Tending the soil with tank silt
Unlike the topography of plains, drylands are marked by an undulating landscape which have significant slopes. Due to massive deforestation, there is little vegetation whose roots can bind the soil. These factors together lead to a high rate of soil erosion, also resulting from high volume of surface run-off after intense showers. Soil erosion reduces the fertility of these common lands and also causes siltation in the water harvesting structures such as earthen dams built downstream of these lands. Siltation reduces the storage capacity of these storage structures and brings down their life. Timely removal of silt from these water storage structures is an important step in ensuring their long term usefulness.
In the summer months when the water levels of the tanks and lakes in the village decline, areas where the silt has got deposited gets exposed. This silt can be removed from these patches and be transported to the farmlands and applied as soil amendments on lighter and less fertile soils.
Application of tank silt on farmland is a win-win solution for farmers. It has multiple benefits:
1. Desilting the water harvesting structures leads to an enhancement of their storage capacity and ensures their longer life.
2. Silt application enhances the soil texture and water holding capacity of the soil. It also provides better aeration and improves the nutrient status of the soil that is essential for good crop growth. The silt in storages with forested catchments is usually rich in organic matter which is an essential component of soil health.
3. Silt removal and its application on lighter soils is a labour intensive activity that can generate off-season employment in the villages. In the context of COVID-19 outbreak and the national lockdown situation, Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) has