墒, refers to the humidity of the soil. The lyrical condition refers to the condition of soil moisture. The soil moisture is the degree of dryness and humidity of the soil, ie, the actual moisture content of the soil, and the available soil moisture content is expressed as a percentage of the dry soil weight: soil moisture content=moisture weight/dry soil weight×100%. It is also possible to express the relative moisture content such as the percentage of soil moisture that corresponds to the amount of water in the field, or the percentage relative to the amount of saturated water. The importance of soil moisture is even greater than soil nutrients. Because of the change in soil moisture, it directly affects the changes in soil nutrients. Soil moisture is the main source of plant absorption. In addition, plants can directly absorb a small amount of water that falls on the leaves. The main source of soil water is precipitation and irrigation water, and it participates in the water cycle of the lithosphere-biosphere-atmosphere circle-circle-water circle. Disable People Elevators,Goods Elevator,Cargo Elevators Deao Elevator Co., Ltd. , http://www.js-elevator.com
There are several different ways to express soil moisture, such as soil moisture content, weight water content, and volumetric moisture content. The relationship between the two is based on soil bulk density. The other is expressed in terms of soil water potential. The negative value of soil water potential is the soil water suction. In general, we talk about soil moisture, which mainly refers to soil moisture content. There are many methods for determining soil moisture, such as titration method, weighing method, microwave method, neutron method, gamma ray method, nuclear magnetic resonance method, instrument method and so on. Among them, the instrumental method has been gradually valued by people in recent years with the birth of scientific instruments. Determination of soil moisture mainly includes soil moisture analyzer, wireless moisture and drought monitoring system, and so on. The emergence of the instrument has greatly improved the efficiency of soil moisture measurement in farmland, and has also allowed agriculture to gradually enter modernization and science and technology.
The main forms of soil moisture are as follows: Soil water exists in the soil pores, especially in small and medium pores, and macropores are often occupied by air. Plant roots interspersed in soil pores draw water from the pores of the aqueous soil for transpiration. There is a gradient of moisture in the water-air interface in the soil. The temperature rises and the gradient increases. Therefore, the water will become water vapor and evaporate out of the soil surface. The transpiration and evaporation of water, together with the addition of evapotranspiration, are two ways that water enters the atmosphere.
Analysis of related concepts of soil moisture