Research Methods of Soil Moisture and Farmland Soil Moisture Research on soil moisture has been underway since the very beginning, and the means of testing have continued to improve. From the initial experience method to the plaster block method to the instrument method using the soil moisture detector, the distribution of water resources in our country is uneven, and the water resources are relatively lacking. Therefore, the research on water in agricultural production is highly valued. The study of soil moisture testing methods mainly focuses on measuring soil moisture content and soil water potential. Richards invented the tensiometer as early as the 1930s, and later scholars connected it to other instruments to make the tensiometer more convenient and quick to operate, record, and carry. The resistance sensing method can indirectly measure the low soil water potential. The gypsum block law is a soil moisture determination method that has been widely used as a conventional method. In China, the earliest mass production was the general-purpose tensiometer developed by the Nanjing Institute of Soil Science, Chinese Academy of Sciences. The improved micro-tension gauge, air-sense tensiometer, and dual-type tensiometer that can simultaneously measure several layers of soil water potential are also successively production. In the determination of soil moisture content, drying and weighing method is still the classic method, neutron method is also widely used. The neutron method originated in the late 1940s. After basic research by many people, it began to be used in 1956. Since about 1963, the neutron method has begun to be applied to the quantification of soil moisture in the hydrology field. After the 1980s, the neutron moisture meter itself has realized computerization of data storage, and has developed a variety of storage, display, and printing. Features. In recent years, with the introduction of portable soil moisture temperature measuring instrument into the market, it is characterized by the convenience of automatic monitoring of long-term field moisture temperature, which is more convenient and accurate than the neutron moisture meter and is a promising one. The instrument for measuring soil moisture. In addition, new techniques such as isotope tracing and remote sensing have also been applied in this field. Second, due to the shortage of water resources in China, agricultural water conservation issues have received much attention. A lot of research work has been done around the conversion of farmland soil moisture and the effective use of farmland water. Since Phillips proposed the SPAC theory, the study of field soil moisture cycling and balance, soil-plant moisture relationships, and groundwater-soil water-atmosphere water conversion are all based on the SPAC continuum. Due to the unification of energy relations, it is convenient to analyze and study the dynamic process of moisture migration and energy conversion. In terms of services for agricultural production, research on soil water mainly focuses on how to fully exploit the potential of soil moisture, that is, the relationship between crop yield and soil moisture. In response, many scholars have made corresponding researches, among which crop water production function research is one of its achievements. On the other hand, how to strengthen farmland water management and make full use of it is also a research hotspot. Therefore, the domestic study of various models of public opinion monitoring and forecasting and the optimization of the field irrigation system have provided guarantees for the development of water-saving agriculture. The understanding and development of the concept of “soil water resources†Since the term “soil water resources†was proposed by the former Soviet hydrologist Livovich, in the past 10 years or so, Chinese scholars have conducted a certain amount of research work on soil water resources. The understanding of water resources has also been continuously developed. Feng Qiancheng and others believe that soil water resources are the amount of water in the soil layer that is often involved in the exchange of land moisture, especially the amount of water in the root belt that can be used by plants and can be recovered. Liu Changming's discussion of effective precipitation is very similar to the concept of modern soil water resources. In recent years, some scholars believe that soil water resources can be divided into soil water storage and soil water regulation. However, the contents and methods of evaluation of soil water resources have not been recognized. However, there are two general evaluation methods. First, soil water content is calculated based on soil moisture and soil bulk density. Second, the concept of soil water turnover is used to study the law of tetrahydrate conversion. When there is little understanding of soil water, the black box model is used for watershed hydrological model or water transformation, that is, only the relationship between input items and output items is studied. With the deepening of research and the development of various models, new types of watershed hydrological models, especially the simulation of soil water movement in distributed hydrological models, have become mainstream models. The evaluation of soil water also puts forward more evaluation indicators, such as available amount, annual recharge amount, storage amount, and adjustable amount, which have a certain guiding effect on agricultural water saving. Fluorescent Pigments, Neon Pigment Powder, Luminous Pigments Kolortek Co., Ltd. , http://www.metallicpigment.com