertaining to residual effect of treatments on durum wheat is given. Significant residual effects of Zn fertilizer sources and summer green manur- ing crops were observed on durum wheat in comparison with control (no Zn application or summer fallow in pre- ceding Basmati rice). With residual effect of Sesbania incorporation, grain and straw yields of durum wheat were 4.5 and 5.16 t/ha, which were 15.9 and 10.0% higher compared to fallow. Among the different Zn fertilizer sources, residual effect of EDTA-chelated Zn was found to be the best with respect to growth, yield attributes, grain, straw, Zn content and uptake and economics. The residual effect of application of EDTA-chelated Zn resulted in the high- est durum wheat grain (4.78 t/ha) and straw yields (5.38 t/ha) compared to control. Highest Zn concentration in grain (43.0 mg/kg) and straw (126.6 mg/kg) and its uptake was recorded with residual effect of Sesbania incorpo- ration compared with sunhemp, cowpea and summer fallow. Highest total Zn uptake (936.6 g/ha) in durum wheat was recorded with residual effect of EDTA-chelated Zn application, followed by ZnSO .7H O, ZnSO .H O, 4 2 4 2 ZnSO .7H O + ZnO (50% + 50%), ZnO and control. The best economical returns were obtained with residual ef- 4 2 fect of Sesbania incorporation and EDTA-chelated Zn combination.