The research was carried out at the Paklihawa Campus’s Agronomy Research Farm in Rupandehi district from April to July 2023. Geographically, the experimental site is located at an altitude of 87 meters above mean sea level in the Terai belt of the Lumbini province and 265 km west of Kathmandu, the capital city of Nepal. The coordinates of the site are 27° 28′ 48.24′′ N latitude and 83° 26′ 50.18′′ E longitude. To examine the chemical properties of the experimental soil, soil samples were randomly obtained using a tube auger from 20cm deep in a Z-shaped pattern from various sites. To create a composite sample, the soil samples were subsequently air-dried, ground, and sieved using a 2 mm sieve. Finally, the soil sample was taken to the Soil Science Laboratory of the Agricultural Technology Centre, Lalitpur, for examination of chemical properties. The chemical properties of baseline soil of experimental site is shown in Table 1 .

The experimental site lies in the sub-tropical humid climate zone of Nepal. Agro-meteorological data were gathered from the National Wheat Research Program, Bhairahawa. The monthly average of maximum and minimum temperatures was 39.81˚C and 24.24˚C, respectively, and total rainfall recorded was 482.28 mm during the experimental period, as illustrated in Figure 1 .

The experiment was conducted in a Randomized Complete Block Design (RCBD) with eight treatments replicated four times. The experimental area measured 1053 m² (27 m * 39 m), with the experimental unit measuring 24 m² (6 m * 4 m). Yield was obtained from a 1 m² area from each plot. The experimental units were separated by one meter. There were eighteen rows of crop spaced 30 by 10 centimeters apart in each of the 32 plots that made up the total, as illustrated in Figure 2 .

Treatments included different sources of nutrients as chemical fertilizers, organic manures, and bio-fertilizers. Farm yard manure and poultry manure were applied during land preparation and incorporated into the soil in T₅ and T_6, respectively. Only SSP and MOP were applied in T_1, whereas urea was also applied in T₂, T_3, and T₄ along the crop zone before sowing. Foliar application of nano urea was done at 20 and 30 days after sowing in T₇. Rhizobium was inoculated in the seed a day before sowing for treatment eight. The details of each treatment is shown in Table 2 . The percentages of nitrogen, phosphorus, and potassium in FYM were 0.45, 1.63, and 2.25%, respectively, while in poultry manure (PM), they were 1.90, 1.50, and 5.10%, respectively (Soil Science Laboratory, Agriculture Technology Centre, 2023).

Primary tillage was done, followed by secondary tillage with the help of a Mini tiller. Planking and leveling were done to make a good tilt of the soil. Kalyan variety of mung bean was collected from the Grain Legumes Research Program (NARC), Khajura, Banke, and seeds are sown at the rate of 25 Kg ha^-1 at a depth of 5cm. Line sowing was done at a spacing of 30cm x 10cm between rows on 2^nd May 2023. Pre-sowing surface irrigation was done 3 days before land preparation for ease of tillage, uniform germination, and to overcome moisture stress during the early period of plant growth. The second irrigation was given at 20 DAS. Manual weeding was done at 15 DAS and 30 DAS. Major weeds recorded in the field were Cynodon dactylon, Cyperus rotundus, Solanum nigrum, and Chenopodium album. A few insect pests (aphids and legume pod borer) and yellow mosaic virus disease were recorded in the field. Disease-infected plants were manually removed from the field. Due to asynchronization in maturity, the mung bean was harvested 2 times at 7-day intervals. Harvesting was done when the leaves were dried, the pods turned from green to grey black, and started to shatter. Pods were plucked manually, and the stalk was collected by cutting plants near to ground surface. Harvested pods were sun-dried for 2 days. Threshing was done to separate seeds and stalks. The biomass was collected and then weighed. The moisture content of the seed was reduced up to 12% by sun drying and stored in an airtight plastic bag.

Well-decomposed FYM and PM were applied at the rate of 4.444 t ha^-1 and 1.05 t ha^-1 in treatments five and six, respectively, as the main source of organic nutrients. Chemical fertilizers applied were prilled urea, Single Super Phosphate (SSP), and Muriate of Potash (MOP). SSP and MOP were applied at the rate of 40:20 Kg PK ha^-1 as a basal dose from treatment one to treatment four. Urea fertilizer was applied in treatments two, three, and four.

To find out a more profitable treatment, the economics of different treatments were worked out in terms of net return (USD/ha) on the basis of the prevailing market rate so that the most remunerative treatment could be recommended. The net return was worked out by using the following formula.

Treatment-wise benefit-cost (BC) ratio was calculated to ascertain the economic viability of the treatment using the following formula.

The collected data were tabulated in Microsoft Excel worksheet. The Analysis of Variance (ANOVA) for all data was statistically analyzed using Genstat software (18^th edition). Duncan’s Multiple Range Test was used to differentiate the means at the 5% significance level (Gomez and Gomez, 1984). The relevant tables and related references were used to interpret the final results. Charts and figures were drawn using MS Excel.

