Decomposition of organic materials in the process of organic fertigation

Abstract

Corn steep liquor (CSL), which is an organic product derived from corn starch factories, contains about 3% each of N, P_2O_5 and K_2O. Attempts were made to use CSL as a sole fertilizer for fertigation of tomato cultivation. The number of aerobic bacteria in the soil of the CSL fertigation plot was ten times higher than that of the plot with basal dressing and fertigation using chemical fertilizers (inorganic fertigation). The activity of the soil enzymes relating to organic matter decomposition, ie. protease, β-glucosidase, α-glucosidase and phosphatase in the CSL plot was higher than that in the plot with basal dressing and inorganic fertigation. The increase of the activity of the bacteria and soil enzymes by CSL application led to the rapid decomposition and mineralization of CSL. The processes involved in organic fertigation were effective in supplying sufficient amount of nutrients for tomato growth, because the yield of tomato grown under CSL application was similar to that of the plants with basal dressing and inorganic fertigation.