Environmental services of Adlay (Coix lacryma-jobi L): A potential agroforestry crop in the uplands

Abstract

This study was conducted to assess the soil erosion rate and soil carbon stock of an adlay (Coix lacryma-jobi L.) farming system at varying slope gradients. The study was carried for a 10-month period following the completely randomized design. The erosion rate was measured using an improvised erosion bar, the infiltration by an infiltrometer, and soil carbon was analysed through a laboratory facility. Findings revealed that erosion rates in the adlay farming system are far beyond the tolerable limit. The slope > 20 % had an erosion rate of 66. 49 tons ha-1 yr-1 while the gentler slope (< 10%) had only 12.5 tons ha-1 yr-1. Soil carbon stock of the area ranged from 1.684 tons ha-1 to 2.2 tons ha-1 across the slope gradients of the farm. The infiltration rate was also found to be higher in a gentler slope (< 10%) at 106.67 mm hr-1 as against 91.33 mm hr-1 in steeper slope (> 20%). Adlay crop may be planted along areas steeper than 10% slope but this requires minimal tillage to minimize soil erosion. The technologies for soil and water conservation measures need to be adopted by the farmers in steeper areas.