| Abstract | Land spreading of crude oil-coconut husk and waste oil-coconut husk mixture at 2.0, 4.0, 6.0 kg/~ application rate each under 0-0-0, 30-40-30 and 60-70-60 NPK levels, was conducted over a 5-month period. Soybeans were planted in all treated plots to determine the physical and chemical
effects of the treatment on a typical plant. Nitrogen, carbon, organic matter, phosphorus, potassium, sulfate, alkali metals, alkali-earth and heavy metals were determined in the soil and partly in the plant tissues, the former at half monthly frequency and the latter at the end of each
month of a three-month period.
Results of the investigations indicate that oil-sorbent degradation can proceed under the conditions imposed, the degree of waste decomposition
being influenced largely by the amount of fertilizer applied into the soil. Within the range 0-0-0 to 60-70-60 NPK application rates, soybeans respond favorably to crude oil-husk dose of from 2.0 to 4.0 kg/m2 while
at the same NPK levels, negative response was observed at waste oil-husk application rates of 2.0, 4 .0 and 6.0 kg/m2.
Correlation analysis for crude oil-husk treatments gave no single
fixed correlation ship with soybean response but a pooled correlation coefficient of -0.407 was obtained for waste oil-husk treatments at the three levels of NPK application considered.
Due to oil-husk treatment, soybean growth was stunted. Translocation of heavy metals in plant tissues was observed and the amount of these metals assimilated by t he plants depended on the type of oil and the oil husk dose. However, the content of these elements in the edible tissues of the plants was way below the established acceptablished limits . |