Bangladesh Agron. J. 2024, 27(2): 108-115 EFFECT OF BIOCHAR AND NPK MANAGEMENT ON GROWTH AND YIELD OF MORINGA (Moringa oleifera) R.K. Das1*, P.K. Biswas1, M.S. Islam1, T.S. Roy1 and M.A. Khan2 1Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh 2Department of Soil Science, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh *Corresponding author, Email: ranjondash@yahoo.com (Received: 30 July 2025, Accepted: 28 August 2025) Keywords: Nutrient management, growth, yield, moringa Abstract A field experiment was conducted at Ukhiya, Cox’s Bazar, Bangladesh, during 2022-2024 to evaluate the performance of Moringa oleifera var. PKM-2 under different bamboo biochar and NPK fertilizer treatments. The experiment was laid out in a randomized complete block design with three replications, consisting of four biochar doses (0, 5, 10, and 15 t ha−1) and four NPK fertilizer levels (0, 50, 100, and 150% of the recommended fertilizer dose, RFD), resulting in 16 treatment combinations. Results revealed that both biochar and NPK significantly improved plant growth and yield attributes. Application of 10-15 t ha−1 biochar enhanced plant height, crown spread, pod number, pod length and 1000-seed weight compared to the control. Fertilizer application at 100-150% RFD increased vegetative growth, pod development, and seed yield. Among the interactions, 10 t ha−1 biochar with 100% RFD produced the highest pod number (90 plant−1) and longest pods (55.69 cm), while 10 t ha−1 biochar with 150% RFD resulted in the tallest plants (3.95 m at 24 months). The heaviest seeds (140.54 g per 1000 grains) were recorded with 15 t ha−1 biochar. These findings suggest that 10 t ha−1 bamboo biochar combined with 100-150% RFD is optimal for maximizing moringa productivity under coastal agro-ecological conditions of Cox’s Bazar. Introduction Moringa (Moringa oleifera Lam.) is a fast-growing, drought-tolerant tree, valued for leaf, pod and seed uses in food, feed and nutraceuticals. Its leaves and pods supply dense proteins, vitamins and minerals (notably Ca, K, Fe and provitamin A), making it a strategic crop for household nutrition and climate-resilient farming across South Asia (Moyo et al., 2011; Gopalakrishnan et al., 2016; Sultana, 2020 and Pareek et al., 2023). In Bangladesh, interest in moringa is rising as farmers diversify beyond rice and seek year-round, nutrient-rich produce under erratic rainfall and heat stress. The crop’s ability to thrive on relatively poor soils, coupled with high nutritional returns per unit area, underpins its appeal for coastal smallholders. Coastal agro-ecosystems, including Cox’s Bazar, face soil constraints that can limit perennial tree-crop performance: coarse textures with low organic matter and nutrient stocks, and seasonal salinity pulses from tidal flooding and saltwater intrusion. Empirical work from Jhilwanja Union (Cox’s Bazar) reports sandy to loam textures, very low organic matter and N, and low-to-moderate soil electrical conductivity, highlighting the need for amendments that build carbon, water retention, and cation exchange capacity (Hossain et al., 2015). At a broader scale, projections indicate substantial salinity intensification across coastal Bangladesh by mid-century, with implications for crop productivity without adaptive soil management (Dasgupta et al., 