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BACKGROUND: Aquaponic systems are sustainable processes of managing water and nutrients for food production. An innovate nutrient‐efficient catfish‐based (Clarias gariepinus) aquaponics system was implemented for producing two cultivars of two leafy vegetables largely consumed worldwide: lamb's lettuce (Valerianella locusta var. Favor and Valerianella locusta var. de Hollande) and arugula (Eruca vesicaria var. sativa and Eruca sativa). Different growing treatments (4 × 2 factorial design) were applied to plants of each cultivar, grown at two light intensities (120 and 400 μmol m−2 s−1). During growth, several morphological characteristics (root length, plant height, leaf number, foliage diameter and biggest leaf length) were measured. At harvest, plants were weighed and examined qualitatively in terms of greenness and health status. Additionally, leaf extracts were obtained and used to determine total phenolic contents, antioxidant capacities, and levels of cytotoxicity to Caco‐2 intestinal model cells. RESULTS: After a 5‐week growth period, both lamb's lettuce cultivars presented high levels of greenness and health status, at both light intensities, particularly the var. de Hollande that also showed higher average performance in terms of plant morphology. In turn, arugula cultivars showed lower levels of greenness and health status, especially the cultivar E. vesicaria var. sativa submitted to direct sunlight during growth. In addition, plant specimens submitted to higher levels of light intensity showed higher contents in antioxidants/polyphenols. Cultivars with a higher content in antioxidants/polyphenols led to higher Caco‐2 cell viability. CONCLUSION: For successful industrial implementation of the aquaponics technology, different and optimized acclimatizing conditions must be applied to different plant species and cultivars. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nutrient deficiencies are a major cause of yield loss under abiotic stress conditions, so proper nutrient management can reduce the negative effects of stress to some extent. Nutrients can alleviate stress by activating resistance genes, enhancing antioxidant enzyme activity, creating osmoprotectants in cells, reducing reactive oxygen species (ROS) activity, increasing cell membrane stability, synthesizing proteins associated with stress tolerance, and increasing chlorophyll content in leaves. The current review highlights changes in soybean metabolic activity caused by drought stress and changes in vital functions caused by the deficiency of primary (N, K, P) and secondary macronutrients (Ca, Mg, S). The role of macronutrients in reducing the adverse effects of water deficit stress is highlighted. Under stressed conditions, appropriate nutrient management options can be implemented to minimize the effects of drought and ensure good yields. Balanced nutrient fertilization helps activate various plant mechanisms to mitigate the effects of abiotic stresses and improve soybean drought resistance/tolerance. Nutrient management is therefore a viable technique for reducing environmental stress and increasing crop productivity. [ABSTRACT FROM AUTHOR]

Agriculture, by its nature, depletes essential nutrients from the soil. If soils are to remain productive, nutrients must be replaced by chemical fertilizers, organic fertilizers, farming practices or a combination. The chemo-centric technological advancement during green revolution period boosted the production potential and provided food security in plains. However, over a period of time, this production system has started exhibiting its limited carrying capacity as reflected by production plateau. The success of industrial agriculture in recent decades has masked significant externalities, affecting natural resources, human health, and agriculture itself. Further, increasing consciousness about conservation of environment and health hazards associated with agrochemicals, and consumers' preference to safe and hazard-free food have shifted interests in organic agriculture. Contrary to this, the farmers of hills/mountains have not tasted the fruit of green revolution and ignored chemical inputs, though they are also facing the major challenge of non-availability of organic inputs, especially, nutrient sources to be used in organic production system. The farmers must be aware about how they can efficiently manage the nutrition under organic production system. This article will provide an insight to the farmers on the availability and usefulness of supplementary nutrient sources to enrich the soil for better crops under organic production system in remote mountain regions. [ABSTRACT FROM AUTHOR]

The combination of no-till farming and green manure is key to nourishing the soil and increasing crop yields. However, it remains unclear how to enhance the efficiency of green manure under no-till conditions. We conducted a two-factor field trial of silage maize rotated with hairy vetch to test the effects of tillage methods and returning. Factor 1 is the type of tillage, which is divided into conventional ploughing and no-tillage; factor 2 is the different ways of returning hairy vetch as green manure, which were also compared: no return (NM), stubble return (H), mulching (HM), turnover (HR, for CT only), and live coverage (LM, for NT only). Our findings indicate that different methods of returning hairy vetch to the field will improve maize yield and quality. The best results were obtained in CT and NT in HM and LM, respectively. Specifically, HM resulted in the highest dry matter quality and yield, with improvements of 35.4% and 31.9% over NM under CT, respectively. It also demonstrated the best economic and net energy performance. However, other treatments had no significant effect on the beneficial utilization and return of nutrients. The LM improved yields under NT by boosting soil enzyme activity, promoting nitrogen transformation and accumulation, and increasing nitrogen use efficiency for better kernel development. Overall, NTLM is best at utilizing and distributing soil nutrients and increasing silage maize yield. This finding supports the eco-efficient cultivation approach in silage maize production in the region. [ABSTRACT FROM AUTHOR]

The importance of implementing recirculating drainage for greenhouse strawberries is often overlooked because of the low electrical conductivity (EC) of drainage and transpiration despite the large area of cultivation in Korea. In this study, we analyzed the growth of strawberry crops and their water and individual nutrient use efficiency when using closed-loop hydroponics in greenhouses. The study consisted of two parts: Experiment (Exp) 1 and Exp 2, each of which employed a different closed-loop hydroponic control method. In Exp 1, the system was controlled solely based on the EC of the drainage mixed with raw water. In Exp 2, the nutrient solution (NS) was corrected according to the ion concentrations in the drainage, with correction intervals of 2 weeks, 4 weeks, and no correction, while the control treatment was open-loop. In Exp 1, a prolonged increase in drainage EC resulted in an imbalance in NS ion composition and reduced fruit yield. In Exp 2, the NS composition was stabilized through periodic nutrient correction, and the fruit yield of the closed-loop treatments did not differ from the open-loop treatment. However, the closed-loop with 2- and 4-week correction in Exp 2 showed 94% and 88% higher nutrient use efficiency (NUE), respectively, than an open-loop system. Among the closed-loop treatments, the 2- and 4-week correction intervals had 36% and 32% higher NUE than the no-correction treatment. Furthermore, the 2-week correction interval showed a 3% improvement in NUE compared to the 4-week interval. These findings highlight the importance of considering a shorter ion correction interval for optimal NUE and normal plant growth in recirculating hydroponic systems of strawberry cultivation. [ABSTRACT FROM AUTHOR]

Applying bokashi (Bok) at 10% volume/volume (v/v), biochar (BC) at 10% v/v, and their combination (Bok_BC) as soil amendments significantly enhances citrus nursery production, improving plant growth and soil health, alongside offering notable economic benefits. Our greenhouse experiment evaluated these treatments across two fertilizer doses, at half (700 μS/cm) and full (1400 μS/cm) electrical conductivity (EC) levels, compared to a control mix, demonstrating improved nutrient availability, water retention, growth rates, and potential for carbon sequestration. Based on the results of this experiment, a cost–benefit analysis was performed; the BC treatment yielded substantial savings, particularly in large nurseries where BC at 700 μS/cm electrical conductivity (EC) saved USD 1356.38 per day and the same treatment at 1400 μS/cm EC saved USD 1857.53. These savings stem from increased nutrient contents (N, P, and K) and improved water retention, reducing irrigation; shortened growth cycles due to enhanced growth rates were observed, indirectly suggesting reduced electricity costs for greenhouse operations. Additionally, the increased carbon content within the soil points toward long-term benefits from carbon sequestration, further contributing to the sustainability and economic viability of these practices. These findings highlight the economic advantage of incorporating Bok and BC into soil mixes, providing a cost-effective strategy for enhancing greenhouse agriculture sustainability. [ABSTRACT FROM AUTHOR]

