Enhancing sorghum productivity through microbial consortia and integrated nitrogen management

Introduction

Sorghum [Sorghum bicolor (L.) Moench] is a diploid, self-pollinated C4 cereal belonging to the family Poaceae, sub-family Panicoideae, tribe Andropogoneae and genus Sorghum, which comprises 24 diverse wild and cultivated species that trace their origin to the wild progenitor S. bicolor subsp. verticilliflorum distributed across the north-eastern quadrant of Africa (Ananda et al. 2020) [1] . The crop is botanically classified into five basic races bicolor, guinea, caudatum, kafir and durra on the basis of spikelet and panicle morphology, and it possesses a fibrous root system, a solid pithy stem, and a terminal panicle inflorescence that together confer remarkable tolerance to moisture stress and marginal soil fertility. Its diploid genome (2n = 20) and close phylogenetic relationship with major cereals have made sorghum a model system for genomic and marker-assisted breeding studies aimed at combining high yield potential with resilience to abiotic and biotic stresses (Altaf et al. 2024) [2] . This botanical plasticity, coupled with a C4 photosynthetic pathway, underlies the crop's wide adaptability across the semi-arid tropics and its continuing relevance as a food, feed, fodder and bioenergy crop. Sorghum ranks among the top five cereal crops of the world after wheat, rice, maize and barley, and is cultivated on roughly 40 to 43 million hectares globally, yielding an average world production in the range of 60 to 63 million tonnes annually, with the United States, Nigeria and Mexico among the leading producers (USDA Foreign Agricultural Service, 2026) [3] . In India, sorghum, popularly known as jowar, is the third most important cereal after rice and wheat among the coarse grains and is cultivated in both the kharif and rabi seasons. As per the third advance estimates for 2023-24, the crop occupied about 47.42 lakh tonnes of production, with kharif sorghum grown predominantly in Rajasthan, Uttar Pradesh, Haryana and Madhya Pradesh, and rabi sorghum concentrated mainly in Maharashtra, Karnataka, Tamil Nadu and Andhra Pradesh (Centre for Agriculture and Rural Development Policy Research [CARD], 2024) [4] .