2015). Biochar, a carbon-rich, porous material from biomass pyrolysis, has emerged as a practical soil amendment to address exactly these constraints by improving soil structure, water- holding, pH buffering, and nutrient retention. Field meta-analyses showed that biochar can raise yields particularly in tropical, low-fertility soils (Jeffery et al., 2017) and that pairing biochar with mailto:ranjondash@yahoo.com 109 Das et al. mineral fertilizers enhances crop response and nutrient-use efficiency (Faloye et al., 2017; Ye et al., 2020). Bamboo-derived biochar is especially attractive in South Asia due to abundant feedstock and favorable physicochemical properties; recent studies document improvements in soil water retention, pH moderation and microbial activity with bamboo biochar additions (Yadav and Bag, 2023; Zhang et al., 2024). Complementarily, judicious NPK fertilization is known to boost moringa growth and yield traits (Atteya et al., 2021). Against this backdrop, the present study evaluates how different rates of bamboo biochar and NPK, influence moringa growth and yield, separately and in combination under coastal soil conditions typical of Cox’s Bazar. Materials and Methods The field experiment was conducted during 2022-2024 at Ukhiya, Cox’s Bazar, Bangladesh. The test crop was Moringa oleifera (var. PKM-2). Seeds were collected from a reliable local source, soaked in water for 24 h, pre-germinated in gunny bags for 48 h, and then sown in a nursery bed on 8 April 2022. Thirty-day-old seedlings were transplanted into the main field on 4 May 2022 at a spacing of 2.5 m × 2.5 m. The experiment was laid out in a randomized complete block design (RCBD) with two factors and three replications. Factor A was biochar dose, with four levels: A₀ = 0 t ha−1(control), A₁ = 5 t ha−1, A₂ = 10 t ha−1, and A₃ = 15 t ha−1. Factor B was NPK fertilizer dose, with four levels: B₀ = 0% of recommended fertilizer dose (RFD), B₁ = 50% RFD, B₂ = 100% RFD, and B₃ = 150% RFD. This resulted in 16 treatment combinations: A₀B₀, A₀B₁, A₀B₂, A₀B₃; A₁B₀, A₁B₁, A₁B₂, A₁B₃; A₂B₀, A₂B₁, A₂B₂, A₂B₃; A₃B₀, A₃B₁, A₃B₂, and A₃B₃. Land was prepared with a power tiller on 17 April 2022, sun-dried for one week, then harrowed and cross-ploughed. Bamboo biochar was incorporated into the soil as pre-treatment. NPK fertilizers were applied using urea (N), TSP (P), and MoP (K) to supply target nutrient levels of 150 kg N, 50 kg P and 75 kg K ha−1, adjusted to the treatment levels (0-150% of RFD). The unit plot size was 2.0 m × 2.0 m with 1.5 m spacing between blocks and 1.0 m between plots to reduce border effects. Irrigation and drainage were managed according to seasonal conditions, with drainage channels maintained during the rainy season. Manual weeding was performed at approximately 30 and 60 days after transplanting (DAT). Pest monitoring was done regularly, but no insecticides were applied. Plants were harvested at physiological maturity when 80-90% of pods had matured. Pods were collected from the central 1 m area of each plot, dried and weighed. Seeds were dried to 14% moisture content before weighing. Five plants per plot were randomly selected for detailed observations. The data recorded included plant height (m) at 6, 12, 18, and 24 months; crown spread (m); stem girth (cm at 15 cm height); number of leaves