Fertilizer Mixing Methods and Taboos: Which Fertilizers Cannot Be Mixed?

In agricultural production, fertilizers are indispensable. Everyone knows that different fertilizers have different effects, and mixing them can sometimes produce better results, but improper mixing can also cause some harm. So how should fertilizers be mixed? Which fertilizers cannot be mixed?

1. How should fertilizers be mixed?

1. Pay attention to application timing

Organic fertilizers act slowly and should be applied early, generally as a single basal application before sowing or before transplanting. It is best to choose fully fermented and decomposed organic fertilizer before use; applying it later as a top dressing is not as effective as using it as a basal fertilizer.

Chemical fertilizers act quickly. When used as a basal fertilizer, apply them about one week in advance; when used as a top dressing, apply them before the crop's critical nutrient period or peak nutrient uptake period to meet its needs.

Microbial fertilizers can only exert their bacteria-inhibiting effect after multiplying in large numbers in the soil, so they should be applied early before transplanting to give them time to multiply and grow. They can be applied to the soil together with organic fertilizer, or applied in holes before or at transplanting.

2. Pay attention to application rate

Different crops have different growth periods and require different amounts of fertilizer; neither too much nor too little should be applied. Fertilizer should be applied according to the proportions they require, and at the same time attention should be paid to the nutrient elements in the soil, taking everything into overall consideration. It is best to conduct a soil test and apply fertilizer according to the soil-testing formula.

3. Pay attention to application method

The main role of organic fertilizer is to improve the soil, and it can also provide nutrients. Generally, organic fertilizer should be applied to the soil before planting crops, so it should be combined with deep ploughing to mix the organic fertilizer thoroughly with the soil and achieve the goal of improving the soil.

In basal fertilizer, because the nutrients in organic fertilizer are mainly phosphorus, potassium and nitrogen, organic fertilizer should be applied together with chemical fertilizer. Phosphate fertilizer and potassium fertilizer can be applied once as a basal fertilizer. Because phosphate fertilizer has poor mobility, later top dressing is very ineffective, so phosphate fertilizer should be applied to the soil as a basal fertilizer.

For top dressing, it is best to use fully soluble quick-acting fertilizers, as such fertilizers can be rapidly absorbed by crops after decomposition and have less impact on the soil.

Microbial fertilizers can be applied repeatedly as top dressing with the same type, in order to strengthen the microbial community and improve phosphate- and potassium-solubilizing ability and disease prevention effects.

2. Which fertilizers cannot be mixed?

1. Superphosphate cannot be mixed with alkaline fertilizers such as plant ash, lime nitrogen and lime. Because superphosphate contains free acid and is acidic, while the above alkaline fertilizers contain relatively more calcium. If mixed with superphosphate, an acid-base reaction will occur, reducing fertilizer efficiency, and the calcium will fix the phosphorus, causing both to suffer losses.

2. Alkaline fertilizers such as calcium, magnesium and phosphate fertilizers cannot be mixed with ammonium nitrogen fertilizers. This is because mixing alkaline fertilizers with ammonium nitrogen fertilizers (such as ammonium sulphate, ammonium bicarbonate, ammonium chloride, ammonium nitrate, etc.) will lead to volatilization of ammonia and reduce fertilizer efficiency. Farmyard manure such as human and livestock excrement and urine cannot be mixed with alkaline fertilizers such as calcium, magnesium and phosphate fertilizers, plant ash, lime nitrogen and lime. This is because the main component of human and livestock excrement and urine is nitrogen. If mixed with alkaline fertilizers, it will be neutralized and become ineffective.