Greengram [Vigna radiata (L.) Wilczek], prevalently termed as mung bean, green bean, moong bean, or golden gram, is vital legume crop belonging to the family Leguminosae. Indigenous to the Indian subcontinent, its domestication dates back to around 1500 BC and it later spread globally through ancient trade routes and migration (Hanumantharao et al., 2016). In India, greengram stands third in importance, preceded by chickpea and pigeon pea. It’s high protein content and accessibility make it a valuable dietary component, earning it the names “poor man’s meat” and “rich man’s vegetable” (Abbas et al., 2011).
       
Greengram, a short-duration crop adapted to warm seasons, is grown on a global scale exceeding 6 million hectares (Nair et al., 2012). In 2024, India had grown around 9.12 million hectares of gram and had a production of 11.11 million tonnes and average yield of 1,218 kg ha^-1. The total productivity of pulses in Tamil Nadu is about 496 kg ha^-1 (Agricultural Statistics at a Glance, 2024). India Despite its agronomic and nutritional significance, its productivity remains low, primarily due to cultivation on low-fertility soils and inadequate nutrient management practices. Nutrient deficiencies, particularly of nitrogen and phosphorus at crucial phases like flowering and pod formation, can lead to flower and pod drop, ultimately reducing yield (Kadam and Khanvilkar, 2015). This is further exacerbated by nitrogen losses through leaching and volatilization and phosphorus fixation in the soil. Additionally, most legumes, including greengram, are often grown in marginal soils with poor rhizobium activity, which limits biological nitrogen fixation (Patel et al., 2016).
       
Proper nutrient management is essential to improve the growth and productivity of greengram. Nutrients can be supplied through organic sources (e.g., farmyard manure, compost, vermicompost), inorganic fertilizers (e.g., NPK fertilizers), or a combination of both. Organic fertilizers improve soil structure and health over time through the gradual release of nutrients, while inorganic fertilizers provide immediate nutrient availability but may contribute to nutrient leaching and soil degradation if misused. Organic sources rely on microbial activity to release nutrients, aligning with plant demand but acting more slowly. In contrast, inorganic fertilizers deliver nutrients in plant-available forms rapidly, which can enhance short-term growth but may also elevate the potential for nutrient depletion and environmental contamination.
       
The use of both organic and inorganic nutrient inputs is considered a sustainable method to sustainable approach to maintain soil fertility and enhance crop productivity (Mohan and Chandaragiri, 2007). Combining appropriate quantities of chemical fertilizers alongside organic manures like farmyard manure or vermicompost can enhance nutrient availability, promote better root development, improve nutrient uptake efficiency and increase the translocation of photosynthates from synthesis to storage. This results in improved growth, yield attributes and overall productivity, particularly under rainfed conditions.
       
Thus, this research is directed toward optimizing greengram development and yield under different organic and integrated nutrient management practices in comparison with complete inorganic nutrient application. The results of the study will give a sustainable and profitable nutrient management as an alternative to unsustainable inorganic fertilizer application.

The field test was carried out on the South Farm of Karunya Institute of Technology and Sciences, Coimbatore, India, at the Kharif (July-October) and Rabi (November-February) seasons of 2022. The experimental area is in Tamil Nadu, Western Agro-Climatic Zone, 10°56' N latitude, 76°44' E longitude and an elevation of 474 m above the mean sea level. The experimental field had soil that was clay loam in texture but the soil pH was 7.6 and electrical conductivity of the soil was 0.40 dS m^-1. The study used greengram (Vigna radiata L.) variety CO 8 and the seeds were planted with spacing of 30 x 15 cm. Three times of irrigating the crop were done using the standard practices.
       
The study was laid out in a Randomized Block Design (RBD) with three replications to evaluate the effect of different nutrient sources and their integrated combinations on crop growth and performance. A total of nine treatments were imposed: T₁-absolute control (no nutrient application), T₂-vermicompost applied at 100% on a nitrogen-equivalent basis, T₃- FYM applied at 100% on a nitrogen-equivalent basis, T₄-50% vermicompost + 50% FYM, T₅-75% vermicompost + 25% FYM, T₆-25% vermicompost + 75% FYM, T₇-100% RDF, T₈-50% RDF + 50% vermicompost and T₉-50% RDF + 50% FYM.
       
The yield and yield attributes were determined using standard procedures. The count of the pods per plant was established to measure pods of five randomly chosen and tagged plants and the mean was computed. Five randomly chosen pods of the tagged plants were used to measure the pod length (cm), the mean pod length was calculated. The average number of seeds per pod was determined by tallying the number of seeds in five randomly selected pods that were gathered using five plant tags and the average data were obtained. Grain yield per plant was determined by weighing the grains of the five randomly selected plants and the mean yield of the grain was in grams. The test weight was calculated by weighing and counting 1000 seeds gathered on five randomly chosen plants using an electronic balance and the mean of the same was measured in grams.
       
In each treatment, the leaf area index (LAI) was estimated by computing the proportion of the total leaf surface area per plant to the corresponding ground surface area covered by the plant, as determined by the spacing arrangement. Crop growth rate (CGR) was computed using Watson (1947).
 

  

 
Where,
W₁ and W₂ = Represent the initial and final dry weights recorded at times.
t₁ and t₂ = In that order, while P denotes the ground area occupied by the plants (m²). The value is expressed in g m^-2 day^-1.
       
Relative Growth Rate (RGR) was computed using Enyi (1962) and expressed as g g^-1 day^-1.
 