Despite its wide distribution, the national average productivity of sorghum continues to lag behind its genetic potential, largely on account of cultivation on marginal, rainfed and nutrientdeficient soils, underscoring the need for improved agronomic and nutrient management interventions to bridge the existing yield gap. Within Uttar Pradesh, sorghum occupies a modest but agronomically important niche, with the state ranking among the top producers of jowar in the country and key growing districts including Jhansi, Hamirpur, Fatehpur, Mathura and Prayagraj (Allahabad) contributing to both grain and fodder production (DesiKheti, 2025) [5] . In the Prayagraj agroclimatic tract, characterised by sandy loam soils, sub-tropical climate and an average annual rainfall of around 1,100 mm, sorghum is grown chiefly as a multi-cut forage and grain crop during the kharif and zaid seasons and remains an important component of diversified cropping systems practised at research farms of the region. Field investigations carried out at the Crop Research Farm, Department of Agronomy, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Prayagraj, have consistently reported that appropriate nitrogen dose and planting geometry substantially influence plant height, drymatter accumulation and green fodder yield of forage sorghum genotypes such as M P Chari under local sandy loam soil conditions (Chand et al. 2023) [6] . These location-specific findings highlight that although Prayagraj does not rank among the major sorghum belts of India, its soil and climatic profile offer considerable scope for productivity enhancement through refined planting geometry and nutrient-management practices tailored to the district's resource base. Nutritionally, sorghum grain is a rich and gluten-free source of dietary energy, containing about 65 to 80 per cent starch, 9 to 13 per cent protein, and appreciable quantities of dietary fibre, B-complex vitamins, phosphorus, magnesium, iron and zinc, along with fatsoluble vitamins such as D, E and K (Tanwar et al. 2023) [7] . The grain additionally harbours a diverse array of phytochemicals, including phenolic acids, tannins, anthocyanins, phytosterols and policosanols concentrated mainly in the pericarp and bran fractions, which impart pronounced antioxidant, anti-inflammatory and anti-diabetic properties and position sorghum as a promising functional food for addressing lifestyle-related and noncommunicable diseases (Chhikara et al. 2018) [8] . Its slowly digestible starch and resistantstarch fractions further make it suitable for lowglycaemic dietary formulations, while its stover and green fodder serve as valuable livestock feed, reinforcing the crop's dual role in human nutrition and animal husbandry. These attributes, combined with its inherent hardiness, have renewed scientific and industrial interest in sorghum as a climate-smart nutricereal capable of strengthening food and nutritional security in dryland farming systems. Microbial consortia, comprising compatible combinations of plant growth-promoting rhizobacteria (PGPR) such as Azotobacter, Azospirillum, phosphate-and potassiumsolubilising bacteria and zinc-solubilising isolates, have emerged as an eco-friendly alternative to sole chemical fertilisation for enhancing crop growth and nutrient-use efficiency. Pot and field evaluations on sorghum have demonstrated that carrier-based dual and multi-strain consortia, when integrated with a reduced dose of inorganic fertiliser and farmyard manure, significantly improve plant height, root and shoot biomass, ear-head characters and grain and stover yield in comparison with either uninoculated or single-strain treatments, owing to synergistic nitrogen fixation, phytohormone production and improved nutrient solubilisation in the rhizosphere (Kavya et al. 2020) [9] . More recent reviews further emphasise that tailored microbial consortia incorporating PGPR, endophytes and arbuscular mycorrhizal fungi not only enhance nutrient acquisition but also confer improved tolerance to drought and heat stress in sorghum, making microbial-based biofertilisation a key pillar of climate-resilient and sustainable sorghum production systems (Srivastava et al. 2025) [10] . Nitrogen is the single most limiting nutrient for sorghum growth and yield, and its judicious management through integration of organic, inorganic and biological sources commonly termed integrated nitrogen management (INM) has been shown to sustain productivity while safeguarding soil health. Field studies combining varying nitrogen rates with different irrigation regimes have revealed that an optimum nitrogen level, generally around 144 to 150 kg N per hectare, interacts significantly with soil-moisture status to maximise plant height, leaf-area index, SPAD value and grain yield while minimising nitrate accumulation and the associated risk of nitrogen loss (Wang et al. 2024) [11] . Complementary evidence from integrated nitrogen trials involving graded substitution of inorganic urea with organic sources such as farmyard manure and castor cake, together with Azotobacter and Azospirillum inoculation, indicates that partial substitution typically 50 per cent recommended dose of nitrogen (RDN) through urea combined with 50 per cent RDN through organic manure and biofertiliser inoculation consistently outperforms sole chemical fertilisation in terms of growth attributes, grain yield and harvest index, besides improving soil biological health (Inaniyan et al. 2026) [12] . Such integrated approaches, by synchronising nitrogen availability with crop demand through complementary organic, inorganic and microbial sources, offer a scientifically sound and sustainable pathway for narrowing the yield gap and enhancing the overall productivity of sorghum-based cropping systems.

Materials and Methods: 2.1 Experimental site and study area

The field experiment was conducted for two consecutive Kharif seasons (2024 and 2025) at the Research Farm of the Department of Agronomy, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Naini, Prayagraj, Uttar Pradesh, India. The experimental site is situated in the sub-tropical belt of the Upper Gangetic Plain agroclimatic zone at approximately 25.38° N latitude and 81.88° E longitude, at an elevation of about 98 m above mean sea level. The region experiences a humid subtropical climate characterised by hot, dry summers, a warm and humid monsoon (July-September), and a cool, dry winter. [14] Available (mineralizable) nitrogen (kg ha-1) 222.7 221. 4 Alkaline permanganate method (Subbiah and Asija, 1956) [15] Available phosphorus (kg ha-1)

12.85 12.61 Olsen's method (Olsen et al. 1954) [16] Exchangeable potassium (kg ha-1) 235.75 235.2 Flame photometer method (Jackson, 1958) Available zinc (mg kg-1) 0.61 0.59 DTPA extractant, estimated on atomic absorption spectrophotometer (Lindsay and Norvell, 1978) [17] Representative soil samples were collected from the plough layer (0-15 cm depth) prior to the layout of the experiment in both years and analysed for chemical properties using standard procedures (Table 1). The soil was slightly alkaline in reaction (pH 7.6-7.7) and nonsaline in nature (EC 0.21-0.22 dS m ¹). The organic carbon status was rated high, while⁻ available nitrogen, phosphorus and potassium were medium to high, and available zinc was marginally below the critical level, indicating scope for micronutrient management.

Experimental design and layout

The experiment was laid out in a Randomized Block Design (RBD) comprising 16 treatment combinations, each replicated thrice, giving a total of 48 plots. Sorghum (variety Amarnath 2000) was grown as the test crop at a seed rate of 12 kg ha⁻¹ , with a recommended dose of nutrients of 80:40:40 kg N: P₂O₅: K₂O ha ¹. Irrigation and drainage channels were ⁻ provided between plots to prevent lateral movement of water and nutrients from one treatment to another, and bunds were maintained around each plot.

