Effects of nitrogen fertilizer on the photosynthetic characteristics and nutrient utilization of drip irrigated silage maize by sequential cropping in north Xinjiang

In order to investigate the effects of nitrogen( N) fertilizer on the physiological indexes of drip irrigated silage maize by sequential cropping in north Xinjiang,to increase N fertilizer utilization efficiency,through the field plot experiments have researched the effects of photosynthetic characteristics and soil NH4+- N distribution under the layout pattern of one row with one lateral pipe and different N fertilizer treatments( i. e.,100,170,240,310 kg·hm- 2and 385 kg·hm- 2). The results showed that: For different N fertilizer treatment condition,the daily change curves of the net photosynthetic rate of the leaves and transpiration rate of the sequential cropping maize displayed a single peak type. Holistically,soil total NH4+- N content decreased at first and then increased with increasing the N application. The yield increased at first and then decreased with increasing N application.Through the comprehensive analysis,we think under the layout pattern of one row with one lateral pipe,the N fertilizer application treatment of 240 kg · hm- 2was the best effect of water- N coupling with the lowest soil total NH4+- N content,highest yield and water use efficiency of the leaf,and a relatively high net photosynthetic rate.