Effects Of Nitrogen Fertilization On Physiological Characteristics And Yield Of Intercropping Maize

Sole cropping and continuous cropping for maize will result in increased pests and diseases,soil degradation.Based on the situation,this research is committed to study the effects of different nitrogen fertilization on physiological characteristics and yield of maize.There were four maize varieties,Xiongyu 581,Xianyu 335,Hengyu 709,Songyu 419,as study materials.Then for each maize variety,Each maize variety was planted with maize-soybean inter cropping(4:2).The main conclusions are below.1.The activity of SPS showed rules of one single peak changing.In silking stage,the value was the maximum,and after the stage,the value rapidly decreased,and the change trend was basically same for the four maize varieties.The SPS of intercropping maize was more active than sole cropping maize,and the activity increased with increasing nitrogen application.2.The activity of nitrate reductase was maxmisum at the big trumpet stage.After the stage,it decreasesed rapidly,and comes to the minimum at the mature stage.The effects of cultivation method and nitrogen application on nitrate reductase activity are same as the effects on SPS activity.3.The activity of PEPC carboxylase was maxmisum at the big trumpet stage,then it decreased slowly until silking stage.After silking stage,the activity decreased rapidly,and comes to the minimum at the mature stage.The effects of cultivation method and nitrogen application on PEPC carboxylase activity are same as the effects on SPS activity and nitrate reductase.4.The SPAD values of the three cultivars at Xianyu 335,Hengyu 709 and Songyu 419 increased with the increase of fertilization amount,and the SPAD value was higher than that of single cropping.SPAD value was higher in intercropping system than in the single cropping at the earlier stage for Xiongyu 581,however,it was higher in sole cropping than the intercropping system at the last stages.The SPAD value of the intercropping system was slightly lower than that of the single cropping.5.For photosynthetic rate,the maximum rate was in big trumpet stage,and the minimum rate was in milking period.The photosynthetic rate of intercropping group was higher than that of sole cropping group in same stage and same nitrogen application.In same stage,the rate was increasing with increased nitrogen application.In same nitrogen application,the rate of intercropping was higher than that of sole cropping group.6.In grouting stage,plant height,ear height and leaf area are all increasing with increased nitrogen application,and these value of intercropping group are all higher than that of sole cropping group.7.In same motivation method,the yield was increasing with increased nitrogen application,but the difference was not significant.In same nitrogen application,yield of intercropping maize was a little lower than that of sole cropping maize.These results show that the yield of maize,whatever planted in the two motivation methods,was similar,therefore the yield of soybean in intercropping group was the increased efficiency.For Xiongyu 581 planted in intercropping method,the highest yield of maize was 11334kg/hm2 when the nitrogen application was level 5,and in same nitrogen application,the yield of sole cropping maize was 13488kg/hm2,higher than that of intercropping maize.For Xianyu 335 planted in sole cropping method,the highest yield of maize was 11057kg/hm2 when the nitrogen application was level 3,and in same nitrogen application,the yield of intercropping maize is 8809kg/hm2 and the difference between the two motivation method was not significant.For all treatments of Xianyu 335,as their yield from high to low are respectively DF3,DF2,DF1,JF3,JF2 and JF1.The yield change trend of Hengyu 709 and Songyu 419 was similar as trend of Xianyu 335.In all the yield components,the effect of spike length was minimal,and the effects of grain number per spike,100 grain weight and bald tip length are all greater.