Optimum potassium fertilizer rate for growth, biomass yield, and fuel properties of Leucaena (Leucaena leucocephala) cv. Tarramba in sandy soil

The results showed that the 187.5, 375 and 750 kg ha-1 application rates increased plant height and stem diameter, while the control (0 kg ha-1) showed a potassium deficit, resulting in stem dieback. High leaf, branch, and stem yield were found at application rates greater than 93.75 kg ha−1, while plant height, stem diameter and biomass yield were slightly further increased in the 187.5, 375 and 750 kg ha-1 treatments. Regarding fuel properties, the potassium application rate did not affect the heating value and ash content but decreased the N and S contents. The potassium content tended to increase with increased potassium application rate. However, the leucaena wood under all the treatments had suitable fuel properties for use as a fuel crop.