Precautions for the use of compound fertilizers
Compound fertilizer has the advantages of high nutrient content, few side components, and good physical properties. It plays a very important role in balancing fertilization, improving fertilizer utilization, and promoting high and stable crop yields. But it also has some disadvantages, such as its nutrient ratio is always fixed, while the types, quantities and ratios of nutrient elements required by different soils and crops are diverse.
1. Compound fertilizer has a long effect and should be used as base fertilizer. A large number of tests show that whether it is binary or ternary compound fertilizer, it is better to apply basal fertilizer. This is because compound fertilizers contain nitrogen, phosphorus, potassium and other nutrients, and the crops are especially sensitive to phosphorus and potassium in the early stage, and phosphorus and potassium fertilizers are required to be applied as base fertilizers early. Compound fertilizer should not be used in seedling stage fertilizer and middle and late stage fertilizer to prevent greed and growth. Compound fertilizer decomposes slowly. For crops that use compound fertilizer as base fertilizer when sowing, fast-acting nitrogen fertilizer should be supplemented in time for top dressing according to the fertilizer requirements of different crops to meet the nutritional needs of crops.
2. The concentration of compound fertilizer varies greatly, and attention should be paid to choosing the appropriate concentration. At present, most compound fertilizers are configured according to the average nutrient status of soil types in a certain area and the proportion of fertilizer required by crops. There are high, medium and low concentration series of compound fertilizers on the market. Generally, the low concentration of total nutrients is between 25% and 30%, the medium concentration is between 30% and 40%, and the high concentration is more than 40%. Because of different regions, soils and crops, choose and use economical and efficient compound fertilizers. Generally, high-concentration compound fertilizers are used in economic crops, with good quality, less residue and high utilization rate. The concentration of compound fertilizer is high, and direct contact between seeds and fertilizers should be avoided. The compound fertilizer has high nutrient content. If it comes into direct contact with seeds or seedling roots, it will affect the emergence of seedlings or even burn seedlings and rot roots. When sowing, the seeds should be 5-10 cm away from the compound fertilizers applied in the holes and strips.
3. The ratio of raw materials of compound fertilizer is different, and attention should be paid to the scope of use of nutrients. Different brands and different concentrations of compound fertilizers use different raw materials, which should be selected and used according to soil types and crop types. Compound fertilizers containing nitrate should not be used in leafy vegetables and paddy fields; compound fertilizers containing ammonium ions should not be applied on saline-alkali soils; compound fertilizers containing potassium chloride or chloride ions should not be used on chlorine-avoiding crops or saline-alkali soils; Compound fertilizers containing potassium sulfate should not be applied in paddy fields and acidic soils. Otherwise, it will reduce fertilizer efficiency and even poison crops. Compound fertilizer contains two or more elements in large quantities. Nitrogen is easily lost by volatilization or lost with rain when applied on the surface. Phosphorus and potassium are easily fixed by soil. It is also not conducive to the deep rooting of the root system. In case of drought, the fertilizer cannot be dissolved, and the fertilizer efficiency is worse. Therefore, the compound fertilizer should be deeply applied to cover the soil.