AbstractLow N-urea rate increased nitrogen use efficiency and grain yield in lowland rice. The questions remain what constitutes low N-urea rate in a derived Savanna and to what extent would there be differential response of these traits in interspecific varieties of lowland rice. Field experiments were conducted in the inland valley, Federal University of Agriculture, Abeokuta, (Latitudes 7° 15'N, Longitude 3° 25'E, altitude 144 above sea level) in 2020 and 2021 to determine the performance of interspecific lowland rice cultivars at low rates of N-urea. Application rates of N-urea (0, 30 and 60 kg N ha−1) were applied on lowland rice cultivars (ARICA 3, NERICA L-34, WITA-4 and Ofada cv.) that constituted the main plot and sub plot, respectively. The Experiments were in split plot arrangement fitted into randomized complete block design and replicated three times. Increased N uptake and delayed phenology were observed with increasing application rates of N-urea, while grain yield of lowland rice sown at 30 and 60 kg N ha−1 were similar. NERICA L-34 had significantly higher Partial Factor Productivity of N (PFPN) and Nitrogen Harvest Index with higher sink strength than other cultivars. Similar pattern was observed on grain yield. These evidences suggested that application of 30 kg N ha−1 could sustain the reproductive growth of lowland rice because of prolonged phenology and N uptake in a derived Savanna with higher efficiency (PFPN, Agronomic efficiency N and Recovery efficiency N) despite the similarities in their root growth and activities. [ABSTRACT FROM AUTHOR]

It has been increasingly important to control N-fertilizers, seeking high efficiency. This study aims to describe, using the von Bertalanffy model, the cumulative losses of nitrogen (N) by ammonia volatilization (NH3-N) from conventional and stabilized N-fertilizers applied in coffee orchard. The experiment was performed in Lavras municipality, Minas Gerais state, Brazil during the 2015/2016 coffee growing season. A randomized block design was used, with seven treatments (stabilized and conventional N-fertilizers) and three fertilizer applications. The evaluated stabilized and conventional N-fertilizers were: 1) prilled urea; 2) ammonium sulfate; 3) urea dissolved in water; 4) ammonium nitrate 5) urea + Cu + B; 6) urea + anionic polymer and; 7) urea + NBPT. Volatilization losses were evaluated, and the highest percentage of NH3-N losses occurred with prilled urea and urea + anionic polymer, with losses greater than 30% of N-applied depending on the number of installments. However, in the 2nd nitrogen fertilization, the von Bertalanffy model did not reach convergence for these treatments, which may have been influenced by the rainfall volume in the period. The lowest NH3-N losses were found for ammonium nitrate and ammonium sulfate, with losses that did not exceed 0.6%. The parameters were all significant and had biological interpretation, and the results will contribute to the development of more efficient fertilizers technologies for farmers. The von Bertalanffy model was adequate to describe the cumulative loss of N by volatilization of ammonia from conventional and stabilized N-fertilizers for coffee crop areas. [ABSTRACT FROM AUTHOR]

This study investigated the interactive effects of nitrogen and silicon fertilization on disease incidence, severity, grain yield, and straw yield in susceptible rice variety under rice blast disease pressure across two consecutive years. The results revealed significant variations in disease parameters across different nutrient combinations. The study involved four levels each of nitrogen (N0: 0 Kg/ha; N1:50 Kg/ha; N2: 100 Kg/ha and N3: 150 Kg/ha) and silicon (Si0: 0 Kg/ha; Si1: 60 Kg/ha; Si3: 90 Kg/ha and Si3: 120 Kg/ha). The treatments with lower to moderate nitrogen levels coupled with higher silicon rates exhibited the lowest disease incidence and severity, highlighting their synergistic effect in enhancing disease resistance. Conversely, high nitrogen levels with low or no silicon supplementation displayed the highest disease susceptibility, indicating that excessive nitrogen without adequate silicon can exacerbate vulnerability. Notably, increasing silicon levels led to decreasing disease incidence and severity, while the opposite trend was observed for nitrogen, underscoring silicon's pivotal role in mitigating disease impact. Regarding yield parameters, the highest silicon rate (120 kg/ha) consistently resulted in superior grain yields, particularly when combined with moderate nitrogen levels (100 Kg/ha). The positive effect of silicon on grain yield was more pronounced at lower nitrogen levels, suggesting its potential to compensate for nitrogen deficiency. Moreover, the highest silicon level consistently exhibited superior straw yields across nitrogen levels. However, moderate nutrient levels occasionally outperformed the highest levels, implying an optimum range for maximizing straw yield while avoiding yield penalties associated with excessive application. [ABSTRACT FROM AUTHOR]

MPROVING agricultural output worldwide to satisfy the demands of a rapidly expanding I population may be possible, in part, through the creation and use of novel fertilizers made possible by cutting-edge nanotechnology. As a matter of fact, according to the literature assessment, there are designed nanomaterials that, at specific concentrations, can improve plant development. These materials could be utilized as nanofertilizers in agriculture to boost crop yields and reduce pollution. Nanofertilizers that enhance plant development, nanofertilizers that include nutrients, and nanofertilizers that contain micronutrients are the four main types of nanomaterials discussed in this article. Concerning the chemical makeup of the nanomaterials, the size of the particles, the concentrations used, the plant species that benefited, the techniques of plant incubation, and the features and rates of plant growth promotion, each category is addressed separately. Furthermore, we take a close look at each type of nanofertilizer to determine its relevance, potential future paths, and special research needs in the pursuit of sustainable agriculture. Lastly, this paper argues that protecting the environment and increasing food production should be top research priorities, and they propose developing macronutrient nanofertilizers containing N and P. [ABSTRACT FROM AUTHOR]

The increasing global population and growing demand for food and mineral fertilizers underscore the urgent need to enhance fertilizer efficiency. This imperative emphasizes the importance of sustainable fertilizer utilization while mitigating environmental impacts, particularly in addressing agricultural water pollution. Excessive fertilizer use contributes significantly to water contamination and food shortages worldwide. In 2018, food shortages were reported in many nations, including the United States (2.3%), Canada (4.6%), the United Kingdom (8.2%), Germany (2.6%), Japan (2.9%), Ethiopia (23.4%), Ivory Coast (22.4%), Bangladesh (12.7%), Pakistan (17.2%), Haiti (45.6%), and India (14.3%). Moreover, agricultural activities, particularly the use of mineral fertilizers, are major contributors to greenhouse gas emissions. Inefficient fertilizer practices lead to economic losses, environmental degradation, and food insecurity. Studies reveal that in sub-Saharan Africa, farmers receive only about $0.50 in increased productivity for every dollar spent on fertilizer due to inefficiencies. The economic cost of nutrient pollution in the European Union is estimated to range between €7 billion and €10 billion annually. Effective strategies like precision nutrient management, best practices, and innovative technologies optimize fertilizer efficiency and support agricultural sustainability. Besides, promising methods include the combined use of organic and inorganic fertilizers, the application of remote sensing and geographical information system technologies, and the implementation of biological approaches to enhance nutrient management. Moreover, monitoring and evaluation are essential for assessing strategy effectiveness, guiding decision-making, and taking corrective actions. Hence, this review aims to address strategies for improving fertilizer efficiency, sustainable agriculture practices, and addressing food security and environmental concerns related to fertilizer use comprehensively.

