Nitrogen fertilizer management method suitable for planting vegetable crops with different buffer actions in cadmium-polluted farmland

Abstract

The invention discloses a nitrogen fertilizer management method suitable for planting vegetable crops with different buffer actions in a cadmium-polluted farmland. The nitrogen fertilizer management method comprises the following steps: applying an ammonium nitrogen fertilizer or urea to the cadmium-polluted farmland when the acid buffering capacity of soil is more than or equal to 500mmol kg<-1>; applying an ammonium nitrate fertilizer or a urea nitrate fertilizer to the cadmium-polluted farmland when the acid buffering capacity of soil is more than 250mmol kg<-1> and less than 500mmol kg<-1>; applying a nitrate nitrogen fertilizer to the cadmium-polluted farmland when the acid buffering capacity of soil is less than or equal to 250mmol kg<-1>, wherein in the ammonium nitrate fertilizer, the use level ratio of the ammonium nitrogen fertilizer to the nitrate nitrogen fertilizer is 1 to 1 based on the quantity of N; in the urea nitrate fertilizer, the use level ratio of the urea to the nitrate nitrogen fertilizer is 1 to 1 based on the quantity of N. According to the nitrogen fertilizer management method, the nitrogen fertilizer suitable for the production of the planting vegetable crops in the cadmium-polluted farmland is selected according to the numerical value of acid buffering capacity of soil, so that the damage caused by cadmium to the growth of the crops is retarded, and the content of cadmium in the crops is decreased.

Description

technical field [0001] The invention relates to a management method for the application of nitrogen fertilizers in the production of vegetable crops polluted by different buffering cadmiums. Background technique [0002] Cadmium (Cd) is one of the most toxic heavy metals, and soil cadmium pollution is a hotspot of environmental pollution that is widely concerned around the world. In China, the phenomenon of Cd pollution in farmland has become serious. According to reports, China has more than 1.3×10 5 hectares of farmland were polluted by Cd. Cd in farmland is easily absorbed by the roots of crops and accumulates in the body, directly affecting the growth and development of crops, resulting in reduced yield and quality of crops. A large amount of Cd accumulated in crops will also endanger human health through the food chain. Among them, vegetables are a kind of crops that are easy to accumulate Cd, and they also occupy a considerable proportion in people's diet. Studies...

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Problems solved by technology

However, the method does not inform how to manage nitrogen fertilizers for Cd-contaminated fields with different buffering properties (i.e., soils for acid buffering capacity)

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