conservation ditching for efficient resource conservation and enhanced productivity of semi- arid vertisols

Abstract

Conservation ditching is primarily adaptable in deep black soils with low infiltration rates (<1 mm hr-1 ) receiving low annual rainfall (< 750 mm). Conservation ditch is a shallow trapezoidal dugout, laid on contour to serve the dual purpose of soil conservation and as a water storage structure at the individual field level in low rainfall area of deep black soils. This can also be vaguely described as an ‘inverted contour bund’ with flatter upstream sides and steep downstream sides. As a terrace structure, a well designed conservation ditch will store the inter-terrace design runoff within its confines; thus drastically cutting down its potential to initiate/accelerate soil erosion on the downstream of the ditch. As a storage structure, due to low infiltration rates in the deep black soils, sufficient volume of the stored water will be available in the ditch for about a week to ten days after the runoff collection in the ditch. The available water at low lifts could be manually lifted and applied to the downstream area to augment the soil profile moisture and stabilize yields of dryland crops.