Salt Leaching and Growth of Physic Nut (Jatropha curcas L.) on Oxisol under Swine Wastewater Fertigation in Southern Brazil

Abstract

Aims: The objective of this study was to evaluate the effect of a 370 m3 ha-1 application of swine wastewater on the vegetative growth of the physic nut (Jatropha curcas L.) and the leaching of salts from an oxisol in southern Brazil. Study Design: The experiment had a randomized design with three treatments (T1 - rain-fed, T2 - irrigated and T3 - fertigated with swine wastewater) and six replications. Place and Duration of Study: Western Paraná State University, between October 2008 and December 2009. Methodology: The following parameters were evaluated: canopy height, leaf area, basal diameter, number of side branches, the height of the 1st branch and the number of inflorescences and fruits per plant. The electrical conductivity and pH of the percolating water were evaluated following five rainfall events, using nine lysimeters installed prior to the planting of the experimental plots. Results: Significant differences among treatments were observed in plant height (P = .045), and the number of inflorescences (P = .00) and fruits (P = .02). The numbers of inflorescences (5.21) and fruits (9.17) were highest in the SW-fertigated treatment (T3). In relation the concentration of salts, electrical conductivity values were higher for SW-fertigated (0.110-0.154 dS m-1) than either rain-fed (0.087-0.115 dS m-1) or irrigated (0.057-0.075 dS m-1) in all samples. Conclusion: The application of SW resulted in a significant increase in some parameters of J. curcas productivity, and may thus be encouraged as an agricultural reuse practice. However, further studies are required to evaluate the potential environmental pollution caused by this practice.