How to improve the effect of applying phosphate fertilizer in newly reclaimed red soil? Is it feasible to apply high amount of phosphorus in phosphorus-deficient soil?

The newly reclaimed land of red soil contains low total phosphorus (generally less than 0.4 g / kg), high content of iron and aluminum, and the main phosphorus in the soil is iron phosphate and aluminum compounds, which is not easy to be absorbed and utilized by crops. Therefore, when planting crops and economic trees in newly reclaimed fields in red soil, it is necessary to emphasize the application of phosphate fertilizer. So, how should we improve the effect of applying phosphate fertilizer to newly reclaimed land in red soil? Is it feasible to apply high amount of phosphorus on phosphorus-deficient soils in China? Experiments show that the following application techniques are effective:

In view of the slow movement of phosphorus in the soil, ① adopts calcium magnesium phosphate fertilizer to mix seeds and dip in roots, and concentrate as base fertilizer, and the effect is better.

In order to reduce the fixation of phosphate fertilizer by red soil, ② emphasizes the mixed application of phosphate fertilizer and organic fertilizer, either as grain fertilizer or as external root spraying.

Appropriate amount of lime is applied to ③ to reduce the fixation of phosphorus by active iron and aluminum in soil and improve the fertilizer efficiency of phosphate fertilizer.

The application rate of ④ calcium magnesium phosphate fertilizer is generally about 30 kg per 667m ².

Attachment: is it feasible to apply high amount of phosphorus on phosphorus-deficient soils in China?

High amount of phosphorus application is to concentrate the phosphate fertilizer applied for several years into the soil at one time to provide phosphorus nutrition for crops. Although this method of fertilization can save labor, it also has the following disadvantages:

The yield of ① decreased and the utilization rate of phosphate fertilizer decreased. According to the experiment of the Institute of soil and Fertilizer of the Chinese Academy of Agricultural Sciences (1979-1985), the cumulative yield of wheat increased by 100% per year in 7 years, but only 77%-79% once in 6 years, and the utilization rate of phosphate fertilizer accumulated in 7 years was 22.4% higher than that of one-time phosphorus application. 23.4%

Excessive phosphorus application at one time by ② can easily induce zinc deficiency and iron deficiency in crops.

The order of the effect caused by a large amount of phosphorus application by ③ is as follows: low hilly red red soil > sandy field > black soil field.

In order to improve the effect of potassium and magnesium fertilizer, we should pay attention to two points:

① should not be used on crops such as saline soil or tobacco, which are sensitive to chlorine, because potassium and magnesium fertilizers contain 30% salt.

② potassium and magnesium fertilizer is a kind of fertilizer mainly containing potassium and magnesium. Only on the basis of applying nitrogen and phosphate fertilizer can it increase yield greatly. Generally, it is appropriate to use 15 kilograms per 667m ².