Cord Integrated Soil Fertility Management (ISFM) On Coconut + Lanzones (Lansium Domesticum Corr) Agro-ecosystem In Southern Mindanao, Philippines (1993 – 2007): With Emphasis On The Multi-nutrient Coconut-Specific Mineral Fert
A 15-year (1993-2007) integrated soil fertility management (ISFM) of coconut + lanzones fruit agro-ecosystem was conducted using five fertilizer combinations (FCs) in a dominantly tropical wet climate (Koppen-Geiger Climate Classification Kottek et al 2006) of Davao, Southern Mindanao (07o05’N 125o37’E), It aimed to determine the response of this agro-ecosystem to the combined multi-nutrient fertilizer N+P+K+Cl+S+B (14-5-20-0.02B-15.5Cl-4.5S) and organic fertilizer (OF) sources at different ratios (IF:OF at 1:0;1:2; 2:4 and 4:4) on coconut yield, lanzones growth, yield and fruit quality; soil properties; leaf nutrient levels; total farm productivity and profitability.
The application of even the lowest rate of the multi-nutrient mineral fertilizer (MNF) at 1 kg/tree/yr produced an appreciable improvement in annual nut and copra yields per ha, from benchmark 8,890 nuts or 1.6 t to levels 3 - 4 t copra after 1-2 years of MNF applications. The average sustained yields of 17,000 nuts or 4 t copra per ha/yr was achieved over the next 12 years at this low MNF input. Application of the combined MNF and OF enhanced lanzones fruiting. Except in 2004, fruit harvest increased from year 8 to year 14 with FC1 and FC2 producing higher yields, and quality of fruits (sweetness, brix reading) improved at lower rates of MNF (0.38kg/tree) and organic fertilizers. The ISFM of the agro-ecosystem is productive and sustainable even at low input of the MNF developed for coconut capable of generating large volume of biomass for a stable soil fertility.
Overall, the profitability indices as benefit-cost ratio (BCR) and internal rate of return (IRR) showed that the best fertilizer application for both crops was FC1------the lowest annual rate of MNF (coconut@ 1kg/tree and lanzones @ 0.38/tree), without organic fertilizer application. At 18% interest, the FC1 has the highest BCR of 2.5, IRR of 328% and NPV of PhP115,645 per ha. A fertilization guide for the coconut + lanzones agro-ecosystem is presented based on this long-term research work. (1USD = 45PHP)
