How should calcium magnesium phosphate fertilizer be applied for the best results?
How should calcium magnesium phosphate fertilizer be applied for good results? Please advise. The main production areas of calcium magnesium phosphate fertilizer are in China. Because its raw materials are widely available and its production process is simple, it has developed rapidly in recent years in the phosphate mining areas of southern China. The fertilizer looks like a grayish-white, blackish-green or brown glassy fine powder, and its composition is fairly complex, mainly Ca3(PO...
How should calcium magnesium phosphate fertilizer be applied for good results? Please advise.
The main production areas of calcium magnesium phosphate fertilizer are in China. Because its raw materials are widely available and its production process is simple, it has developed rapidly in recent years in the phosphate mining areas of southern China. The fertilizer looks like a grayish-white, blackish-green or brown glassy fine powder, and its composition is fairly complex, mainly Ca3(PO4)2, along with P2O5, CaO, MgO, SiO2, CaMg and other components. Because production areas differ, product specifications vary considerably; generally the P2O5 content is between 14% and 20%, the CaO content is between 25% and 30%, the MgO content is between 10% and 15%, and the SiO2 content is between 25% and 40%. It can thus be seen that calcium magnesium phosphate fertilizer is a multi-element fertilizer based mainly on phosphorus and also containing calcium, magnesium, silicon and other components. Calcium magnesium phosphate fertilizer is insoluble in water, non-toxic, non-corrosive, does not absorb moisture and does not cake, and is a chemically alkaline fertilizer. It is widely suitable for various crops and for phosphorus-deficient acidic soils, and is especially suitable for the acidic red soils of southern China where calcium and magnesium leaching is severe. Its specific use characteristics are as follows:
(1) It is best suited for deep application as a base fertilizer. After calcium magnesium phosphate fertilizer is applied to the soil, its phosphorus can only be dissolved by weak acids, and it must undergo a certain transformation process before it can be used by crops, so its fertilizer effect is relatively slow and it is a slow-release fertilizer. Generally it should be applied together with deep ploughing, spreading the fertilizer evenly into the soil and mixing it with the soil layer, so as to facilitate its dissolution by soil acids and to facilitate its uptake by crops.
(2) In paddy fields in southern China it can be used to coat rice seedling roots. The dosage is about 10 kg per mu; it does no harm to the seedlings and the effect is also fairly good.
(3) Mix it with more than 10 times its amount of high-quality organic fertilizer and compost it for more than 1 month; the composted fertilizer can be used as a base fertilizer or seed fertilizer, and can also be used to coat rice seedling roots.
When using calcium magnesium phosphate fertilizer, the following points should be noted:
(1) Calcium magnesium phosphate fertilizer works fairly well when used in combination with superphosphate and nitrogen fertilizer, but it must not be mixed with them for application.
(2) Calcium magnesium phosphate fertilizer generally must not be mixed with acidic fertilizers, otherwise the fertilizer effect will be reduced.
(3) The dosage of calcium magnesium phosphate fertilizer should be appropriate; generally the dosage per mu should be controlled between 15 and 25 kg. Applying too much calcium magnesium phosphate fertilizer will not only fail to increase the fertilizer effect but will also lead to diminishing returns. Usually, when 35 to 40 kg of calcium magnesium phosphate fertilizer is applied per mu, it can be applied every other year.
(4) Calcium magnesium phosphate fertilizer is best suited to crops with a strong ability to absorb citrate-soluble phosphorus, such as rapeseed, radish, leguminous green manure, leguminous crops and cucurbit crops.
When calcium magnesium phosphate fertilizer is applied to acidic and neutral soils, its yield-increasing effect is better than that of superphosphate; when applied to calcareous soils, its fertilizer effect is longer lasting than that of superphosphate. Applying calcium magnesium phosphate fertilizer to paddy fields has the effect of regulating soil pH and preventing the soil from becoming acidic in soils and waters where ammonium phosphate and superphosphate have been used for a long time. To use it in a way that achieves better and greater fertilizer effect, there are the following methods:
To grow strong seedlings, when preparing the seedling bed, put calcium magnesium phosphate fertilizer in a basin, mix in some yellow mud to make a paste, and coat the roots of bundled rice seedlings evenly with the fertilizer. Coating rice seedling roots with calcium magnesium phosphate fertilizer is relatively safe and will not burn the seedlings; the dosage is about 7.5 kg per mu, using little fertilizer with great results.
As a surface fertilizer, before the last harrowing of the field before transplanting rice, broadcast 25 kg of calcium magnesium phosphate fertilizer per mu, and after harrowing mix the fertilizer evenly with the surface layer, then transplant the rice seedlings. Surface fertilizer after harrowing is equivalent to the role of a base fertilizer; the dosage is relatively large, it saves labor, and its after-effect is long, still having a strong effect by the third or fourth crop.
Click to get more nitrogen, phosphorus and potassium application techniques
Click to get more fertilizer application techniques