AGROFORESTRY FOR SOIL AND WATER CONSERVATION IN THE WESTERN HIMALAYANVALLEY REGION OF INDIA 2 - CROP AND TREE PRODUCTION

A ten-year-study (1983 to 1992) conducted on nine 15 x 90 m runoff plo ts at 4% slope compared production efficiency of Leucaena leucocephala and Eucalyptus hybrid based agroforestry as well as monocropping land use systems in the warm, subhumid climate of the western Himalayan reg ion of India. Treatments for the first sequence were: monocropping sys tems of leucaena, eucalyptus, Chrysopogon fulvus grass and maize - whe at rotation, and alley cropping systems of grass and crops at 4.5 and 10.5 m alley widths with paired contour tree rows of leucaena and euca lyptus. In the second sequence, alley width increased to 22.5 m in 198 9, grass was replaced by turmeric Curcuma longa and paired contour row s of leucaena hedges were introduced in monocropping systems of grain crops and turmeric. Integration of leucaena and eucalyptus trees with crops caused severe reduction of crop yields ranging from 21 to 92% fo r wheat grain, 59 to 69% for maize grain, 60 to 67% for dry grass and about 50% for turmeric rhizome depending upon the age of trees and all ey width. The grain yield of crops stabilized at about 50% reduction w ith 22.5 m alley width. Total crop biomass (grain + straw) also reveal ed a similar trend; however, its magnitude of reduction was less sever e than for grain. Production of biomass was much lower near the tree r ows than in mid alleys. Managing leucaena as contour hedgerows elimina ted crop yield reduction in alleys. Performance of grass and turmeric in alleys was not found to be satisfactory. Biomass produced from tree s adequately compensated the crop yield reduction. Land equivalent rat ios of agroforestry landuses were comparable or even better than monoc ropping systems indicating suitability of these systems for the wester n Himalayan valley region.