The global population is increasing at a rapid pace, posing significant challenges to sustainable development and food security. This review paper examines the advantages and challenges of organic farming as a potential solution to address the pressing issues in modern agriculture and food production. Organic farming offers a range of benefits, including improved soil fertility, higher profitability, reduced external input usage, land reclamation, improved market access, and enhanced farmer capacity and self-reliance. Organic farming practices prioritize environmental sustainability by reducing chemical usage and reliance on biological methods of pest control, as well as enhancing biodiversity, which strengthens ecological balance and resilience against pests and diseases. However, organic farming also faces challenges that need to be addressed for its widespread adoption. These challenges include uncertainty surrounding legislative environments, psychological and sociological costs of conversion, financial risks during the transition period, securing marketing channels for organic produce, and diminishing profit margins. Efforts should be made to provide farmers with the necessary support, including technical assistance, subsidies, and access to markets, to overcome these challenges. Despite the challenges, the potential of organic farming in promoting sustainable agriculture and ensuring a secure food system cannot be overlooked. It offers a natural and environmentally friendly approach to food production, prioritizing the health of both humans and the ecosystem.

A study using the assigned Complete Block Design with three replications was carried out at Hobigong, Bangladesh from January to August 2021 to investigate the impact of different combinations of organic and inorganic fertilizers on the growth and production of bitter gourd. The experiment employed five different combinations of organic and inorganic fertilizers, which are listed below: T1: 4 kg of organic fertilizer per plant, T2: 4 kg of organic fertilizer + 2 liters of cow urine + 2 liters of bc (biochar), T3: 2 liters of liquid bc (biochar)) + NPK (44 g urea + 43 g TSP (Triple Super Phosphate) + 77 g MoP (Muriate of Potash), T4: NPK (44 g urea + 43 g TSP + 77 g MoP), and T5: 4 kg of organic fertilizer + 2 liters of bc+ NPK (44 g urea + 43 g TSP + 77 g MoP) on three distinct soils in the villages of Kalonjhora, Madhabpur, and Jointure. The growth and yield of bitter gourd at different study locations were significantly affected by the application of both organic and inorganic fertilizers, according to the results. The results showed that the use of both organic and inorganic fertilizers had a significant effect on the development and yield of bitter gourd at the different study sites. Maximum germination rate (90%), at 45 DAS (days after sowing), longest plant (173.28 cm) at 100 DAS, maximum number, longest and heaviest fruit (6.30 number of fruits per plant, 15.51 cm and 82.50 g, respectively) were obtained from crops grown in Jointer village that were applied with 4 kg organic fertilizer + 2 liters bc + NPK (44 g urea + 43 g TSP + 77 g MOP). According to the previously described research, most development and yield characteristics of bitter gourd are improved when grown in a mixture treated with 4 kg organic fertilizer + 2 liters bc + NPK (44 g urea) + 43 g of TSP + 77 g of MoP.

Agarwood is a highly valued fragrant wood and has been traded for its economic and medicinal value. The resin in agarwood is used to produce high value downstream products such as fragrances, oils, medicines, teas, cosmetic carvings, and luxury goods where the demand for these products remains consistent. Most of the agarwood-producing trees come from the genera of Aquilaria and Gyrinops, which belong to the Thymelaeaceae (Malvales) family. In addition, Aquilaria malaccensis and Gyrinops versteegii are the most cultivated agarwood producing trees in Malaysia and Indonesia, respectively. Nevertheless, the survival of the species is threatened by the overharvesting of the forest, which leads to strict regulation by the exporting nations for international trade. Interestingly, agarwood plantation is a viable option which able to generate income for local population without causing any harm to the ecosystems. However, a lack of research on seedling preparation for large-scale plantations, and the optimum nutrient management practices have slowed down the agarwood industry. Hence, this review article will highlight the most effective strategy for enhancing agarwood cultivation by focusing on proper nutrient management to boost agarwood production.

Industrial hemp (Cannabis sativa L.) holds promise as a crop for more sustainable supply chains given its potential as a source of high-strength fibers, adsorbents, and nutrient-dense feedstuffs. Developing nutrient management guidelines for hemp will be an important part of optimizing the crop’s sustainability attributes. This study measured hemp seed yield in response to N fertilization rate (0, 60, 120, 180, and 240 kg N ha−1). Treatments were tested with four hemp cultivars (‘Joey’ and ‘Grandi’ in 2020, 2021, and 2022 and ‘NWG 2463’ and ‘NWG 4113’ in 2023) in Virginia. Nitrogen input influenced (p ≤ 0.0177) seed yield in all four experimental years, although the pattern of response varied substantially. In 2020, following delayed seeding, hemp showed a weak quadratic (p = 0.0113) response to N inputs, with peak yield (1640 kg ha−1) occurring with 120 kg N ha−1. In 2021, hemp displayed a strong linear (p < 0.0001) response to N inputs, with the highest seed yield (2510 kg ha−1) at 240 kg N ha−1. In 2022, a season characterized by low precipitation and high weed pressure, a weak, linear (p = 0.0111) response to the N rate was observed. The greatest seed yield (380 kg ha−1) was again observed with 240 kg N ha−1. In 2023, weed pressure remained an issue, but the response to N was strong and linear (p < 0.0001), with the greatest seed yield (831 kg ha−1) again measured at 240 kg N ha−1. These findings indicate hemp can be quite responsive to N inputs but that the magnitude of response is sensitive to other factors such as available soil moisture, weed pressure, and growing period.

Sequestration of carbon (C) in arable cropping systems is considered one of the potential climate change mitigation strategies. In this context, assessing the potential of sugarcane cropping systems should be a priority, as it leaves substantial amounts of recyclable residues essential for maintaining soil organic carbon (SOC), improving soil health, and strengthening overall resources. We evaluated the impacts of residue retention and nutrient management practices on SOC and its pools, storage, soil biology, and yield in a multi-ratooning sugarcane system. A field experiment was conducted in the split-plot design with residue burning (RB) and residue retention (RR) as the main plot treatments and three nutrient management practices, that is, 25% of the recommended dose of fertilizers (RDF, i.e., 300:150:150 kg of N, P2O5, and K2O kg ha-1, respectively) as basal + 75% through fertigation (N1); 50% of RDF as basal + 50% through fertigation (N2); and 75% of RDF as basal + 25% through fertigation (N3) as subplot treatments in ratoon sugarcane. Soil samples were collected initially and after 6 years of multi-ratooning (one plant and four ratoon crops) from a soil depth of 0-30cm. The results indicated that RR plots had 21% higher total SOC with 42, 47, 17, and 13% higher very labile, labile, less labile, and non-labile C pools, respectively, than RB plots (P < 0.05). RR also had a higher lability and recalcitrant index than RB. Of the total SOC stock, the contribution of passive pools was higher (72-75%) than active pools. Significantly higher dehydrogenase activity (DHA) (86%), alkaline phosphatase activity (APA) (16%), and ß-glucosidase activity (BGA) (22%) were observed in RR plots as compared to RB plots, whereas for nutrient management practices, it followed the order of N2 > N3> N1. Microbial counts also followed the same trend as that of enzyme activities. Residue retention practices reported higher C sequestration (0.68Mg C ha-1 yr-1), carbon retention efficiency (37%), and yield (38%) with a potential to reduce GHG emissions by 2.72Mg CO2 ha-1 yr-1 as compared to traditional practices. Residue retention and 50-75% RDF as basal is recommended for higher soil C retention and soil biology for sustained sugarcane productivity. [ABSTRACT FROM AUTHOR]

