Shelterbelts: A sustainable strategy to improve farm incomes in arid regions

Abstract

Technologies which help make cropping more feasible and the landscape more manageable, especially in difficult terrains like the arid zones, are always of great importance in ecological and economic viewpoint. Shelterbelt plantations with single or multiple tree and/or shrub combinations are known to be one of the biggest ecofriendly technologies to address wind erosion, sand dune stabilization and related problems in the arid areas, which cover 12% of India and more than half of Rajasthan. Shelterbelts, when planted on field boundaries, across the wind direction, are observed to support agricultural production, by lowering air and soil temperature and fertile topsoil erosion, increasing humidity and organic carbon, and improving diversity of soil microorganisms. Selection of tree species is also an important criterion, with preference presently given to fast growing species with economical use. A survey was undertaken to study the established shelterbelts in farmers’ fields in the hyper-arid district of Bikaner. It was noted that most shelterbelts were planted along farm boundary, both in single and double rows; as well as along irrigation channels. Though old shelterbelts were mainly of Acacia tortilis, farmers now prefer Dalbergia sissoo (47% prevalence), since it does not hinder crop growth and for its economic timber value. Other species like Eucalyptus sp., A. nilotica, Ziziphus mauritiana, Cordia myxa, A.senegal were also observed. Among the observed timber yielding trees, wood volume calculated on the basis of tree height and DBH was also the highest in D.sissoo, ranging from 0.027-1.926 m3 tree-1 in 4-20 year old plantations. Species like shisham, ber, eucalyptus, gonda etc. when used as shelterbelts serve dual purpose of sustaining crop production and provision of fruits and timber which provide additional income to farmers; without occupying much productive area.