Studies On Dry Matter And Nutrient Accumulation In Maize//Soybean Intercropping System Under Different N Application In Jinzhong Dry-land

A field experiment was carried out to study the influence of different applied amount of N fertilizer on the dry matter accumulation, nutrient accumulation and yield of maize and soybean in maize//soybean intercropping system by setting the split-block design including a mainly nitrogen area and a subplot of planting patterns. The aim was to explore the optimal applied amount of N fertilizer in maize//soybean intercropping system in jinzhong dryland, also to provide the basis for the development of maize//soybean intercropping mode in Jinzhong dryland. This experiment mainly results were as follows:?1?The land equivalent ratio ?LER? of the grain yield in maize//soybean intercropping system were greater than 1. The 150kg·N·hm^-2 level could play maximum grain yield advantage in maize//soybean intercropping mode. Intercropping maize and soybean grain yield and biological yield were greater than monoculture, which showed that maize//soybean intercropping could develop yield advantage. Under Intercropping pattern, yield increase amplitude was the largest in the 150 kg·N·hm^-2 levels.?2?Compared with the monoculture, intercropping did not affect the ear hight and rate of seed. In 150 kg·N·hm^-2 level, intercropping maize in side row significantly improved the grain weight per ear, and had obvious intercropping advantage. Under fertilizing levels (150 kg·N·hm^-2 and 300 kg·N·hm^-2 ), maize//soybean intercropping in the maize ear length, bald level and ear rows showed no intercropping advantage. Under maize//soybean intercropping pattern, the appropriate amount of fertilizer (150 kg·N·hm^-2 ) helped to reduce intercropping maize bald level, and significantly increase the intercropping maize grain weight per ear, ear length and ear rows. Compared with the monoculture, under no fertilizer and 150 kg·N·hm^-2 levels, intercropping significantly heighted intercropping soybean 100-grain weight, which showed obvious intercropping advantage; only under 150 kg·N·hm^-2 level, intercropping could significantly improve the intercropping soybean seeds weight per plant, grain per plant and pods per plant, especially side row; under no fertilizer level, intercropping soybean rate of disease and pests decreased significantly. Under maize//soybean intercropping pattern,150 kg·N·hm^-2 fertilizer level significantly increased intercropping soybean 100-grainl weight, seeds weight per plant, grain per plant, pod per plant, and significantly reduced the soybean rate of disease and pests. It showed that in intercropping condition, the appropriate amount of fertilizer application were favorable for the formation of intercropping soybean yield factors, and could decrease the rate of intercropping soybean rate of diseases and pests, especially there was a advantage tendency for side row than middle row. In summary,150 kg·N·hm^-2 levels helped to maximize the advantages of yield and yield characteristics of maize//soybean intercropping pattern, also there was an advantage tendency for side row than middle row.?3?At Most of the growth stages, the leaf area index of side row and middle row of the intercropping maize and soybean were greater than monoculture, which showed that intercropping could improve crop leaf area index. And intercropping maize and soybean had the greatest leaf area index in 150 kg·N·hm^-2 levels at different growth stages.?4?Under the same N fertilizer level, dry matter accumulation of intercropping maize was increased significantly, especially side row. The dry matter accumulation of intercropping soybean in the 150 kg-N-hm"2 had significantly intercropping advantage, also especially side row. In intercropping pattern, the N fertilizer could significantly increase dry matter accumulation of intercropping maize and soybeans, especially under the 150 kg·N·hm^-2 level.?5?The logistic equation of dry matter accumulation of maize and soybeans showed that although the days to MIR of dry matter accumulation of intercropping maize and soybean was later than monoculture, under different fertilizer levels, dry matter accumulation and the largest maximum growth rate of intercropping maize and soybean were greater than monoculture. Fertilizing were conducive to the increase of dry matter accumulation and the maximum growth rate of intercropping maize and soybean, especially under the 150 kg·N·hm^-2 level.?6?The Maize//soybean intercropping pattern could improve the concentration and the accumulation of plant nitrogen, phosphorus, iron, zinc of intercropping maize and soybean, which showed intercropping was advantage. Increasing N application rate could significantly improve the concentration of plants nitrogen, phosphorus, iron, zinc of intercropping maize and soybean, but excessive N levels, such as 300 kg·N·hm^-2 levels, did not explore maximum the accumulation potential of plant nitrogen, phosphorus, iron, zinc of intercropping maize and soybean in maize//soybean intercropping pattern.