Crop and cropping system yield
Hey Won fertilizers (14:14:14, 14:5:21 and 20:8:12) significantly (p<0.05) improved yields in maize-based systems over two years, with the most notable increases in spring potato, potato, cabbage, eggplant and maize (Table 1). Maximum yields were crop-specific: potato, eggplant and onion under T2; spring potato and cabbage under T3; pea, maize and summer moong under T4. This variability reflects crop genetic differences and fertilizer-crop compatibility
(Setiawati et al., 2020). Control (T1) consistently yielded the lowest, while RDF (T5) out performed control but underperformed compared to Hey Won treatments.
Yields under T2, T3 and T4 surpassed T5, with eggplant (T2 and T3, +77.01%) and summer moong (T2, +1.27%) showing the highest and lowest percentage increases, respectively. T3 notably boosted yields in four crops, likely due to improved nutrient synergy, root development and humic acid-enhanced soil health
(Kolage et al., 2018; Bhatt and Singh, 2022).
System-wise, M-C-Sp (570.33 q/ha) and M-P-O (466.42 q/ha) under T3 outperformed M-Pe-E (411.40 q/ha) and M-P-Sm (339.71 q/ha) under T2. The M-C-Sp system’s superior yield suggests enhanced nutrient and resource use efficiency. Regression analysis (R
2 = 0.80-0.96) confirms strong model-data fit (Fig 3). This approach allows us to observe how changes in fertilizer types and application rates can interact with the specific components of each cropping system, leading to varying yield outcomes
(Shi et al., 2021).
Overall, Hey Won fertilizers improved crop and system yields, aligning with
Chimonyo et al. (2019) and
Abid et al. (2020), who emphasized integrated nutrient management benefits. Vegetable-based systems may also offer better economic returns depending on crop and conditions.
Walder et al. (2023) and this study highlight higher yields under organic-based fertilizers versus pure chemical inputs. Intercropping (
e.g., maize-potato) further enhances yield and water efficiency, reducing water use by 3-13%
(Xie et al., 2021).
Equivalent yield and resource use efficiency
Table 2 and 3 show significant differences in MEY and SP across cropping systems. The maize-potato-onion (M-P-O) system recorded the highest MEY (324.28 q/ha) and SP (117.49 kg/ha/day), while maize-potato-summer moong (M-P-Sm) had the lowest MEY (225.60 q/ha) and SP (80.00 kg/ha/day), likely due to poor maize-summer moong compatibility
(Xie et al., 2021). M-Pe-E and M-C-Sp outperformed M-P-Sm in MEY, with onion inclusion boosting nutrient uptake (
Singh and Sikka, 2007).
Fertilizer treatments significantly affected MEY and SP, with T3 (14:5:21) consistently outperforming other treatments, while the control (T1) yielded the least
(Xie et al., 2021). Also, the M-Pe-E system showed the highest LUE (79.18%), while M-C-Sp had the lowest (71.51%), Fig 4, suggesting longer land utilization but potentially lower productivity due to factors like soil nutrient depletion
(Walder et al., 2023). Similar patterns were noted by
Kumar et al. (2014) in jute-based and by
Sammauria et al. (2020) in pearl-millet based cropping systems.
Ali et al. (2021) described the maximum pearl millet EY and SP in cotton-summer pearl millet cropping system under 75% RDN- inorganic fertilizer + 25% RDN-FYM, an integrated fertilization approach.
Other studies confirm the benefits of intercropping: Maize-soybean systems improved yield, water use and land productivity
(Liu et al., 2018; Xu et al., 2020). Islam et al. (2020) reported maximum system productivity, profitability, sustainable yield index, production efficiency and relative economic efficiency but least land use efficiency in Maize + Green gram(1:2)- green gram + maize (1:1)-tomato, cropping system indicating that the sustainable production might not linked with the efficiently utilization of land cover.
Sikka et al. (2024) also reported significant yield and MEY improvements with Sardar amin granules and Bentonite Sulphur in maize-based systems. The highest production efficiency was observed in soybean-onion cropping system than soybean-potato under 100% RDN (Recommended Dose Nutrient) applied with FYM@ 5 t per ha and biofertilizer suggesting the important role of onion and nutrient fertilizer amendments in improving the cropping system (CS3) performance
(Patil et al., 2024).