There was a positive linear relationship between seed yield and the number of branches per plant, explaining 54.25% of the yield variation. Similarly, pods per plant showed a positive relationship with seed yield, accounting for 62.30% of the variation. Pod length also had a positive linear relationship with seed yield, contributing 51.23% to the variation. The strongest relationship was observed between seed yield and the number of seeds per pod, explaining 68.33% of the variation, with the rest influenced by other factors. The strongest relationship was observedbetween seed yield and the number of seeds per pod, explaining 68.33% of the variation, with the rest influenced by other factors as shown in Figure 6 .

Gross return, net return, and benefit-cost (B:C) ratio were significantly affected by the application of organic and inorganic nutrient sources in mung beans. Results showed that the highest gross return (1,412.84 USD/ha) was obtained from the poultry manure applied plot, surpassing the returns from the other treatments. The lowest gross return (686.83 USD/ha) was recorded from the control. Net return varied significantly among different treatments. The highest net return was observed in poultry manure with 930.68 USD/ha, while the lowest was in control with 315.90USD/ha. The maximum benefit-cost ratio was found in poultry manure with a value of 2.93, whereas the lowest was in control, with a value of 1.85. Both net return and benefit-cost ratio increased significantly with the application of poultry manure. The increase in net return can be attributed to the higher yield resulting from organic manure sources. Additionally, the B:C ratio increased with the rising dose of prilled urea as shown in Table 5 .

The maximum shoot length of the mung bean was obtained from poultry manure applied plots. This may be due to the availability of most of the macro and micro nutrients in poultry manure and farm yard manure, and their role in improving soil properties and creating a favorable growing environment for the plants. Similar results were reported by Gurjar et al. (2022) and Mahabub et al. (2016). Among the prilled urea applied plots, shoot length increased with an increase in dose of prilled urea, which might be due to the low government recommendation dose of prilled urea and its key role in the physiological processes in plants. These results are in line with the findings of Omran et al. (2018) and Achakzai et al. (2012), which indicate that adding nitrogen fertilizer to mung bean plants resulted in a slight to extremely significant increase in shoot length.

The root growth in mung bean was accelerated by the application of farm yard manure, leading to increased branching and increased uptake of nutrients and water. Plots treated with farm yard manure (FYM) have the longest roots, which could be because FYM creates a more favorable soil environment. As a result, moisture and nutrients supply increase and promote better plant growth. It also forms the physico-chemical and organic properties of the soil. Mishra et al. (2016) also found similar results that farm yard manure-treated plots give higher root length in mung beans. Increased nitrogen dose increased the availability of nutrients and increased root length up to the recommended dose of nitrogen. An additional increase in nitrogen levels caused nutritional toxicity and decreased root length (Razzaque et al., 2015). Similar results were discovered by previous researchers. Higher root length results from Rhizobium inoculation at 45 DAS after poultry manure and FYM. It is commonly recognized that Rhizobia influence plant growth and development through a variety of pathways such as enhanced mineral absorption, N₂ fixation, the synthesis of plant growth regulators (PGRs) and the inhibition of plant diseases, which is in line with the statement of Kennedy et al. (2004) and Patten and Glick (1996).

Application of farm yard manure led to considerably higher values for the number of effective root nodules plant^-1. It might be due to higher microbial activity in the soil by the FYM. This finding is consistent with previous research findings of Giri et al. (2024) and Das et al. (2014). Similarly, Yasmin et al. (2016) recorded the highest number of effective nodules plant^-1 from the farm yard manure applied plots, which agreed with the observation of Nagarajan and Balachandar (2001). Farm yard manure produced a higher number of nodules due to slow nitrogen release at an earlier stage, which agreed with the observations of Ganeshamurthy and Sammi Reddy (2000). There is an inhibitory effect of higher doses of N fertilizer on nodulation; this finding is in line with the result of Pons et al. (2007).

Mung beans produced a maximum number of leaves under the application of poultry manure. Poultry manure improved soil aeration, root development, and increased microbial and biological activities in the rhizosphere. This, in turn, would have improved assimilation of nutrients, and thus, dry weight might be increased. These results are in agreement with Sachan et al. (2020) and Islam et al. (2023). Maximum leaf area index was obtained from poultry manure applied plots, which is consistent with previous research findings of Anwar et al. (2018) and Zaman (2010). Higher CGR was found in organic manure applied plots (PM followed by FYM), which is in line with the result statement of Kumar et al. (2023). This is because organic manures are concentrated sources of macro and micronutrients that improve plant growth by enhancing growth attributes through quick cell division and elongation. CGR increased with an increase in dose of prilled urea, which is in line with the findings of Razzaque et al. (2017). Higher N levels increased N in chlorophyll, which increased photosynthesis and enhanced the meristematic activity of the plant.

