Review on enhancing the efficiency of fertilizer utilization: Strategies for optimal nutrient management

1 Introduction

The study of fertilizer use efficiency (FUE) improvement is directly linked to the anticipated population growth, with projections indicating a global population surge to 9.7 billion by 2050 [1,2]. As the population expands, so does the demand for food and mineral fertilizers, underscoring the critical need to enhance fertilizer utilization. This connection highlights the urgency of optimizing fertilizer use, particularly mineral fertilizers, to meet the escalating food demands sustainably while mitigating environmental impacts.

The phrase “Enhancing the Efficiency of Fertilizer Utilization” encapsulates a multifaceted approach aimed at maximizing the benefits derived from fertilizers while minimizing potential negative impacts on the environment. This concept is particularly relevant in the context of global food security and the increasing demand for agricultural products to feed a growing population. Since FUE affects both the environment and the economy, it is critical for sustainable agriculture [3]. In addition to costing farmers money, ineffective fertilizer application can result in nutrient losses, water contamination, and greenhouse gas emissions [4].

Various contaminants contribute to agricultural water pollution with agricultural runoff, including excess fertilizer, e.g., in the United States it contributes to the pollution of more than 100,000 miles of rivers and streams, as well as 2,500 square miles of lakes each year [5,6]. Agricultural operations can also release pollutants into bodies of water, such as bacteria, heavy metals, and salts, and cause pollution and barren land, which results in a food shortage. According to the reports of Zahoor and Mushtaq [5], food shortages were reported in 2018 in different countries of the world, including the United States (2.3%), Canada (4.6%), the United Kingdom (8.2%), Germany (2.6%), Japan (2.9%), Ethiopia (23.4%), Niger-Ivory Coast (22.4%), Bangladesh (12.7%), Pakistan (17.2%), Haiti (45.6%), and India (14.3%).

Agriculture is blamed for emitting 10–12% of all greenhouse gases (GHGs) worldwide, with organic or mineral fertilizers accounting for 38% of these emissions [7]. It also contributes up to 30% of global GHG emissions [8], primarily from the application of mineral fertilizers and manures to crop and soil systems [9], with annual demand for N, P, and K expected to rise by 1.4, 2.2, and 2.6%, respectively, from 2014 to 2018 [10], as well as cultivation of peatlands [7,11]. Economic impacts include reduced crop yields, as studies have shown that for every dollar spent on fertilizer in sub-Saharan Africa, farmers receive only about $0.50 in increased productivity due to inefficiencies of fertilizer utilization caused by its overuse and improper application [12]. Increased production costs are evident in the European Union, where the economic cost of nutrient pollution from agriculture, including the impacts of inefficient fertilizer use, is estimated to be between €7 billion and €10 billion annually [13].

Although fertilizers are crucial inputs for modern agriculture, their misuse significantly diminishes utilization by crops and contributes to the above-stated environmental pollution. Therefore, prioritizing optimized fertilizer application is essential for achieving sustainable and efficient crop production. Accordingly, integrated fertilizer strategies emerge as key methods to enhance fertilizer utilization, playing a significant role in curbing the substantial costs associated with chemical fertilizers. For example, a study by Abebe et al. [14] conducted in Bako, Ethiopia, showed that combining 12 t ha⁻¹ of farmyard manure (FYM) with 28-12 N-P₂O₅ kg ha⁻¹ led to savings of up to 75% in the cost of commercial fertilizer. Similarly, a study by Laekemariam and Gidago [15] in Wolaita, Ethiopia, suggested that using 5 t ha⁻¹ compost in conjunction with inorganic fertilizer (50 kg Urea and 100 kg DAP ha⁻¹) could result in improved maize yields and soil quality on a sustainable basis.

Therefore, farmers need to use fertilizers efficiently to minimize wastage and reduce environmental impacts while still maintaining high crop yields. The pursuit of optimal nutrient management involves a deep understanding of soil health, plant physiology, and the intricate interactions between various nutrients. Farmers and agricultural scientists are increasingly turning to precision agriculture techniques, data analytics, and advanced technologies to tailor fertilizer applications to specific crop needs and soil conditions.

