Changes in the Chemical and Physical Soil Conditions of a Marginal Land Planted with Three Strata Forage System under Three Years of Grazing

This study was conducted to evaluate the changes in the chemical and physical conditions of marginal planted with three strata forage system (TSFS) during three years of grazing period. A-3.2ha of marginal land was divided into eight plots (each plot was 40m×100m), then four plots were planted with TSFS and other four plots were planted with native grasses (Control:C). Eight head of male Bali cattle (average body weight 150kg) grazed continuously in the experimental land (1 cattle/plot). The experiment was carried out for three consecutive years (1992-1995). Results of this study indicated that at the end of the third year, the physical chemical conditions of the soil planted with TSTF were better than the C. Sand percentage in the soil of the TSFS was less than that of the C (71.81 versus 77.86%). Total-N, total-P and total-K contents of the TSFS were higher than those of the C (0.27 versus 0.20%, 224.07 versus 114.34ppm, 6.89 versus 5.79ppm). Similarly, top soil of the TSFS was thicker than that of the C (17.86 versus 9.53cm), and water run off the TSFS was slower than that of the C (19.88 versus 34.88mm/h). However, soil pH, P Bray and infiltration rate were not singificantly different (P>0.05) between the TSFS and the C(6.81 versus 6.78; 16.43 versus 17.01ppm, and 1.55 versus 1.40mm/h, respectively). Results also revealed that the experimental period affected soil pH, total-N, infiltaration rate, top soil, and water run off in the TSFS and the C, but the effects among the periods were not persistent. Analysis also showed that there was no interaction between the planting system (TSFS and C) and the growing periods