Applying poultry manure greatly increased the number of branches plant^-1 of the mung bean which was significantly superior to other treatments. The increased number of branches seen in poultry manure applied plots may be due to the result of a sufficient supply of macro and micronutrients, which aided in the plant’s vegetative growth. These outcomes are consistent with findings of Chandekar and Umesha (2023); Gurjar et al. (2022), and Verma et al. (2022). Rao et al. (2013) also observed similar results regarding the number of branches. The number of branches plant^-1 was affected by nitrogen level, and the number of branches plant^-1 increased with increasing nitrogen level, which aligns with findings of Khan et al. (2017).

Poultry manure exhibited a greater number of pods plants^-1 of mung beans. Poultry manure can improve soil physical properties, which provide favorable soil health and conditions and thereby increase the growth and yield contributing parameters. It is consistent with previous research findings of Santhosh Kumar et al. (2021) and Tarafder et al. (2020). Increasing nitrogen level led to an increase in pod plant^-1, this finding aligns with the result of Anjum et al. (2006). This indicates that mung beans require additional N for better pod development, although it is capable of fixing atmospheric N through rhizobium species living in root nodules. Higher number of pods per plant might have been possible due to more vigor and strength attained by the plants as a result of better photosynthetic activities with sufficient availability of light, and supply of nutrients in balanced quantity of the plants at growing stages. This ultimately resulted in a higher number of seeds pod^-1 and a higher length of the pod of the mung bean which is similar to the statement of Anwar et al. (2018) and Gadi et al. (2017). Length of pod increased with an increase in the number of seeds pod^-1 on the mung bean.

Mung beans produced the maximum number of seeds pod^-1 from poultry manure applied plots. The application of poultry manure may have contributed to a larger root system and increased nodulation, which has increased metabolite production and its translocation to different sinks, particularly the productive structures (seeds and pods), that may have increased the number of pods plant^-1 in addition to overall growth. These findings are similar to the statements of different researchers. Mainul et al. (2014) and Verma et al. (2022) found the maximum number of seed pod^-1 of mung bean by application of poultry manure. Application of nitrogen enhances the plant growth that increases fruit-bearing branches, seed setting, and seed development, which is consistent with findings from previous research of Basu and Bandyopadhyay (1990), indicating that the number of seeds pod^-1 of mung bean increased with an increase in prilled urea.

Poultry manure applied plots give the highest thousand-seed weight of mung bean. Poultry manures contain plant nutrients, growth-promoting substances, and beneficial microbes, which provide favorable soil conditions to enhance nutrient use efficiency, ultimately producing healthy and bold seeds. Baghlani et al. (2024) and Gadi et al. (2017) also reported the maximum thousand-seed weight from poultry manure applied plots. Mainul et al. (2014) also found similar results. Basu and Bandyopadhyay (1990) found a significant effect of increased nitrogen level on the thousand-seed weight of mung bean.

Maximum seed yield, stalk yield, and biological yield were recorded from plants treated with poultry manure followed by farmyard manure. The higher seed yield might be attributed to the increased supply of almost all plants’ essential nutrients by translocation of photosynthates accumulated under the influence of the source of organic nutrients. The increased stalk yield might be because of better vegetative growth and higher dry matter production due to the availability of all plant nutrients and better physical properties of soil. These results are in agreement with the findings of Chandekar and Umesha (2023). As in this experiment, Singh et al. (2015) and Yadav et al. (2007) observed that the poultry manure gives maximum seed yield, stalk yield and biological yield in their trial. The enhanced seed and stalk yield was due to the supply of different nutrients attributed to the activation of metabolic processes, which role in faster cell division and cell elongation with enhanced assimilation rates is well known.

Plots treated with poultry manure had the highest harvest index. Addition of organic sources of nutrients (poultry manure, FYM) improves soil structure, porosity, water holding capacity and decreases bulk density and chemical properties such as soil organic carbon and available nutrients will also be improved. All these promote soil health, crop growth, yield and harvest index on a sustained basis. Similar findings are given by Santhosh Kumar et al. (2021); Karangwa et al. (2015) and Zaman (2010). Harvest index of mung bean increased with increasing nitrogen dose, which is in line with findings of Malik et al. (2003). All the growth and yield attributing parameters increased as the nitrogen level increased which increases yield and harvest index.

The economic analysis showed that the profitability of mung bean production was greatly influenced by the management of nutrient sources. Poultry manure was found to perform better economically, and therefore, it had the best gross return, net return, and B: C ratio. This might be due to its capacity to increase the soil fertility and enhance the crop yield, thus creating greater returns in the market than the other treatments. The findings of the study align with the results from Agbede (2025). The least economic gains achieved in control further demonstrate the significance of nutrient supplementation in the mung bean production. It is worth noting that the highest B: C ratio is 2.93 under the poultry manure, which shows that the investment in this organic input proved to be very profitable which yielding almost three times the cost. Also, the finding that the B: C ratio increases with increased doses of prilled urea implies that inorganic fertilizers, too, have a positive effect on profitability, although not to the same degree as poultry manure (Yeasmin et al., 2024). Altogether, the results highlight the promise of poultry manure as a low-cost and sustainable alternative enhancing the yield and economic profits of growing mung beans.