This study explored the economic dynamics of cotton (Gossypium hirsutum L.) production in Msilale village, Chato District, Tanzania. The experiment utilized a factorial design with sowing dates on November 25th, December 15th, and January 4th, and phosphorus levels at 0, 20, 40, and 60 kg P ha-1, replicated three times. Results indicated significantly higher cotton yields (6.1 t ha-1 and 6.3 t ha-1) for November and December sowings compared to January (3.8 t ha-1). This is a 61% and 66% increase in cotton yields for November and December sowings, respectively relative to January sowing. Though not significant, 20 kg P ha-1 and 40 kg P ha-1 applications yielded 5.8 t ha-1 and 5.4 t ha-1, respectively, while 60 kg P ha-1 yielded 5.3 t ha-1. This is a 9.4% and 1.9% increase in cotton yields at 20 and 40 kg P ha-1, respectively relative to absolute control and 60 kg P ha-1 application. Economic analysis revealed that late sowing (January) had the lowest net profit (Tshs. 3,723,400 ≈ USD 1,486) and benefit-to-cost ratio (BCR) of 11.2. Early sowings recorded higher net profits (Tshs. 6,679,527 ≈ USD 2,666 and Tshs. 6,861,283 ≈ USD 2,738) and BCRs (18.4 and 18.8, respectively). This is a 79% (BCR = 64%) and 84% (BCR = 68) increase in net benefits from early sowings compared to late sowing. Applications of 20, 40, and 60 kg P ha-1 resulted in net benefits of Tshs. 5,452,572 ≈ USD 2,176 (BCR = 19.2), Tshs. 5,209,904 ≈ USD 2,079 (BCR = 15.1), and Tshs. 5,748,786 ≈ USD 2,294 (BCR = 14.1), respectively, with a significant (p = 0.017) BCR at 20 kg P ha-1 indicating cost-effectiveness. This is a 36% and 7.1% economic benefit at 20 and 40 kg P ha-1, respectively compared to 60 kg P ha-1 application. Optimizing sowing dates and P levels can boost economic returns in cotton production and promote sustainability. [ABSTRACT FROM AUTHOR]

To assess the consequences of nutrient reduction strategies on water quality under climate change, we investigated the long-term dynamics of dissolved oxygen (DO) and pH in Narragansett Bay (NB), a warming urbanized estuary in Rhode Island, where nitrogen loads have declined due to extensive wastewater treatment plant upgrades. We use 15 years (January 2005-December 2019) of measurements from the Narragansett Bay Fixed Site Monitoring network. Nutrient-enhanced phytoplankton growth can increase DO in the upper water column while subsequent respiration can reduce water column DO and enhance bottom water acidification, and vice-versa. We observed significant decreases in surface DO levels, concurrent with a significant increase in bottom DO, associated with the nitrogen load reduction. Surface DO decline was primarily attributed to reduced intensity of primary productivity, supported by a concurrent decrease in surface chlorophyll concentrations. Meanwhile, the influence of reduced organic matter respiration led to the increase of bottom DO levels by 9 µmol kg-1 (approximately 0.2 mg L-1 for typical summer temperature and salinity) over a 15-year period, which overcame the opposite influence of oxygen reduction from solubility decreases due to warming temperatures. In contrast, long-term changes in surface pH have not exhibited discernible trends beyond natural variability, likely due to the complex and sometimes opposing influences of biological activity and changing river flow conditions. We observed a slight increase in bottom pH, associated with the increase in DO in bottom water. Notably, future variations in freshwater discharge, particularly linked to extreme precipitation events, may further influence water carbonate chemistry and thereby impact pH dynamics. This study highlights the necessity of long-term time series measurements in helping understand the impacts of environmental management practices in improving water quality in coastal regions during a changing climate. [ABSTRACT FROM AUTHOR]

Crop productivity, soil quality and fertility have been degraded due to intensive conventional tillage and poor crop management practices. Conservation tillage along with proper crop establishment methods (including seed priming, integrated nutrient management) helps in sustaining the productivity of crops, especially under rainfed conditions. A field experiment was carried out to evaluate the effect of seed priming, tillage and nutrient management practices on nutrient balance; chemical and microbial properties of soil; and productivity of maize-wheat cropping system in rainfed conditions. The experiment was laid out in factorial randomized block design with three factors (tillage, seed priming and nutrient management) and control as independent treatment for general comparison of results. The findings showed that chemical and microbial properties of soil were enhanced under zero tillage+ mulch as compared to other tillage practices. However, crop productivity was higher in conventional tillage+ mulch (70.28 q/ha (maize), 35.27 q/ha (wheat)). Under nutrient management practices, integrated nutrient management proved to be better as compared to recommended dose of fertilizers. Highest production efficiency (32.8 kg ha−1 day−1) was found under CT+M,Hydro,Int. Nutrient balance (N, P, K) was found higher in treatments with integrated nutrient management. [ABSTRACT FROM AUTHOR]

Industrial hemp (Cannabis sativa L.) holds promise as a crop for more sustainable supply chains given its potential as a source of high-strength fibers, adsorbents, and nutrient-dense feedstuffs. Developing nutrient management guidelines for hemp will be an important part of optimizing the crop's sustainability attributes. This study measured hemp seed yield in response to N fertilization rate (0, 60, 120, 180, and 240 kg N ha−1). Treatments were tested with four hemp cultivars ('Joey' and 'Grandi' in 2020, 2021, and 2022 and 'NWG 2463' and 'NWG 4113' in 2023) in Virginia. Nitrogen input influenced (p ≤ 0.0177) seed yield in all four experimental years, although the pattern of response varied substantially. In 2020, following delayed seeding, hemp showed a weak quadratic (p = 0.0113) response to N inputs, with peak yield (1640 kg ha−1) occurring with 120 kg N ha−1. In 2021, hemp displayed a strong linear (p < 0.0001) response to N inputs, with the highest seed yield (2510 kg ha−1) at 240 kg N ha−1. In 2022, a season characterized by low precipitation and high weed pressure, a weak, linear (p = 0.0111) response to the N rate was observed. The greatest seed yield (380 kg ha−1) was again observed with 240 kg N ha−1. In 2023, weed pressure remained an issue, but the response to N was strong and linear (p < 0.0001), with the greatest seed yield (831 kg ha−1) again measured at 240 kg N ha−1. These findings indicate hemp can be quite responsive to N inputs but that the magnitude of response is sensitive to other factors such as available soil moisture, weed pressure, and growing period. [ABSTRACT FROM AUTHOR]

Soil acidification is a serious constraint to food production worldwide. This review explores its primary causes, with a focus on the role of nitrogen fertilizer, and suggests mitigation strategies based on optimal N management. Natural acidification is determined by the leaching of weak acid mainly caused by climate and soil conditions, whereas the use of ammonium-based fertilizers, nitrate leaching and removal of base cations (BCs) by crop harvesting mostly accounts for anthropogenic acidification. In addition, low soil acid buffering capacity, mainly determined by soil parent materials and soil organic matter content, also accelerates acidification. This study proposes targeted mitigation strategies for different stages of soil acidification, which include monitoring soil carbonate content and pH of soils with pH > 6.5 (e.g., calcareous soil), use of alkaline amendments for strongly acidic soils (pH < 5.5) with aluminum toxicity risk to pH between 5.5 and 6.5, and decreasing acidification rates and supplementing BCs to maintain this optimal pH range, especially for soils with low acid buffering capacity. Effective mitigation involves optimizing the rate and form of N fertilizers used, regulating N transformation processes, and establishing an integrated soil-crop management system that balances acid production and soil buffering capacity. [ABSTRACT FROM AUTHOR]