Moreover, the adoption of organic and sustainable farming practices is gaining momentum as a means to improve the overall efficiency of nutrient utilization, promoting long-term soil health and resilience [16]. This comprehensive approach goes beyond traditional methods and embraces a holistic perspective, acknowledging the interconnectedness of soil, plants, and the broader ecosystem in the quest for sustainable and efficient fertilizer utilization. In this dynamic landscape, continual research and collaboration are essential to refine existing strategies and develop new ones that contribute to both increased agricultural productivity and environmental stewardship.

As agricultural practices continue to evolve, there is a growing recognition of the need to adopt innovative strategies that not only enhance crop yields but also prioritize the judicious use of fertilizers to mitigate environmental degradation. To maximize FUE and advance sustainable agriculture, this article addresses the significance of nutrient management planning, precision agriculture approaches, improved fertilizer formulations, and application techniques, in addition to nutrient stewardship and best management practices.

2 Importance of FUE

The FUE is a measure of the potential of an applied fertilizer to increase the productivity and utilization of the nutrients present in the soil/plant system. FUE is a critical aspect of sustainable agriculture as it directly impacts both the environment and the economy. As cited in the studies by Ali and Pilbeam [17,18], significant amounts of nitrogen fertilizer are annually distributed across agricultural lands, resulting in considerable financial expenditure. Nevertheless, the efficiency of this nitrogen application generally ranges from 30 to 70%, signifying notable losses. To bolster crop productivity, conserve energy, reduce expenditures, and mitigate environmental hazards, maximizing the plant’s uptake of applied nitrogen is imperative.

Understanding inefficient fertilizer use’s environmental and economic implications is crucial for ensuring long-term agricultural productivity while mitigating adverse effects on ecosystems. Inefficient fertilizer application can result in nutrient losses through runoff and leaching, leading to water pollution and the eutrophication of aquatic ecosystems [19,20]. Moreover, excessive fertilizer use contributes to greenhouse gas emissions and poses financial burdens for farmers. According to a recent study by Ren et al. [21], optimizing FUE can lead to substantial cost savings and reduce agriculture’s environmental footprint. It is essential to recognize the negative consequences associated with inefficient fertilizer use and shift toward more sustainable practices to ensure long-term agricultural productivity and environmental stewardship.

Sustainable agricultural practices play a vital role in addressing the challenges posed by inefficient fertilizer use. By adopting sustainable approaches, such as precision nutrient management and conservation practices, farmers can minimize nutrient losses and enhance FUE. A study by Singh et al. and Shankar et al. [22,23] demonstrated that precision agriculture techniques, such as variable rate fertilization based on soil characteristics, resulted in improved nutrient utilization and reduced environmental impact. Additionally, incorporating cover crops and crop rotation can enhance soil fertility, reduce nutrient runoff, and mitigate the need for excessive fertilization [24,25,26]. These sustainable practices promote resource conservation and contribute to long-term soil health and resilience, supporting the goals of sustainable agriculture.

The urgent need for sustainable agricultural practices is evident in the face of increasing global food demand and environmental challenges. As highlighted by Penuelas et al. [27], adopting sustainable fertilizer management practices is crucial for achieving food security while minimizing the negative impacts on ecosystems and human health. Transitioning to precision nutrient management, implementing best management practices, and embracing innovative technologies will facilitate the optimization of FUE [28]. Moreover, Gebska et al. [29] stated that promoting awareness among farmers, policymakers, and consumers about the importance of sustainable agriculture can drive the adoption of practices that balance productivity with environmental stewardship, ensuring a sustainable future for agriculture and the planet.

3 Nutrient management planning

Nutrient management planning is the management of the amount (rate), source, placement (method of application), and timing of plant nutrients and soil amendments [30]. Its purpose is to budget, supply, and conserve nutrients for plant production, minimize agricultural nonpoint source pollution of surface and groundwater resources, properly utilize manure or organic byproducts as a plant nutrient source, protect air quality by reducing odors, nitrogen emissions (ammonia, oxides of nitrogen), and the formation of atmospheric particulates, and maintain or improve the physical, chemical, and biological condition of the soil.

