Soil nutrient integrated system evaluation method and balanced fertilization technology achievements

Soil nutrient integrated system evaluation method and balanced fertilization technology achievements

The “Comprehensive Systematic Assessment Method for Soil Nutrients and Balanced Fertilization Technology” won the second prize for scientific and technological progress in the Ministry of Agriculture in 1996 and the third prize for national scientific and technological progress in 1999.
This technology is a scientific and technological achievement that was developed during the implementation of the China-Canada (PPI/PPIC) intergovernmental cooperation project and the “Eighth Five-Year Plan” scientific and technological research project at the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences. It is currently being applied in the “Ninth Five-Year Plan” related scientific and technological research projects and large-scale agricultural science and technology development projects, and will be promoted and applied in a wider range.

The results of the "Comprehensive Systematic Assessment of Soil Nutrients and Balanced Fertilization Technology" were jointly developed by the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences and other relevant organizations. A total of more than 9,000 soil samples were taken in 28 provinces, municipalities, and autonomous regions across the country, and a large number of laboratories, Wimbledon rooms, and field research work were conducted. During the “Eighth Five Year Plan” period, comprehensive soil nutrient system evaluation and balanced fertilization studies were carried out on 1.1 million mu of cultivated land in Yutian County, Hebei Province. A comprehensive set of soil nutrient comprehensive system assessment methods suitable for China's soil conditions and planting systems was gradually developed. And balanced fertilization techniques.

In the evaluation of soil nutrient status and recommended fertilization for soil testing, this achievement comprehensively considers the comprehensive and balanced supply of macronutrients, micronutrients, and micronutrients to more accurately assess soil nutrient status and maximize fertilizer use efficiency; The adsorption capacity of seven major nutrient elements was used as one of the parameters for evaluating soil nutrient status and recommended fertilization. In the soil nutrient status measurement and fertilizer effect experiment, the “optimum treatment” design was proposed and adopted creatively. The study of each element is carried out under the “optimum” equilibrium of adjustment of other elements, avoiding the neglect of the possible absence of other elements or the influence of excess on the effect of the element being studied; the use of joint extractants and the realization of series The operation has significantly improved the work efficiency of soil testing and reached the level of advanced soil testing laboratories in the world. Based on a large number of soil tests, pots and field experiments and demonstrations, a complete database, data management system, and high-yield and high-efficiency balanced fertilization consulting service system were established from soil testing to fertilization.

More than 9000 soil samples were taken in 28 provinces (municipalities and autonomous regions) across the country. The soil was measured using ASI combined with extractant (0.25mol/L NaHCO3+0.01mol/L EDTA+0.01mol/L NH4F). The available nutrients, micronutrients, and available nutrients were tested for the adsorption of major nutrients in some soils, pot experiments, and corresponding field trials. In the basic determination of soil nutrients and adsorption tests, the addition of extracts and reagents, agitation and filtration of the sample, transfer, dilution and determination of the filtrate, and washing of the experimental vessels were all serialized. One person can complete the determination of 60 samples and 11 nutrients in 840 items a day, which is 8-10 times more efficient than conventional soil testing techniques. The basic soil test can send a test report within 3 days after receiving the sample, and the adsorption test can also be completed within 5 days, so that the work efficiency of the soil test can reach the international advanced level, and the timeliness of the soil testing recommended fertilization work can be greatly improved.