The nutrients essential for primary production are inorganic salts and it is important to fully understand nutrient dynamics in coastal oceans. There are three major sources of nutrients in the Seto Inland Sea: loadings from terrestrial run-off, advection from the open sea, and release from bottom sediments. Among these sources, information concerning release from bottom sediments has been limited due to infrequent observations. In this study, we took monthly samples over a two-year period, measuring nutrient concentrations in pore water from 0 to 12 cm at a sampling station in Harima Nada (depth 43 m), with the aim of clarifying the variation of nutrient concentrations in, and fluxes from, the sediment. Nutrient concentrations in the pore water were characterized by high concentrations of dissolved ammonium, dissolved inorganic phosphorus (DIP) and dissolved silicate (DSi), with minor amounts of nitrate and nitrite. The daily nutrient supply to the water column was 8.7 ± 4.6 mg-N m−2 day−1 for dissolved inorganic nitrogen (DIN), 2.5 ± 3.0 mg-P m−2 day−1 for DIP and 65.1 ± 36.7 mg-Si m−2 day−1 for DSi. DIN and DIP fluxes from sediments were compared to those of terrestrial loadings into Harima Nada, which were estimated to be comparable to or about two times higher than river loadings for DIN and more than ten times higher than terrestrial loading for DIP. Overall, the results of this study provide important basic information on nutrient dynamics from sediments and their management in Harima Nada. [ABSTRACT FROM AUTHOR]

Aquatic macrophytes, notably the invasive water hyacinth, exhibit proficiency in nutrient removal from polluted water bodies, rendering them appealing for water remediation applications. This study investigates the potential of water hyacinth in phytoremediation, focusing on the effect of using nutrient-rich biogas slurry mixed with water in varying concentrations, i.e., 16.6, 33, 66.6, 100, and 133 mg/L for the investigation. The physiochemical properties of the liquid biogas slurry were evaluated before and after treatment with water hyacinth over eight weeks, with continuous monitoring of nutrient reduction rates. Results showcased substantial average reductions of nitrogen, phosphorus, and potassium, with a relative growth rate of 5.55%. The treatment also decreased pH, total dissolved solids, hardness, and chemical oxygen demand. The theoretical BMP of water hyacinth was determined using Buswell's equation. Water hyacinth grown in the concentration of the biogas slurry exhibited the highest methane yield at 199 mL CH4/gm VS, along with the highest relative growth rate. This study used experimental data to create a mathematical model that describes how the relative growth of water hyacinth depends on the number of days and biogas slurry concentration (C). The model's quality and effectiveness were evaluated using the goodness of fit (R2) and observable approaches. The polynomial model, referred to as Poly model 1, 2, is the best fit for describing the relationship between the growth percentage of water hyacinth, days, and nutrient solution concentration. In this model, C has a polynomial degree of one (normalized mean of 69.84 ± 43.54), while D has a degree of two (normalized mean of 30 ± 21.65). [ABSTRACT FROM AUTHOR]

Soil dehydrogenase (14.2, 11.3 mg TPF g-1 day-1), alkaline phosphatase (109.5, 86.7 mg PNP g-1 soil h-1), acid phosphatase (69.7, 51.6 mg PNP g-1 soil h-1) and urease activity (60.4, 39.9 mg NH4 g-1 2 h-1) in chickpea at flowering and harvest with seed rate @ 105 kg ha-1. Among, nutrient management the corresponding activity (14.9, 11.7 mg TPF g-1 day-1), (120.7, 96.7 mg g PNP g-1 soil h-1), (70.5, 52.7 mg g PNP g-1 soil h-1) was higher with 75% RDF + microbial consortia (MC). Contrarily, urease activity (62.3, 38.7 mg g NH4 g-1 2 h-1), soil available soil nitrogen (181.3, 179.0 kg ha-1) and phosphorus (78.3, 76.5 kg ha-1) were higher under 125% RDF + MC. PCA indicated that among nutrient management, first principal component explained 71.37% variability to urease activity, available soil potassium and dehydrogenase activity and second component (22.34%) to available soil phosphorus and nitrogen. Among planting density, first component explained variability (66.87%) to acid phosphatase and second component (32.11%) to available phosphorus. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Rajasthan Agricultural Research Institute, Jaipur during two consecutive rabi seasons of 2018–19 and 2019–20 to study the effect of integrated nutrient management and seed priming on seed yield and quality in quinoa. Experiment was laid out in a split plot design with twelve treatment combinations comprising four nutrient management practices i.e. no fertilizer (NM0), N45P23K30+2% FeSO4 (NM1), N45P23K30+2% DAP (NM2); and NC125+VC1250+PSB10+KSB10+AZ10 (NM3) as main-plot treatments and three pre-sowing seed priming technologies i.e. no seed priming (SP0), 1.5% Trichoderma harziannum (SP1) and, 20% Pseudomonas fluorescence (SP2) as sub-plot treatments. Results showed that application of NM2 and SP1 exhibited significantly higher plant height (19.5 and 7.2%), number of branches (40.5 and 11.6%), seed weight (12.9 and 4.6%), total dry matter (TDM) (30.5 and 3.9%), chlorophyll content (47.4 and 3.8%) and crude protein content (27.6 and 1.8%) over control. Cumulative effect of these parameters was exhibited in terms of highest yield potential (24.64 and 23.14q ha−1) (28.5 and 9.4% higher) and excellent seed/seedling quality and energy parameters along with highest net return (₹61974 and 55501 ha−1) and B:C ratio (2.55 and 2.22) over control. A positive significant correlation for seed yield was also observed with plant height (0.983), seed weight (0.990), TDM (0.955), chlorophyll content (0.950), protein content (0.946) and seed/seedling quality parameters. Overall, application of N45P23K30+2% DAP spray at pre-flowering stage along with pre-sowing seed priming with 1.5% Trichoderma harziannum is recommended as suitable strategy to improve yield and quality in quinoa under semi-arid conditions. [ABSTRACT FROM AUTHOR]

Mandarin fruits are the most widely grown citrus fruits in the world, particularly in the eastern Himalayas of India, which is the primary center of citrus diversity. Diagnosing potential nutritional imbalances using leaf tissue analysis is a mandatory practice for a higher yield. Regarding the nutritional diagnosis of Khasi mandarin plants, particularly in the acidic soil of the hilly ecology of the Eastern Himalayas, India, there is currently no information available. Therefore, the present study was conducted to identify nutrient constraints, establish leaf-based diagnostic recommended and integrated system (DRIS) norms, and determine nutrients' relationship with fruit yields in 144 orchards. The result showed that the DRIS indices predicted a nutritional optimum value for Khasi mandarin: 2.26–2.83% N, 0.11–0.16% P, 1.86–2.07% K, 1.85–2.12% Ca, 0.33–0.48% Mg, 170.10–225.10 mg kg−1 Fe, 74.03–83.43 mg kg−1 Mn, 1.24–2.45 mg kg−1 Cu, and 19.84–21.28 mg kg−1 Zn. The DRIS norms identified the nutrients Zn, P, Ca, K, N, and Mg as deficient to low levels (14.15→2.14), while Fe, Mn, and Cu were at high to excessive levels (5.50→18.25). The nutritional balance index had a significantly negative relationship with the fruit yield. Leaf nutrient concentrations of N (0.909**), P (0.827**), K (0.867**), Zn (0.833**), Ca (0.827**), and Mg (0.592**) had a significant positive correlation with fruit yield. The finding will facilitate the correct interpretation of leaf nutrient analysis, and the norms developed will enable a precise intervention through nutrient management for higher yields in mandarin citrus. [ABSTRACT FROM AUTHOR]

The role of modified biochar in enhancing phosphorus (P) availability is gaining attention as an environmentally friendly approach to address soil P deficiency, a global agricultural challenge. Traditional phosphatic fertilizers, while essential for crop yield, are costly and environmentally detrimental owing to P fixation and leaching. Modified biochar presents a promising alternative with improved properties such as increased porosity, surface area, and cation exchange capacity. This review delves into the variability of biochar properties based on source and production methods and how these can be optimized for effective P adsorption. By adjusting properties such as pH levels and functional groups to align with the phosphate's zero point of charge, we enhance biochar's ability to adsorb and retain P, thereby increasing its bioavailability to plants. The integration of nanotechnology and advanced characterization techniques aids in understanding the structural nuances of biochar and its interactions with phosphorus. This approach offers multiple benefits: it enables farmers to use phosphorus more efficiently, reducing the need for traditional fertilizers and thereby minimizing environmental impacts, such as greenhouse gas emissions and P leaching. This review also identifies existing research gaps and future opportunities for further biochar modifications. These findings emphasize the significant potential of modified biochar in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Nutrient management recommendations for strawberry are described according to the standard UF/IFAS recommendation format of 1) a calibrated soil test result; 2) target soil pH; 3) the "4Rs" of fertilizer management: rate, timing, placement, and source; and 4) water management factors.

