EFFECT OF CORNCOB COMPOST ON PLANT-GROWTH IN AN ACID RED SOIL

A comparison of corncob compost with lime on plant growth was studied in acid red soil with pH of 4.07. Lettuce, pea, and corn were selected as test plants for their varying tolerance to acid soil. The pot expe riment compared six soil treatments and a check. Soil amendments were 1, 2, and 4 cmol calcium carbonate (CaCO3) kg(-1) and 5, 10, and 20 g corncob compost kg(-1) soil. Results showed higher manganese (Mn) than aluminum (Al) content of the shoot in all check group plants. Reduced shoot Mn content increased shoot dry weight in all test plants, regar dless of acid soil tolerance or soil treatment. The higher the test pl ant resistance to soil acidity, the weaker the detoxification effect o f corncob compost was on Al uptake when compared with the check group. Liming was more effective at reducing shoot Mn content than corncob c ompost with the exception of the more acidity sensitive lettuce. Shoot phosphorus (P) content, however, increased with corncob compost from enhanced organic matter rates. Corncob compost treatments significantl y increased shoot dry weight over liming in the acid soil. This study demonstrated an environmentally acceptable use for an agricultural was te.