Treatment Details

The treatments comprised two factors, viz., (A) method of microbial consortia application and (B) integrated nitrogen management, laid out in all possible combinations.  (A) Method of microbial consortia application: C₁ -seed treatment (30 g consortia kg⁻¹ seed); C₂ -soil application (2.5 kg consortia mixed with 50 kg well-decomposed FYM); C₃ -seed treatment + soil application; and C₄control (no consortia).

 (B) Integrated nitrogen management: N₁ -100% N through urea; N₂ • 50% N through FYM + 50% N through urea; N₃• 50% N through vermicompost (VC) + 50% N through urea; and N₄ -25% N through FYM+25% N through VC + 50% N through urea, against a recommended dose of nutrients of 80:40:40 kg N-P-K ha⁻¹ . The 16 resultant treatment combinations are listed in Table 4.

Meteorological conditions during the crop-growing period

The weather during the crop-growing period (June-November) has an important bearing on crop growth, nutrient availability and the activity of the microbial consortia. As station-specific weekly meteorological records for the exact experimental period were not available for compilation, the prevailing weather conditions during the Kharif cropping season based on the long-term (normal) climatological data published for the Prayagraj region. Maximum temperature during the crop season ranged from about 29.6 °C to 40.0 °C and declined progressively from June to November, while the minimum temperature ranged from 14.0 °C to 29.0 °C . The bulk of the rainfall (about 80%) was received during July-September, coinciding with the monsoon, after which the crop matured under receding soil moisture and declining relative humidity.

Statistical analysis

The data recorded for various observations were statistically analysed following the analysis of variance (ANOVA) technique applicable to a Randomized Block Design, as described by Gomez and Gomez (1984), to test the significance of treatment effects at the 5% level of probability. Treatment means were compared using the standard error of mean (SEm±) and critical difference (CD at 5%).

Pooled analysis (2024-2025)

The pooled data (Table 1) confirmed the consistency of the trend across both years. T 12 recorded the maximum pooled length of head (27.80 cm), statistically at par with T 11 (26.39 cm) (CD at 5% = 1.53). The minimum pooled length of head was recorded under T 1 (22.63 cm), statistically at par with T 13 (22.71 cm) and T 14 (22.77 cm).

The superiority of the combined seed-cum-soil application of microbial consortia integrated with 50% urea, 25% FYM and 25% VC (T 12 ) over other treatments in length of head can be attributed to the additive and synergistic action of dual inoculation, which ensured continuous rhizosphere and phyllosphere colonisation by the beneficial microbial community throughout the crop growth cycle. Seed treatment establishes an early microbial population around the emerging radicle, while the subsequent soil application replenishes and sustains this population during the vegetative-to-reproductive transition, when nutrient demand for panicle differentiation and elongation is at its peak. The consortia, comprising nitrogenfixing, phosphate-and potassium-solubilising and plant growthpromoting microorganisms, enhance the mineralisation of native and applied organic nutrients and secrete indole acetic acid, gibberellins and cytokinin-like substances that stimulate cell division and elongation in the meristematic tissue of the developing rachis, thereby increasing the length of the earhead. The partial substitution of inorganic nitrogen with FYM and VC further contributed to a more synchronous nutrient release pattern, since FYM mineralises slowly and provides a steady basal nutrient supply, whereas VC, being partially humified through earthworm gut passage, releases nutrients relatively faster and additionally supplies humic and fulvic acid fractions that improve nutrient and water use efficiency and elicit hormone-like physiological responses in the plant. Similar synergistic improvement in panicle/earhead characters following integration of microbial consortia with organic and inorganic nutrient sources has been reported by Inaniyan et al.

(2026) [12] , who observed that integrated nitrogen substitution with FYM combined with microbial inoculants markedly improved yield-attributing characters of sorghum over sole chemical fertilisation. Likewise, Sande et al. (2024) [18] , in a systematic review on integrated nutrient management, concluded that combining vermicompost with inorganic fertiliser consistently enhanced crop growth and developmental attributes relative to either input applied alone, owing to improved nutrient synchrony and rhizosphere biological activity. In contrast, the lowest length of head under sole seed treatment with 100% urea (T 1 ) and the no-consortia treatments reflects the absence of a sustained microbial population in the root zone coupled with the well-documented susceptibility of urea-nitrogen to volatilisation and leaching losses under semiarid conditions, which restricts nitrogen availability during the critical panicle elongation phase and consequently curtails head length.