Plant macronutrient status
Nitrogen (N), phosphorus (P) and potassium (K) levels varied significantly under different cropping systems and Hey Won fertilizer treatments (Fig 5). The M-P-O system recorded the highest N (11.46%) and K (3.36%) levels, likely due to the synergistic interaction of maize, potato and onion
(Xie et al., 2021). Conversely, N (6.05%) and K (1.16%) were lowest in M-C-Sp and M-P-Sm, respectively. P content peaked in M-C-Sp (2.25%) and was lowest in M-P-O (0.93%), suggesting cabbage with spring potato may enhance P uptake under certain conditions, but may limit N and K due to competition (
Thummanatsakun and Yampracha, 2018).
Macronutrients spiked under T2, slightly declined at T3, stabilized at T4 and dropped at T5, with T1 showing the lowest levels. Despite lower nutrient levels under T3, yield and productivity were highest, indicating that efficient nutrient use and agronomic practices also drive yield
(Xie et al., 2021). Nitrogen was generally dominant across all systems and treatments. Notably, P exceeded K in M-C-Sp, reflecting the plant’s ability to manage limiting factors.
Previous studies
(Kumar et al., 2014; Ghosh et al., 2020; Jiang et al., 2024) support these findings, highlighting the importance of balanced NPK fertilization for enhanced nutrient uptake and yield. Our highest yield under T3 and strong M-P-O system performance align with
Luitel et al. (2024), who reported optimal onion bulb yield under medium organic matter and high K
2O in maize-based systems.
Soil health status
The root-nutrient uptake association is very strong at 0-15 cm as crops roots are highly concentrated at this depth. No significant changes were observed in soil pH, EC and K after two cropping cycles, indicating soil stability and balanced K dynamics (Table 4). However, fertilizer treatments significantly influenced soil OC, N and P levels. T3 (14% N, 5% P
2O
5, 21% K
2O) showed the highest OC (at par with T2) and N, along with elevated P. Fertilization likely boosted microbial activity, enhancing nutrient cycling and soil fertility
(Dinca et al., 2022). Available P peaked under T4, while K remained stable across T2, T3 and T4, suggesting no nutrient imbalance. T5 (100% RDF) improved soil parameters over control but was less effective than Hey Won fertilizers. Cropping systems had no notable effect on soil properties.
Organic amendments with fertilizers significantly improve soil health and productivity
(Dhaliwal et al., 2019). The humic acid in Hey Won fertilizers appears beneficial for sustaining soil quality
(Sikka et al., 2024). Similarly, integrating organic and inorganic sources enhances soil fertility and yield
(Bangre et al., 2024). Singh et al. (2021) also reported increased OC and N under high NPK doses in maize-vegetable pea systems, boosting yield and profitability.
Correlation, regression analysis (Prediction modeling) and Performance evaluation
Pearson correlation analysis was conducted for four cropping systems (CS1-CS4) using key variables: yield, MEY, SP, plant NPK and soil OC, N and P (Tables 5-8). Yield correlated significantly (p≤0.05/0.01) with P.P and P.K in CS1; P.N in CS2; P.N, P.K and S.OC in CS3 and P.K in CS4. This highlights system-specific nutrient-yield dynamics requiring tailored nutrient management
(Roy et al., 2006; Yousaf et al., 2016). Yield, MEY and SP showed near-perfect correlations (r≈1.000), confirming their alignment as performance indicators
(Bahadur et al., 2024).
Post-multicollinearity removal
(Hair et al., 2014), regression models were developed for each system using Python (Table 9) to predict yield, with independent predictors showing minimum residuals
(Kutner et al., 2005). Model performance was assessed
via R², RMSE and MAE. CS3 outperformed others (R² = 0.975, RMSE = 15.34, MAE = 12.45), followed by CS1, CS2 and CS4. A composite score, integrating these metrics, confirmed CS3 as the optimal system (score = 0.52)
(Crookston et al., 2021).
Plots of actual vs. predicted yield and residuals vs. predicted yield (Fig 6-9) validated CS3’s high explanatory power and prediction accuracy (
Chatterjee and Hadi, 2015). This suggests CS3 as the best maize-based system for enhancing yield. These findings align with prior studies linking nutrient dynamics and yield prediction using correlation and regression tools
(Chimonyo et al., 2019; Macholdt et al., 2020). Similar modeling and composite scoring approaches have been applied by
Di Paola et al. (2023) and
Murthy et al. (2022) in other cropping systems.