Pemanfaatan Campuran Limbah Padat (Sludge) Industri Benang Karet dengan Tanah Gambut sebagai Pupuk Tanaman Kedelai (Glycine max (L) Merrill)

Abstract

The aim of this research is to use sludge of rubber thread industry with peat soil as fertilizer for soybean.

This exsperiment be hold at Rumah Kasa Pusat Penelitian Perkebunan Karet Sei Putih, in the elevation about 55 m on above sea level. This research be hold since March 1998 up to August 1998.

This research use the factorial group random sampling with three factors. The first factor is the mixture of sludge and peat that consist of four level, namely: 0; 100; 200; 300 and 400 g sludge-peat mixture per 10 kg soil as G0, G1, G2, G3 and G4. The second factor is the application time that consist of three level, namely: As time as cultivation, 1 week before cultivation and 2 weeks before cultivation as W0, W1, and W2, respectivelly. The thrid factor is fertilizer application that consist of two level, namely: without basic fertilizer and with the basic fertilizer as Do and D1, respectivelly.

The result of research indicate that the utilization of mixture of sludge of rubber thread with peat and turn them into compost can increase the soil pH, and available of N and P on the soil. The changeable calium on the soil will increase by the utilization of sludge-peat mixture, G, compared to the control.

The utilization of sludge-peat mixture will increase the dry-weight of soybean on the age of 3 BTS and the production per polybag up to the level of G1 (100 g/10 kg Soil), but it’s production will decrease up to the higher dosage G4 (400 g/10 kg Soil).

The early application time of sludge-peat mixture will increase the Soil pH, availability of N and P on the Soil. The content of N, P, K and soil pH will increase by the utilization of basic fertilizer.

The application time has not a significant effect to the dry weight on the age of one, two and three month after cultivation and to the production of soybean but there are thrend that utilization of mixture in a long time befor cultivation will provide the good result.

Based on the preliminary research, the other research be encourage to continue this research with the early time application of sludge. The results of this research indicate that the sludge can be used as fertilizer with appropriate dosage and time application. It can be used as organic resource for agricultural plants.