Abstract
Corn steep liquor (CSL) is an industrial waste from corn starch factories. It is a browncolored viscous liquid, which contains many kinds of organic materials and about 3% each of N, P2O5 and K2O. We examined the use of CSL as a liquid fertilizer. Calcium should be supplemented, because its calcium content is not enough for vegetable production. Tomato growth was possible through the application of the immature organic material but only if it was applied in small amounts frequently, within the decomposition ability of the soil. When CSL was applied in appropriate concentrations, plants grew normally : Shoot weight was about 80%, but the root weight was similar to inorganic liquid fertilizer application. Liquid fertilizer caused the change of root distribution : Both types of liquid fertilizer made the roots shallower than the basal dressing in the whole layer of the soil. This caused more water uptake in the surface layer of plant cultivated by liquid fertilizer. Organic liquid fertilizer made the root thicker than that of inorganic fertilizer. Liquid fertilizer application method is effective to reduce residual ions, especially for sulfate, calcium and magnesium, from the soil.
