Fertilizer of chelated calcium, and preparation method

Abstract

This invention relates to a chelated calcium fertilizer, which is prepared from: catalyst 1-2 wt. %, inorganic calcium raw material 58-69 wt. %, and chelating agent 30-40 wt. %. The chelating agent is composed of: oxalic acid 5-10 wt.%, malic acid 8-20 wt.%, citric acid 15-25 wt.%, maleic acid 10-25 wt.%, sorbitol 3-8 wt.%, gallic acid 8-10 wt.%, and lactic acid 2-8 wt.%. The catalyst is composed of: gadolinium chloride 0.1-0.35 wt.%, selenium dioxide 0.1-0.2 wt.%, chalcanthite 0.05-0.1 wt.%, KOH 0.05-0.1 wt.%, potash 0.1-0.2 wt.%, and palladium carbonate 0.05-0.2 wt.%. The chelating agent has appropriate stability and low cost, and can chelate with calcium in solid state. Besides, the chelating agent cannot be deactivated in plants by hydrolysis or reacting with phosphate, sulfate and oxalic acid. This invention also relates to a method for preparing the chelated calcium fertilizer, which specifies the production process, process parameters, and chelating agent and high-efficiency catalyst needed.

Description

technical field [0001] The invention relates to the field of chemical fertilizers in agricultural science and technology, in particular to a chelated calcium fertilizer and a preparation method thereof. Background technique [0002] Calcium deficiency in crops is a troublesome thing in the field of plant nutrition and fertilization at present. A large amount of calcium is leached from the soil in southern my country, and the available calcium content in the soil is low. Calcium deficiency in crops is normal. However, calcium deficiency in crops in calcareous soil in the north is not common. It is not caused by the lack of available calcium in the soil, so it is difficult to solve the problem of calcium deficiency in plants by applying calcium fertilizer to the soil. Spraying the traditional calcium fertilizer (usually calcium nitrate) on the leaves has a certain effect, but even if the traditional calcium fertilizer is absorbed by the plant, it still has its own defects. Calc...

AI Technical Summary

Problems solved by technology

[0004] Traditionally used chelated calcium includes EDTA-Ca, calcium citrate and amino acid zinc. In addition to the high price of traditional EDTA-Ca and calcium citrate, there are also adverse effects of EDTA on plant growth and poor water solubility of calcium citrate. question

Although amino acid calcium will not have adverse effects on plants, the stability constant of amino acid calcium is too low to prevent calcium from being hydrolyzed in plants and inactivated by reacting with some anions