Effects Of N Alleviatory Effect Of Intercropping Maize To Pea

On the question of the high demand for the high yield of cereal/legume intercropping,but the legume will not fix nitrogen or the nitrogenase will not compose with the nitrogenapplication, it is “N repression”. And the study on interspecific interactions of cereal/legumeintercropping is poor. Therefore, this study took maize/pea intercropping as sample, discussedthe critic reason of “N alleviatory effect” of pea at different nitrogen level, in hexi oasisirrigation area. The purpose is to provide new theoretical basis and technical approach for theefficient management of nitrogen resources in cereal/legume intercropping systems. The mainresults are follows:1The N alleviatory effect was lower than0at N0nitrogen level based on the nodulenumber, so the intercropping mode had no N alleviatory effect; at the three N1, N2, N3level,the N alleviatory effect was range from21%to194%; The N alleviatory effect was also lowerthan0at N0nitrogen level based on the nodule weight, the N alleviatory effect was rangefrom80%to200%at N1, N2, N3level. So the intercropping system alleviated “N repression”obviously, and then the N alleviatory effect was stronger with the increased nitrogen level atthe early growing period of pea. At the0-40cm soil depth, the total nitrogen, ammoniacalnitrogen and nitrate nitrogen of intercropped maize was greater than the intercropped pea inintercropping system. At the N0, N1, N2level, the total nitrogen of intercropped maize wasgreater2%-7%than the intercropped pea, the ammoniacal nitrogen of intercropped maize wasgreater1%-15%than the intercropped pea; and at the N0, N1, N2, N3level, the nitratenitrogen of intercropped maize was greater5%-70%than the incropped pea. Moreover, at the0-40soil depth with the four N0, N1, N2, N3level, the total nitrogen of intercropped pea waslower2%-10%than the solecropped pea, the total nitrogen of intercropped maize was higher1%-14%than the solecropped maize; the ammoniacal nitrogen of intercropped pea was lower5%-29%than the solecropped pea, the ammoniacal nitrogen of the intercropped maize washigher1%-26%than solecropped maize at the N2, N3level; at the N0, N1, N3level, thenitrate nitrogen of intercropped pea was lower5%-34%than solecropped pea, and the thenitrate nitrogen of intercropped maize was higher2%-15%than the solecropped maize.Therefore, the intercropping system produced obviously N alleviatory effect. Meantime, the Nalleviatory effect was more strong with high nitrogen application.2At the symbiotic period of maize ang pea, nitrogen uptake of intercropped maize was lower14%-97%than intercropped pea at the different nitrogen application. In addition, thenitrogen uptake of intercropped pea was greater3%-73%than the solecropped pea. Therefore,combining the soil nitrogen amounts and nitrogen uptake: the soil nitrogen amount ofintercropped maize was higer than intercropped pea, the soil nitrogen amount of intercroppedpea was lower than the solecropped pea, the soil nitrogen amount of intercropped maize wasgreater than solecropped maize; moreover, the nitrogen uptake of intercropped maize waslower than incropped pea, the nitrogen uptake of intercropped pea was greater thansolecropped pea. So the intercropping system alleviated the N repression effect. And this Nalleviatory effect was done with interspecific competition, not the hypothesis of this study: theN alleviatory effect will conduct which the intercropped maize will dilute the nitrogenamounts of intercropped pea.3LER was ranged from1.34to1.40, and the intercropping modes have the advantage toincrease production. Under the different fertilizer level, the economic yield of intercroppedpea was greater than solecrop by24%-35%, the economic yield of intercropped maizeincreased38%-44%. Compared to the economic yield of solecropped pea and maize, theintercropped maize has higher economic yield at the N2lever. In addition, the biological yieldof intercropped pea was greater30%-56%than solecrop, the intercropped maize increasedbiological yield37%-47%at different fertilizer level. In the solecrops, pea and maize had thehigher biological yield at the level of P1and M2. However, the intercrops had the higherbiological yield at the N2level.4On the whole, compared to the no nitrogen application, the nitrogen utilizationefficience of intercropped pea was lower25%-93%than the solecropped pea, and the nitrogenutilization efficience of intercropped maize was greater51%-785%than the solecroppedmaize. Therefore, the intercropping system alleviated the N repression effect.