Nutrient management planning increases fertilizer utilization and efficiency [31] by precisely tailoring fertilizer applications to crop needs, optimizing timing and placement, promoting nutrient cycling and soil health, protecting the environment, and enhancing economic sustainability.

Effective nutrient management planning is crucial for sustainable agriculture, as it allows farmers to optimize nutrient use and minimize environmental impacts. Developing a comprehensive nutrient management plan is the foundation of efficient fertilizer application. By considering factors such as crop nutrient requirements, soil properties, and environmental considerations, farmers can modify their fertilizer practices to meet the specific needs of their fields [32]. This approach ensures optimal crop nutrition and reduces the risk of overapplication, minimizing nutrient losses and potential pollution of water bodies.

Assessing soil fertility and nutrient requirements is a key step in nutrient management planning [33]. Soil testing provides critical information about the nutrient content, pH levels, and other soil characteristics that influence nutrient availability to plants, enabling farmers to make informed decisions about fertilizer application [34]. Through soil analysis, farmers can identify nutrient deficiencies or excesses, enabling them to apply fertilizers in a targeted manner [35]. Moreover, soil testing can help identify specific nutrient management strategies, such as the use of organic amendments or specific fertilizer formulations, to address nutrient imbalances effectively [36,37]. For example, an assessment of soil fertility status employing Geomatics in the West Nile Delta, Egypt, conducted by AbdelRahman et al. [38], revealed that enriching medium and poor fertile soils with organic fertilizers such as compost and manure promotes the development of the clay-humic complex. This process significantly enhances water retention within the soil. Furthermore, the application of mineral fertilizers helps rectify the Cation Exchange Capacity and boosts the levels of exchangeable cations, thereby augmenting the soil’s overall base saturation.

Utilizing soil testing and analysis for informed decision-making is critical for optimizing FUE. By understanding the nutrient content and variability within their fields, farmers can implement site-specific nutrient management strategies. For instance, adopting variable rate fertilization based on soil testing results allows farmers to adjust fertilizer rates according to the nutrient requirements of different areas within a field [39].

By integrating livestock into their farming systems, farmers can develop comprehensive nutrient management plans that optimize nutrient utilization and minimize nutrient losses. As described by Lemaire et al. [40], integrating crop and livestock production systems allows for better nutrient cycling, as animal waste can be utilized as fertilizer for crops.

Table 1 offers vital insights into the nutrient content of manure, serving as a valuable resource for farmers engaged in integrated crop-livestock systems for nutrient management planning. By understanding the nitrogen, phosphorus, and potassium content of manure, farmers can make informed decisions regarding its application, ensuring optimal nutrient utilization while safeguarding water resources.

The ultimate goal of developing a nutrient management plan is to maximize crop productivity and minimize nutrient losses. Factors such as crop type, growth stage, and final yield goals affect the optimal amount of nutrients required for specific crops [42]. A well-designed nutrient management plan takes into account the crop’s nutrient uptake patterns throughout the growing season, ensuring that nutrients are supplied when the plants need them the most. Additionally, it incorporates sustainable practices such as incorporating organic amendments, utilizing cover crops, and practicing crop rotation to enhance soil fertility and nutrient availability [26]. By integrating these strategies into the nutrient management plan, farmers can achieve long-term sustainability while optimizing FUE and minimizing potential environmental impacts.

4 Precision agriculture techniques

Precision agriculture techniques have transformed modern farming by enabling farmers to optimize fertilizer use and improve nutrient management practices. Implementing precision farming technologies such as GPS and sensor-based equipment allows for targeted fertilizer application, ensuring that nutrients are delivered to crops in the right quantity, at the right time, and in the right place [22,43]. This approach not only improves FUE but also minimizes environmental impacts by reducing nutrient losses. For instance, [39] stated that the use of variable rate fertilization based on soil characteristics and crop requirements allows farmers to adjust fertilizer rates within a field, optimizing nutrient distribution and avoiding over-application. By adopting precision agriculture techniques, farmers can achieve higher crop yields while minimizing fertilizer waste and potential environmental harm.

