关键词: 间作绿肥, 减量施氮, 产量, 光能利用率, 玉米, 箭筈豌豆

Abstract:

【Objective】 This study aimed to clarify the response of maize growth and yield with different nitrogen application rates to intercropped green manure, so as to provide the basis for establishing maize production pattern with nitrogen fertilizer saving via green manure in arid irrigation area.【Method】 A split plot experiment design was adopted, and two planting patterns of maize intercropping with common vetch (MV) and sole maize (SM) were set up in the main plot. Five nitrogen application rates were set up in the split plot: the recommended nitrogen application rates were N360: 360 kg N·hm^-2, application rates reduced with 25% (N270): 270 kg N·hm^-2, and that reduced with 50% (N180): 180 kg N·hm^-2, reduced with 75% (N90): 90 kg N·hm^-2, and no nitrogen application (N0). Leaf area index (LAI), daily leaf volume (LAD), light energy utilization rate, dry matter accumulation and yield of maize were investigated.【Result】 In 75-150 days after maize emergence, the LAI, total LAD and light use efficiency of maize with reduced nitrogen application rate (N270, N180, N90, N0) were increased by intercropped green manure. The maize LAI, total LAD and light use efficiency under M||V with N270, N180, N90, and N0 were significantly increased by 9.8%, 8.2% and 4.6% than that under SM, respectively. The maize LAI, total LAD and light use efficiency under M||V with N270 was not different with that with N360, in 75-150 days after maize emergence, and which was greater than that of other treatments. Somehow, the maize LAI, total LAD and light use efficiency of SM was decreased with reduced nitrogen application rate. The dry matter accumulation of maize under N270, N180, N90, and N0 was significantly increased by intercropped with green manure than that of sole maize, in 90-150 d days after maize emergence, which was increased by 4.6%. In 75-130 days after maize emergence, the growth rate of maize under M||V was significantly increased by 5.9% compared that with SM. With the same reduced nitrogen application rate (N270, N180, N90, and N0), the maize grain yield under M||V was significantly increased by 8.5% than that under SM. The grain yield of intercropped maize under N270 was significantly higher than that of sole maize under N360. Compared with SM, the kernel number per ear and 1000-grain weight of maize under M||V were significantly increased by 6.0% and 6.3%, respectively. The results of the fitting curve showed that the greatest grain yield of maize intercropped with green manure was 14 876.4 kg·hm^-2 with nitrogen application rate 261.4 kg·hm^-2. While the greatest grain yield of sole maize was 14 012.5 kg·hm^-2 with nitrogen application rate of 348.6 kg·hm^-2. The effect of reducing nitrogen application on the fresh yield and nitrogen accumulation of green manure was significant. The fresh yield of green manure under M||VN270 was significantly higher than that under M||VN360, M||VN90 and M||VN0 by 3.8%, 4.6%, and 9.7%, respectively, while the nitrogen accumulation with M||VN 270 was significantly higher than that with M||VN90 and M||VN0 by 5.3% and 11.9 %, respectively. The total dry matter accumulation of maize with reduced nitrogen applied rate was increased by intercropped green manure, and then the number of grains per ear and thousand grains weight of maize was increased. Therefore, the intercropped maize could obtain a greater level of grain yield with the condition of reduced nitrogen application rate.【Conclusion】 The treatment of 25% reduced nitrogen rate with intercropped green manure could make maize obtain higher yield than sole maize with the recommended nitrogen application rate. This pattern could be used as a recommended production method for chemical nitrogen fertilizer reduced application of maize in the research region and even similar ecological region.

Key words: green manure intercropping, nitrogen reduced application rate, yield, light use efficiency, maize, common vetch