Developing Conservation Agriculture Production Systems for Sloping Acid Upland in the Philippines.

Degraded landscapes are expanding rapidly in the Philippines. Agricultural productivity is decreased which in turn heightens food insecurity and exacerbates poverty particularly on the sloping acid uplands which soils are inherently poor. Through conservation agriculture (CA) principles and practices of minimal soil disturbance, continuous mulching and diverse species rotations, constitute the best ‘tool box’ to create sustainable permanent cropping systems for annual crop production for sloping tropical uplands. These practices reverse soil degradation, increase crop yield and profits and reduce the labor burden on women.    Researchers-managed and farmer-managed conservation agriculture production systems (CAPS) were evaluated across the landscape of   Claveria, Philippines including crops and soil fertility management component researches. We found out that cassava (Manihot esculenta) + Stylosanthes guianensis yielded the highest biomass and total sales followed by  maize-maize system which yielded better compared with other maize based CAPS. Interplanting maize either with cowpea or ricebean did not give better total grain and biomass yield, but provided higher sales due to relatively better price of beans. Interplanting of maize with cowpea and relayed with upland rice insured food and nutritional security to smallholders by shortening harvest periods to 60 days and increasing harvest cycles.   Stylosanthes grown with cassava and maize yielded significantly better than Arachis pintoi than grown with maize. We found out the limiting nutrients were nitrogen (N) > phosphorus (P) > Potassium (K). Omitting N application reduced maize yield by 67%, P by 59% and 21% without K application. Optimum rate of NPK application for maize was 120-20-0, but maintenance K of 17 kg/ha was necessary.  Promising varieties of maize, upland rice, cowpea, forage grasses, forage legumes, sweet potato, cassava, sorghum including “adlai” (Job’s tears) were identified out-yielding locally grown varieties in economic and biomass yield which are suitable for CAPS. Our research results can be extrapolated to other upland areas in the Philippines as well as other areas in Southeast Asia as Claveria represents the bio-physical and socio-economic environment of these areas