3Pc Ball Valves , 3Pc Ball Valve ,Stainless Steel 3Pc Ball Valve,3Pc Ball Valve With Extended Pipe WENZHOU DIYE VALVE&FITTINGS CO.,LTD , https://www.diye-valve.com
Answer: In the soil testing and formula fertilization, the methods for determining the amount of fertilization are: nutrient abundance index method, nutrient balance method and fertilizer effect function method. No matter what method, as long as it is reasonable and feasible through field trials and production practices, it is a good method.
Nutrient abundance indicator method. The principle is to divide soil fertility into different grades according to relative yield through field trials and soil tests. For example, the relative nutrient levels of a certain soil with a relative yield of less than 50%, 50% to 75%, 75% to 95%, and greater than 95% are determined to be extremely low, low, medium, and high, respectively, and then according to each level. The corresponding relationship between the nutrient test value of the soil and the amount of fertilizer applied is used to estimate the amount of fertilizer applied. For example, the soil available phosphorus content of a winter wheat before fertilization is 20 (Pmg/kg). Check the nutrient test value, soil fertility and fertilization amount table to find out that the nutrient level belongs to medium fertility, and the yield per mu is over 400 kg. The yield, the corresponding amount of phosphorus (P2O5) is about 5 kg. By dividing the nutrient application amount by the fertilizer nutrient content, the amount of fertilizer applied can be calculated. Thus, 5 kg of phosphorus nutrients are equivalent to 30 to 35 kg of superphosphate per acre, or 11 kg of diammonium phosphate. The advantage of this method is that it is simple and intuitive, and the disadvantage is that it is semi-quantitative and the precision is not high.
Target production method. Also known as the nutrient balance method. According to the balance of nutrient balance in the production of crops, the nutrient content absorbed by the crops in the first season minus the nutrient content of the soil supply is obtained. In the calculation formula, in addition to the nutrient determination value, it also includes parameters such as target yield, fertilizer utilization rate, and soil nutrient supply. The target production is estimated by increasing the average annual production of the first three years by 10% to 15%, but other parameters need to be obtained through field tests. China has a vast territory, and the specific conditions of fertilization vary widely from place to place. The parameters are not the same. Therefore, the estimation of fertilization should be adapted to local conditions.
Fertilizer effect function method. On the basis of the field fertilizer test, through the regression analysis, the fertilizer effect equation is established to indicate the relationship between the amount of fertilizer applied and the yield and calculate the amount of fertilizer applied. The advantage of this method is that it can estimate the highest yield and the maximum economic benefit of the fertilization amount, that is, the optimal fertilization amount; but under the field test conditions, it is difficult to obtain a rational test result that can calculate the reasonable application of fertilizer.
Q: Is it necessary to solve the fertilization amount according to the above method for each soil testing and formula fertilization?
Answer: The calculation methods or mathematical formulas of the above-mentioned several kinds of fertilization amount are based on the field test to obtain the relevant parameters. With these test results or parameters, the soil testing formula fertilization expert or expert system can estimate the amount of fertilizer applied accordingly. In the actual soil testing and formula fertilization, it is generally not necessary to carry out such complicated calculations, and according to the soil test results, the fertilization amount or fertilization suggestion corresponding to the test value can be directly obtained through the look-up table or computer software. However, the recommended fertilization parameters of general computer software are mostly large-scale and multi-point test results, which are not targeted to specific fields. Therefore, when recommending fertilization, it is necessary to adapt to local conditions and listen to the opinions of local experts. When the recommended amount of fertilizer is controlled within a reasonable range.
Q: Can a portable soil nutrient speed meter be used to guide formula fertilization?
A: As mentioned above, the real soil testing formula fertilization needs to be completed under the guidance of relevant experts based on a large number of field trials, soil nutrient determination and farmer's field file. For the quick measurement of soil nutrients such as NPK, the nutrient speed measuring box is better than the blood glucose meter, which is helpful for guiding fertilization. The key to soil testing and formula fertilization is not only to obtain accurate test results, but also how to interpret and apply these test results, so it is necessary to be scientifically defined under the guidance of experts or after necessary training to test the fertilization significance of test results.
Peasant Daily (Senior Consultant of Sinofert, Professor of China Agricultural University Wang Xingren)
How to determine the amount of fertilizer applied in soil testing and formula fertilization
Q: How is the amount of fertilizer applied in soil testing and formulating?
ã€Comment】 ã€Print this article】 ã€Close this page】 ã€Large, medium and small】