Geographic information system (GIS) is a powerful tool for highlighting agricultural land suitability and analyzing the cross-tabulation between various thematic map classes concerning agricultural land suitability and can be applied at various scales [44]. The integration of remote sensing and GIS technologies in precision agriculture plays a crucial role in site-specific nutrient management. Remote sensing techniques, such as aerial imagery and satellite data, provide valuable data on crop health, biomass, nutrient status, and soil variability, enabling farmers to make informed decisions regarding nutrient application [45,46,47] utilized GIS, Landsat OLI satellite images, and multi-temporal satellite image analysis to assess the scale and progression of salinity in designated areas. The findings of the investigation affirm the efficacy of these established methodologies in delivering precise and timely geospatial data delineating soil conditions. The process of zoning or categorizing these regions facilitates improved management and mitigation efforts across varying salinity gradients. Such an approach stands as a pivotal management strategy, effectively enhancing crop productivity.

GIS platforms, in combination with remote sensing data, allow for the creation of nutrient management maps that highlight spatial variations in soil fertility and nutrient requirements. This spatially explicit information enables farmers to implement variable rate fertilization, adjusting fertilizer rates according to the specific nutrient needs of different areas within a field [48]. This integration of remote sensing and GIS technologies enhances nutrient management precision, optimizes fertilizer use, and contributes to sustainable agriculture.

A study conducted by AbdelRahman and Metwaly [49] in the West Nile Delta, Egypt focused on digital soil characteristics mapping for aiding site-specific management practices revealing the nutritional status of the study area and suggesting soil management and conservation practices. The study concludes that widespread shortages exist in N, P, K, S, B, and Cu. Soil management measures such as conservation tillage, crop residue management and incorporation, and soil conservation practices are recommended to maintain and enhance soil carbon, as well as to correct nutrient deficits. Chemical fertilizer comprising N, P, S, B, and Cu is advised, with K fertilizer recommended in locations where Mg-induced K shortages exist. Additionally, lime can be used to address calcium and magnesium.

Incorporating variable rate fertilization based on soil characteristics is a key aspect of precision agriculture for efficient nutrient management [50]. In harmony, a study conducted by AbdelRahman and Metwaly [49] within the West Nile Delta region of Egypt, verified that Digital Soil Characteristics Mapping (DSM) facilitates the delineation of various management zones, thereby obviating the necessity for generalized soil nutrient interventions. Utilizing the DSM data, farmers can receive tailored recommendations for crop cultivation, optimizing nutrient applications according to site-specific requirements. Furthermore, AbdelRahman et al. [51] in their publication entitled “Soil Fertility Assessment for Optimal Agricultural Use Using Remote Sensing and GIS Technologies” concluded that employing modern irrigation techniques is advantageous for seamlessly integrating various fertilizers with irrigation water, thereby maximizing crop yield. Soil characteristics, including pH, texture, and organic matter content vary spatially within a field and, influence nutrient availability and crop nutrient requirements. By utilizing soil sensing technologies, such as electromagnetic induction or soil electrical conductivity measurements, farmers can identify these spatial variations and tailor fertilizer application rates accordingly [52]. This approach also allows for the adjustment of fertilizer rates based on the specific nutrient requirements of different areas within a field, ensuring that nutrients are supplied in optimal amounts where they are most needed. This approach maximizes nutrient uptake by crops, minimizes overapplication in areas with high fertility, and reduces nutrient losses, ultimately leading to improved FUE and sustainable nutrient management [3,53].

In the research by Tripathi et al. [54], multiple studies have confirmed the advantages of using precision tools and techniques for applying nitrogen fertilizer in rice compared to traditional methods. These methods include deep placement of urea briquette, drip fertigation, fertilizer application through micro irrigation (fertigation), integrated precision rice management systems, and variable rate application. Studies referenced in Table 2 have shown that different techniques and application methods like enhancing crop and water management and optimizing nutrient application at specific sites, increase crop yields and nitrogen use efficiency (NUE) in rice farming.

