Biomass production of Moringa oleifera as affected by N, P, and K fertilization

Abstract

Moringa (Moringa oleifera Lam.) is a high value, multiuse tree species in tropical and subtropical regions. The objective of this study was to evaluate the effect of different levels of N, P, and K fertilizations on the biomass yield of moringa. Five levels of N (0 to 2200 kg ha⁻¹) were tested either with a fixed N:P:K ratio of 2:1:1, or tested in factorial combination with two levels of P (0 and 290 kg ha⁻¹) and three levels of K (0, 290, and 580 kg ha⁻¹). The biomass yield showed a quadruple increase with the N fertilization levels (R² = 0.96 and 0.62 for fixed and factorial combination of N, P and K, respectively; P < 0.001). In the factorial experiment, N, P, and K fertilizations each had significant effects on the biomass yield with an interaction effect between N and P. The highest biomass occurred at 290 kg P and K ha⁻¹. The maximum biomass yield was achieved from applying N at 1425 kg ha⁻¹. The actual timing of the N application requires further study based on uptake and soil conditions. At the high N rates, available P at 25 ppm appeared to be sufficient in this study. The critical level of tissue N content was 2.75%. Marginal increase in biomass could be achieved with extra inputs of N, P, and K above the sufficient levels. However, the feasibility of maximizing N, P, and K is questionable based on the economic and environmental assessments.

Keywords:

• Benzoil tree
• drumstick tree
• horseradish tree
• soil fertility
• woody forage

Additional information

Funding

This work was funded by the Forestry Technology Innovation Program from the Department of Forestry of Guangdong Province (2018KJCX001) and Guangzhou Science Technology and Innovation Commission (201707010462).