| The cotton was tested through field plot experiments at the Water-saving Irrigation Station of Xinjiang Academy of Agricultural and Reclamation Science in 2015. Research different growth stages under Film Drip Irrigation Fertilization(bud stage, flowering stage, boll stage) Nitrogen Application on cotton growth, yield, water use efficiency, soil moisture variation, Soil Nitrate and cotton on nutrient absorption and utilization. A total of seven treatments was set(B8,0:5:5;B9,1:4:5;B10,2:4:4;B11,1:3:6;B12,2:3:5;B13,1:5:4;B14,2:5:3). The main conclusions are as follows:(1) The effect that different nitrogen distribution ratio on plant height showed a significant result, and accompanied with a significant increase in the distribution ratio is different between strains of cotton height, when the bud fertilizer amount in 20%.florescence fertilize amount is 40% and bell fertilization amount is 40% that the cotton plant height in max, that is the processing of B10. When the cotton full into bud stage, vegetable growth started strong, different fertilization amount on stem diameter have significant differences, when fertilization amount is 20% it reached maximum value, after entering the flowering, the increase of fertilization amount, cotton stem diameter increased first and then decreased, a parabolic trend growth, so generally, in the bud stage when the fertilization amount of cotton stalk was 20%, the amount of fertilizer was 40%, that is to deal with B10. Similar to the situation of plant height and stem diameter, the different amount of nitrogen fertilizer distribution quantity is conducive to the increase of branch number, with the advance of growth period, increasing nitrogen application amount. The number of fruiting branch will increase firstly and then decreased, and the processing of stem diameter in B10 achieve the best. The fertilization rate of bud stage was beneficial to the increase of leaf area index. With the advance of the growth period, the amount of nitrogen application increased, the leaf area index of cotton had no significant change, and processing of stem diameter in B10 was the best.(2) With the increase of the amount of fertilizer applied in the bud, the amount of dry matter in cotton increased, which indicated that increasing the amount of nitrogen fertilizer in a certain range is beneficial to improving the quality of cotton ground. In flowering stage, with the increase of fertilization amount and cotton above ground dry mass increased first and then decreased, showing a parabolic trend growth, that is to say when the bud stage and florescence fertilize amount is 60%, cotton shoot dry weight reached the maximum. With the increase of the rate of fertilizer application, the dry matter quality of cotton in the boll stage first increased and then decreased, and showed a parabola trend growth. The content of dry matter in B10 treatment was the biggest. With the increase of fertilization amount, the cotton root dry mass and root shoot ratio increased first and then decreased, showing an parabolic trend growth, namely when the amount of fertilizer of bud stage is 20%,florescence fertilize amount is 40%, cotton root dry mass reaching the maximum, the B10 root dry mass maximum. Seed cotton yield and above ground dry mass and water use efficiency showed a linear correlation. Above ground dry mass and water use efficiency was also showed a linear relationship.(3) In 0cm 10 cm from the horizontal drip holes and the water rate are mainly distributed in the vertical depth of 40-60 cm. the main root of cotton in vertical depth of 60 cm above, so in this range,it is more conductive to the absorption of cotton roots to water and fertilizer, so as to further promote the yield improvement; drip holes 20 cm, 30 cm in the horizontal distances, the soil moisture mainly distributed below the vertical depth of 60 cm, is different to be absorbed by the roots. The soil nitrate nitrogen is mainly distributed in the soil layer of 0-40 cm. in 0cm,10 cm, the content of nitrate nitrogen in soil were decreased with the increase of soil depth,nitrate nitrogen mainly concentrated in the 20-40 cm soil layer at the level of 20 cm soil layer. In the horizontal direction, with the increase of the distance from the drip irrigation zone, the content of nitrate nitrogen in soil increased firth an then decreased, which mainly focused on the 20 cm from the eye level.(4) In the early growth stage of cotton,nitrogen was mainly accumulated in cotton leaves,with the advance of the growth period, nitrogen was mainly accumulated in cotton boll, in a certain range,with the increase of the amount of fertilizer, the water use efficiency of cotton will increased,but the high amount of fertilizer plays a role in inhibiting. In the case of different nitrogen distribution ratio, the water use efficiency and irrigation water use efficiency of each treatment are as follows: B10>B13>B9>B12>B8>CK>B11>B14. Reasonable fertilization in different growth stage can improve cotton yield but also improve nutrient use efficiency. |
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