5 Enhanced fertilizer formulations and application methods

In contemporary agriculture, advancements in fertilizer formulations and application methods have revolutionized nutrient management, promoting enhanced crop productivity while minimizing environmental impact. The exploration of slow-release and controlled-release fertilizers offers promising solutions for sustained nutrient release over an extended period, matching the nutrient requirements of crops with their growth stages [64]. These fertilizers are designed to release nutrients gradually, reducing nutrient losses due to leaching and volatilization, and improving nutrient uptake by plants [65]. Slow-release and controlled-release fertilizers provide a more balanced nutrient supply, minimizing the risk of nutrient deficiencies or excesses and promoting more efficient nutrient utilization in agricultural systems [66,67].

Coated and encapsulated fertilizers have emerged as effective tools for optimizing nutrient availability and reducing nutrient losses in agricultural systems [68]. These fertilizers are coated or encapsulated with materials that control the release of nutrients, protecting them from environmental factors and regulating their availability to plants [65,69]. The coating or encapsulation technology allows for a controlled release of nutrients, ensuring a more targeted nutrient supply that aligns with crop needs. The efficacy of coated and encapsulated fertilizers depends on the selection of appropriate coating materials, the thickness of the coating layer, and the nutrient release characteristics [70]. By preventing nutrient losses due to volatilization, runoff, or immobilization, coated and encapsulated fertilizers help maximize nutrient uptake by crops and minimize potential negative impacts on the environment [3,68].

Through innovations like super granular urea (SGU) and precision application techniques, farmers can also deliver nutrients more efficiently, reducing losses due to volatilization and leaching. These methods enable tailored nutrient delivery based on soil and crop needs, optimizing nutrient use efficiency while mitigating environmental risks. SGU fertilizer typically refers to a type of urea fertilizer that has undergone a granulation process to create larger, more uniform granules compared to traditional urea granules. These granules are often more resistant to breakage, dust formation, and nutrient loss through volatilization. Accordingly, in a field experiment conducted under rain-fed conditions in the Tigray Regional State of Ethiopia, the application of SGU fertilizer increased wheat crop yield and NUE as compared to conventional urea (CU) fertilizer, but losses increased as the application rate increased [71]. Taking into account NH₃ volatilization and NO₃ leaching as potential factors influencing the observed results emphasizes the significance of strategically managing nitrogen fertilizer applications to reduce losses and enhance both efficiency and environmental sustainability in agricultural practices. Figure 1 demonstrates that the utilization of SGU results in superior apparent fertilizer recovery, agronomic use efficiency, and physiological use efficiency compared to CU (46% N) when applied to wheat.

Figure 1

Comparison of fertilizer recovery and use efficiency metrics across different types of Urea and application rates in wheat cultivation: Insights from Tigray, Ethiopia. Source: [71].

Other innovative application methods, such as fertigation and foliar spraying, offer potential avenues for improving fertilizer efficiency and nutrient uptake by crops. Fertigation involves the simultaneous application of water and fertilizers through irrigation systems, allowing for precise and efficient nutrient delivery to the root zone [72]. This method ensures that nutrients are supplied in a targeted manner, matching the crop’s requirements and reducing nutrient losses due to runoff or leaching. On the other hand, foliar spraying involves applying liquid fertilizer directly to the leaves, allowing for rapid nutrient absorption and utilization by plants [73]. This method is particularly useful for supplying micronutrients or correcting nutrient deficiencies during critical growth stages. By exploring and implementing innovative application methods like fertigation and foliar spraying, farmers can enhance FUE, improve nutrient uptake, and reduce environmental impacts [36].

