Agroforestry for increasing farm productivity in water-stressed ecologies

Abstract

Water-scarcity is increasing in many countries, and more regions are moving into increasing water-stressed conditions. According to an estimate, about 4500 km3 year-1 more water will be needed to feed the world population in 2050 at current crop water productivity levels. There is little scope to increase food production by increasing the area under cultivation. Hence, there is a need to devise such production systems that can produce food from marginal agricultural land and is also capable of maintaining and improving quality of soil and environment. This can be achieved through agroforestry. In India, the current area under agroforestry is estimated as 25.32 million hectares (m ha). There is further scope of increasing the area under agroforestry by another 28.0 m ha in the future. Thus, a total of 53.32 m ha area of the country could potentially be brought under agroforestry in the near future, which will make agroforestry a major land use activity, after agriculture (140.86 m ha) and forestry (69.63 m ha). There is substantial experimental evidence to support the hypothesis that agroforestry may increase productivity by making better use of available resources. Significant complementarities of water use may occur naturally if trees with suitable leafing phenology or rooting architecture are used in agroforestry systems. To achieve this, the trees and crops must capture a greater proportion of the available resources and use them more efficiently to produce dry matter than equivalent sole stands. A number of technologies with suitable tree and crop combinations have been identified for different agroecological zones of the country. These technologies provide options for improving livelihood, environmental and energy security. This paper describes the promising agroforestry systems to achieve higher productivity in water-stressed ecologies.