The Controlling Effect And Mechanism Of Maize Density On The Intercropping Peas "N Min Inhibitory Effect"

Gramineous/crops with full used of environmental resources and increased crop yield that plays animportant role in our country traditional agriculture. Predecessors have done a lot of research aboutintercropping system yield, water use, nutrient use of advantages, etc, but mechainism and technologyresearch of through the intercropping gramineous density control leguminous "N min inhibitory effect"relatively weak, that makes the model in improving the potentia of N utilization was not fully develop. Thesudy on maize interplanting peas, in low (45000plants/hm2),(52500plants/hm2), high (60000plants/hm2)three maize density, discusses the different density of intercropping maize interplanting peas " N mininhibitory effect " controlling effect, studies the symbiotic period﹑after peas harvest﹑maize harvest themaize/peas system the mechanism of the advantages using nitrogen. The main results are as follows:1. With the increase of density intercropping maize production﹑N-uptake amount﹑land equivalent rate(LER)﹑nitrogen use efficiency of agriculture(ANUE)﹑nitrogen use efficiency(NUE)and nitrogen useefficiency(PNUE) of agriculture of interplanting system gradually increased, compared with the soleweight average, biological yield﹑grain yield increased12.50-41.74%﹑1.31-55.33%, the total N-uptake ofplant﹑the N-uptake of grain increased9.63%-100%﹑1.09%-14.68%. Compare high density interplantingmode of LERANUE﹑NUE﹑PNUE with medium density interplanting mode increased15.74%﹑279%﹑13.27%﹑239%, with lower density interplanting mode increased23.76%﹑385%23.47%﹑317%.2. With the increase of density intercropping maize the " N min inhibitory effect " phenomenon ofinterplanting peas was more seriously.In thelower﹑medium﹑high density intercropping modle, compareroot nodules number of components peas under nitrogen treatment with no-nitrogen treatment reduced30.17-62.24%﹑49.6-92.13%﹑48.78-90.41%; compare root nodules number of components peas undernitrogen treatment with no-nitrogen treatment reduced56.11-79.28%67.95-97.08%﹑73.61-91.01%. Lowdensity intercropping system is good for peas nodular and have obvious alleviated "N min inhibitory effect"; High, medium density of intercropping system is not good for peas nodular and have not obviousalleviated "N min inhibitory effect".3. Interplanting significant influence on the main use of nitrogen to soil physical and chemicalindex.Before peas harvet, the total nitrogen concentration of soil between peas and intercropping systemhave no significant difference, but are significantly higher than maize; after pea harvest the total nitrogenconcentration of soil: sole pea>pea/corn>sole maize, the total nitrogen concentration of high densityinterplanting processing is significantly lower than other interplanting processing;maize harvest, the soiltotal nitrogen concentrations of intercropping peas was significantly lower than sole,soil total nitrogen concentration of intercropping and sole maize was no significant difference.The harvest-time of peas, with maize density increased soil NO-3-N of interplanting pea﹑maizegradually increased;after the peas harveste, of sole pea higher than intercropping, with density increasessoil NO-3-N of intercropping gradually lowed; soil NO-3-N of intercropping maize gradually increased withdensity increase, and greater than the sole;maize harvest, with the increase of density soil NO-3-N ofintercropping peas﹑maize gradually reduced.The symbiotic period, trend of soil NH4+-N concentration of each treatment: sole pea> intercropping>sole maize, each intercropping treatment have no significant difference, soil NH4+-N concentration of theD3density of intercropping peas higher than D1﹑D2density of intercropping peas, soil NH4+-Nconcentration of intercropping maize less than soie; after peas harvest:sole maize, low﹑medium densityintercropping system> high density intercropping system> sole pea, and the high density of intercroppingpeas less than and low, medium density of intercropping, intercropping maize higher than sole;maizeharvest: sole pea>low density intercropping system>medium, high density intercropping system, solemaize, with density increases, soil NH4+-N of peas, maize gradually reduce.The symbiotic period,the trend different treatment: sole maize> intercropping system>sole pea, and withthe increase of density gradually increased; peas harvested,0-30cm soil water content, temperature ofintercropping higher than sole,with density increases, intercropping system of the soil moisture graduallyincrease, geothermal gradually reduced.4. Along with the increase of intercropping maize density, the competitiveness of intercropping peasgradually reduced, significantly different. after seedling20d，low﹑medium density of intercropping peasrelative competitiveness weaker than maize, other period relative competitiveness stronger than maize;after seedling64d, high density of intercropping peas relative competitiveness stronger than maize, otherperiod weaker than maize.5. Intercropping pea alleviated " N min inhibitory effect" of different intercropping maize densitynegatively correlated to total nitrogen concentration of pea, have a positively correlated to the pea relativecompetitiveness of the maize. Reduce interplanting peas root zone soil total nitrogen concentration﹑NO3--N﹑NH4+-N, improve the competitiveness of intercropping peas the better cut interplanting pea"nitrogen deter" effect.Yield, N fertilizer utilization ratio have a negatively correlated to total nitrogen concentration, peasrelatively competitiveness themaize. The high density intercropping have biggest relative competitiveness,so the root zone soil total nitrogen less than other two low density. Peas harvested, the concentration oftotal nitrogen intercropping system is higher than the sole, the maize belt transfer nitrogen of from peas, the D3density of the maize was added the largest value, transfer the most nitrogen, a period of maize quicklyabsorb nutrients, to harvest the corn intercropping system total nitrogen concentration and sole was nosignificant differences. Symbiotic period, the stonger competitiveness of the grasses, the better ability oftransferinf nitrogen of peas after harvest, more conducive to gramineous crop of the accumulation ofphotosynthesis product, the more beneficial to intercropping system of increased production, N fertilizerutilization rate increase, so high desity was the biggest advantage processing.