Environmental assessment of farm household wastewater for vegetable production in Maria Paz, Tanauan City, Batangas, Philippines

Environmental assessment on the potentials of using farm household wastewater for irrigating radish crop was conducted for two croppings in Maria Paz, Tanauan City, Philippines to address the scarcity of water for irrigation during the dry season. Maria Paz is an upland Conservation Farming Village, which is located within the Taal Lake Protected Landscape.The wastewaters were obtained from two most common water-consuming household chores in the area, laundrying, and cleaning of pigpens and bathing of the swine. The field experiment consisted of nine treatments that include types of irrigation water, combination of the two kinds of wastewater, and varied concentration of mixed wastewater and methods of irrigation. The farm household wastewaters are potential sources of irrigation for radish. The yields of radish irrigated with domestic water and the wastewaters were not significantly different. The nutrient contents of the roots, leaves, and stems were not significantly different among treatments. The nutrient analysis cover N, P, K, Ca, Mg, Na, Zn, Cu, Fe, Mn, Pb, and SO4. Wastewater irrigation had no significant effect on soil chemical environment and earthworm population. The levels of elements (Na, Ca, NH4-N, N03, B, P, K, Mg, Cl, Pb, and Cd) in the soil declined one month after the harvest of the second cropping at the onset of the rainy season. The analyses of these were done in accordance with the DENR [Department of Environment and Natural Resources] Administrative Order 34 series of 1990. The application of an improvised micro irrigation technique has water application and water use efficiencies of 82% and 78%, respectively, as compared with the conventional handwatering. The use of wastewater for irrigation improved farmers' productivity and income in terms of cost of water saved is P1,500/ha per cropping. The use of the improvised micro irrigation with mixed wastewater increased the saving to P2,200/ha per cropping. This advantage contributed to social acceptability of the technology to the farmers of Barangay [village] Maria Paz.