plant−1; fresh leaf weight (g plant−1); number of pods plant−1; pod length (cm, average of five pods); fresh pod weight (g plant−1); and 1000- seed weight (g). Data were subjected to analysis of variance (ANOVA) following the RCBD two- factor design. Mean separation was carried out using the least significant difference (LSD) test at the 5% level of probability. Results and Discussion Effect of biochar doses Relative to A₀, biochar enhanced vegetative growth and reproductive traits throughout 6-24 months (Tables 1-4). By 24 months, plant height rose from 3.36 m (A₀) to 3.69 m (A₂) and 3.67 m (A₃) (Table 1); canopy size increased from 318 to ~387-389 leaves plant−1 under A₂-A₃, with leaf mass rising from 132.14 g (A₀) to 180.68 g (A₂) (Table 2). Reproductive gains followed: pods plant⁻¹ increased from 62.08 (A₀) to 73.75 (A₂) and 72.25 (A₃), and pod length from 48.57 cm (A₀) to ~50-51 cm (A₂-A₃) (Table 3). Seed traits improved, with 1000-seed weight moving from 121.99 g (A₀) to 140.54 g (A₃) (Table 4). Effect of biochar and NPK management on growth and yield moringa 110 Table 1. Effect of biochar, NPK doses and their interaction on plant height of Moringa Treatments Plant height (m) at 6 Months 12 Months 18 Months 24 Months Biochar effect A0 1.26 b 2.02 b 2.70 c 3.36 b A1 1.52 a 2.31 a 2.92 b 3.64 a A2 1.56 a 2.32 a 3.03 a 3.69 a A3 1.36 b 2.26 a 3.09 a 3.67 a CV (%) 11.9 6 5.72 2.91 4.83 SE (±) 0.05 0.04 0.02 0.05 NPK effect B0 1.32 b 2.02c 2.67 d 3.45 b B1 1.42 ab 2.20b 2.87 c 3.52 b B2 1.49 a 2.38a 3.05 b 3.58 b B3 1.46 ab 2.31a 3.15 a 3.82 a CV (%) 11.96 5.72 2.91 4.83 SE (±) 0.05 0.04 0.02 0.05 Interaction effect A0B0 1.12 cd 1.65 g 2.28 j 3.14 d A0B1 1.41 bc 1.987 f 2.72 hi 3.34 cd A0B2 1.02d 1.98 f 2.79 gh 3.35 cd A0B3 1.49 b 2.46 b 2.99 cdef 3.61 bc A1B0 1.36 bc 2.14 def 2.63 i 3.61 bc A1B1 1.52 b 2.17 def 2.86 fgh 3.57 bc A1B2 1.52b 2.497 b 3.07 bcde 3.53 bc A1B3 1.66 ab 2.42 bc 3.13 bcd 3.86 ab A2B0 1.41 bc 2.08 ef 2.85 fgh 3.48 c A2B1 1.39 bc 2.35 bcd 2.93 efg 3.49 c A2B2 1.88 a 2.83 a 3.20 ab 3.84 ab A2B3 1.54 b 2.02 f 3.15 bc 3.95 a A3B0 1.39 bc 2.20 cdef 2.91 efg 3.57 bc A3B1 1.36 7bc 2.3 bcde 2.98 def 3.67 abc A3B2 1.53 b 2.21 cdef 3.14 bc 3.58 bc A3B3 1.13 cd 2.33 bcd 3.34 a 3.85 ab CV (%) 12.1 5.72 2.91 4.83 SE (±) 0.03 0.07 0.05 0.01 In a column, means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. (A0:0 t ha−1, A1: 5 t ha−1, A2: 10 t ha−1, A3: 15 t ha−1and B0:0% of RFD, B1: 50% of RFD, B2: 100% of RFD, B3: 150% of RFD). These outcomes agree with evidence that biochar improves soil moisture retention, cation-exchange capacity, pH buffering and nutrient availability, thereby supporting larger canopies and stronger sink formation (Jeffery et al., 2017; Ye et al., 2020). Mechanistically, biochar can stabilize macro-aggregates and curb N losses, which reinforces sustained biomass and pod/seed filling over multiple seasons (Khan et al., 2023; Han et al., 2023). 