Efficient phosphorus fertilizer application methods: this way, the fertilizer utilization rate is higher

Phosphorus is one of the three essential nutrients for crop growth. Phosphorus in the soil generally cannot meet the needs of crop growth and development, so phosphorus fertilizer must be applied artificially to meet crop growth needs; at the same time, phosphorus fertilizer is easily fixed by the soil, has low mobility in the soil, and its fertilizer effect converts slowly, making it difficult for crops to absorb and utilize it in time. Based on analysis of fertilizer trial results in recent years, the seasonal utilization rate of phosphorus fertilizer is 10%-25%. Therefore, scientifically applying phosphorus fertilizer and improving its utilization rate is an issue that urgently needs to be solved in current agricultural production.

Efficient application methods for phosphorus fertilizer

1. Determine the phosphorus fertilizer application rate based on soil nutrient test results. According to soil nutrient abundance-deficiency indicators, when soil available phosphorus content is below 10mg/Kg (low level), increase phosphorus fertilizer application to raise crop yield and build soil fertility, with the phosphorus fertilizer application rate being 2 times the amount removed by crops; when soil available phosphorus content is 10--20mg/Kg (medium level), the goal of phosphorus fertilizer application is to maintain the existing soil available phosphorus level, and the phosphorus fertilizer application rate equals the amount removed by crops; when soil available phosphorus content is 20--30 mg/Kg (relatively high level) and above 30mg/Kg (extremely high level), the phosphorus fertilizer application rates are 0.5 times the amount removed by crops and no application at all, respectively, reducing the economic waste and agricultural environmental pollution caused by excessive phosphorus fertilizer application. Generally, poor thin plots far from villages, newly leveled raw land plots, and plots that have not received farmyard manure for years should be given priority for phosphorus fertilizer application; fertile fields, fertile land, and plots that have continuously received large amounts of phosphorus fertilizer in previous years can appropriately receive less; dry land, yellow clay fields, cold waterlogged fields, etc. show significant yield increases from phosphorus fertilizer application and should receive heavy phosphorus fertilizer application.

2. It should be applied to crops that are sensitive to phosphorus response. These crops are mainly rice, rapeseed, wheat, peanuts, legumes, tuber crops, melons, etc. Applying phosphorus fertilizer can achieve the effect of using phosphorus to increase nitrogen.

3. Change broadcast application to concentrated band application or hole application. Phosphorus fertilizer must be dissolved and dissociated by water before crop roots or stems and leaves can absorb and utilize it, so if phosphorus fertilizer is broadcast on the soil surface or in dry soil during application, it will cause waste and loss. Therefore, for rice, phosphorus fertilizer is best applied by sticking it to rice seedling roots, or applied deeply in furrows; for dryland crops, phosphorus fertilizer can be applied in holes or bands, so that the phosphorus fertilizer is concentrated around the seeds or root system.

4. Phosphorus has relatively poor mobility in the soil, so basal application gives good results.

5. Phosphorus fertilizer is best composted and mixed with organic fertilizer (such as farmyard manure) before application. Phosphorus fertilizer easily undergoes chemical reactions with iron, aluminum, calcium, magnesium and other elements in the soil, becoming poorly soluble phosphorus fertilizer and reducing the effectiveness of the phosphorus fertilizer. Therefore, mixing and composting phosphorus fertilizer together with organic fertilizer: during the piling process, the organic acids decomposed from the organic fertilizer can promote the solubility of the phosphorus fertilizer, thereby increasing the effective phosphorus content of the phosphorus fertilizer. In particular, composting calcium magnesium phosphate fertilizer together with organic fertilizer can convert the poorly soluble phosphorus in calcium magnesium phosphate fertilizer into effective phosphorus that crops can easily absorb.

6. Phosphorus fertilizers such as superphosphate, calcium magnesium phosphate fertilizer, and phosphate rock powder should be applied in combination with nitrogen and potassium fertilizers. These phosphorus fertilizers do not contain nitrogen and potassium nutrient elements; using them in combination with nitrogen and potassium fertilizers can coordinate crop nutrient needs, give play to the mutually promoting effects among nitrogen, phosphorus, and potassium, and their yield-increasing effect is better than applying phosphorus alone.