| Two studies were conducted to determine the technical and financial feasibility of agroforestry systems in Punjab, Pakistan. One study was on cultivated land and examined the effects of single row, 6 to 7;In the shelterbelt study, photosynthetically active radiation (PAR) was the variable most strongly correlated with production of wheat (r = 0.67) and sorghum (r = 0.89). Wheat yield was least within 1 m of the trees and increased as distance from the trees increased up to 5 m. Beyond 5 m there was no significant difference in yield. Wheat production was greater adjacent to B. ceiba than E. camaldulensis. There was no significant difference in wheat yield between year six and seven, but the seventh year yield was consistently lower than the sixth. The benefit cost ratio (B:C) and net present value (NPV) were greater in all agroforestry treatments than the agronomic monoculture and they were greater in narrow tree row spacing than wider row spacing.;In the block plantation study, E. camaldulensis had a greater bole length and girth in the mixed plantations, possibly because of the greater availability of nitrogen associated with the presence of the leguminous A. nilotica. All three treatments had a very attractive B:C, NPV and internal rate of return; the mixed plantation had a greater return than the monocultures. Organic matter, N, P, and K increased and Na, SAR, pH, EC, and bulk density decreased in the soils under the trees compared to fallow plots. |