Carrot is a significant root crop in Ethiopia but its production faces challenges such as nutrient loss and unfavorable growth conditions, which hinder its productivity. The objective of this review was to evaluate the impact of nitrogen fertilizer rates on carrot yield in Ethiopia. A systematic review using databases like PubMed and Scopus focused on peer-reviewed, English-language studies with quantitative data on nitrogen fertilizer and carrot yield in Ethiopia, excluding non-peer-reviewed articles and those lacking quantitative data or in other languages. Globally, carrot yields are 30–100 tons per hectare, but only 5.5 tons in Ethiopia. Carrots are rich in vitamins A, C, and B, proteins, minerals, and fiber, with vitamin C boosting immunity and aiding in wound healing and allergy management. Meanwhile, vitamin A plays a crucial role in vision, bone growth, immune function, and reproduction. It is a rich source of carotenoids and anthocyanins. The application of nitrogen fertilizer significantly improved carrot yield (root length, fresh weight, and dry weight). In Ethiopia, the use of nitrogen fertilizer affects the marketability and total yield of carrots, with small-scale farmers employing diverse rates for cultivation. Current recommendations suggest 69 kg/ha of phosphorus (P2O5) and 46 kg/ha of nitrogen, but farmers often do not follow these guidelines. In conclusion, optimizing nitrogen fertilizer usage is crucial for enhancing carrot yields among small farmers, underscoring the need for government support to tailor recommendations to local soil conditions and boost productivity.

Hydrologic restoration at the watershed scale is a complex process that can influence other processes and conditions within the watershed and downstream systems. Given these interrelated watershed scale processes, tools like models are essential to assess the potential effectiveness of sub-watershed to regional remediation strategies for ecological restoration. The goal of Everglades restoration is to restore the quality, quantity, and timing of water to one of the most ecologically unique and complex systems. This study aimed to evaluate changes to water quality associated with hydrologic restoration efforts within the Feeder Canal Basin as identified by the Western Everglades Restoration Project (WERP) by demonstrating, through simulations the potential effectiveness of implementing water quality remediation measures such as Best Management Practices (BMPs) and Stormwater Treatment Areas (STAs) within the WERP area. Additionally, to understand potential phosphorus sources and pre-develpoement conditions within the basin, a pre-development baseline was developed. Using the Watershed Assessment Model (WAM) various model alternatives including the WERP tentatively selected plan (TSP) were developed for a 22 year period of simulation. The implementation of both moderate and aggressive BMPs significantly reduced total phosphorus concentrations within the canal system at various levels indicating an improvement to near-field conditions. Meanwhile, not until the moderated BMPs and operation of an STA do water quality improvement become realized further downstream. The combined strategy of BMPs and STA demonstrates the integrated nature of nutrient remediation with both near and far-field benefits to the system with hydrologic restoration. This integrated strategy of water quality and hydrologic restoration can lead to a more sustainable and resilient restored ecosystem.

Abstract The global mineral fertiliser crisis increased the pressure on the EU agricultural sector. In response, the EU Commission released a Communication on ensuring availability and affordability of fertilisers in November 2022. This Policy Brief discusses the Fertiliser Communication and critically questions whether (1) the proposed measures can contribute to combat the fertiliser crisis, and (2) whether they can make the EU agricultural sector more resilient and sustainable to comply with the Paris Agreement and the Aichi Targets to the Convention on Biological Diversity. Results show that the Fertiliser Communication falls short on both challenges. It relies on existing, insufficient policies and public support measures and fails to propose innovative and effective solutions. Moreover, existing fertiliser and fossil fuel import dependencies are maintained and shifted. To overcome these shortcomings and to comply with legally binding climate and biodiversity goals, a comprehensive governance approach for nutrient management and sustainable agriculture by economic instruments that apply to livestock husbandry and fossil fuels is introduced.

This study aimed to use a GIS-based approach in producing soil fertility maps and utilize the spatial data on achieving site-specific management of major nutrients in Morogoro, Tanzania. Soil samples were collected in six mapping units and analyzed for chemical properties such as pH, cation exchange capacity and electrical conductivity. ArcGIS 10.8 was used to produce nutrient variability maps of organic carbon, available P, total nitrogen and exchangeable K, Ca and Mg using the Inverse Distance Weight (IDW) interpolation method. The soil pH values ranged from 5.5 to 7.2. OC varied between 1.2 and 4.9 g kg−1, TN ranged from low to medium (1.0 to 5.0 g kg−1) whereas Av. P varied between l3.3 and 14.3 mg kg−1. Exchangeable K, Ca and Mg had ranges (in cmol kg−1) of between 0.1 to 0.8 (low to medium), 3.8 to 15.6 (low to high) and 0.3 to 0.5 (low), cmol kg−1. The recommended amounts were 74, 44, 36, 35 and 12 kg ha−1 for N, P2O5, K2O, MgO and CaO, respectively. Conducting soil analysis is key for monitoring the amount of nutrients that are available in the soil at time and space, to achieve site-specific nutrient management.

The search for ecofriendly products to reduce crop dependence on synthetic chemical fertilizers presents a new challenge. The present study aims to isolate and select efficient native PGPB that can reduce reliance on synthetic NPK fertilizers. A total of 41 bacteria were isolated from the sediment and roots of mangrove trees (Avicennia marina) and assessed for their PGP traits under in vitro conditions. Of them, only two compatible strains of Bacillus species were selected to be used individually and in a mix to promote tomato seedling growth. The efficiency of three inoculants applied to the soil was assessed in a pot experiment at varying rates of synthetic NPK fertilization (0, 50, and 100% NPK). The experiment was set up in a completely randomized design with three replications. Results showed that the different inoculants significantly increased almost all the studied parameters. However, their effectiveness is strongly linked to the applied rate of synthetic fertilization. Applying bacterial inoculant with only 50% NPK significantly increased the plant height (44-51%), digital biomass (60-86%), leaf area (77-87%), greenness average (29-36%), normalized difference vegetation index (29%), shoot dry weight (82-92%) and root dry weight (160-205%) compared to control plants. Concerning the photosynthetic activity, this treatment showed a positive impact on the concentrations of chlorophyll a (25-31%), chlorophyll b (34-39%), and carotenoid (45-49%). Interestingly, these increases ensured the highest values significantly similar to or higher than those of control plants given 100% NPK. Furthermore, the highest accumulation of N, P, K, Cu, Fe, Zn, and Ca in tomato shoots was recorded in plants inoculated with the bacterial mix at 50% NPK. It was proven for the first time that the native PGP bacteria derived from mangrove plant species A. marina positively affects the quality of tomato seedlings while reducing 50% NPK. [ABSTRACT FROM AUTHOR]

