1 The Necessity of Quick Measurement of Soil Nutrient Costs Since the reform and opening up, China's soil and fertilizer work has made great progress and remarkable achievements. However, effective technologies such as soil testing, fertilization, economic fertilization, etc. are still largely unaccepted by the majority of farmers in most regions and are converted into productivity. This is why, although there are many reasons for this, I believe that the most fundamental one must be analyzed from the perspective of economic reasons. Related equipment: soil moisture measuring instrument soil temperature and humidity recorder Balls Massager,Grid Foam Roller,Mini Foam Roller,Diy Slant Board Calf Stretch nantong pinli fitness co.,ltd , https://www.cnpinlifitness.com
Soil testing and fertilization is a technical activity as well as an economic activity. Under the socialist market economy, its operation must comply with its own economic laws. This law can be expressed in two ways:
1 The input-output ratio of soil testing and fertilization should be acceptable to farmers. Referring to the VCR (Value-Cost Ratio) of fertilizers in some countries, this value is generally 3 to 5, not less than 2, which is a critical condition for farmers to accept compensated soil fertigation.
2 The ratio of the profit of soil testing and fertilizer sales to the cost of soil testing should be greater than 1. This is the minimum requirement for fertilizer producers or distribution units to engage in the sale of fertilizers for unpaid soil testing.
According to China's national conditions, the most important factor affecting the above two ratios is the field size and soil testing cost. Most of the areas in China are scattered with uneven fertility, and the crops are not the same, which makes the area of ​​the soil to be measured. It is often very small, which greatly reduces the farmers’ soil test output and the sales income of the manufacturers. On the other hand, the conventional analytical soil testing cycle is long and costly, so that the actual output input ratio is doubled below the above critical value. Economic analysis shows that there is no vitality in soil testing and fertilization without increasing the speed of testing and reducing the cost of soil testing. Therefore, it is necessary to develop a low-speed soil nutrient rapid measurement technology suitable for China's national conditions, so that the cost of soil testing or fees can be reduced by a factor of ten, so as to establish a mechanism for soil testing and fertilization that meets the laws of the market economy. 
2 Accuracy of soil nutrient fastness meter The national standards of the People's Republic of China stipulate the accuracy requirements of soil analysis. The National Soil and Fertilizer Station of the Ministry of Agriculture has also made similar requirements, as shown in Table 1. These are requirements for routine soil analysis, and speed testing should also meet this requirement. At present, the performance indicators of the soil speed measurement instruments are mostly based on the National Filter Photoelectric Colorimeter Verification Procedure JJG179-90. It should be said that it reflects the minimum requirements of general electro-optical colorimetry (Table 21 column) in order to ensure the accuracy of soil nutrient determination at various fertility levels. This requirement is roughly equivalent to the level of a Class 1 grating spectrophotometer (column 23). With the application of electronic technology in speed measurement, some speedometers have met this requirement (Table 22).
It can be seen from Table 2 that the stability and reproducibility of the rapid-measuring filter opto-electronic colorimeter has been almost the same as that of the conventional class 1 spectrophotometer (Table 23). Basically met the needs of the Department of Agriculture's technical specifications.