Heavy metal cadmium passivation repair slow-release multifunctional urea fertilizer and preparation method

Abstract

The invention mainly relates to heavy metal cadmium passivation repair slow-release multifunctional urea fertilizer and a preparation method. The fertilizer comprises urea, a biochemical inhibitor, asoil heavy metal cadmium passivation material, water-soluble salt ions of medium-trace elements needed by plants and / or beneficial elements for plant growth, the heavy metal cadmium passivation material comprises one or multiple of charcoal modified by hydrochloric acid, ground phosphate rock modified by hydrochloric acid, sepiolite modified by hydrochloric acid and lime, the medium-trace elementsalt ions needed by the plants include one or multiple of calcium, magnesium, sulfur, iron, copper, zinc, manganese, boron, molybdenum and chlorine, and the beneficial elements for plant growth are silicon, selenium, urea and various beneficial elements for plant growth. The fertilizer can control cadmium in medium-mild cadmium contamination within a reasonable range, so that cadmium absorbed by crops can be reduced, and intake of cadmium content by people can be reduced; the fertilizer can promote crop root system growth, strengthen plants, remarkably enhance resistance to diseases, draught lodging and promote prematurity.

Description

technical field [0001] The invention relates to the field of soil and environment, specifically, it can not only passivate the heavy metal cadmium in farmland soil, but also promote crop growth, strengthen plants, and significantly enhance multiple functions of disease resistance, drought resistance, lodging resistance and early maturity promotion. Background technique [0002] Common urea fertilizers currently used in industrial and agricultural production are instant fertilizers, which dissolve and transform quickly in water and soil. After ordinary urea is applied to the soil, it is quickly converted into ammonium nitrogen under the action of urease in the soil. A large amount of ammonium nitrogen makes the soil pH rise rapidly and ammonia volatilization increases; under the condition of good ventilation, the nitrification in the soil Under the action of bacteria, nitrification will occur, and ammonium nitrogen will be converted into nitrite nitrogen and nitrate nitrogen ...

AI Technical Summary

Problems solved by technology

After ordinary urea is applied to the soil, it is quickly converted into ammonium nitrogen under the action of urease in the soil. A large amount of ammonium nitrogen makes the soil pH rise rapidly and ammonia volatilization increases; under the condition of good ventilation, the nitrification in the soil Under the action of bacteria, nitrification will occur, and ammonium nitrogen will be converted into nitrite nitrogen and nitrate nitrogen in a short period of time. Nitrate nitrogen is easily lost in the soil, and nitrite nitrogen will also be converted into nitrogen oxides. The form of gas is lost, resulting in a large loss of fertilizer nitrogen, thereby reducing the utilization rate of fertilizers

Ordinary urea fertilizer has a short fertilizer effect period and low nitrogen utilization rate. The overall utilization rate of urea nitrogen is only 30%-35%. In addition to nitrogen leaching, volatilization, surface runoff, etc., the economic benefits of fertilizer application are seriously reduced. Increases the cost of agricultural production and has a host of adverse environmental impacts

On the other hand, when the ammonium nitrogen in the fertilizer is converted into nitrate nitrogen, the acidity of the soil will increase, the pH will decrease, and the available cadmium content in the cadmium-contaminated soil will increase sharply, which will increase the plant-absorbable cadmium content and increase Plant enrichment, after being absorbed by the human body through the food chain, will be enriched in the human body, endangering human health

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