6 Nutrient stewardship and best management practices

Nutrient stewardship and best management practices are crucial for sustainable agriculture and optimizing nutrient use efficiency. Nutrient stewardship emphasizes applying the appropriate nutrient source, in the correct amount, to the precise location, and at the optimal timing [74]. These practices offer economic, social, and environmental benefits essential for sustainable agricultural systems, thereby providing a solid foundation for tailored strategies to enhance NUE [75]. Promoting responsible fertilizer use through proper timing and placement is a key aspect of nutrient stewardship [76]. By applying fertilizers at the right time, farmers can ensure that nutrients are available to plants when they are most needed for growth and development [27,77]. Additionally, proper placement of fertilizers, such as deep placement or banding, targets nutrient delivery to the root zone, minimizing nutrient loss and improving nutrient uptake [78]. Hence, these practices help prevent nutrient runoff and leaching, reducing the risk of water pollution and environmental degradation while maximizing crop nutrient utilization. In harmony, Figure 2 illustrates the 4R nutrient stewardship concept, emphasizing the importance of selecting the appropriate nutrient source, rate, time, and place for fertilizer application to achieve desired economic, social, and environmental outcomes within the plant ecosystem.

Figure 2

The 4R nutrient stewardship concept defines the right source, rate, time, and place for fertilizer application as those producing the economic, social, and environmental outcomes desired by all stakeholders in the plant ecosystem. Source: [79].

Integrating cover crops and crop rotation is an effective practice for enhancing nutrient cycling and reducing nutrient losses in agricultural systems [26]. Cover crops are grown between cash crops to cover the soil and capture nutrients, preventing them from being lost through leaching or erosion. The cover crops absorb excess nutrients from the soil, which can be later released and made available to the following cash crops. This improves nutrient cycling and reduces the need for synthetic fertilizers. Crop rotation, on the other hand, involves alternating different crops on the same field in a planned sequence. This practice disrupts pest and disease cycles, improves soil health, and enhances nutrient cycling. By adopting cover crops and crop rotation, farmers can enhance nutrient stewardship by improving nutrient retention, reducing fertilizer requirements, and promoting sustainable soil fertility management [80].

Adopting conservation practices is essential for reducing nutrient losses and preserving environmental quality [81]. Erosion and leaching are major pathways through which nutrients are lost from agricultural fields. Conservation practices, such as the use of vegetative buffers, terracing, and conservation tillage, help minimize soil erosion and nutrient runoff [82]. By reducing soil erosion, these practices preserve the nutrient-rich topsoil and prevent nutrient loss from reaching water bodies. Additionally, Yang et al. [83] also reported that precision irrigation techniques, such as drip irrigation or soil moisture sensors, can be employed to ensure that water and nutrients are efficiently delivered to plants while minimizing leaching and runoff. By integrating conservation practices into nutrient management strategies, farmers can protect water quality, conserve soil fertility, and contribute to sustainable agricultural production [82].

Utilizing a combination of organic and inorganic fertilizers is another effective management strategy to improve crop yield, optimize fertilizer usage, and enhance efficiency. An experiment conducted by Kakraliya et al. [84] confirmed that different components of fertilizer use efficiencies exhibited significant enhancements through the combined use of manures, chemical fertilizers, and bio-fertilizers, surpassing both the control and application of chemical fertilizer application alone. As a result, the partial factor productivity, agronomic efficiency, and physiological efficiency experienced notable improvements of 36.36, 125, and 15.3%, respectively, when applying an integrated approach involving chemical fertilizers, vermicompost, FYM, and Azotobacter, in contrast to sole application of chemical fertilizer.

In harmony, a study by Tsegaye [85] stated that the agronomic efficiency and apparent recovery of nitrogen (N) and phosphorus (P) on potato exhibited significant enhancement in plots receiving the integrated application of FYM and blended NPSZnB + K fertilizer compared to those with the sole application of FYM, DAP, or blended NPSZnB + K.

Moreover, a study by Khan et al. [86] confirmed that compared to plots receiving only manure or no fertilizer (control), the treatment combining farm yard manure (25% N) with mineral fertilizer (75% N) showed both greater overall productivity (agronomic efficiency) and improved NUE. Table 3 also illustrates that the utilization of integrated fertilizer leads to an improvement in nutrient utilization efficiency.

