J. Sci. Agri. Technol. (2022) Vol. 3 (1): 25-29
DOI: https://doi.org/10.14456/jsat.2022.5
Abstract
A study on the effects of leonardite and nutrient management on growth and yield of cowpea (Cigna unguiculata L. Walp.) was established in the greenhouse from July to October 2021 at the Agricultural Technology Research Institute, Rajamangala University of Technology Lanna, Lampang, Thailand. The experimental design was a completely randomized design (CRD) with nine treatments and ten replications: (1) control, (2) 500 kg/rai leonardite, (3) 1,000 kg/rai leonardite, (4) 500 kg/rai leonardite + 100% chemical fertilizer based on soil analysis, (5) 1,000 kg/rai leonardite + 100% chemical fertilizer based on soil analysis, (6) 500 kg/rai leonardite + 75% chemical fertilizer based on soil analysis, (7) 1,000 kg/rai leonardite + 75% chemical fertilizer based on soil analysis, (8) 100% chemical fertilizer based on soil analysis and (9) 75% chemical fertilizer based on soil analysis. The result showed that the combination of leonardite with chemical fertilizers based on soil analysis affected the vegetative growth and yield of cowpea. The application of 500 kg/rai of leonardite in combination with 100% chemical fertilizer based on soil analysis gave the highest plant height, canopy width, stem diameter, leaf width, leaf length, leaf greenness (SPAD), fresh weight, and dry weight of pod per plant. Therefore, applying leonardite with chemical fertilizers based on soil analysis could enhance cowpea growth and yield.
Keywords: leonardite, nutrient management, cowpea
Received: December 25, 2021. Revised: April 19, 2022. Accepted: May 5, 2022.