111 Das et al. Table 2. Effect of biochar, NPK doses and their interaction on number of leaves plant−1 and weight of leaves of Moringa Treatments Number of leaves plant−1 at Weight of leaves (g) at 6 Months 12 Months 18 Months 24 months 6 Months 12 Months 18 Months 24 Months Biochar effect A0 33.42 c 127.08c 227.42 c 318 c 28.82 b 120.01 c 129.92 c 132.14 c A1 55.25 a 152.83 ab 241.25 b 351 b 35.20 a 148.61 b 161.83 b 166.83 b A2 53.58 a 149.00 b 253.50 a 387 a 35.32 a 166.62 a 181.26 a 180.68 a A3 46.50 b 153.08 a 252.42 a 389 a 27.38 c 149.91 b 164.50 b 165.20 b CV (%) 5.96 3.19 2.58 2.56 5.96 3.19 3 2.5 SE (±) 0.81 1.34 1.82 1.89 0.81 1.34 2.11 1.92 NPK effect B0 34.50 d 130.50 d 223.92 c 316c 29.09 c 127.57 c 138.56 c 140.36 c B1 51.42 b 140.08 c 236.83 b 337b 32.06 b 148.84 b 161.67 b 163.75 b B2 48.50 c 153.50 b 254.42 a 391a 31.11 b 148.19 b 160.73 b 161.69 b B3 54.33 a 157.92 a 259.42 a 412a 34.46 a 160.55 a 176.56 a 179.04 a CV (%) 5.89 3.05 2.12 2.07 4.56 2.74 4.3 4.86 SE (±) 0.89 1.89 1.78 1.56 0.42 1.16 1.98 2.26 Interaction effect A0B0 32.00 g 117.00 h 207.67 j 296.67 h 30.81 d 117.93 g 128.44 ef 108.01 j A0B1 27.67 gh 107.00 i 221.00 h 313.67 g 25.18 e 110.54 h 116.86 f 122.73 hi A0B2 24.00 h 137.00 fg 233.33 fgh 324.33 fg 21.97 f 109.27 h 117.73 f 124.61 ghi A0B3 50.00 e 147.33 de 247.67 cde 342.67 cd 37.32 bc 142.28 e 156.65 d 132.60 def A1B0 40.33 f 130.00 g 222.67 gh 317.33 fg 31.56 d 119.05 g 128.43 ef 120.62 i A1B1 66.67 ab 159.67 abc 235.00 efg 329.00 ef 35.81 c 156.86 c 172.12 bc 125.85 f-i A1B2 54.33 de 166.67 a 247.00 c-f 343.33 cd 36.67 c 153.54 cd 166.87 cd 134.48 de A1B3 59.67 c 155.00 bcd 260.33 bc 355.33 bc 36.76 c 164.97 b 179.92 b 139.67 cd A2B0 26.00h 136.33 fg 230.33 gh 318.67 fg 22.34 f 129.74 f 139.52 e 122.82 hi A2B1 52.33 e 144.67 ef 244.67 def 329.67 ef 37.60 bc 170.18 b 183.29 b 130.90 efg A2B2 71.33 a 152.67 cde 279.33 a 370.00 a 41.52 a 183.36 a 195.65 a 152.24 a A2B3 64.67 b 162.33 ab 259.67 bc 360.00 ab 39.84 ab 183.20 a 206.59 a 131.71 efg A3B0 39.67 f 138.67 f 235.00 efg 320.33 fg 31.65 d 143.56 e 157.84 d 128.49 e-h A3B1 59.00 cd 149.00 de 246.67 c-f 338.00 de 29.64 d 157.77 c 174.42 bc 139.60 cd A3B2 44.33 f 157.67 bc 258.00 bcd 351.00 bcd 24.29 ef 146.58 de 162.66 cd 144.50 bc A3B3 43.00f 167.00 a 270.00 ab 368.33 a 23.93 ef 151.74 cd 163.10 cd 149.55 ab CV (%) 5.96 3.19 2.58 2.16 4.56 2.74 4.29 3.16 SE (±) 1.62 2.68 3.64 4.21 0.83 2.32 3.95 2.4 In a column, means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. (A0: 0 t ha−1, A1: 5 t ha−1, A2: 10 t ha−1, A3: 15 t ha−1 and B0: 0% of RFD, B1: 50% of RFD, B2: 100% of RFD, B3: 150% of RFD). Effect of NPK doses Increasing fertilizer from B₀ to B₃ steadily raised plant stature and canopy size and improved pod traits (Tables 1-3): at 24 months, height rose from 3.45 m (B₀) to 3.82 m (B₃) (Table 1), leaves plant−1 from 316 (B₀) to 412 (B₃), and leaf mass from 140.36 g (B₀) to 179.04 g (B₃) (Table 2). Pods plant−1 climbed from 56.42 (B₀) to 78.67 (B₃), while pod length rose from 46.23 cm (B₀) to 51.79 cm (B₃) (Table 3). For yield components, diminishing returns appeared Effect of biochar and NPK management on growth and yield moringa 112 at the highest dose: at 24 months pod weight peaked at B₁-B₂ (182.63-182.49 g) rather than B₃ (176.09 g) and 1000-seed weight plateaued at B₂-B₃ (~139 g) (Table 4). Table 3. Effect of biochar, NPK doses, and their interaction on number of pods plant−1 and length of pods of moringa Treatments Number of pods plant−1 at Length of pods (cm) at 6 Months 12 Months 18 Months 24 Months 6 Months 12 Months 18 Months 24 Months Biochar effect A0 1.25 c 16.50 d 42.50 c 62.08 c 2.79 c 25.54 d 36.47 c 48.57 c A1 2.25 b 19.92 c 46.75 b 66.58 b 2.33 c 27.41 c 38.12 