The study attempted to attain the following objective: To evaluate the soil fertility management practices in marginal soils at Bulusukan, San Ildefonso, Bulacan. Specifically, the study assessed the soil fertility management practices of BSWM-JICA techno-demo farms in the following areas of concern: a) phosphorus fertility b) nutrients dynamics c) optimal use of organic and inorganic materials d) interaction between microorganisms and plants. Results of the study show that the low fertility and productivity of marginal land can be improved by using appropriate soil fertility management practices. The soil phosphorus problem can be alleviated by using inorganic fertilizer like superphosphate. The loss of macronutrients like nitrogen and potassium through leaching can be reduced by using organic fertilizer alone or in combination with inorganic fertilizer. The use of organic fertilizers in combination with organic fertilizers can also significantly increase the kernel yield of corn. Microorganisms like rhizobia used as inoculants can increase peanut dry matter yield, pod and seed weight especially in combination with soil ameliorants like rice hull and lime. Treatments with the higher application of phosphorus produced the highest yield.
