Soil Moisture Monitoring with Instrumentation

Soil moisture is a measure of soil moisture and is extremely critical to agricultural production as it directly affects the growing conditions of crops. Moisture content is measured by the percentage of soil water content, which can be expressed as the ratio of the weight of water in the soil to the weight of the soil after drying, or to the maximum water holding capacity of the soil. Moisture monitoring is a fundamental work in agricultural technology promotion, which is of great significance in ensuring food security and promoting agricultural water conservation.

In the past, crop monitoring in China mainly relied on manual work in the field, and there are two major problems with this method: firstly, the monitoring speed is slow and the information cannot be obtained quickly; secondly, it relies on empirical judgement and the accuracy is not high. Especially when encountering serious meteorological disasters such as low temperature or drought, the measures taken often lag behind the development of the disaster due to the lack of timely warning and response, which affects the efficiency of agricultural production and the healthy growth of crops.

Traditional methods of judging soil moisture rely mainly on observing the appearance and feel of the soil, which is divided into the following categories:

Full moisture: The soil is dark in colour and moist, and when pinched in the hand it forms a ball that does not easily disperse, with obvious traces of water, which is the best condition for cultivation.

Moderate moisture: the soil is dark in colour and can be pinched by hand to form a ball, but it crumbles when thrown and leaves moisture in the hand, which is suitable for sowing but has a moderate moisture content.

Yellowish moisture: The soil is yellowish in colour, crumbles easily when pinched by hand, feels cool and is suitable for ploughing, but needs irrigation to add moisture.

Dry soil: Soil is greyish in colour, with hard clods and loose fines, lacking in moisture that can be absorbed by crops and unsuitable for cultivation.

Soil moisture monitoring is critical for conserving water and supporting sustainable agriculture. It helps us to detect drought conditions in time, arrange irrigation scientifically to ensure crop growth needs, and is an indispensable technology for modern agriculture.