Field-holding capacity measurement should pay attention to the problem

Field-holding capacity measurement should pay attention to the problem

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 activity of soil microorganisms, and has many influences on soil productivity. . Therefore, soil moisture measurement is very important. Soil moisture can usually be used with a soil moisture meter, which can quickly produce results. The soil moisture determination process also includes determination of soil bulk density, determination of field water holding capacity, and determination of withering moisture. Below we mainly analyze the issues that need attention in the determination of field water holding capacity.

(1) The key to determining the success or failure of field water holding capacity is the amount of irrigation water is sufficient. In addition to calculating the approximate amount of irrigation, it is necessary to pay attention to the observation during irrigation, how much water is absorbed into the soil at the beginning, how much water is absorbed, and then the water absorption speed becomes slower. When irrigation water can not penetrate for a long time can be. (2) When determining the weight water content at the point of selection in the irrigation area, the four measurement points should be separated from each other appropriately, and should not be too concentrated to avoid the measured value being too high or too low due to the influence of the area. (3) When taking soil samples, pay attention to the observation of soil samples to determine roughly whether the soil moisture reaches the field capacity. When you see the soil is sticky, if you insert it into the soil with a knife (shovel), it will stick when you pull it out (except soil with strong sandy nature). If you grab the soil by hand, it will leave mud marks; Thin cylindrical and curved will not break. The soil moisture at this time is close to the capillary holding capacity and higher than the field holding capacity. When the soil moisture content is equal to or slightly lower than the field water capacity, the soil is no longer tacky, but becomes soft and malleable; the soil can be made into thin cylinders, but the bending will break.

The soil moisture detector has been recognized as the designated instrument for soil moisture measurement, and the instrument has many advantages over similar instruments. One of the biggest advantages is that the soil moisture detector has a GPS global positioning system that can determine the latitude and longitude information of the current northern point while measuring soil moisture.