Study On N Management And Nutrition Diagnosis Techniques Of Corn In Cold Region

For maize production in China in recent years, especially in the northern winter maize yield increment due to excessive use of nitrogen fertilizer production caused by the effects of nitrogen fertilizer, decreasing nitrogen use efficiency and severe environment pollution, etc. Aming at those problems, field trials applied to the test methods of randomized block experiment in base of operations in Northeast Agricultural University, Donguan Village in Shuangcheng City. Tested for the black soil, the two varieties of corn, Fenghe-1, Xinxin-808, we made systematic analysis on SPAD ofcorn leaves, nitrogen absorption characteristics and dry matter accumulation from both of nitrogen amount and nitrogen time.1,The best fertilizer time of two varieties of corn from the SPAD value is ten leafage -stage , and the best fertilization amount is 150 kg/hm2.But SPAD threshold is different which SPAD threshold of Fenghe1 is 61~62, and that of Xinxin808 is 53~55.2,Studying on the two varieties of corn stems, leaves, seeds accumulated Nitrogen ,we thought excessive nitrogen present in the stems and leaves during eight and fourteen leafage-stage, and that is neither helpful to the accumulation of nitrogen in the grain ,nor high yield. From two varieties, the most beneficial transfer from nitrogen to the grain is in 7 treatment.3,Nitrogen is beneficial to dry matter accumulation of the whole corn, and the more accumulated grain eventually, the higher utilization rate of nitrogen in this treatment. The highest dry matter accumulation of each organ in two corn varieties is in 5 treatment which is most contribution to the formation of high-yield.4,Nitrogen amount and nitrogen time did little effect on hectograin weight, but greater impact on corn yield, and the analysis of variance is significant that F value of Fenghe-1 is 9.849, and Xinxin-808 is 18.470.The highest production values are in 5 treatment which nitrogen content is 150 kg/hm2.The most obvious effects of fertilizer is in ten leafage -stage, which can significantly increase corn yield5,The impact on the content of proteins, fat and starch was not obviously between the different treatments of nitrogen, and analysis of variance was not significant. The content of proteins and fat in each treatment had significant correlation with that of compared treatment, but not significant in starch content. In total,nitrogen did little effect on the content of starch.