Swine Effluent for Tomato in a Plasticulture Production System

Abstract

Tomato was grown in Fall 1997 with swine effluent or commercial soluble fertilizer in a plasticulture production system. Four cultivars, `Mountain Delight', `Celebrity', `Equinox', and `Sunbeam', were transplanted to raised beds with plastic mulch and drip irrigation. Preplant fertilizer was not applied. Effluent from the Wiley L. Bean Swine Demonstration Unit's secondary lagoon was filtered through in-line screen filters and applied directly to the plants through the irrigation system. Toward the end of each application, sodium hypochlorite was injected in the line to achieve a free chlorine concentration of ≈1%. Clogging of filters or drip emitters did not occur. Control plants received 100 ppm N from soluble fertilizer injected in irrigation lines supplied by a municipal water source. Number and weight of tomatoes from plants receiving swine effluent were equal to that of plants receiving soluble fertilizer. No differences in fruit quality were evident between treatments. Plant dry weight was also equal for three out of four cultivars. No differences in soil characteristics were detected between treatments after the study. Chemical analysis of the effluent showed a pH of 7.8 and nutrient concentrations of ≈110 ppm NH4-N, 57 ppm P2O5, 150 ppm K2O, and trace amounts of Cu and Zn. Though no differences in yield were detected in this study, the effluent's high pH and high NH4-N content need to be managed more closely for commercial tomato production.