Analysis of Mistakes in the Determination of Field Water Holding Capacity

Analysis of Mistakes in the Determination of Field Water Holding Capacity

Soil moisture is one of the components of soil and has certain influence on the content of gas in the soil and the structure, physical structure and physical properties of the soil. It restricts the dissolution, transfer and absorption of soil nutrients and the activities of soil microorganisms, and has many influences on soil productivity. . Soil moisture is a component of water balance, and it is the main direct source of water for plants, and has a major impact on the physiological activities of plants. The determination of soil moisture is also a need for agricultural modernization and technology. The determination of soil moisture can be achieved through a variety of specific instruments, such as wireless public opinion monitoring systems. The greatest advantage of wireless public opinion monitoring systems is the ability to achieve wireless data transmission. It uses internal GPRS and GSM devices to achieve data transmission without Need data line. At the same time, it can also be called the wireless public opinion and drought management system.

In soil moisture determination, it is often necessary to determine a number of parameters, one of which is the amount of water in the field. In the process of measuring the amount of water in the field, we need to pay attention to some problems. We will do a detailed analysis below.

Some stations, after measuring the soil moisture content of each layer, found that the weight water content of a certain level (referring to the average value of 4 repetitions) increased compared with the weight water content of the previous level. No matter how much it is increased, it is considered that the weight water content of this level cannot be regarded as the field water holding capacity at this level, and the measurement should be continued until the next soil moisture content of the layer is lower than the previous time and the second time is worse. If the absolute value is less than or equal to 2.0%, the soil moisture content at the next level is the field capacity at that level. All kinds of understanding are wrong. According to the specification, if the absolute value of the second-order difference between soil water content before and after a certain layer is ≤ 2.0%, the weight water content will be high and low both before and after the second time (since the measurement points are different, even if the soil weight measured later If the rate is greater than the previous time it is also normal, the soil moisture content of the next soil is taken as the field water holding capacity at that level, otherwise the field water holding capacity at this level will continue to be measured until the absolute value of the 2nd difference is ≤ 2.0%. The last measured value is the field capacity at this level. Some stations understand that when comparing two levels of moisture content before and after a certain level, it is to compare each repetition of the level with the previous corresponding repetition. This understanding is also wrong. It should be a comparison of the two values ​​before and after the average value of the four repeated weight water contents at a certain level.