Maximizing yield with novel Napier grass breed for tropical region: A case study of Thailand

Growing environmental concerns caused by fossil fuel power plants have increased the interest in agricultural biomass for energy production. Among energy crops, Napier grass ( Pennisetum purpureum ) has gained attention due to its rapid growth and high biomass yield. This study explored the potential of four Napier grass cultivars— Dwarf, Pak Chong 1, Bana, and Suvarnabhumi—grown in southern Thailand by comparing fertilization strategies and harvest intervals (60, 90, and 120 days). Using a split-plot design in a randomized complete block design (RCBD), the study examined the effects of fertilization, cultivar, and harvest interval on both soil health and biomass yield. The one-year trial presented remarkable improvements in soil quality, including reduced bulk density and increased levels of organic matter and plant nutrients, especially in the fertilized plots. These results demonstrate the dual potential of Napier grass as a bioenergy crop and as a tool for soil rehabilitation. Among the cultivars studied, Suvarnabhumi, when fertilized and harvested at 60-day, produced the highest fresh biomass yield of 139,744 kg/ha. Its high productivity makes it exceptionally suitable for sandy loam soils. The findings position Napier grass as a sustainable and efficient bioenergy source that also improves soil health, contributing to the global transition towards alternative energy and agricultural sustainability. • Napier grass is a potent dual-purpose crop, providing sustainable bioenergy and soil rehabilitation, especially in sandy loam soils. • Napier grass emerges as a key player in alternative energy production, aligning with global efforts to reduce reliance on fossil fuels. • Napier grass cultivation combined with fertilization NPK (15–15–15) and urea significantly improves soil quality. • Strategic fertilization and harvest intervals boost plant height, stem diameter, shoot count, and biomass yield across all Napier grass species. • Suvarnabhumi, a new species of Thailand, outperforms others with optimum fertilization and every 60-day harvest.