Sloping agricultural land technology (SALT), otherwise known as contour hedgerow intercropping (agroforestry) technology (CHIAT), is a system in which dense hedgerows of fast growing perennial nitrogen-fixing tree or shrub species are planted along contour lines thus creating a living barrier that traps sediments and gradually transforms the sloping land to terraced land. The nitrogen-fixing hedgerows lining the terrace help improve soil fertility through nitrogen fixation at the roots and incorporation of the hedgerow trimmings into the soil. The hedgerows both markedly reduce soil erosion and contribute to improving and/or maintaining soil fertility. The technology was developed by the Mindanao Baptist Rural Life Centre, internationally known by the name of its sister affiliate Asian Rural Life Development Foundation (ARLDF), on a marginal site in Kinua Kusan, Mindanao Island, in the Philippines.
SALT has been studied in considerable detail at the Godavari site. The aim was first to determine whether this method, originally developed for tropical areas, could be used in the cooler climate of the HKH mid hills, and second to discover the optimum conditions for establishment and use of nitrogen-fixing hedgerows. Detailed investigations have been made of the impact of SALT on soil erosion, water runoff, and soil fertility; the conditions for establishment; appropriate nitrogen-fixing hedgerow species for mid-hill areas; crop/hedgerow combinations; and potential competition between crops and hedgerows. SALT offers a potentially very valuable method for controlling soil erosion and increasing soil fertility in the HKH mid-hills. It can be established on farmland slopes with gradients ranging from 5 to 25 per cent or more. Various SALT plots are demonstrated at different locations in the Godavari site, and training in the technique has been and is offered at regular intervals.