Studies On Differences Of Nitrogen, Phosphorus And Potassium Uptake And Utilization Among Different Genotypes Maize

It could increase yield, improve quality, increase fertilizer use efficiency and reduce resources waste and environmental problems to take some reasonable fertilization measures according to characteristics of nitrogen,phosphorus and potassium of maize different cultivars.In this study, four maize cultivars, Xundan 20 (XD20), Xianyu 335 (XY335), Denghai 662 (DH662) and Zhengdan 958 (ZD958) were used as the testing materials, and a nutrient solution culture experiment and field experiments were conducted to investigate different responses of maize growth, nutrient uptake and utilization and grain yield among four maize cultivars to nitrogen, phosphorus and potassium at seedling stage and during the whole growth period , in order to provide scientific evidence for rational fertilization according to characteristics of cultivars.The main results were as follow:1, Under the same deficiency level, the effect of nutrients deficiency to maize growth at seedling stage was N deficiency >P deficiency >K deficiency. Root dry weight, root volume, root number, shoot dry weight, leaf area per plant, plant height and stem diameter all decreased under N-, P-, K-deficient condition. However, compared with plants under NPK control, the response degree of four cultivars to the same nutrient element deficiency was different. Under N-deficient condition, the increment of root length and N use efficiency, and the decrease of root dry weight, root volume, N, P, K content of root , transport ratio of N, P and K of ZD958 was significantly less than those of other three cultivars. Under P-deficient condition, the relative root dry weight, relative root volume and relative K content of root of XY335, DH662 and ZD958 were significantly smaller than those of XD20, and the decrease of dry weight of XD20 was least, XY335 and ZD 958 following behind, DH662 the third. Under K-deficient condition, the relative shoot dry weight and relative N,P,K content of shoot of XY335 were highest. The response difference of four maize cultivars to N, P, K were presented as, capacity of tolerance to low-N: ZD958 > XY335> XD20> DH662, capacity of tolerance to low-P: XD20> XY335> ZD958 > DH662; capacity of tolerance to low-K: XY335> ZD958 > DH662> XD20.2, The effect of N fertilizer on the growth and grain yield of maize was greater than that of P fertilizer and K fertilizer. Applying mixed NPK fertilizers was more beneficial to maize growth and significantly increased maize yield. The response degree of four cultivars to applying the same fertilizer was different.XD20 had a higher capability of absorption and utilization of nitrogen. The LAI, SPAD value, dry matter accumulation, N,P,K accumulation and absorption in different stages of XD20 increased greatly with the application of nitrogen, which made yield of XD20 increased 13.26%; After applying N fertilizer, The LAI of DH662 decreases slowly in the late stage of grain filling, the plant height,dry matter accumulation, nitrogen and potassium accumulation, nitrogen and potassium absorption in seedling stage and spiking period of DH662 increases heavily, and the agronomic efficiency of applied N of DH662 was higher, the N-fertilizer increased the yield of DH662 by 10.50%; Application of Nitrogen increased the LAI, dry matter accumulation, nitrogen accumulation and N,P,K absorption in spiking period of XY355, the recovery efficiency of applied N of XY335 was higher while the agronomic efficiency of applied N was lower, the N-fertilizer increased the yield of XY335 by 7.12% only. The recovery efficiency of applied N and the agronomic efficiency of applied N of ZD958 were lower, and the LAI, dry matter accumulation, N,P,K accumulation and nutrient absorption in different stages of ZD958 increased slightly with nitrogen application. This indicated that the responsivity of ZD958 to nitrogen application was lower, that is to say, the barren tolerance of ZD958 was higher.The recovery efficiency of applied P of DH662 was higher and the agronomic efficiency of applied P of DH662 was the highest in all cultivaras. After P-fertilizer application, the LAI, SPAD value, plant height, stem diameter, dry matter accumulation, N,P,K accumulation and nutrient absorption in different stages was higher than the other three cultivars, which made yield of DH662 increased 7.50%.This illuminated that the effect of P-fertilizer on DH662's yield increase was greater; the responsivity of XD20, XY355 and ZD958 to P-fertilizer application was lower, the amount of yield increase ranged 2.01%-3.40%.Applying K-fertilizer made DH662's dry matter weight at seedling stage and silking stage, N,P,K accumulations, N absorption in different stages, P and K absorption in seedling stage and spiking period increased more significantly, and the agronomic efficiency of applied K of DH662 was the highest, this finally appear as the K-fertilizer increased the yield of DH662 by 4.35%; After K-fertilizer application, the LAI, SPAD value, plant height, dry matter weight at silking, K accumulation, N and K absorption in spiking period of XY335 increased greatly, the recovery efficiency of applied K of XY335 was the highest in all of cultivars although the agronomic efficiency of applied K of XY335 was lower, this finally appear as the K-fertilizer increased the yield of XY335 by 3.88%; The LAI, stem diameter, dry matter weight at seedling stage and maturity, P and K accumulation, N and K absorption in grain filling period of XD20 increased greatly with the application of potassium, which made yield of XD20 increased 3.49%; The LAI,dry matter weight, N,P,K accumulation and nutrient absorption in different stages of ZD958 increased slightly, and the recovery efficiency and the agronomic efficiency of applied K of XY335 were lower, this made yield of ZD958 increased 3.49% only.