Another best management practice is the foliar fertilizer application method. Foliar fertilization, which delivers nutrients directly to leaves, presents a promising avenue for enhancing FUE. Circumventing the intricate soil processes inherent in traditional soil application, not only ensures targeted nutrient delivery but also mitigates the risk of nutrient loss and environmental dispersion [90]. A study by Škarpa et al. [91] explored foliar phosphorus (P) application’s impact on pea growth and quality, revealing differential responses among cultivars. Similarly, foliar magnesium fertilization, regardless of the application method (soil or leaf), enhanced wheat yield and NUE [92]. A similar author suggests magnesium plays a key role in optimizing nitrogen uptake by the plant. Moreover, a study by Škarpa et al. [93] combining foliar Urea Ammonium Nitrate fertilizer with waste elemental sulfur from biogas production can harvest improved maize growth, suggesting a more economical and environmentally friendly approach.

7 Role of biological approaches to improve nutrient cycle and uptake

Biological approaches play a crucial role in improving nutrient uptake and cycling in agricultural systems. Harnessing the potential of beneficial microorganisms is a promising strategy for improving nutrient uptake and cycling in agricultural systems [94,95,96]. Certain microorganisms, such as mycorrhizal fungi, rhizobacteria, and plant growth-promoting rhizobacteria (PGPR) form symbiotic relationships with plant roots, aiding in nutrient acquisition and uptake [97,98]. Mycorrhizal fungi extend the root system’s reach by forming a network of fungal hyphae that can access nutrients from a larger soil volume, while rhizobacteria can enhance nutrient solubilization and mineralization. Etesami et al. and Bücking et al. [99,100] also stated that mycorrhizal fungi establish mutualistic associations with plant roots, extending their nutrient-absorbing surface area and enhancing nutrient uptake, especially phosphorus. Similarly, Gupta et al. [101] stated that PGPR can also solubilize phosphorus, fix atmospheric nitrogen, and produce growth-promoting substances that improve plant nutrient uptake and overall growth. By promoting the presence and activity of these beneficial microorganisms in the rhizosphere, farmers can enhance nutrient uptake efficiency and reduce reliance on synthetic fertilizers.

According to Kaushik et al. [102], the combined application of Azospirillum with phosphate-solubilizing bacteria has been shown to boost both grain and straw yields, while also augmenting the levels of micronutrients such as iron (Fe), manganese (Mn), and zinc (Zn). The use of biofertilizers and microbial inoculants is another effective approach for improving nutrient availability and cycling [103]. Biofertilizers are composed of beneficial microorganisms, such as nitrogen-fixing bacteria or phosphate-solubilizing fungi, which can supplement or replace chemical fertilizers [104]. The utilization of biofertilizers on crops enhances nutrient availability for plants, fosters resistance against plant diseases, and reduces the nitrogen requirement for plants by 25% [105]. These microorganisms facilitate the conversion of atmospheric nitrogen into plant-available forms or increase the solubility of phosphorus in the soil. Even though it depends on soil type, fertilizer type, and plant, the amount of nutrients taken by a plant is smaller than the lost portion in the form of N leaching and P fixation. Microbial inoculants, on the other hand, involve the application of specific microbial strains that have been selected for their ability to enhance nutrient acquisition or cycling [106]. Figure 3 depicts the typical pattern of fertilizer application, the percentage absorbed by plants, the percentage lost to the environment, and the potential for addressing this issue through the use of inoculants.

Figure 3

Model illustrating enhanced plant nutrient utilization efficiency with the integration of inoculants. (a) Demonstrates the total quantity of fertilizer or manure applied to plants. (b) Depicts the range of 10–40% of the applied fertilizer or manure being utilized by plants. (c) Illustrates the range of 60–90% of the applied fertilizer or manure being lost to the environment. (d) Represents the potential increase in nutrient utilization efficiency due to the integration of inoculants, resulting in a higher percentage of nutrients being absorbed by plants and a reduced loss to the environment. Adapted from [107].

