Effects Of Cover Mode And Nitrogen Content On Growth,yield And Nutrient Uptake Of Winter Whent

Nitrogen is the necessary nutrient of the growing,nitrogen fertilizer can slow senescence of plant leaf,raise photosynthetic rate production,to a great extent, affecting the growth and development,quality and yield of crops,in October 2013 in agriculture in arid northwest agriculture and forestry university of science and technology key laboratory of irrigation station of winter wheat in the field experiment was carried out, the test set the four pattern of covering film in the whole stages(M1),uncovering plastic film at the jointing stage(M2),biodegradable film(M3),no film processing(M4) and two kinds of N application rate of low nitrogen(N1) and high nitrogen(N2),studied the coverage model and applied amount of N fertilizer on winter wheat growth,yield and nutrient uptake,to explore suitable model and N application rate for the best effect of winter wheat growth, indicating the growth,photosynthesis, nutrient of winter wheat and the dynamics of soil N content, draw the conclusion:(1) Accoding to the study of the winter wheat growth index and yield in the different mulching model with fertilizer treatments,the results showed:the changes of plant height and leaf area is simily in the different growth period,plant height and leaf area grows vigorous in the early growth stage,in the late growth stage,mainly to carry on the reproductive growth,plant height and leaf area almost no change,and even to the aging,gradually decreases,Under the same film mode treatment,the growth of high nitrogen treatment faster than that of low nitrogen treatment,and has a significant difference,under the same nitrogen level,the growth of processing parameter faster than that of no film processing,at the early stage of growth,in, there was no significant difference of the whole stages(M1),uncovering plastic film at the jointing stage(M2), biodegradable film(M3) there were no significant difference of uncovering plastic film at the jointing stage,biodegradable film,no film treatment in the late growth, considering the mutual influence of nitrogen and the film model, wheat plant height,leaf area and dry matter per quality is the largest on the covering film in the whole stages with high nitrate(M1N2) treatment,and the most yield is 11.76 t.hm-2(2) Accoding to the study of the chlorophyll and photosynthesis of winter wheat in the different mulching model with fertilizer treatments,the results showed that the change rule ofchlorophyll will be increased in the first then decreases,in the jointing stage,wheat grows quickly, chlorophyll content is high, with the development of growth period, plant is gradually aging,with yellow leaves,chlorophyll content will be decreasing,and lowest in mature period,because the nitrogen is one of the important component of chlorophyll,the effect of the two factors of model and amount of N fertilizer,The amount of N fertilizer is the main factor affecting the chlorophyll, the Film model is the secondary factor. The higher chlorophyll content,the stronger the photosynthesis of plants, photosynthesis directly affect on wheat production,the daily variation of photosynthetic rate presents a single-peak trend,peaked 22.5 umol. m-2.s-1 at 10:00 in the morning, then photosynthetic rate decreases gradually after 10:00. In the daily variation of transpiration rate and stomatal conductance present a trend of "twin peaks",respectively,peaked at 10:00 a.m and 14:00 pm,and stomatal conductance and transpiration rate is positive correlation.(3) Accoding to the study of the nitric nitrogen of soil in the different mulching model with fertilizer treatments,the results showed: soil nitric nitrogen gradually reduce in the depth of 0-50 cm,soil nitric nitrogen has no obvious change below 50 cm,the content is stable,in the mature period,after several growth period, the nitric nitrogen promote growth after root system absorbed enough N,the content of nitric nitrogen will decrease rapidly,soil nitric nitrogen change quickly in the depth of 0-100 cm,showing first increased then decreased,soil nitric nitrogen has no obvious change below 100 cm,the content is stable.(4) Accoding to the study of nitrogen,phosphorus and potassium nutrient dynamics of wheat in the different mulching model with fertilizer treatments, the results showed: the influence of N application and film mode for plant nitrogen, phosphorus and potassium nutrient is obvious,a period of strong growth,concentrations of nitrogen,phosphorus,and potassium of wheat plant is higher, at different stages,nutrient content of wheat stem, leaf and fruit is in different proportion,in the early growth stages,mainly carries on the vegetative growth, the nutrient concentration of stem and leaf is higher,in the late growth stages,mainly to carry on the reproductive growth,nutrient concentration of fruit is higher.