Number of grains per head 2024

Data on the number of grains per head ( The number of grains per head is largely a function of successful floret initiation, pollination and reduced floret/grain abortion during the anthesis-to-grain-set period, all of which are highly sensitive to the availability of assimilates and nutrients at this critical growth stage. The superior performance of the dual seed-and-soil applied consortia integrated with 50% urea + 25% FYM + 25% VC (T 12 ) can be explained by the sustained enzymatic activity (dehydrogenase, urease and phosphatase) that microbial consortia impart to the rhizosphere, which improves the synchrony between nutrient release from organic sources and the nutrient demand of the crop during panicle development, thereby minimising floret abortion and improving fertilisation efficiency of a greater proportion of florets on the panicle. Sahib et al. (2020) [19] demonstrated that increasing rhizobacterial species richness in the root zone of sorghum enhanced soil nutrient synergism and plant nutrient assimilation relative to uninoculated or single-strain treatments, supporting the greater nutrient-acquisition efficiency observed under the consortia-based treatments in the present study. Similarly, Inaniyan et al. (2026) [12] reported that integrated nitrogen management combining urea with organic manures and Azospirillum inoculation significantly increased the number of grains per head in sorghum over sole inorganic fertilisation, attributing it to improved nitrogen-use efficiency and prolonged photosynthetic activity of the flag leaf and upper canopy during the grain-filling window. Conversely, the significantly lower grain numbers recorded under the no-consortia sole-urea treatments (T 13 , T 14 , T 15 ) are attributable to a mismatch between the pulse-release nature of inorganic urea and crop demand, greater susceptibility of urea nitrogen to volatilisation and leaching under semi-arid kharif conditions, and the absence of a beneficial microbial community to buffer nutrient supply, all of which predispose the crop to source limitation and consequent abortion of the terminal and lower florets on the panicle.

The data on grain yield ( [18] , who reported through a systematic review that the combined application of vermicompost with inorganic fertiliser increased cereal grain yield substantially over sole mineral fertilisation on account of improved soil biological activity and nutrient availability, and Inaniyan et al. (2026) [12] , who observed that integrated nitrogen management with organic manures and microbial inoculants recorded significantly higher grain yield of sorghum compared with sole chemical fertiliser application. The consistently lowest grain yield recorded under the no-consortia sole-urea treatments (T 13 -T 16 ) and plain seed-treated, 100% urea treatments (T 1 , T 2 ) can be ascribed to the absence of sustained microbial activity in the rhizosphere, which otherwise assists in nutrient mineralisation, solubilisation and hormonal stimulation, coupled with greater gaseous and leaching losses of urea nitrogen typical of light-textured semi-arid soils, resulting in a lower number of grains per head and reduced overall sink capacity.

The data presented in Table 2 [20] similarly reported that integration of organic biomass sources with mineral fertiliser improved rainwater-use efficiency and biomass accumulation in sorghum under semi-arid rainfed conditions, while Sande et al. (2024) [18] noted that vermicompost-based integrated nutrient management enhances soil organic carbon and microbial biomass carbon, both of which are closely linked with greater vegetative growth and stover accumulation in cereals. The comparatively lower stover yield under the no-consortia, sole-urea treatments reflects restricted root development and shorter canopy duration arising from erratic and often insufficient nitrogen availability, compounded by the absence of the soil-structural and biological benefits conferred by organic manures and microbial inoculation.

The data presented in Table 3 revealed that the effect of microbial consortia and integrated nitrogen management on test weight was statistically non-significant (F-test: NS) during 2024, 2025 as well as on pooled basis. Numerically, the highest test weight was recorded under T 12 (30.47 g in 2024, 30.81 g in 2025 and 30.64 g pooled), while the lowest was recorded under T 14 (27.00 g in 2024, 27.34 g in 2025 and 27.17 g pooled). Since the Ftest was non-significant in all three data sets, the treatments could not be statistically differentiated, and no critical difference (CD) value could be computed.

