Growth and nutritional responses of sesbania sesban (L) merr to rock phosphate, biofertilizer and rhizobial applications

Abstract

Continuous crop cultivation without adequate fertilizer input has led to poor yields and soil degradation in the tropics. To restore soil fertility through agroforestry practices, N2-fixing tree fallows are planted to produce nutrient-rich biomass that is incorporated in soils. The quantity and quality of biomass produced can be improved by phosphorus fertilization, inoculation with rhizobia or use ofbiofertilizers. My study examined the effects of rhizobial inoculation, biofertilizer and rock phosphate applications and their interactions on growth and nutrition of S. sesban planted in potted acidic soils of western Kenya. Rhizobial inoculation improved nodulation only when rock phosphate was added. Although biofertilizer failed to stimulate root nodulation, it enhanced plant nutrient absorption. Fertilization with rock phosphate enhanced growth and nutrition of S. sesban most and is recommended for use in agroforestry. There was a small but significant beneficial interaction between rock phosphate and biofertilizer use on Sesbania growth and nutrition.