ASSESSING SOIL CHARACTERISTICS AND GUAVA ORCHARD PRODUCTIVITY AS INFLUENCED BY ORGANIC AND INORGANIC SUBSTRATES

Abstract

Guava cultivation in subtropical region of India is mainly confined to marginal lands under rainfed conditions resulting in low productivity and poor fruit quality. Restoration of the soil quality of such guava orchards with low soil fertility is one of the important aspects for enhancing orchard productivity and sustainability as millions of farmers are engaged in guava production for their livelihood and nutritional security. Keeping this in view, effects of organic and inorganic substrates on soil characteristic and guava orchard productivity were studied through field experimentations during 2007- 12. Different combinations of organic (FYM, vermicompost, mulching, Azotobacter, PSM and Trichoderma harzianum) and inorganic (N, P, K) substrates were applied each year within the tree basin under subtropical environmental condition. At the end of the study, soils fertilized with vermicompost, biofertilizers and organic mulching showed improvement in yield as compared to NPK+ FYM application. Higher soil moisture retention, soil fertility and organic carbon build up and better soil temperature regulation was observed under mulching treatment. Microbial population and dehydrogenase activity were significantly higher in plots treated with vermicompost, microbial inoculants and mulching as compared to NPK+FYM application. The highest pooled data of dehydrogenase activity (3.1µgTPFg-1h -1) was recorded in the treatment receiving 10 kg vermicompost which was superior over application of 5 kg FYM + 5 kg vermicompost or 10 kg FYM. The correlation studies revealed positive and significant relationship among the soil factors and yield. Highest correlation was observed between yield and microbial populations (r = 0.93 * to 0.97 * * ). Dehydrogenase activity was also positively correlated with the soil organic carbon content (r = 0.99 * * ), soil moisture (r =0.99 * * ), soil temperature (r = 0.95 * ) and soil nutrients (r = 0.91 * to 0.97 * * ).