b 49.98 b A2 3.25 a 21.17 b 46.42 b 73.75 a 3.65 b 29.13 b 39.41 a 51.38 a A3 2.83 a 22.33 a 49.17 a 72.25 a 4.49 a 30.12 a 40.34 a 50.70 ab CV (%) 21.04 5.48 2.75 4.17 10.54 2.32 3.06 2.74 SE (±) 0.15 0.32 0.37 0.83 0.1 0.19 0.34 0.4 NPK effect B0 1.25 c 14.17 d 38.08 c 56.42 c 2.55 c 24.30 d 35.20 d 46.23 c B1 2.25 b 18.33 c 44.58 b 63.83 c 2.24 d 26.97 c 37.51 c 49.83 b B2 2.58 b 22.08 b 50.83 a 75.75 b 4.06 b 29.52 b 39.82 b 52.79 a B3 3.50 a 25.33 a 51.33 a 78.67 a 4.40 a 31.42 a 41.81 a 51.79 a CV (%) 21.04 5.48 2.75 4.17 10.54 2.32 3.06 2.74 SE (±) 0.15 0.32 0.37 0.83 0.1 0.19 0.34 0.4 Interaction effect A0B0 2.00 d 12.00 i 34.33 g 53.00 k 5.06 b 22.18 g 33.35 i 45.00 d A0B1 0.00 f 16.00 g 39.67 f 59.33 ij 0.00 f 24.66 f 35.88 h 47.37 d A0B2 1.00 e 18.00 f 46.33 d 65.67 gh 4.05 c 26.58 e 37.31 fgh 50.12 c A0B3 2.00 d 20.00 e 49.67 bc 70.33 efg 2.06 e 28.73 d 39.35 def 51.81 bc A1B0 0.00 f 14.00 h 36.33 g 55.00 jk 0.00 f 24.13 f 35.35 h 45.53 d A1B1 2.00 d 18.00 f 44.00 e 61.67 hi 2.08 e 26.03 e 36.13 gh 49.69 c A1B2 3.00 c 22.33 d 50.67 b 72.00 ef 3.00 d 29.18 d 39.50 cde 52.02 bc A1B3 4.00 b 25.33 bc 56.00 a 77.67 cd 4.22 c 30.30 c 41.51 bcd 52.68 b A2B0 1.00 e 15.00 gh 39.33 f 57.67 ijk 1.98 e 24.82 f 35.95 h 47.05 d A2B1 3.00 c 19.00 ef 47.00 d 66.33 gh 3.12 d 28.38 d 38.18 efg 50.05 c A2B2 4.00 b 23.67 cd 51.33 b 90.00 a 4.21 c 30.60 c 40.83 bcd 55.69 a A2B3 5.00 a 27.00 b 48.00 cd 81.00 bc 5.28 b 32.72 b 42.68 ab 52.73 b A3B0 2.00 d 15.67 gh 42.33 e 60.00 ij 3.15 d 26.05 e 36.13 gh 47.35 d A3B1 4.00 b 20.33 e 47.67 cd 68.00 fg 3.77 c 28.80 d 39.87 cde 52.21 bc A3B2 2.33 cd 24.33 c 55.00 a 75.33 de 4.99 b 31.71 b 41.66 abc 53.32 b A3B3 3.00 c 29.00 a 51.67 b 85.67 ab 6.03 a 33.92 a 43.70 a 49.92 c CV (%) 21.04 5.48 2.75 4.17 10.54 2.32 3.06 2.74 SE (±) 0.29 0.63 0.73 1.65 0.2 0.37 0.68 0.79 In a column, means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. (A0: 0 t ha−1, A1: 5 t ha−1, A2: 10 t ha−1, A3: 15 t ha−1 and B0:0% of RFD, B1: 50% of RFD, B2: 100% of RFD, B3: 150% of RFD). This pattern matches moringa studies where balanced N and P boost leaf growth and tissue nutrition, while adequate K underpins pod elongation, assimilate transport, and seed filling; excessive N can shift partitioning toward foliage at the expense of seed mass (Kumar et al., 2006; Atteya et al., 2021). 113 Das et al. Interaction of biochar and NPK Co-application produced the strongest outcomes, with A₂ × (B₂-B₃) and A₃ × B₃ repeatedly leading (Tables 1-4). For height, A₂B₃ achieved the overall maximum of 3.95 m at 24 months (Table 1). Pod set and pod length peaked at A₂B₂ (90 pods plant−1; 55.69 cm), with A₃B₃ and A₁B₃ also high across stages (Table 3). Vegetative yield was likewise strongest under A₂B₂/A₂B₃ and A₃B₃ (Table 2). An interesting exception is the very high pod weight at 24 months under A₀B₁ (204.99 g) (Table 4), plausibly reflecting a source-sink compensation: with fewer pods and a lighter canopy, assimilates can be preferentially allocated to each pod, increasing unit mass (Baï ram et al., 2019). Table 4. Effect of biochar, NPK doses, and their interaction on pod weight and 1000-seed weight of Moringa Treatments Weight of pods (g) at 1000 seeds weight (g) 6 Months 12 Months 18 Months 24 Months Biochar effect A0 10.72 d 120.64 c 139.45 c 177.47 b 121.99 d A1 15.64 c 