Fruit-based agroforestry systems for saline water-irrigated semi-arid hyperthermic camborthids soils of north-west India

摘要

Large areas in arid and semi-arid regions remain barren due to lack of irrigation. The underground aquifers in these regions are either saline or sodic. Groundwater surveys indicate that poor-quality water is used to irrigate arable crops in 25-84 % of the total groundwater development areas in north-western states of India. The present long-term study assessed the performance of low-water-requiring, salt-tolerant fruit-based (Carissa carandas, Emblica officinalis, Aegle marmelos) agroforestry systems with saline irrigation under sem-iarid conditions. The companion crops such as Hordeum vulgare for malt, Brassica juncea, a seed oil (winter), and Cyamopsis tetragonoloba for gum and Pennisetum typhoides, a coarse grain/fodder (summer), were grown in inter-row spaces. The fruit trees were successfully established in the sill of furrows using low (EC 4-5 dS m(-1)) salinity water. Subsequently, all the systems were irrigated with water of low and high (8.5-10.0 dS m(-1)) salinity and their alternate use as per treatments. Fruit yields under alternate and high saline irrigation reduced by 18-27.5 % in Carissa, 41.6 % in Emblica and 31.7-54.8 % in Aegle, respectively. There was no significant reduction in grain yields of Pennisetum and Hordeum. However, in subsequent years, the seed yields of Cyamopsis and Brassica reduced with saline water and more so when intercropped with Aegle. Carissa with Pennisetum and Hordeum performed best with saline water. The study shows that saline water (ECiw up to 10 dS m(-1)) could be used sustainably for these fruit-based agroforestry systems without significant salinity build-up in sandy loam calcareous soils. Thus, such fruit-based agroforestry systems could be a viable option for the areas with only saline groundwater available for irrigation.