In soil, water available for plants is (a) gravitational water (b) chemically bound water (c) capillary water (d) hygroscopic water.
Option C Water occurs in the soil in the different forms as: free water, gravitational water, hygroscopic water, chemically combined water and capillary water. Free water is that water which runs away and is not held by the soil. Obviously it is not available to the plants. Gravitational water goes down into the deeper strata of earth and it is also, not available to the plants. Hygroscopic water is present in the form of thin films around the soil particles and it is also not available to the plants under normal condition but it may be available under adverse conditions. Chemically combined water is not available to the plants at all. The only water which is available to the plants capillary water. Capillary water makes up about 75% of the total water available to plants. The rest of soil water (hygroscopic, combined, free, gravitational and 25% capillary water) are not available to plants. These are called echard or unavailable water.
