Distance Between Adjacent Rows Of Maize And Pea Affect Nitrogen Facilitation And Competition In Intercropping Systems

In order to solve the problem of confusion for intercropping patterns, failure to give full play to theadvantages of intercropping and low nitrogen utilization in the arid oasis irrigation.In the intercropping systemthe distance was D1(15cm),D2(30cm),D3(45cm),respectively; P/PN,M/MN,PMi/PMNi(i=1,2,3)represent thesole pea,sole maize and intercropping maize and pea,respectively, in the no N treatment and N treatment. Theexperiment studied intercropping system yield, yield formation and nitrogen utilization, and quantifieddifferent competition and complementary relationship by different spatial layout in intercropping systems, inorder to give full play to intercropping advantage in the area. the results showed that:1.The effct of distance on Intercropping yield：Intercropping grain yield were higher than the weightedaverage of the corresponding sole cropping，Performance of D2> D3> D1> sole cropping, Improved by13.2%-27.3%;and the right amount of nitrogen fertilizer had promoted yield. Peas and maize intercropping yieldwere greater than sole cropping weighted average of7.1%-17.6%,14.5%-27.3%, respectively, maize hadgreater yield effect in intercropping, and the D2treatment was best.2. The effct of distance on interspecific relationships of Intercropping: In the early symbiotic growth stage,the LER calculated by dry matter is less than1, and intercropping advantage was not obvious in intercroppingsystems. After May25LER was basically greater than1, showing the advantages of intercropping, and D2>D3> D1. The LER calculated by grain yield was greater than1, and in the PMN2treatment was highest up to1.27. In peas/maize early symbiotic, the aggressivity of pea is greater than maize, after gradually theaggressivity of maize increased. Aggressivity of each spacing treatment showed D1> D3> D2. Interspecificaggressivity calculated by grain yield of maize was greater than that of relatively, and it reduced with thespacing row increased.Edge lines had obvious advantage in pea intercropping cultivation, the edge-lines improved the dry matteraccumulation compared to the inside-lines and the sole planting by19.3%-67.2%,45.3%-82.6%, respectively.And it increased and then decreased after with the spacing increased and with the growth process of peas, edgelines advantage effect tended to decrease; During the early symbiotic growth stage, the side-lines advantage ofmaize was not obvious, even in the inferior. After pea harvest, the side-line maize had a significantly fastergrowing rate. In the whole growth period,the grain yield of side-lines of maize was greater than that ofinside-lines and sole cropping maize,by26.1%-63.8%,48.5%-126.4%,averagely. And with increasing spacingthe side-lines advantage tended to increase.The LER in intercropping calculated by N uptaken were greater than1and it increased and decreased afterwith spacing increased, showing PM2>PM3>PM1，PMN2>PMN1>PMN3，PMN2treatment LER was highest up to1.34,and had significant differences between other treatments. The aggressivity maize to pea calculated byN uptaken (AGM>0),showing that the aggressivity of maize was greater than that of pea. In no nitrogenintercropping treatments the aggressivity increased with spacing increased, but in the treatments of nitrogenapplication it decreased with increasing spacing. The nitrogen uptake and utilization could be increased inmaize/pea intercropping systems compared sole cropping planting, and this effect increased first and thendecreased after with the spacing increased.3. The effct of distance on Nitrogen use in different treatments: After pea harvest,0-30cm soil nitrateaverage level in intercropping maize were higher than sole cropping maize, by0.3%-43.4%,the difference inoverall showed that it decreased with increasing distance between intercropping. The soil nitrate average levelin pea intercropping were less than that of sole cropping pea, by8.1%-41.9%and the difference decreasedwith increasing intercropping spacing distance. After maize harvest, soil nitrate content significantly decreasedand it showed sole-crop maize> intercropping pea> intercropping maize> sole pea cropping. The decline inintercropping maize increased with the spacing distance increased, D3> D2> D1,decreased by10.1%-26.7%.After maize harvest, soil nitrogen content over the0-30cm layers decreased significantly in sole croppingcorn and intercropping systems compared after pea harvest,especially in the10-20cm soil layers. The declinein sole cropping maize was greater than that in intercropping maize, and the decline in intercropping maizeshowed that PM3>PM2>PM1，PMN2>PMN3>PMN1. In the separate growing stage maize roots couldabsorb and use soil nitrogen in the pea field of the intercropping pea/maize systems, and the amount ofabsorption use increased with the spacing distance decreased. The total nitrogen utilization was showed that:intercropping system> sole cropping maize> sole cropping pea, and intercropping treatment could significantlyimprove crop nitrogen use efficiency, and the D2treatment was the best.