The use of plastic mulch, water-soluble fertilizers, and drip irrigation has grown in popularity recently for banana (Musa acuminata L.) farming. A field experiment was carried out at Kharagpur, West Bengal, India, to examine the impact of different fertigation intervals and plastic mulch on the response of the Grand Naine cultivar of banana. A randomized complete block design with four fertigation intervals both with and without plastic mulch was used in the study. Biometric characteristics including plant height, pseudo stem girth, leaf area, number of suckers, and crop duration were measured. The outcomes demonstrated the superiority of two-day fertigation interval and black plastic mulchtreatment by displaying higher plants height, a greater stem girth, more leaf area, the greatest number of suckers, and a shorter crop duration. For both the main crop and the ratoon crop, the maximum banana production was achieved with a fertigation interval of two days alongwith black plastic mulch (T1), yielding 66.3 t/ha and 52.2 t/ha, respectively. The yield obtained under the T1 treatment was statistically similar to the fertigation intervals of bi-weekly and weekly treatments for both main and ratoon crops. Fertigation intervals of bi-weekly and weekly treatments showed statistically similar values for pulp: peel ratio, TSS, and reducing sugar of banana fruit when compared to the fruit quality parameters of the T1 treatment. Consequently, using fertilizer interval advised at weekly for the banana. The results highlight the significance of systematic fertigation scheduling and mulching procedures, providing insightful information for effective banana growing practices. [ABSTRACT FROM AUTHOR]

The wastewater treatment industry could benefit from new technologies for the removal and recovery of phosphorus (P). The CalPrex precipitation reactor has the potential to recover P in a readily land-applicable form by treating organic acid digestate with calcium hydroxide to produce brushite. Using data from a pilot-scale reactor at the local Nine Springs Wastewater Treatment Plant in Madison, WI, we modified the plant's BioWin configuration using BioWin 6.2 to model the CalPrex technology and estimate performance under a variety of conditions. We produced dose/response curves for a range of possible lime dosages to estimate the impact of reagent dosage on the quantity and composition of precipitate produced by the CalPrex reactor and characterize the effects on downstream anaerobic digester performance. CalPrex was found to capture 46% of the plant's influent P, reducing nuisance struvite precipitates by 57% and biosolid sludge production by 14%. The CalPrex module was also tested in two predesigned plant configurations in the BioWin cabinet with the intention of testing applicability to other configurations and searching for the impacts of CalPrex on treatment train performance. This is the first work simulating a full-scale implementation of CalPrex and the first to model interactions of CalPrex with other treatment processes. [ABSTRACT FROM AUTHOR]

Two methods were compared to determine crop nutrient uptake by tomato crops in free-draining perlite substrate. They were the nutrient balance method (applied minus drained) and the dry matter method (DM) (nutrients in plant material). Uptake of N, P, K, Ca, Mg, and S was determined using both methods, in three consecutive tomato crops planted in the same perlite. Nutrient uptake determined using the balance method was consistently higher than with the DM method. Relative differences (balance minus dry matter, with respect to the DM method) were N: −1 to 16%, P: 27–45%, K: 14–46%, Ca: 17–87%, Mg: 28–111%, and S: 15–65%. There was a clear tendency for the difference between the methods to reduce with successive crops. The differences between the methods were reduced when the measured retention of nutrients in the perlite substrate and estimated nutrient retention in roots (using a model) were included. However, these data did not explain all of the observed differences between the two methods. Various retention and loss processes may explain the differences. The results suggest that the DM matter method estimates nutrient uptake by the crop, and the balance method estimates nutrient consumption by the cropping system. [ABSTRACT FROM AUTHOR]

Due to the nature of nitrogen cycling, policies designed to address water quality concerns have the potential to provide benefits beyond the targeted water quality improvements. For example, actions to protect water quality by reducing nitrate leaching from agriculture also reduce emissions of nitrous oxide, a potent greenhouse gas. These positive effects, which are incidental to the regulation's intended target, are termed "co‐benefits." To quantify the co‐benefits associated with reduced nitrate leaching, we integrate an economic model of farmer decision making with a model of terrestrial nitrogen cycling for the watershed surrounding Lake Mendota, Wisconsin, USA. Our modeling approach provides a framework that links air and water pollutants in an agri‐environmental system and offers a direction for future studies. Our model results highlight the finding that the co‐benefits from nitrous oxide abatement are substantial, and their inclusion increases the benefit–cost ratio of water quality policies. Consideration of these co‐benefits has the potential to reverse the conclusions of benefit–cost analysis in the assessment of current water quality policies. [ABSTRACT FROM AUTHOR]

Extreme weather and the declining organic matter content of soils cause serious sustainability problems in agriculture. Therefore, soil conditioner composites (chicken manure, bentonite and super absorbent polymer) were developed and tested in an integrated apple orchard characterized by poor nutrient and water management to study their effects on soil, leaf and fruit attributes. Composites with higher doses of additives increased soil organic carbon by 4–9 g/kg, and organic nitrogen by 1.8–2.8 g/kg compared to the control (p < 0.05). Similarly, soil nitrate content steadily increased from 8–10 mg/kg to 30–38 mg/kg by composites. Composites effectively elevated leaf N, K, Ca, and Mg while not affecting the leaf P (p < 0.05). Treatments significantly enhanced the yields by 14–63% on average compared to the control. Treatments with bentonite improved the fruit weight by 2% and 24% compared to the chicken manure. On average, composite treatments increased the titratable acidity of fruits by 26–43% compared to the control and 0.5–10% compared to the treatment containing solely chicken manure. Overall, the developed organic-based composites are able to cope with changing circumstances that could help mitigate the negative effects of climate change, especially in arid areas, thus contributing to sustainable nutrient management. [ABSTRACT FROM AUTHOR]

Nutrition management affects soil carbon (C), nitrogen (N), and phosphorus (P) cycles, as well as their stoichiometry, causing further stoichiometric imbalances. However, research on the effect of nutrient management on soil stoichiometric imbalance is restricted to a single soil type, limiting our understanding of the interactions between these parameters. Therefore, we conducted a study comprising 212 sites throughout the Yangtze River Basin pear districts, for which nutrient management and soil properties were available under different soil types. Soil stoichiometric imbalances varied widely among the districts, with an average C:P imbalance value (C:Pim) of 6.67, higher than that of C:N imbalance (C:Nim; 6.43) and N:P imbalance (N:Pim; 2.83). Meanwhile, soil and microbial biomass stoichiometry, particularly for soil C:P and soil microbial biomass carbon and phosphorus (MBC:MBP), were significantly influenced by nutrient addition. Large N and P fertilizer inputs altered soil C:N and C:P in yellow–brown earth, while soil C:P was influenced by organic nutrient management in purplish soil. Moreover, adding organic nutrients altered the MBP, which further influenced MBC:MBP and MBN:MBP in saline–alkaline soil and yellow–brown earth. Furthermore, C:Pim increased with increasing organic nutrient input in purple soil and decreased with a large chemical fertilizer input in red soil. N:Pim and C:Nim were weakly associated with nutrient management in different soil types. In addition, nutrition management, soil type, soil properties, and microbe content collectively accounted for 45%, 32%, and 38% of the C:Pim, C:Nim, and N:Pim variation, respectively. Nutrient management also exerted a positive direct impact on C:Pim, while soil type elicited a negative direct impact on C:Nim and N:Pim. Meanwhile, all three stoichiometric imbalances were indirectly influenced by soil type. Taken together, our results indicate that soil stoichiometric imbalances, especially for C:Pim, are sensitive to nutrient management and soil type, providing novel insights into these imbalances that can inform the development of potential remedial strategies. [ABSTRACT FROM AUTHOR]

