The application of phosphate fertilizers due to land, season and crop science is a problem that needs to be solved urgently in agricultural production. Phosphorus is easily fixed by divalent cations in the soil and is less mobile in the soil. According to the determination, the movement radius of phosphorus in the soil is only 0.5 cm -1 cm, which makes it difficult for the crop to absorb phosphorus. In order to increase the effect of phosphate fertilizer application, we must master the following technical points: Phosphorus due to soil. Phosphorus is applied to soils that lack phosphorus. Infertile lands that are generally far from villages, new flat lands, and farms that do not use farmhouse fertilizers all year round should give priority to the use of phosphate fertilizers. Seen from the soil types, the application of superphosphate is significant in Huangtian, cold soaking, "duckling" soil, boulder yellow mud fields, and acid red dry land. Water-soluble superphosphate is best applied to neutral and calcareous alkaline soils; calcium magnesium phosphate fertilizer, steel slag phosphate fertilizer, defluorinated phosphate fertilizer, etc. are weak acid-soluble phosphate fertilizers and should be applied to neutral or acidic soils; phosphate rock powder, bone meal, etc. Insoluble phosphate fertilizer can only be used if it is applied in acidic soil. 2. Early, concentrated and stratified application. The critical period of phosphorus demand in general crops is at the seedling stage. When the crop grows short of phosphorus, it is often used again, and the utilization rate is often low. The effect of increasing production is not obvious, so it should be applied early to ensure that there is no phosphorus deficiency at the seedling stage. In addition, phosphorus is a nutrient element that can be reused in plants. When the crop grows to form a younger tissue, it will be transported to the new tissue, so the effect of applying phosphorus to the crop early is good. Phosphorus is easily deactivated by elements such as iron, aluminum, and calcium in the soil. The general utilization rate is only 15% to 20%. Phosphate fertilizers are particularly applied to various viscous soils such as calcareous soil, silt, and yellow mud. Lower utilization rate. If the methods of furrow application, acupoint application, and sticky root application are adopted, the contact surface between soil and phosphate fertilizer can be reduced, and the fixation of phosphorus on soil can be reduced, and the utilization rate of phosphate fertilizer can be increased. After the application amount of phosphate fertilizer was determined, some of the good phosphate fertilizers were piled and used as seed fertilizers and concentrated in the soil to facilitate the absorption of seedlings. The rest of the phosphate fertilizer is combined with ploughing before sowing, and is applied deep into a 15 cm to 20 cm soil layer as a base fertilizer for absorption in the middle and later stages of the crop. This will neither waste fertilizer nor ensure the need for phosphorus during the whole growing period of the crop. 3. According to the characteristics of crop phosphorus and rotation system to allocate phosphate fertilizer. Due to slow phosphate fertilizer efficiency and sufficient stamina, it is not always necessary to apply sufficient phosphate fertilizer to every crop. In the rotation, phosphorus fertilizer should master the principles of “dry, heavy, light and water†fertilization. Apply phosphate fertilizer to crops sensitive to phosphorus fertilizer, such as paddy-upland cropping, use rice--rice or rapeseed, green manure crop rotation, and phosphate fertilizer should be given priority. In wheat, rape, green manure and other dry crops. Rice uses phosphate fertilizer aftereffect. In dryland rotations, such as wheat--beans, cotton, and green manure crops, phosphorus fertilizers can be applied mainly to legumes, cotton, and green manure crops, and if it is wheat-spinning maize crops, phosphorus fertilizers should be mainly applied to wheat crops. , corn use aftereffects. 4. Nitrogen, phosphorus with the application. Combined application of superphosphate and urea, ammonium nitrate and other nitrogen fertilizers can increase fertilizer efficiency. In the soil with phosphorus deficiency and nitrogen deficiency, the combination of nitrogen fertilizer and phosphate fertilizer can promote each other, especially the soil is rich in available nitrogen, the effective phosphorus is relatively low, that is, the proportion of nitrogen and phosphorus imbalance on the soil, with the application of phosphate fertilizer is better . 5. Mixed with organic fertilizer stacking application. Organic fertilizers produce a large amount of carbon dioxide and organic acids during the decomposition process, which is conducive to the conversion of non-water-soluble phosphorus compounds in phosphate fertilizers. At the same time, humic acids produced by organic fertilizers have strong adsorption and substitution properties and can be activated and protected. Phosphorus, improve fertilizer efficiency. In addition, the combination of phosphate fertilizer and organic fertilizer can reduce the contact area between phosphate fertilizer and soil and reduce the fixation of phosphorus. Therefore, before the application of phosphate fertilizer is best mixed with high-quality organic fertilizer or peat rich in humic acid and other heaps. According to experiments, phosphate rock and manure were piled for 30 days. The content of weak acid-soluble phosphorus in the heap was more than four times higher than that of the compost without adding phosphate rock. Phosphate fertilizers added during stacking are generally about 5% of organic fertilizers. 6. Root spray. At the late growth stage of crops, the roots are aged, the ability to absorb nutrients is weakened, and phosphorus deficiency is easy. At this time, water-soluble superphosphate can be sprayed on the leaves to make the phosphorus enter the crop through the stomata or the stratum corneum of the leaves. Rice, wheat and other gramineous crops available 2% - 3% of the concentration of rape, vegetables available 1% concentration. After the dew had dried on a sunny day or before the dew had appeared in the evening, the production increased significantly. 7. Appropriate application. Generally, the application of 40 kg – 50 kg of phosphate fertilizer per acre is appropriate, and the increase in production when the dosage is too small is not significant and it is not economical. 413100 Cao Dihuan of the Rural Office of Lijiang River in Hunan Province was selected from the sixth issue of Rural Practical Technology in 2003