Discussion

Test weight, being largely an expression of grain density, endosperm compactness and pericarp thickness, is a relatively conservative trait that is under stronger genetic control and is comparatively less plastic to short-term variation in nutrient management compared with attributes such as the number of grains per head. The non-significant response observed in the present study suggests that, irrespective of the nutrient source or microbial inoculation regime, the assimilate supply during the grain-filling phase was adequate across all sixteen treatments to permit near-complete grain filling, so that any additional benefit accruing from microbial consortia and organic nutrient sources was channelled predominantly into increasing the number of grains formed (sink number) rather than into further augmenting the weight of individual grains (sink size), a compensatory source-sink relationship frequently observed in cereals under favourable growing conditions. This observation is broadly in agreement with Biswas (2024) [21] , who noted in a comprehensive review of PGPR-based bioinoculants that while microbial consortia consistently improve nutrient acquisition and yield-contributing characters, their influence on grain density-related traits such as test weight is often marginal and genotype-dependent. Kugedera et al.

(2022) [20] likewise reported that in rainfed sorghum, treatmentinduced gains in yield were driven mainly by improvements in panicle and grain-number-related traits rather than by test weight, which remained relatively stable across nutrient management regimes. The slightly higher numerical test weight under the fully integrated consortia treatments may still be agronomically meaningful, reflecting marginally improved grain filling associated with prolonged stay-green duration, even though the difference did not attain statistical significance at the given level of replication.

The pooled data (Table 3) confirmed T 10 as the superior treatment for harvest index (37.97%), statistically at par with T 12 (37.95%) and T 11 (37.69%) (CD at 5% = 0.98). The lowest pooled harvest index was recorded under T 13 (34.17%), statistically at par with T 15 (34.23%), T 2 (34.27%), T 14 (34.31%), T 16 (34.45%) and T 1 (34.52%).

Harvest index represents the efficiency of partitioning of total dry matter towards economic (grain) yield and is governed by the source-sink balance established during the reproductive and grain-filling phases. It is noteworthy that T 10 , involving a 1:1 substitution of the recommended urea dose with FYM under the dual consortia application, recorded the highest harvest index even though its absolute grain and stover yields were marginally lower than those of T 11 and T 12 , indicating a more favourable partitioning efficiency rather than sheer biomass superiority. This may be explained by the moderating effect of FYM on the carbon-to-nitrogen ratio of the rhizosphere, which tempers excessive vegetative luxuriance that is typically promoted by higher doses of readily available inorganic nitrogen, thereby favouring a proportionately greater allocation of photosynthates towards the developing grains rather than towards additional vegetative tissue. Microbial consortia further reinforce this balance by improving phosphorus and potassium availability, both of which are critical for phloem loading and translocation of photosynthates to the grain during the grain-filling period. These results are consistent with Sapkota et al. (2025) [22] , who reported that integrated nutrient management combining organic and inorganic nitrogen sources produced the highest harvest index in cereals relative to either sole organic or sole inorganic nutrition, and with Sande et al. (2024) [18] , who attributed improved harvest index under integrated nutrient management to better source-sink coordination arising from balanced and sustained nutrient availability throughout the crop cycle. The lowest harvest index recorded under the noconsortia sole-urea treatments (T 13 and related treatments) reflects a nutrient supply pattern skewed towards early vegetative growth with limited residual nitrogen available for translocation during grain filling, resulting in proportionately greater stover accumulation relative to grain yield and, consequently, a lower harvest index.

Conclusion

The study demonstrated that integrating microbial consortia with inorganic and organic nitrogen sources significantly improved sorghum productivity. Among all treatments, T 12 (Seed treatment + Soil Application + 50% Urea + 25% FYM + 25% Vermicompost) consistently produced the highest yield attributes, grain yield, and stover yield, while remaining statistically at par with T 11 . Test weight was not significantly influenced by the treatments. Overall, integrated nutrient management involving microbial consortia with partial substitution of urea by FYM and vermicompost proved to be an effective and sustainable strategy for enhancing sorghum yield.

Acknowledgement

The authors are thankful to Department of Agronomy, Naini Agricultural Institute, Prayagraj, Sam Higginbottom University of Agriculture Technology And Sciences, (U.P) India for providing necessary facilities to undertaken the studies.