128.43 b 148.22 b 172.87 c 130.16 c A2 22.93 b 131.49 a 155.01 a 182.52 a 134.42 b A3 26.92 a 128.36 b 149.14 b 177.55 b 140.54 a CV (%) 9.95 1.91 1.73 1.61 3.16 SE (±) 0.55 0.7 0.74 0.83 1.2 NPK effect B0 11.67 d 121.04 d 142.43 b 169.19 c 119.98 c B1 15.18 c 123.56 c 143.01 b 182.63 a 129.77 b B2 21.96 b 133.34 a 153.73 a 182.49 a 138.96 a B3 27.39 a 130.98 b 152.66 a 176.09 b 138.38 a CV (%) 9.95 1.91 1.73 1.61 3.16 SE (±) 0.55 0.7 0.74 0.83 1.2 Interaction effect A0B0 12.91 gh 115.32 i 137.04 f 166.07 hi 108.01 j A0B1 0.00 i 108.40 j 121.26 g 204.99 a 122.73 hi A0B2 12.22 h 127.42 ef 147.59 de 172.74 fg 124.61 ghi A0B3 17.73 ef 131.43 de 151.92 cd 166.08 hi 132.60 def A1B0 0.00 i 120.39 h 139.81 f 164.02 i 120.62 i A1B1 15.83 fg 125.89 fg 144.91 e 171.25 fg 125.85 f-i A1B2 20.88 de 131.39 de 150.52 cd 174.65 efg 134.48 de A1B3 25.85 c 136.04 bc 157.64 b 181.56 cd 139.67 cd A2B0 15.38 fgh 122.54 gh 147.41 de 171.56 fg 122.82 hi A2B1 20.98 de 127.19 ef 153.78 bc 176.00 ef 130.90 efg A2B2 25.02 c 135.06 cd 154.12 bc 196.04 b 152.24 a A2B3 30.33 b 141.16 a 164.74 a 186.46 c 131.71 efg A3B0 18.39 ef 125.89 fg 145.46 e 175.13 efg 128.49 e-h A3B1 23.91 cd 132.77 cd 152.11 cd 178.27 de 139.60 cd A3B2 29.72 b 139.50 ab 162.68 a 186.53 c 144.50 bc A3B3 35.67 a 115.28 i 136.31 f 170.26 gh 149.55 ab CV (%) 9.95 1.91 1.73 1.61 3.16 SE (±) 1.09 1.4 1.47 1.65 2.41 In a column, means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. (A0: 0 t ha−1, A1: 5 t ha−1, A2: 10 t ha−1, A3: 15 t ha−1 and B0:0% of RFD, B1: 50% of RFD, B2: 100% of RFD, B3: 150% of RFD). Overall, these patterns fit the well-documented synergy where biochar improves fertilizer- use efficiency, P availability and moisture buffering, delivering yield advantages beyond fertilizer alone across seasons (Ye et al., 2020; Faloye et al., 2017). Practically, targeting A₂ with B₂-B₃ Effect of biochar and NPK management on growth and yield moringa 114 (≈10 t ha−1 biochar plus 100-150% RFD) appears optimal for maximizing combined growth, pod set and seed traits under comparable conditions. Conclusion Across 6-24 months, both biochar and NPK fertilizer substantially improved moringa growth and yield. Relative to no biochar and no fertilizer, applying 10-15 t ha−1 biochar together with 100-150% of the recommended fertilizer dose increased plant height, canopy size, leaf mass, pods per plant, pod length, pod weight and 1000-seed weight. The best overall performance occurred around 10 t ha−1 biochar combined with the recommended-supra fertilizer range:10 t ha−1 + 150% RFD produced the tallest plants at 24 months (3.95 m), while 10 t ha−1 + 100% RFD gave the highest pod number (90) and the longest pods (55.69 cm). Vegetative traits (leaf number and leaf weight) were likewise strongest under 10-15 t ha−1 with 100-150% RFD. Seed size peaked with 15 t ha−1 biochar (1000-seed weight 140.54 g) and plateaued near 100-150% RFD (~139 g). One notable exception was a very high pod weight under 0 t ha−1 biochar with 50% RFD (204.99 g), likely reflecting source-sink compensation rather than superior overall productivity. For similar environments, a practical recommendation is ~10 t ha−1 biochar with 100-150% of the recommended NPK dose to maximize combined vegetative and reproductive performance. 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