Take this from researchers of the Pampanga Agricultural College (PAC) in Mt. Arayat, Magalang who conducted a study titled "Enhancing the Fertility and Productivity of Lahar-Deposit Areas Using Agro-Industrial Waste."
Done by V. M. Gonzales, N.G. de Jesus, J.V. Bagunu, E.A. Calumpit, E. Gonzales, E. Pangilinan, and R. Basa, the study was funded by the Commission on Higher Education (CHED) and monitored by the Los Baños-based Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD).
The plot experiment was done at San Martin, Concepcion, Tarlac.
As reported by Ofelia Domingo of PCARRD, the pig waste effluent was applied 27 days after transplanting (DAT) tomato seedlings (Apollo variety). Inorganic nitrogen was applied in two split doses (at 14 and 30 DAT).
The amount of fertilizer applied was 90-kilogram nitrogen (N), 60-kg phosphorus (P), and 30-kg potassium (K), based on soil analysis.
The experimental crop was grown without irrigation.
Results showed that by applying a combination of 60-kg nitrogen from inorganic fertilizer and 60-kg N from pig waste effluent, yield of tomato increased by 32 percent over that of full dose application of inorganic NPK.
Analysis of the nutrient composition of the pig waste slurry indicated that it has a high concentration of phosphorus and other micronutrients such as zinc, copper, manganese, and iron.
"These nutrients are essential for a healthy soil and healthy plant," the researchers said. – Rudy A. Fernandez