Spatial arrangement and harvesting schedule in a silvipastoral system

Abstract

An experiment was conducted in the Social Forestry Plantation located at Viyoor, near Trichur from August 1987 to June 1988 to evaluate different spatical arrangements and harvesting schedules in a silvipastoral system. The crop components were subabul and guinea grass. The experiment, replicated thrice, was laid out in a factorial RBD with twenty treatments, involving five spatial arrangements and four harvesting schedules. The results revealed that subabul – guinea grass intercrop gave higher green fodder yields during the summer season compared to a sole crop of either species. Dry matter yields of 1.83 T and 9.36 T/ha/year were obtained from subabul and guinea grass, respectively. The spatical arrangement in which subabul was planted at 1.5 x 1.5 m spacing with five rows of guinea grass between two adjacent rows of subabul and the harvesting schedules in which subabul was harvested every second month and guinea grass 15 days earlier or later recorded higher green fodder yields. Percentage rate of increase in height of grass decreased with increasing light intensity, while tillering rate increased. Light intensity received during the experimental period steadily increased and the maximum lux readings were obtained between 12.20 and 14.20 MST. Soil chemical analysis conducted before and after the experimental period indicated that the organic carbon, available N and soil pH of the intercropped treatments increased significantly. This proved the soil ameliorating properties of subabul.