Drip Fertilization Beneath Mulched Film And Frostbite Of Cotton At Seedling Stage

Drip fertilization beneath mulched film is an approach to accurately and evenly apply fertilizers near crop root systems for direct crop uptake depending on nutrient requirements and soil nutrient supply at different growth stages. Drip fertilization beneath mulched film makes cost reduction and efficiency improvement come about thus becoming an important measure to help sustainable agricultural development. The paper presents the study of the effects of drip fertilization beneath mulched film on cotton growth and development, the cotton-up taking patterns of nitrogen, phosphorus and potassium fertilizers, and the extension and use of the fertilizers designed for drip fertilization, and reaches the following conclusions: 1. The drip fertilization of nitrogen and phosphorous fertilizers could significantly increases the boll number per plant, the weight per boll and the un-ginned cotton yield. The boll number per plant, the weight per boll and the un-ginned cotton yield with the drip fertilization of nitrogen fertilizers increased by 0.76—1.17 bolls, 0.17—0.74g and 34%—56%, respectively , compared with those without nitrogen fertilization; Compared with the boll number per plant, the weight per boll and the un-ginned cotton yield without phosphorous fertilization, the boll number per plant, and the weight per boll with the drip fertilization of phosphorous fertilizers insignificantly increased and that the un-ginned cotton yield increased by 8%-10%. 2. The optimal nitrogen amounts for medium-fertility cotton lands by drip fertilization were as follows: 217.67kg/hm2 for loam land and 242.39 kg/hm2 for clay land; the optimal phosphorous amounts for medium-fertility cotton lands by drip fertilization were103.71kg/hm2 for loam land and 93.69 kg/hm2 for clay land. 3. The drip fertilization of nitrogen fertilizers was capable of increasing nitrogen and phosphorous uptakes by cotton presenting better performance on loam land than on clay land,and gradually increased the amounts of nitrogen and phosphorous up-taken by cotton plants with increased nitrogen amounts. With phosphorous fertilizers applied at increasing rates, cotton plants increased their phosphorous uptake but decreased their nitrogen uptake. 4. The fertilizers designed for drip fertilization were capable of raising fertilizer-utilization rates. The utilization rates of nitrogen and phosphorous fertilizers designed for the drip fertilization to cotton loam lands were 14.0%—20.3% and 3.7%—7.1% higher than those in normal fertilization; The utilization rates of nitrogen and phosphorous fertilizers designed for the drip fertilization to cotton clay lands were 5.8%—17.2% and 3.6%—12.8% higher than those in normal fertilization. The effects of three formulated fertilizers designed for drip fertilization on the yield components of cotton indicated that formulated fertilizer A was suitable for sandy loam lands, formulated fertilizers B was suitable for loam lands and formulated fertilizer C was suitable for clay lands. 5. According to the effects of the drip fertilizations of nitrogen and phosphorous fertilizers beneath mulched film and the extension and use of the fertilizers designed for drip fertilization, and in combination with the production practices adopted by the Fangcaohu Farm of the sixth Farming Division, the model of drip fertilization beneath mulched film for north Xinjiang was put forward. 6. With such farming conditions and measures keeping basically unchanged, cotton yield would not suffer from negative effects where the frostbite severity stood below 10%; where the frostbite severity stood above 15%, the period of cotton growth would lengthen, which thus affected cotton yield and quality.