UTILIZATION OF INDONESIA NATURAL ZEOLITE IN AGRICULTURE
Suwardi and I. Goto (1996)
Although Indonesia is rich in natural zeolites. The really aplication in agriculture, is still limited in small scale. In an effort to utilize natural zeolites, it is important to do research to match the specific zeolite properties with the specific uses. The most important properties of natural zeolites are cation exchange capacity (CEC) and capability to capture ammonium ion. These properties might be exploited for many utilization including agriculture. The objectives of these experiments were to evaluate the possibility of utilization natural zeolites for carrier of slow-realese fertilizer and growth media of horticultural plants. Powdered zeolites were mixed with N fertilizerof diammonium hydrogen phosphate (DAP) with the amount equivalent to 0,3,5,7,0 and 10,5 t ha-1. The mixture of zeolites and DAP were applied to paddy soil for growing rice plant. Zeolites were also used forgrowth media, so called “zeolite-growth media” by mixing with peat and feretilizer in different compositions. The quality of zeolite-growth media was evaluated from chemical properties and growth of tomato plant. The results showed that addition of zeolites 3,5 t ha-1 to DAP increased the rice yield 3-28% due to increasing the panicle number. Slow-release action of zeolites increased the efficiency of N fertilizer. Zeolite-growth media composed of zeolites and peat with the proportion of 1:1 have favorable chemical properties and gave the best growth of tomato plant.