How to supply nitrogen, phosphorus, potassium and trace elements in soil

Soil nutrient abundance and fertilizer effect research progress Soil fertility is the basis for crop growth. Defining the soil fertility of cultivated land and the characteristics of the crop's need for fertilizer, because of reasonable crop fertilization is an important guarantee for ensuring high yield and quality and cost-effectiveness of crops. . China has complex terrain and diverse climate. The differences in soil fertility and crop fertilization in different ecological types are quite different. Although there are many researches on soil nutrient abundance and fertilizer effects, soil nutrient testers have been used in various regions, but they have not been systematically summed up. For this purpose, the soil nutrient status and crop fertilization effects are summarized and clarified. The nutrient status of arable land and the status quo of crop fertilization research, and put forward the focus of the next major research, provide support for soil testing and formula fertilization and crop quality and efficiency.
Soil nutrient supply capacity includes two aspects of nutrient supply and supply process. In most cases, the former is the main aspect affecting crop yield. Soil nutrient supply capacity is considered to be a practical and comprehensive assessment of soil fertility and productivity. It is one of the most important indicators for scientific fertilization guidance in production practice.
Nitrogen, phosphorus and potassium are the three elements of fertilizer, which are the largest nutrient elements for crops and are mainly absorbed from soil. Nitrogen is one of the main components of many important compounds in crops. In addition to carbon, hydrogen, and oxygen, phosphorus is second only to nitrogen and potassium, and it is generally the highest in seeds. Potassium is one of the three factors that affect the yield of crops. It can eliminate the adverse effects caused by the use of excess nitrogen and phosphorus and play an important role in balancing nitrogen and phosphorus nutrition. Studying the abundance of these three nutrients in the soil and conducting scientific fertilization is particularly important for increasing crop yield and quality. The large area of ​​soil organic matter is in relatively short and medium conditions, and the area of ​​shortage is expanding. Soil alkali-hydrolyzed nitrogen accounted for most of the deficiency and deficiency, and the area of ​​deficiency was expanding. The available phosphorus content in soil has increased significantly and it is already in a medium and rich condition. The content of available potassium in the soil decreased significantly, the large area was in rich and medium conditions, and the medium area increased significantly. The soil is extremely deficient in nitrogen fertilizers, and its effective content is below and far below the corresponding nitrogen deficiency threshold. Potassium and phosphorus also showed different degrees of lack, with a large spatial variation of 13.2% -452.7%, the highest coefficient of variation of ammonium nitrogen, followed by available phosphorus, organic matter and available potassium is smaller. Soil nutrients in the newly abandoned land in the middle of the corridor were characterized by extremely low organic matter content, extremely low availability of phosphorus, lack of ammonium nitrogen, lack of available potassium, and large variations in soil organic matter and available phosphorus content. Available potassium and ammonium nitrogen The. Trace elements have a relatively small effect on crop growth compared to a large number of elements. According to Liebig's theory of minimum nutrient limitation, it is also crucial that the imbalance of trace elements affects the yield and quality of crops when a large number of elements are satisfied. With the optimization of high-yielding, high-efficiency varieties and cultivation techniques, more and more nutrients are brought out from the soil by the crop, and the reduction in the input of organic fertilizer makes trace elements unable to be replenished in time.
The soil potassium pool in the belt soil was in a deficit state for a long time, and even if organic potassium fertilizer was used, the input of potassium would not be affected by the crop load. The deficit rate was 39.5%-75.4%; the organic potassium fertilizer combined with chemical potassium fertilizer applied to the soil potassium deficiency rate. It reached 19.4%-47.8%; soil potassium content showed a trend of continuous decrease, and annual application of organic fertilizer decreased by 83.7mg/kg, including a large decline in the field; slowdown of potassium is several times faster than the available potassium; When the potassium productivity was increased by 5%, the available potassium in the soil was about 150 mg/kg, and the preliminary survey of potassium-deficient land reached 50.7%. The combined application of organic fertilizer and chemical potash is an effective measure to increase potassium production. Researches on trace element fertilizers mostly focus on the study of zinc fertilizers, but less on other trace element fertilizers. Irrigated desert soil on maize application of zinc increased by 6.8-16.6%, the trend is to increase production base> seed dressing> topdressing> foliar spray. The yield of zinc maize, broad bean, millet and wheat increased by 11.9%-33.8% in oasis salinized soil, 8.8%-15.2% in autumn sowing cabbage, and it can improve the cold resistance of Chinese cabbage; the root yield of sugar beets increased by 3.8%, sugar content 7.7% increase, ash content decreased 2.6% -10.8%. Appropriate application of zinc can accelerate the average growth rate of maize in the early stage of male tasseling compared with that in the early stage of maturity, and increase the grain weight per spike and 1000-grain weight. However, over-application of zinc can cause symptoms similar to magnesium poisoning.
In general, studies on soil nutrient abundance are mostly concentrated on the study of nitrogen and phosphorus, while potassium is the most common research on fertilization, and there are few studies on trace elements in soil. The lack of systematic research. However, with the introduction of high-yield crops and the high input of large amounts of nitrogen and phosphorus fertilizers, it will inevitably lead to the imbalance of nutrients in the soil. Some studies have found that some of the medium-sized elements are at or below the critical value. Therefore, the focus of future research should be on the abundance and abundance of macroelements K and trace elements, their application methods, fertilizer efficiency, and their effects on crop quality. In the past, a soil moisture tester has been used to determine soil fertility based on soil moisture status, and for nitrogen and phosphorus it is recommended that more research be conducted on the impact of crop quality, environmental safety, and improved utilization efficiency.

Special Coating

Special Coating,Aluminum Coated Magnet,Everlube Coated Magnet,Parylene Coated Magnet

ZHE JIANG PUFEITE MAGNETICS CO; LTD , https://www.pftmag.com