Microbial inoculants increase the efficiency of applied fertilizer by reducing N leaching and P fixation [108]. By incorporating biofertilizers or microbial inoculants into nutrient management strategies, farmers can improve nutrient availability, reduce fertilizer inputs, and promote sustainable soil fertility. Understanding the interactions between soil microbiota and plant nutrient uptake is essential for optimizing nutrient management practices [107,109]. The soil is a complex ecosystem inhabited by diverse microbial communities that play crucial roles in nutrient transformation and cycling. Research efforts are focused on unraveling the intricate interactions between soil microbiota and plant roots, including nutrient exchange, hormone signaling, and disease suppression [110]. By gaining insights into these interactions, farmers can develop targeted approaches to manipulate the soil microbiome and promote beneficial microbial communities that enhance nutrient availability and uptake. Generally, by understanding the role and application of microorganisms, growers can enhance nutrient acquisition, reduce reliance on chemical fertilizers, and improve the sustainability of agricultural practices.

8 Monitoring and evaluation of nutrient management practice

Monitoring and evaluation are critical components of effective nutrient management strategies, enabling farmers to assess FUE and optimize nutrient application [4]. By establishing monitoring protocols, farmers can track key indicators such as nutrient levels in the soil, crop nutrient uptake, and nutrient loss through runoff or leaching [111]. These measurements provide valuable insights into the effectiveness of nutrient management practices and help identify areas for improvement. Based on the report of Dhanaraju et al. [112], regular monitoring allows farmers to make informed decisions regarding fertilizer rates, timing, and application methods, ensuring that nutrients are applied in a targeted and efficient manner. Additionally, Yi et al. [113] also stated that monitoring can help identify early signs of nutrient imbalance or deficiency, enabling timely corrective actions to be taken.

Evaluation of the impact of nutrient management strategies on crop productivity and soil health is essential for assessing the effectiveness of different approaches [114]. By comparing different nutrient management practices, such as different fertilizer formulations, application methods, or timing, farmers can determine which strategies are most effective in achieving desired crop yields and maintaining soil fertility [115]. Evaluating crop productivity involves measuring parameters such as yield, plant growth, and quality attributes. Soil health evaluation includes assessing indicators such as soil organic matter content, nutrient cycling rates, and microbial activity [116]. These evaluations provide valuable feedback on the performance of nutrient management strategies and inform future decision-making.

Analyzing different fertilizer management approaches’ economic feasibility and cost-effectiveness is crucial for guiding farmers’ decision-making processes [117]. Fertilizer represents a significant input cost in agriculture, and optimizing its use can lead to economic savings. By conducting economic analyses, farmers can assess the profitability and cost-effectiveness of different nutrient management approaches [118]. This includes considering factors such as fertilizer prices, crop market prices, application costs, and potential yield gains. Economic feasibility assessments help farmers make informed decisions about the most suitable fertilizer management strategies that balance crop productivity and profitability [119].

9 Conclusion

FUE is a critical issue in modern agriculture. Farmers must use fertilizers efficiently to reduce costs, minimize waste, and promote long-term sustainability. Inefficient fertilizer application leads to nutrient losses, water pollution, greenhouse gas emissions, and financial burdens for farmers. However, by adopting various strategies, such as nutrient management planning, precision agriculture techniques, enhanced fertilizer formulations and application methods, and nutrient stewardship practices, farmers can enhance nutrient utilization, minimize nutrient losses, reduce environmental impacts, and contribute to long-term agricultural productivity and environmental stewardship. Additionally, by adopting best practices, using alternative fertilizers and organic methods, and monitoring and adjusting fertilizer use, farmers can optimize FUE and maintain high crop yields while minimizing environmental impacts. Moreover, long-term strategies like crop rotation, conservation tillage, precision farming, and sustainable farming practices can reduce the dependency on industrial fertilizers and promote improved soil and crop growth. Farmers, policymakers, and consumers alike must recognize the pivotal role of sustainable agriculture in shaping our collective future. To this end, concerted efforts are necessary to raise awareness and drive the widespread adoption of practices that harmonize productivity with environmental stewardship. By fostering a collective commitment to sustainable agriculture, we can pave the way for a resilient and flourishing agricultural landscape that not only sustains livelihoods but also safeguards the health of our planet for generations to come.