In the design of pot experiments and field experiments, based on the results of soil testing and adsorption tests, an optimal treatment (OPT) for each of the soils to achieve a comprehensive balance of large, medium, and trace elements, and corresponding verification of each element Abundant other processing. The results showed that in the test soil, available nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), iron (Fe), sulfur (S), boron (B), magnesium (Mg), manganese (Mn), copper (Cu), and calcium (Ca) below the critical level accounted for 95%, 51.7%, 59.7%, 69.2%, 30%, 25.8%, 20.3%, 17.5%, 10.4%, 5.6% u, respectively. , 3.6%. The results of potted plants that examined nutrient limitation factors and their severity indicated that 98% of the 140 soils from 17 provinces (municipalities, autonomous regions) were nitrogen, phosphorus, potassium, and zinc, respectively, which were the limiting factors for crop growth. 90%, 60%, and 49%, the lack of these elements are distributed in 17 provinces where earth is taken. Soils deficient in calcium and magnesium accounted for 14% and 18%, respectively, mainly from soils in southern provinces. There are 12% of soil iron deficiency, mainly from the soil in the northern region. In addition, soils deficient in sulfur, boron, copper, manganese, and molybdenum accounted for 32%, 26%, 26%, 24%, and 20% of the tested soil, respectively, and were distributed in soils in the south and north.

Based on the results of a large number of pot trials and field trials, Cate and Nelson used the method of Cate and Nelson to calculate the critical values ​​of nutrient elements in the nutrient elements determined by the method under potted and field conditions, and divided the test values ​​of macronutrients, micronutrients and micronutrients. The high, medium and low indicators of the determination of the general limits of the determination method through field verification, nitrogen 50mg/L, phosphorus 14mg/L, potassium 78mg/L, calcium 400mg/L, magnesium 120mg/L, sulfur 12mg /L, Boron 0.2 mg/L, Copper 1 mg/L, Iron 10 mg/L, Manganese 5 mg/L, Zinc 2 mg/L. When the recommendation of fertilization is put forward, the application amount of each nutrient element is determined according to soil test and adsorption test results, crop type and yield target, and a complete set of soil nutrient comprehensive system evaluation and balanced fertilization recommendation technology are formed.

Using Microsoft Excel spreadsheet software, for the first time, a computer database that integrates statistical analysis and calculation functions, subtotal functions, database management functions, graph editing functions, dynamic linkage functions, print form functions, fertilization recommendation functions, and search query functions has been established. And database management system. By using this system, one-time entry of soil test values ​​can be performed, and the completion of test results analysis, database entry, potted plant design, test result report, and fertilization amount recommendation can be gradually completed.

Based on a large number of soil tests, adsorption tests, pot experiments, field tests and demonstrations, a high-yield and high-efficiency balanced fertilization model suitable for wheat, corn, rice, vegetables, fruits and other crops was established. The available nutrient content of macronutrients, micronutrients, soil phosphorus and potassium adsorption and fixation capacity, interactions between various elements, soil pH, soil organic matter content, different years and different locations, etc. are used as model parameters, and appropriate Consider economic factors such as food and fertilizer prices and risk factors. The model was used to calculate the appropriate amount of fertilizer for different crop yield levels. Through the link between the model and the established database, a unified soil testing recommended fertilization consulting service system was formed. It is used to guide high-yield, high-efficiency balanced fertilization and crop special fertilizer production for various crops.

