Permanent Wilting Point Moisture Content for a Crop

Permanent wilting point (PWP) is the moisture content of soil at which plants are unable to extract water from the soil, resulting in permanent wilting of the plant. PWP is a critical parameter in agriculture, as it determines the ability of plants to survive in a given soil condition.

Hygroscopic Water

Hygroscopic water is the water that is bound to soil particles due to the attractive forces between water molecules and soil particles. This water is not available to plants, as it is held too tightly by the soil particles. Hygroscopic water content is typically low, in the range of 0.1-2% by weight.

Relation to PWP

Permanent wilting point moisture content for a crop represents the hygroscopic water in soil. This is because at PWP, all available water in soil has been extracted by plants, leaving only hygroscopic water behind. Therefore, PWP represents the lower limit of plant-available water in soil.

Other Soil Moisture Contents

Field capacity water is the maximum amount of water that soil can hold against gravity, after excess water has drained away. Capillary water is the water that is held in soil pores due to capillary forces. Water of adhesion is the water that is held on soil surfaces due to adhesive forces.

Conclusion

In conclusion, permanent wilting point moisture content for a crop represents the hygroscopic water in soil, which is not available to plants. PWP is a critical parameter in agriculture, as it determines the ability of plants to survive in a given soil condition. Understanding the different types of soil moisture content, including hygroscopic water, field capacity water, capillary water, and water of adhesion, is important for managing soil moisture and optimizing crop growth.

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