Developing optimum level of soil nutrient management for maize in conservation agriculture production system (CAPS)

Maie is the main staple crop in the conservation agriculture production system in this acid upland soil where it is traditionally grown twice a year. Appropriate fertility management is important so that optimum yield and profit can be achieved particularly for smallholder upland farmers cultivating acid soils in the Philippines as well as in Southeast Asia in which environment dominates most of the non-irrigated areas. Identifying the most limiting nutrients and the optimum rates of their application are important for fertility management particularly in conservation agriculture production systems. In order to achieve this objective, we conducted an NPK omission experiment in two different planting spacing and this was followed by experiments on the different rates of NPK.