The established high-yield and high-efficiency balanced fertilization models and soil testing recommended fertilization consulting service systems for wheat, corn, rice, vegetables, fruits and other crops were verified and modified in Yutian County, Hebei Province through extensive field trials and demonstrations. In 281 soil samples taken in 10 townships, more than 5,000 samples were taken to determine the major nutrient limiting factors in the soil. All soils were nitrogen deficient, 67% soil phosphorus deficient, and 76% soil potassium depletion. , 49% of soil lacks manganese, 92% of soil lacks zinc and 45% of soil lacks sulfur. Among them, 34% are very deficient in phosphorus, 47% are extremely deficient in potassium, 15% are deficient in manganese, 11% are deficient in zinc, and 11% are deficient in sulfur. The results of field trials of 20 maize, rice, wheat and celery carried out in Yutian County, Hebei Province, showed that the optimal treatment (OPT) yield determined by the Soil Nutrient Integrated System Assessment method was the highest in all tests. Subtraction of phosphorus, potassium, manganese, zinc, and sulfur on a 0PT basis caused a significant reduction in production. In 214 field demonstrations on maize, wheat, cotton, rice, celery, Chinese cabbage, scallion, and watermelon, the application of soil nutrient comprehensive system assessment method recommended fertilization treatment to increase the yield compared with the control farmers, and the average maize yield increased by 26.1 per mu. In terms of kilograms, the increase in income is 40.6 yuan, and the average output of wheat is 29.8 kilograms per mu, which is an increase of 47.3 yuan. Rice yields increase by an average of 29.7 kilograms per mu, increasing income by 53.4 yuan. Watermelon farmers are accustomed to applying pure nitrogen (N) as high as 50-60 kilograms per mu, which is 2-3 times higher than the actual demand. According to the comprehensive evaluation method of soil nutrients, the recommended application of nitrogen (N) 20-25 kg, while increasing the application of phosphorus, potassium, manganese, zinc, etc., to achieve a comprehensive balance of fertilization, resulting in improved yield and improved quality. In most of the comparative demonstrations, farmers are accustomed to applying nitrogenous fertilizers, using phosphorus and potassium fertilizers inadequately, and ignoring the supplementation of medium and trace elements. As a result, crop yield is low, quality is poor, nitrogen resources are wasted, and environmental quality is reduced. According to the comprehensive evaluation method of soil nutrient system and the fertilization provided by the balanced fertilization technology, it is recommended to appropriately reduce nitrogen input, increase the application of phosphorus and potassium fertilizers, and the use of trace elements, so that the supply of various nutrient elements is balanced and reasonable, and the yield and quality of crops are improved, and reductions are made. The waste caused by excessive fertilization and the adverse effects on the environment. The results of field trials and demonstrations have further validated the reliability of soil nutrient comprehensive system assessment methods for recommended fertilization. The results of field trials and demonstrations were input into corresponding databases to further validate and modify crop fertilization models and improve soil testing and recommended fertilization consulting service systems.

The project has been promoted and applied in more than 20 provinces, municipalities and autonomous regions throughout the country, resulting in significant economic, social and ecological benefits. In 1995, the Ministry of Agriculture regarded this achievement as a key technical achievement formed during the “Eighth Five-Year Plan” period and included it in the promotion project of the Ministry of Agriculture's bumper harvest plan, which was promoted and applied within a relatively large scope. In 1995-1996, only 442,500 mu of corn was applied to Yutian County in Hebei Province in the two years, which was an increase of 106.5 kg compared with the average yield in the first three years of the project. The new output was 47.34 million tons and the new output value was 35.79 million yuan. From 1995 to 1997, the areas of wheat, corn, cotton, rice, and other crops in Shandong, Hebei, Henan, Jilin, and Liaoning were used for a total area of ​​39.453 million mu with direct economic benefits of 1.447 billion yuan.

The results have been successfully used to guide the production of special fertilizers for crops. Through the application of special fertilizers for crops, science and technology are delivered to farmers along with their supplies. Without increasing input, the balance of fertilizers can be achieved with high yield and high efficiency by adjusting the ratio of fertilizers. Increase fertilizer use efficiency while preventing the adverse effects of excessive nitrogen fertilizer application on product quality and the environment.

Since 1993, a total of more than 200 training courses for the promotion of this technology have been held at different levels across the country and at the provincial and county levels. More than 20,000 attendances, one monograph and collection of essays, one television video, and the Central The TV station Agricultural Science and Technology Education Section and the Central Agricultural Broadcasting and Television School were broadcast several times. Has a major impact across the country.

The formation, development, improvement, and successful use of soil nutrient comprehensive system assessment methods are a major advancement in soil fertility research and fertilization science, in soil fertility research, soil nutrient limitation factor detection, crop-specific fertilizer production, soil Evaluation of productivity and carrying capacity, evaluation of soil resources, soil environmental protection, and high-yield, high-quality and high-efficiency agricultural production systems have broad application prospects.