DEVELOPMENT OF NUTRIENT MANAGEMENT TECHNOLOGY TO ENHANCE SWEET TAMARIND PRODUCTION EFFICIENCY IN UTTARADIT PROVINCE

Abstract

The objectives of this study were to develop optimal nutrient management for sweet tamarind by using chemical fertilizers combined with biofertilizers, and examine the return on investment costs using chemical fertilizers in combination with biofertilizers. The experiment was conducted using a randomized complete block design (RCBD) with four treatments and five replications of 2 plants each. Treatments 2–4 were set to provide all-year nutrient rates of 0.8-0.4-1.2 kg N-P₂O₅-K₂O per tree. For Treatment 1, fertilizer and soil amendments were applied according to the farmers' conventional practices. For Treatment 2, Chemical fertilizers were applied at the specified rates. For Treatment 3, Chemical fertilizers at the specified rates and phosphate-solubilizing biofertilizers were applied at 500 g/tree. For Treatment 4, Chemical fertilizers at the specified rates and manure (cow dung at 20 kg/tree) and phosphate-solubilizing biofertilizers were applied at 500 g/tree. The experiments were conducted in farmers' sweet tamarind fields in Fak Tha District, Uttaradit Province, from October 2022 to September 2023.The result showed that Treatment 4 produced the highest yield at 554 kg/rai, with the highest pulp weight of 450 g. and the highest average pod weight of 30.30 g. Regarding the Benefit-Cost Ratio (BCR), Treatment 3 yielded the highest return on investment at 3.05. Farmers could adopt the tested technologies to improve their practices effectively which could lead to the development of nutrient management knowledge for sweet tamarind cultivation in Fak Tha District. Collaborative learning emerged alongside the development of product quality, transforming the community into a source of high-quality sweet tamarind. This also created a positive image for Uttaradit Province.