China's soil testing and fertilization has been carried out for many years, carrying out soil surveys, monitoring soil fertility, determining fertilization strategies based on monitoring conditions, and conducting macroscopic guidance on fertilization. Great achievements have been made, but it has not been able to enter the stage of targeted soil fertilization according to the specific land value, which seriously restricts the economic benefits of soil testing and fertilization. The main reason is that China’s national conditions have its own characteristics:
1 The area of the measured soil is too small, and its size determines the contribution of soil testing to farmers, and also determines the contribution of soil testing to fertilizer manufacturers and businesses. Some countries in Europe and America have large farms and relatively uniform farming. The area of the fields is not the limiting factor for soil fertilization, but China is different. In most areas, not only the fields are scattered, the labor is uneven, and even the planting is different, making the soil being tested. The area of the field is often small, reducing the eradication ratio of soil testing and fertilization.
2 The cost of conventional soil testing is relatively high. Due to the above reasons, the input ratio of soil fertilization is small, which leads to strict requirements on cost threshold. At present, it takes about 3 to 5 days to measure a soil sample by conventional conventional methods. The charge is about 50 to 150 yuan, depending on the number of test items. Under the specific national conditions of China, farmers are unbearable.
The cost of soil testing is also a serious problem for fertilizer manufacturers that implement free soil testing services. According to the average of two acres of soil testing, the total value of fertilization per field is 200 yuan, and the profit of manufacturers is 10%. The affordable earth-measuring cost is 20 yuan, while the actual cost of conventional analysis is generally around 50-150 yuan, which is higher than the above-mentioned critical value. The main reason for the high cost is the long test period, high analysis of labor costs, and large investment in equipment housing. It can be seen that without improving the test speed and not reducing the cost of soil testing, soil testing can only be used for macroscopic guidance of fertilization, and it cannot be extended to soil testing and fertilization of specific plots. There is no motivation and no vitality in the development of soil testing and fertilization.
Both domestic and foreign experience and our practice show that the fertilization output input has a critical value of 2 for the value of the VCR (Value Cost Ratio), that is, when the VCR>2 (generally 2-5), the soil fertilization will be accepted by the farmers. As far as the current national conditions are concerned, we believe that the cost of soil testing must be reduced to 15 yuan/soil. Only soil testing and fertilization can have internal developmental dynamics. This is a unique economic law in China's national conditions. At present, only speed measurement can adapt to the requirements of this economic law.