Effects of rainwater harvesting and afforestation on soil properties and growth of Emblica officinalis while restoring degraded hills in western India

Abstract

Effect of rainwater harvesting (RWH) structures like Contour trench (CT), gradonie (GD), box trench (BT), V-ditch (VD) and afforestation with Emblica officinalis Gaertn (planted in August, 2005) were studied in <10%, 10-20% and >20% slopes with a view to improve soil status, plant growth, sequester carbon and rehabilitate hills for local benefits. Soil pH and EC decreased and percent soil, SOC, NO3-N and PO4-P increased in June 2010 over 2005. Enhanced soil water and nutrients in <10% slope
facilitated height and collar diameter growth of E. officinalis. Soil water was 14.0 and 51.4% greater in >20% and <10% slopes, respectively than in 10-20% slope, whereas it was 17.8, 16.1, 24.2 and 14.0% greater in CT, GD, BT and VD treatments, respectively over control. The highest plant growth was in CT plots in all slopes. Second best treatment was BT in <10% slope and VD in other slopes. Conclusively, RWH and afforestation facilitated soil improvement but CT/BT treatments were more efficient in
conserving soil and water facilitating plant growth and helped restore the degraded hill. However, further research is required on soil water use and its partitioning in different vegetation component and the benefits accrued from it for the local people.