  

 
Where,
W₁ and W₂ = Represent the whole plant dry weights at times.
t₁ and t₂ = Correspondingly and t₁ and t₂ denote the time interval in days.
       
Statistical analysis was performed through the application of the web-based software “OPSTAT,” developed by Sheoran et al., (1998).

Influence on growth and physiological parameters
 
Table 1 indicates the total number of trifoliate leaves and Fig 1, 2, 3 indicate the LAI, RGR and CGR respectively. Among the treatments, T₇-RDF 100% recorded the highest values for these parameters compared to the different inorganic and integrated nutrient treatment combinations. The application of phosphorus and nitrogen under RDF stimulated the growth characteristics of the greengram because of increased nitrogen efficiency and boosted the photosynthetic activity of the crop, resulting in cell elongation. Phosphorus additionally helps in cell division. Findings consistent with the present study were documented by Joshi et al., (2016) and Hossain et al., (2021). The distinctly higher LAI observed in the crop is primarily associated with adequate nitrogen supply provided by the NPK fertilizer, which stimulates cellular proliferation and elongation. This, in turn, enhances leaf development, which is consistent with the observations of Gul et al., (2015).



 

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Incorporation of phosphorus fertilizers has been shown to not only stimulate growth of plant but also enhance nutrient availability over a prolonged period, thereby supporting sustained physiological development. Phosphorus, a crucial component of adenosine diphosphate (ADP) and adenosine triphosphate (ATP), serves as the primary energy currency within plant cells. As nearly all vital metabolic reactions involve phosphate derivatives, phosphorus plays a central role in key processes such as photosynthesis, protein and phospholipid biosynthesis, nucleic acid synthesis, membrane transport and cytoplasmic movement (Mishra, 2003). This likely contributed significantly to the improvement in physiological parameters such as CGR and RGR. This may be attributed to the higher fertilizer dosage, which enhances nutrient availability to the crop. These findings are also supported by the work of Marimuthu and Surendran (2015).
       
After T₇-RDF 100% treatment, the succeeding higher growth and physiological parameters were among the organic treatments, T₂-100% Vermicompost on N equivalent basis, recorded the highest growth and physiological parameters. Several studies have reported that vermicompost-amended soils exhibit elevated microbial activity and enriched macro and micronutrient contents, leading to enhanced soil nitrogen levels and plant growth relative to other nutrient sources (Singh et al., 2011). Following T₂-100% Vermicompost treatment, T₈ comprising 50% RDF and 50% vermicompost, resulted in improved growth and physiological characters. The combined application of 50% RDF and 50% vermicompost in greengram cultivation likely improved the availability of both major and minor nutrients, thereby facilitating early root growth and promoting active cell division. This, in turn, enabled more efficient nutrient absorption from the lower soil horizons, which enhanced various plant growth parameters and ultimately contributing to higher CGR and RGR (Kumar et al., 2020).
 
Influence on yield and yield attributes
 
Table 1 indicates the yield attributes of greengram, while Fig 4 and 5 illustrate the yield characteristics. The yield attributes including number of pods plant^-1, length of pod, number of seeds pod^-1 and test weight were positively influenced by the treatment T₇-100% RDF (inorganic) because inorganic nutrients enhance the utilization of added nutrients and ensuring a continuous supply over the entire crop growth period and it promotes different physiological activities in the crop that are considered essential for proper growth and development of yield attributes. A greater fertilizer dosage may enhance crop nutrient availability, followed by the rest of the organic and inorganic treatments. Consistent results were documented by Kalsaria et al., (2017). The least yield attributes were recorded under control.

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Subsequently, higher yield attributes next to T₇ were among the organic treatments, T₂-100% vermicompost, which recorded a higher yield attributes. The positive response to vermicompost is likely attributed to the enhanced availability of both macro and micronutrients, which promotes greater assimilation of nutrients and their effective translocation to the sink. Consequently, improved yield attributes by supporting both vegetative and reproductive growth, ultimately leading to an improvement in yield attributes. The present findings are consistent with the results reported by Sharma and Abraham (2010).
       
Following 100% vermicompost treatment, the succeeding higher yield attributes were recorded under integrated nutrient management treatments, the better performance was observed with T₈-50% RDF + 50% vermicompost. Combining organic and inorganic fertilizers improves yield attributes by limiting nutrient leaching, with organic inputs helping retain nutrients after chemical fertilizer application. Moreover, vermicompost serves as an effective means of maintaining soil health and improving crop productivity, particularly when used together with inorganic fertilizers. The present findings align with those of Kumar and Yadav (2018).

The study revealed that organic, inorganic and combined nutrient management approaches significantly influence the growth performance and productivity of greengram. Among the treatments, 100% RDF (inorganic) showed superior growth and yield components due to enhanced nitrogen and phosphorus availability, which improved cell division, photosynthesis and overall plant development. However, vermicompost at 100% nitrogen-equivalent basis succeeded by integrated application of 50% RDF and 50% vermicompost, performed best among organic treatments by improving vegetative and reproductive growth subsequently which provided a balanced and continuous nutrient supply. This not only improved growth parameters such as LAI, CGR and RGR but also enhanced yield and soil health. Based on the results of the study, the combined application of 50% RDF and 50% vermicompost can be recommended over sole application of inorganic fertilizers. Thus, integrated nutrient management, combining organic and inorganic sources, proves to be a sustainable and efficient strategy for maximizing greengram productivity while maintaining long-term soil fertility.

The authors express their sincere gratitude to the Division of Agronomy at the School of Agricultural Sciences, Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu-641 114.
 

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.