Effects of Row Spacing on Carbon and Nitrogen Transportation, Grain Nitrogen Input in Winter Wheat

Field plot experiments were carried out to examine the effects of row spacing on carbon and nitrogen transportation,nitrogen input to grain in winter wheat with two spike types on the farm of Henan Agricultural University during 2006-2007.The results showed that the assimilation accumulation after anthesis and contribution of assimilation accumulation to grain weight firstly increased and then decreased with reaching peak value at 20 cm row spacing in large-spike wheat Lankaoaizao8,and gradually decreased in multi-spike wheat Yumai49 with row spacing increasing.The assimilation stored before anthesis and contribution of assimilation stored to grain weight increased with row spacing increasing in two spike types culticars,with the highest shoot assimilation translocation rate at the treatment of 15 cm row spacing in Lankaoaizao8 and 20 cm row spacing in Yumai49.All shoot N translocation amount was the highest at 15 cm row spacing and next at 20 cm row spacing,with higher value of wider row spacing than narrower row spacing for all shoot N translocation rate in Lankaoaizao8.All shoot N translocation amount was the highest at 10 cm row spacing and next at 25 cm row spacing,with higher value of narrower row spacing than wider row spacing for all shoot N translocation rate in Yumai49.There was a significant correlation between grain N accumulation and grain N input duration(S)and the average rate of grain N input(V)with the longest grain N input duration and highest average rate of grain N input at 15 cm row spacing.The grain N accumulation mostly depend ed on N input rate such as the average rate of grain N input(V),the highest rate of grain N input(Vmax)and the grain N input rate in valid grain N input duration(Vs),with the highest N input rate at 20 cm row spacing.