Introduction

Water is a critical factor in the growth and development of plants. Soil water content, availability, and distribution are crucial for maintaining plant life, and understanding the best type of soil water for plants is vital to maximize plant growth and yield. This article explores which soil water is most available to plants.

Types of soil water

Soil water exists in different forms, and each form has different availability to plants. The three main types are gravitational water, capillary water, and hygroscopic water.

Gravitational water occurs when rainwater or irrigation water infiltrates the soil and then percolates downwards due to gravity, and eventually seeps out of the root zone. Root uptake of gravitational water is low as it drains away rapidly, making it less available to plants.

Capillary water is held in soil pores and is under tension between soil particles. Plants can take-up capillary water from the soil, but the rate of uptake is dependent on the soil's ability to maintain the tension. Capillary water is more available to plants than gravitational water.

Hygroscopic water is the water molecules that are held tightly on the surface of soil particles. This water tends to be unavailable for plants, as it is not held in pores but adheres strongly to soil particles.

The most available soil water for plants

Among the three types of soil water, capillary water is the most available and most significant source of water for plants. It is held in soil pores and is under tension between soil particles, allowing plants to withdraw it from the soil slowly.

The capillary water supply is dependent on soil properties, such as texture, organic matter content, and soil structure, and the amount present in the soil will vary according to soil type and moisture conditions.

A soil with a higher percentage of fine particles such as silt and clay has a capacity to store high capillary water, which can improve plant's water holding capacity over a longer period of time. A soil with low organic matter content has lower capacity to retain water due to lower pore space for water storage.

Overall, the most important factor in ensuring an adequate supply of available soil water for plants is maintaining proper soil structure through proper management techniques such as conservation tillage and cover crops, which can help increase water retention in the soil.

Conclusion

Understanding which soil water is most available to plants is critical for maximizing plant growth and yield. Capillary water is the most significant source of water for plants, but its availability is dependent on soil properties and texture. Proper management techniques can help increase water retention in the soil and maximize the availability of soil water to plants.