References

1. Ananda GKS, Myrans H, Norton SL, Gleadow R, Furtado A, Henry RJ. Wild sorghum as a promising resource for crop improvement. Frontiers in Plant Science. 2020;11:1108.https://doi.org/10.3389/fpls.2020.01108
2. Altaf MT, Liaqat W, Jamil A, Mohamed HI, Fahad M, Jan MF, et al. A critical review: Breeding objectives, genomic resources, and marker-assisted methods in sorghum (Sorghum bicolor L.). Journal of Soil Science and Plant Nutrition. 2024;24:45974623.https://doi.org/10.1007/s42729-024-
3. Centre for Agriculture and Rural Development Policy Research [CARD]. Sorghum -June to May, 2023-24: Agricultural market intelligence outlook report. Acharya N. G. Ranga Agricultural University; 2024.
4. DesiKheti. Top 10 jowar-producing states in India. DesiKheti Knowledge Hub. 2025.https://knowledge.desikheti.com/top-10-jowarproducing-statesin-india/
5. M P Chari. International Journal of Plant and Soil Science. 2023;35(8):64-68.
6. Tanwar R, Panghal A, Chaudhary G, Kumari A, Chhikara N. Nutritional, phytochemical and functional potential of sorghum: A review. Food Chemistry Advances. 2023;3:100501.https://doi.org/10.1016/j.focha.2023.10050 1
7. Chhikara N, Abdulahi BA, Munezero C, Kaur R, Singh S, Panghal A. Exploring the nutritional and phytochemical potential of sorghum in food processing for food security. Nutrition and Food Science. 2018;49(2):318332.https://doi.org/10.1108/NFS-05-2018-0149
8. Kavya Y, Trimurtulu N, Vijaya Gopal A, Madhu Vani P, Prasad NVVS D. Influence of carrier-based microbial consortia on the growth and yield attributes of sorghum [Sorghum bicolor (L.) Moench]. Applied Biological Research. 2020;22(2):109-117.
9. Srivastava AK, Riaz A, Jiang J, Li X, Uzair M, Mishra P, et al. Advancing climate-resilient sorghum: The synergistic role of plant biotechnology and microbial interactions. Rice. 2025;18(1):41.https://doi.org/10.1186/s1228411.
10. Wang Z, Nie T, Lu D, Zhang P, Li J, Li F, et al. Effects of different irrigation management and nitrogen rate on sorghum (Sorghum bicolor L.) growth, yield and soil nitrogen accumulation with drip irrigation. Agronomy. 2024;14(1):215.https://doi.org/10.3390/agronomy1401021 5
11. Inaniyan A, Choudhary BL, Ola MP, Prajapat N. Soil health and yield dynamics under nitrogen substitution and microbial inoculants of sorghum (Sorghum bicolor L.). Chemical Science Review and Letters. 2026.https://doi.org/10.37273/chesci.cs022057051
12. Jackson ML. Soil chemical analysis. Prentice-Hall of India Pvt. Ltd; 1973.
13. Walkley A, Black IA. An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Science. 1934;37(1):29-38.
14. Subbiah BV, Asija GL. A rapid procedure for the estimation of available nitrogen in soils. Current Science. 1956;25:259-260.
15. Olsen SR, Cole CV, Watanabe FS, Dean LA. Estimation of available phosphorus in soils by extraction with sodium bicarbonate (USDA Circular No. 939). U.S. Department of Agriculture; 1954.
16. Lindsay WL, Norvell WA. Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Science Society of America Journal. 1978;42(3):421-428.
17. Sande TJ, Tindwa HJ, Alovisi AMT, Shitindi MJ, Semoka JM. Enhancing sustainable crop production through integrated nutrient management: A focus on vermicompost, bio-enriched rock phosphate, and inorganic fertilisers -A systematic review. Frontiers in Agronomy. 2024;6:1422876.https://doi.org/10.3389/fagro.2024.14228 76
18. Sahib MR, Pervaiz ZH, Williams MA, Saleem M, DeBolt S. Rhizobacterial species richness improves sorghum growth and soil nutrient synergism in a nutrient-poor greenhouse soil. Scientific Reports. 2020;10:15454.https://doi.org/10.1038/s41598-02072516-3
19. Kugedera AT, Nyamadzawo G, Mandumbu R. Augmenting Leucaena leucocephala biomass with mineral fertiliser on rainwater use efficiency, agronomic efficiency and yields on sorghum (Sorghum bicolor [(L.) Moench]) under rainwater harvesting techniques in semi-arid region of Zimbabwe. Heliyon. 2022;8(4):e09826.https://doi.org/10.1016/j.heliyon.2022.e 09826
20. Biswas A. Plant growth promoting rhizobacteria (PGPR): Reports on their colonization, beneficial activities, and use as bioinoculant. Advances in Agriculture. 2024;2024:8173024.https://doi.org/10.1155/2024/8173024
21. Sapkota S, et al. Integrated nutrient management in spring maize production in Nepal. Agrosystems, Geosciences and Environment. 2025;8(3):e70178.https://doi.org/10.1002/agg2.70178