| Phosphorus fertilizer recommendation system was based on tests of the phosphorus leaf petioles and rapid P in soil by hybrid cotton phosphorus nutritious diagnosis and fertilizer commendation with rapid inorganic P testing tecnology, which combined with plant testing technology, were studied in the field under drip irrigation in southern Xinjiang.The possibility of using Reflectance Meter immedately effect method was studied on hybrid cotton P nutritious diagnosis. The main results were as follows:1. The content of soil available phosphorus increased with P application rate increasing, The higher the amount of phosphorus constructed is , the higher the available phosphorus content is. In low phosphorus constructed levels, crops depended on absorbing soil vailable phosphorus. So when available phosphorus content in the soil was low, it could lead to the production of crops dropped .2. Application of phosphate fertilizer can significantly increase the biomass of hybrid cotton; excessive application of phosphorus fertilizers between 0-166.5 kg·hm-2on hybrid cotton yield and biomass had some significant effects. Different P rate application could make different effects on cotton yield and the partial factors, the ginned cotton and the lint cotton yield condition inceeased with the inceeasing concentrations of phosphorus fertilizers in southern Xinjiang. The production would drop when P rate application exceed 166.5 kg·hm-2.There was an obviously increase in the output cotton field with that compared with that before phosphorus manuring. The relationship between the quantity of applied phosphorus fertilizer and the cotton yield was simulated, as the results shows that, under drip irrigation in south Xinjiang, the highest yield was 6424.05kg·hm-2, while the optimal quantity of applied phosphorus fertilizer was166.5kg·hm-2, and the economical yield of 6416.4 kg·hm-2 was 150.82 kg·hm-2. High phosphorus levels and low phosphorus levels on little effect on cotton yield, so the hybrid cotton production, control, cost considerations P fertilizer control in cotton fields could be controlled under150-200kg·hm-2.3.Three different phosphorus application rate on the hybrid cotton and soil available phosphorus has a significant effect Bud,florescence and flower boll stage of of soil available phosphorus content and P application rate, plant total phosphorus, total phosphorus leaves, biomass, single-leaf stem weight and yield a good correlation between the could serve as a hybrid cotton nutrition diagnosis periods phosphorus nutrition diagnosis.4.The inorganic P concentration of hybrid cotton bud stage, the beginning of flowering and flower and boll had remarkably relevance with phosphorus, biomass, leaf dry weight, plant total phosphorus and yield. Phosphorus fertilizer recommendation model were set up by virtue of the inorganic phosphorus diagnosi s of hybrid cotton, and the phosphorus fertilizer dosage of testing value of different inorganic phosphorus was calculated by the model(.2008)The critical value of inorganic P concentration were 85.76 mg·L-1,144.05mg·L-1 and 111.78mg·L-1separately as diagnostic index of three of the main growth stage. (2009)The critical value of inorganic P concentration were 226.16mg·L-1,365.01mg·L-1and 269.30mg·L-1separately as diagnostic index of three of the main growth stage. Based on the good relationship above, a cotton phosphorus fertilizer commendation model was established. Then,the rate of phosphorus topdressing could be recommended according to the recommendation model. There had no difference in yield of the nutrition index on phosphorus. So it could be suitable indicators for status diagnosis throughout the cotton growth . |
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