Adubação NPK na produtividade de folhas de Moringa oleifera em três anos de cultivo em São João Evangelista - MG

Moringa oleifera Lam., known as the “Tree of Life,” is a species of significant interest due to its various nutritional applications. It exhibits a high protein content and provides vitamins A, B, and C, in addition to essential minerals (iron, calcium, phosphorus, potassium, and zinc). The species also possesses medicinal qualities since its leaves contain flavonoids with anti-inflammatory properties. Its adaptability to different climates, drought resistance, and high regrowth capacity make it a promising crop for economic exploitation in various regions, including Brazil. This study aimed to evaluate the impact of nitrogen (N), phosphorus (P), and potassium (K) fertilization on the leaf productivity of Moringa oleifera over three years of cultivation in a semi-intensive system at the experimental farm of the Federal Institute of Minas Gerais (IFMG), São João Evangelista Campus. The experiment was conducted using a randomized complete block design with a fractional factorial scheme (4×4×4)(1/2), employing combinations of four doses each of N, P, and K. Seedlings were transplanted at a spacing of 1.0 m between rows and 0.6 m between plants, totaling 16,666 plants per hectare. Over the three year period, harvests were conducted every 60 days, and the aerial biomass (branches and leaves) was evaluated based on fresh and dry matter productivity, allowing analysis of the impact of different fertilizer doses over time. The first-year results indicated that nitrogen was the only nutrient with a significant effect on biomass productivity, markedly increasing both fresh and dry matter production. Increasing doses of N produced quadratic responses, with maximum productivity estimated at 10,360.3 kg ha⁻¹ of fresh matter and 2,184.0 kg ha⁻¹ of dry matter, achieved with doses of 88.7 kg ha⁻¹ and 85.8 kg ha⁻¹ of nitrogen, respectively. For maximum economic efficiency (90% of maximum productivity), the required N doses were reduced to 37.6 kg ha⁻¹ and 36.3 kg ha⁻¹, demonstrating the potential for optimizing fertilizer use. In the following two years, the effects of NPK doses on the aerial biomass were statistically non-significant. This suggests that after the initial establishment, Moringa oleifera maintains its productivity even with low levels of NPK fertilization. The lack of response may be attributed to the species’ high rusticity and adaptability, which allow it to develop in soils with limited nutrient availability and under adverse conditions. It is concluded that, under the evaluated edaphoclimatic conditions, the tested doses of NPK fertilization do not significantly enhance the productivity of Moringa oleifera in semi-intensive systems.