Vegetables are hi calcium crops. People tend to pay attention to the application of nitrogen, phosphorus, and potassium fertilizers when planting, and contempt for calcium fertilizers. With the emergence of a large number of facility cultivation, it is more likely to cause calcium deficiency in the greenhouse. So, how to properly supply calcium to crops?
Reasonable selection of calcium fertilizer Different calcium fertilizers have different properties. The soil pH in the greenhouse is mostly 6.5-7.5. Alkaline substances or neutral fertilizers such as slaked lime, calcium nitrate, etc. should be used, but less acidic or physiologically acidic. substance. Ordinary phosphate fertilizers such as superphosphate, calcium magnesium phosphate, and heavy superphosphate are important sources of calcium. Bone meal and grass ash all contain a certain amount of calcium, which is also a non-negligible source of calcium.
In the best fertilization period, the calcium nutrition in the soil began to decrease after the vegetables grew into a prosperous period. At the same time, the calcium in the leaves of the vegetables began to decrease. At this time, calcium fertilizer was the best period. In order to prevent calcium deficiency in the early stage of vegetable growth, basic application of calcium fertilizer can be used. In greenhouses planted for many years, generally, 2000-3000 kg of decomposed organic fertilizer is applied to Mushi, and then superphosphate is added to 30-45 kg.
The fertilization method is suitable for growing vegetables, especially after entering the vigorous growth period, calcium fertilizer can be added by top dressing method. Generally, 40 to 60 kg of slaked lime is used per mu, and the amount of lime used in sandy soil is appropriately reduced. This will not only be able to supplement calcium, but also help to neutralize soil acidity and improve the soil pellet structure. Can also be combined with disease-prevention spray using foliar fertilizer topdressing calcium, top dressing concentration is generally 0.3% ~ 0.5% is appropriate. Generally can be sprayed with 0.1% to 0.2% of calcium nitrate or 1% of superphosphate, spraying once every 15 days or so, even spray 3 to 4 times, the effect is good.
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