Land Application of Food Processing Wastewater Residuals Effect on Dry Matter Yield of Tanner Grass

Finding alternative avenues for disposal of food manufacturing waste has become important in the Caribbean Region due to increasing populations, concerns about environmental pollution, increased growth in the manufacturing sector, as well as limited land availability for disposal. Two field trials were conducted on a mixed loamy isohyperthermic Fluventic Eutropepts in the dry (Trial 1) and wet (Trial 2) seasons to evaluate the effect of adding food processing wastewater residuals on the crop productivity of Tanner grass (Brachiaria arrecta). The wastewater residual was compared to inorganic sources of nitrogen (N) and phosphorus (P) from urea and triple superphosphate, respectively at 0, 50 and 200 kg N/ha and 0, 50 and 100 kg P/ha respectively in a randomized complete block design. In the dry season, the inorganic Ν resulted in a Tanner grass dry matter (DM) yield of 4357 kg/ha, which was significantly (P<0.05) higher than that resulting from the wastewater residual Ν (1835 kg/ha). However, similar yields of 2898 kg/ha and 2610 kg/ha for inorganic Ν and wastewater residual Ν respectively were obtained in the wet season. The wastewater residual applied at 200 kg N/ha with no supplemented Ρ resulted in a higher (P<0.05) DM yield of 2875 kg/ha compared to the yields of 1535 kg/ha from the unfertilized control in the wet season. Tanner grass dry matter yields for both seasons were higher in response to application of the wastewater residual at 50 and 200 kg N/ha versus the unfertilized control. Food processing wastewater residual can be used in pasture production as an organic soil amendment as an alternative to disposal since it is capable of supporting plant growth.