Abstract
The effect of chemical fertilizer and city compost application was evaluated on the biomass of Stylosanthes guianensis on the barren land after a tin mining at the Mine Area Rehabilitation Station, Takuapa, Phang-nga, Thailand. Clayey materials were added to every plot at the ratio of 300 m3 ha-l to prevent plant from mortality and to enhance the nutrient holding capacity. An optimum biomass yield (5.12 t ha-l), which was lower than the maximum yield (6.15 t ha-l) realized through heavy fertilization, was obtained by the application of city compost (6.25 t ha-l) and chemical fertilizer (1.25 t ha-l). The soil fertility was improved at the end of the experiment, through the cultivation of S. guianensis.
The amount of precipitation, soil moisture (at 15 cm in depth) and soil temperature (at 0 and 15 cm in depth) was monitored throughout the experiment. The severe drought and over-wetting conditions reduced the biomass yield of S. guianensis, significantly. The crude fiber and crude protein content in the stems and leaves showed an appropriate amount as food for cattle.
It can be concluded that the cultivation of S. guianensis is one of the promising way of agriculture in Takuapa and very good practice to improve the very low native soil fertility, in combination with the incorporation of clayey materials to diminish the water deficiency problem and to increase the nutrient retention capacity.