The global mineral fertiliser crisis increased the pressure on the EU agricultural sector. In response, the EU Commission released a Communication on ensuring availability and affordability of fertilisers in November 2022. This Policy Brief discusses the Fertiliser Communication and critically questions whether (1) the proposed measures can contribute to combat the fertiliser crisis, and (2) whether they can make the EU agricultural sector more resilient and sustainable to comply with the Paris Agreement and the Aichi Targets to the Convention on Biological Diversity. Results show that the Fertiliser Communication falls short on both challenges. It relies on existing, insufficient policies and public support measures and fails to propose innovative and effective solutions. Moreover, existing fertiliser and fossil fuel import dependencies are maintained and shifted. To overcome these shortcomings and to comply with legally binding climate and biodiversity goals, a comprehensive governance approach for nutrient management and sustainable agriculture by economic instruments that apply to livestock husbandry and fossil fuels is introduced. Key points: The Fertiliser Communication aims at ensuring availability and affordability of fertilisers for the internal market and globally. The proposals for domestic and international actions for a functioning fertiliser market are insufficient. The Fertiliser Communication fails to propose effective measures for making the EU agricultural sector more resilient and sustainable. [ABSTRACT FROM AUTHOR]

Florida sweet orange production has declined largely due to Huanglongbing (HLB) disease. The causative agent, Candidatus Liberibacter asiaticus (CLas) bacteria, lowers tree performance by reducing water and nutrient uptake. HLBaffected trees have a fibrous root density loss of about 30 to 50%, which increases as HLB symptoms develop in the canopy. Currently, no guidelines exist for optimal nutrient concentrations in citrus roots. This study aimed to develop root nutrient and fertilization guidelines for HLB-affected sweet orange trees. The research was conducted on two sites with 5- to 6-year-old 'Valencia' sweet orange trees grafted on 'Swingle' rootstock. The two sites were representative of the different soil characteristics of the state of Florida, namely Ridge and Flatwood regions. Seven treatments were tested using a randomized complete block design. The Ridge soils site has a high density of trees of about 1359 trees ha-1 while the Flatwoods soils site of southwest Florida has a lower tree density of about 716 trees ha-1. The experiment began in May 2019 and concluded in May 2021. Foliar, root and soil samples were collected from both sites twice a year and nutrient concentrations were analyzed. No significant patterns were observed; however, differences in soil nutrients were found between sites. The obtained data represent trends that could become significant over a longer-term study which encompasses the two different citrus-growing regions in Florida. These lengthier trials are especially needed in the age of HLB in order to curb the declining citrus production. [ABSTRACT FROM AUTHOR]

The current study identified two new climate-resilient groundnut-based cropping systems (GBCSs), viz., groundnut–fenugreek cropping system (GFCS) and groundnut–marigold cropping system (GMCS), with appropriate system-mode bio-compost embedded nutrient management schedules (SBINMSs) for semi-arid South Asia. This 5-year field study revealed that the GMCS along with leaf compost (LC) + 50% recommended dose of fertilizers (RDF50) in wet-season crop (groundnut) and 100% RDF (RDF100) in winter-season crop (marigold) exhibited the highest system productivity (5.13–5.99 t/ha), system profits (US$ 1,767–2,688/ha), and soil fertility (available NPK). Among SBINMSs, the application of 5 t/ha leaf and cow dung mixture compost (LCMC) with RDF50 showed the highest increase (0.41%) in soil organic carbon (SOC) followed by LC at 5 t/ha with RDF50 and RDF100. Legume–legume rotation (GFCS) had significantly higher soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) than legume–non-legume rotations (groundnut–wheat cropping system (GWCS) and GMCS). Among SBINMSs, the highest SMBC (201 µg/g dry soil) and SMBN (27.9 µg/g dry soil) were obtained when LCMC+RDF50 was applied to groundnut. The SMBC : SMBN ratio was the highest in the GWCS. LC+RDF50 exhibited the highest SMBC : SOC ratio (51.6). The largest increase in soil enzymatic activities was observed under LCMC+RDF50. Overall, the GMCS with LC+RDF50 in the wet season and RDF100 in the winter season proved highly productive and remunerative with better soil bio-fertility. SBINMSs saved chemical fertilizers by ~25%’ in addition to enhanced system productivity and system profits across GBCSs in semi-arid regions of South Asia. Future research needs to focus on studying the potential of diversified production systems on water and environmental footprints, carbon dynamics, and energy productivity under semi-arid ecologies. [ABSTRACT FROM AUTHOR]

Rice self-sufficiency is central to Indonesia's agricultural development, but the country is increasingly challenged by population growth, climate change, and arable land scarcity. Agroecological nutrient management offers solutions though optimized fertilization, enhanced organic matter and biofertilizer utilizations, and improved farming systems and water management. Besides providing enough nutrients for crops, the agroecological approach also enhances resilience to climate change, reduces the intensity of greenhouse gas emissions, and improves the biological functions of rice soil. Organic and bio fertilizers can reduce the need for chemical fertilizers. For example, blue-green algae may contribute 30–40 kg N ha−1, while the application of phosphate solubilizing microbes can reduce the use of chemical phosphorous fertilizers by up to 50 percent. The country currently experiences substantial yield gaps of about 37 percent in irrigated and 48 percent in rain-fed rice. Achieving self-sufficiency requires that Indonesia accelerates annual yield growth through agroecological nutrient management from a historical 40 kg ha−1 year−1 to 74 kg ha−1 year−1. The aim is to raise the average yield from the current 5.2 t ha−1 year−1 to 7.3 t ha−1 year−1 by 2050. Simultaneously, controlling paddy field conversion to a maximum of 30,000 hectares per year is crucial. This strategic approach anticipates Indonesia's milled rice production to reach around 40 million metric tonnes (Mt) by 2050, with an expected surplus of about 4 Mt. [ABSTRACT FROM AUTHOR]

Context. Overseer® is the primary software tool used to estimate farm-level nutrient cycle and management for regulatory purposes in New Zealand. The model compares feed demand among different livestock by using 'revised stock units' (RSUs, the annual energy requirement of a mature ewe to raise a single lamb to weaning; 6000MJ metabolisable energy). The RSUs for several common equine stock classes are not yet available, while those currently available within the model are based on the linear scaling of feed demand to liveweight, which does not consider allometric scaling of metabolism to liveweight or the differences in digestive physiology and nutrient metabolism between ruminants and monogastric hindgut fermenters (horses). Aim. To compare the current RSU values used in Overseer® for different equine stock classes, with the equineRSU values calculated using equine-specific models. Methods. Weighted average estimates of the bodyweight for the different equine livestock classes were calculated from the published literature. These weighted average estimates of bodyweight were used to estimate the energy requirements on the basis of data published by National Research Council. The resulting dry-matter intake and N intake from the equineRSU values and the current RSU values in use within Overseer® were modelled using published data on diet composition, crude protein content and the digestibility of the different feeds offered. Results. The current RSUs in Overseer were 2.5-6.8 units higher than the equineRSU values obtained from the equine-specific models. This overestimation in feed demand resulted in N-intake estimates at an animal level being 52-108% higher than values derived using the equine-specific estimates. Conclusion. The use of RSUs based on linear scaling of feed demand from ruminants on the basis of liveweight overestimates feed demand and N intake in horses. If horses are to be included within nutrient management models, feed demand must be based on published equine data for energy requirements to avoid over-inflation of N excretion. The equineRSUs calculated in this study reduce the risk of over-inflation of N intake and excretion, and subsequently the N leaching estimations. Implication. Failure to accurately model feed demand of horses within nutrient management software would unfairly compromise stocking density and horse management on large commercial breeding farms. The implication for these errors on economic impact and restricted livestock number is greatest for the Thoroughbred breeding industry due to the scale of the operations. [ABSTRACT FROM AUTHOR]