GROWTH AND YIELD FOR VARIOUS USES OF EUCALYPTUS CAMALDULENSIS DEHNH. PLANTED IN AN AGROFORESTRY SYSTEM ON THE DEGRADED LAND

Abstract

This study was conducted at Somdet district, Kalasin province where the degraded land was a lowland shifting cultivation for a continuous cropping of cassava for about 12 years. The land was subjected to various soil treatments included; plowing, fertilization (compost and chemical fertilizer), intercropping with some agronomic crops, mixed planting with some leguminous tree species and Eucalyptus camaldulensis Dehnh. was grown as a test tree species. Growth and yield of trees and crops were monitored for about 5 years. The study showed that satisfactory results of growth and yield of E. camaldulensis were obtained and it' s yield could be used for various purposes in forms of chipwood, wood for charcoal and firewood making and large amount of tree and crop residues from both monocropping and intercropping plots (residues of groundnut and sorghum included). Crop yields in the intercropping plots were comparatively lower than in the monocropping plots with different soil treatments but the total production and uses of tree and crops especially the groundnut and E. camaldulensis were promising. The study was also attempted to relate the yield of both plants aiming to explain the interspecific competitive interactions and explore some adverse effects of this kind of tree on crop. The results revealed that the significantly reduced yield of crop was mainly due to the increasing yield of tree and no particular adverse effect was observed