Effects of Different Soil Fertility Levels and N Application Rate on Wheat Yield and Matter Production after Rice

Took Huaimai 19 and Yannong 19 as materials,the effects of nitrogen application rate on yield and matter production in wheat after rice in northern of Jiangsu winter wheat growing areas under high,middle,low soil fertility levels were studied.The results showed that there were significant Conics relations between nitrogen application rate and wheat yield in high and middle soil fertility level,but it was a linear correlation under low fertility soil.The appropriate nitrogen rate were 246.7 and 286.1 kg·hm-2 for high-yield of Huaimai 19 in high,middle soil fertility level,and 247.9 and 292.6 kg·hm-2 for high-yield of Yannong 19;there were high-quality crops population with the higher yield treatment in every growth stages.There was a highest wheat production at nitrogen rates in different soil fertility level because of the combined effects in wheat matter production,and the highest wheat production improved with the soil fertility level increasing.In contrast,the nitrogen rates for highest wheat production declined with the soil fertility level increasing.Therefore,we should decide different target output and accurate nitrogen rate in accordance with different soil fertility levels in practice of wheat production.