Effect Of Nitrogen Fertilizer And Intercropping On Crop Productivity, Nitrogen Utilization And Soil Ecological Environment In Dry Land Red Soil

In order to study the effect of maize, soybean intercropping and nitrogen rates on crop productivity and ecological environment in red upland soil, the two-year(2013-2014) field experiments were conducted in the agricultural science and technology park at Jiangxi Agricultural University. The experiments were designed in two-factor random block, 2 nitrogen rates(0 and 150 kg·hm-2) and 3 cropping patterns(maize monoculture, maize‖soybean intercropping, soybean monoculture), each treatment had three repeats. We studied the maize, soybean planting system in crop productivity(yield, dry matter and nitrogen accumulation), mechanism of interspecific competition, characteristics of nitrogen utilization, soil nutrient and soil fauna diversity. The results showed as fellows:1. From the point of crop productivity, and nitrogen use features,the nitrogen utilization can improve crop productivity(yield, dry matter and nitrogen accumulation) of the maize,soybean planting system, which improve the nitrogen use efficiency, partial factor productivity from applied nitrogen, nitrogen absorption and physiological utilization rate, soil contribution rate of nitrogen in the planting seasons(except 2013) at a certain degree.2. From the point of maize soybean intercropping system interspecific competition relations, Whatever nitrogen applied or not, maize‖soybean intercropping system had obvious advantage of yield(LER>1, AYL>0). Maize was the dominant species in maize‖soybean intercropping as indicate by competition ratio of maize to soybean(Ams>1, CRm>CRs>0, Km>Ks>0).3. From the point of soil ecological environment, in the process of two years experiments, the soil nutrients were fluctuated change, nitrogen application significantly increased the soil nitrate nitrogen and ammonium nitrogen content. collembola and acarina were dominant population under five cropping patternstreatments. The the highest average density was soybean monoculture, nitrogen application significantly increased the average density of soil animals, soil animals mean density and the number of groups have obvious seasonal change. From CCA analysis, from 2013 to 2014, most impact soil environmental factors changed from the soil pH to soil alkali-hydrolysable nitrogen content from 2013 to 2014.