Mulch effects of a seedless Leucaena Hawaiian hybrid on growth and productivity of okra (Abelmoschus esculentus [L.] Moench) in pots

Leucaena spp. ( Leucaena ) may be pruned and the biomass applied to the soil to improve soil quality in crop production. This pruned biomass may improve soil water retention and contribute plant nutrients as it decomposes. However, traditional seeded Leucaena accessions and cultivars can become invasive weeds. Leucaena cv. “KX4-Hawaii” is a seedless interspecific cultivar that cannot become invasive, but no studies have used its biomass as a soil amendment. A full factorial pot study was conducted in 2020 to evaluate combinations of Leucaena leaf mulch (0, 100, 200, 300, 400g) and repeated applications of 20-20-20 NPK synthetic fertilizer (0, 2.5, 5g) to promote the growth and yield of okra ( Abelmoschus esculentus [L.], Moench ) and to investigate its soil effects during growth. “KX4-Hawaii” mulch treatments increased okra pod yield and vegetative biomass production by up to 22 and 21%, respectively. Mineralization of nutrients from the mulch appeared to be slow and most recorded variables only responded to synthetic fertilizer. The highest mulch application also increased soil CO 2 respiration by 91.5% (an indicator of soil health and microbial activity), as determined by a Solvita ® lab test.