| Mineral nutrients have small percentage in dry weight of crop plants, but they play important role in regulating crop plants, especially the effects of nitrogen, phosphorus and potassium on crop yield and quality. The relationship between grain yield and quality formation and fertilization, and the fertilization projects for the cultivar 8901-11 with strong gluten have not been reported, therefore, two field experiments were conducted on The Teaching and Demonstration Farm of Agricultural University of Hebei, Baoding, during 2002-2003. In one of the experiments, with four field-grown winter wheat cultivars, namely 8901-11 with strong gluten (simply 8901), Shi 4185 with high grain yield (simply 4185), Henong 341 with high grain protein content (simply 341) and Henong 859 with high grain yield and drought tolerance (simply 859), as experimental materials, the role of nitrogen from leaves of different layers on stems in grain yield and quality formation was studied. In another experiment, with a rotating regression design of three decisive variants, nitrogen, phosphorus and potassium, the superior fertilizing projects for 8901-11 was studied with grain yield and quality parameters as target functions. The main results are summarized as follows.1. The effects of the three elements, nitrogen, phosphorus and potassium on yield and quality parameters were different. Nitrogen was the element which had the largest effects on yield and quality, especially on grain protein contents. The effect of phosphorus on grain yield was much larger than that of potassium. For grain quality parameters, the effects of phosphorus on wet gluten content and sedimentation value were also larger than that of potassium, but the effects of potassium on grain protein content and test weight were larger than that of phosphorus. In general, the effects on grain yield and quality parameters were in the order of nitrogen> phosphorus>potassium. Nitrogen was the most important factor affecting yield and quality parameters.2. The ratio of the three elements for maximum grain yield of the cultivar 8901 was N:P2O5:K2O=1:1:0.94. The ratio for maximum grain protein content was N:P205:K2O=1.25:1:0.19, but the corresponding grain yield was lower. Potassium fertilizer had a role to stabilize the grain yield of 8901 under the fertility of the trialsite. The suitable fertilizing levels for high yield were middle-high nitrogen, middle phosphorus and higher potassium. The nitrogen fertilizing level for high grain content was middle to high level. Nitrogen fertilizer played an important role in increasing and maintaining grain protein content, but phosphorus and potassium played only a part to maintain it. Increasing phosphorus and potassium fertilizers may accelerate photosynthate accumulation and translocation to grains, so that decreasing grain protein content relatively.3. Multiple target decision was conducted by synthesizing score method according to the regression equations for grain yield and quality parameters of 8901. Several superior fertilizing projects were selected for application in wheat production according to price fluctuations of wheat products and fertilizers. The project with highest score was that with highest grain yield. The range of fertilizing amounts of the selected projects was N 239.25-300 kg hm~2, P2O5 150-300 kg hm-2, and K2O 112.5-225 kg hm-2.4. The nitrogen content in stems of the cultivars 8901, 4185, 859, 341 in different growth stages was in the order of joining >anthesis> maturity stage. The nitrogen content in stems for different treatments were NP>N>CK (no fertilizing) during the period from jointing to maturity. The responses of stem nitrogen content to fertilization were not different among cultivars. The nitrogen content in spikes was different among cultivars. The cultivar 8901 was more sensitive to phosphorus than other cultivars. Phosphorus fertilization was beneficial to nitrogen translocation from leaf to grain in 8901. Nitrogen accumulation reached maximum at anthesis for al...
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