Improving Nutrient Use Research Articles

Seasonal and altitudinal dynamics in secondary metabolite composition of Commelina forage species in Konso zone, southern Ethiopia.

Exploring the type and amounts of the secondary metabolites (SMs) in a given fodder species was considered as a meaningful act for safe and profitable utilization of that particular feedstuff in the livestock industry. This study was conducted in the Konso zone, southern Ethiopia, to explore the secondary metabolite composition of Commelina species in two seasons and at two different altitudes. Samples were collected from the two altitudes and seasons. A completely randomized design was used in a factorial arrangement (five species (C. benghalensis, C. imberbis, C. diffusa, C. albescens, and C. africana), two altitudes, and two seasons) with three repetitions per treatment. The SM contents of the Commelina species were reasonably influenced by both seasonal and altitudinal changes. The mean alkaloid (3.67%), total phenols (9.76 mg GAE/g), flavonoid (3.81 mg CE/g) and condensed tannin (1.10 mg CE/g) values for the herb species in wet season inclined (p < 0.001) to 7.02%, 14.07 mg GAE/g, 7.68 mg CE/g and 2.38 mg CE/g, respectively, in dry season. The wet season saponin concentration of the species (2.65 g/Kg) significantly decreased (p < 0.001) to 1.28 g/Kg in the dry season. Similarly, the lowland saponin (2.26 g/Kg), alkaloid (3.70%), total phenols (10.89 mg GAE/g), flavonoid (4.71 mg CE/g), and condensed tannin (0.98 mg CE/g) contents were increased (p < 0.01) to 3.03 g/Kg, 5.47%, 13.61 mg GAE/g, 6.37 mg CE/g, and 1.81 mg CE/g, respectively, in the midlands. Alkaloids, total phenols, flavonoids and condensed tannin concentrations showed positive correlations with each other (P<0.05) and with seasonal (P<0.001) and altitudinal changes (P<0.001) as well. The findings of this study suggested that the SM concentrations of Commelina species were within the limits tolerable for ruminants. In conclusion, Commelina species could serve as a safe and beneficial forage herb to boost nutrient intake, improve nutrient use efficiency and hinder methane emissions, for animals consuming them, in areas where they are available in abundance.

Editorial on special issues: “regional nutrient management in the circular economy” &amp; “nitrogen and carbon recycling: benefits from the stakeholders’ perspective”

AbstractThe intensification and specialization of global agriculture has led to a nutrient surplus resulting in regional environmental issues such as eutrophication and loss of biodiversity due to nutrient accumulation. Addressing these challenges requires a shift towards regional nutrient circularity, inspired by the principles of a circular economy, to create a more resource-efficient agricultural system. Circular agriculture, particularly in Europe, provides a model for sustainable nutrient management at various scales—local, regional, national and international. Existing technologies enable the production of fertilizers from secondary or waste streams and can improve nutrient use efficiency. The development of a market with transparency of supply and demand dynamics, standardized products, and reliable traceability is essential for the effective implementation of nutrient circularity. However, practical nutrient management takes place on a local level, with significant variability in environmental, economic, and social conditions at the farm and field levels due to differences in nutrient demand by crops or farm management, e.g. organic farming with often lower total nutrient intensity. Therefore, the successful development of a regional circular nutrient economy necessitates a stronger stakeholder perspective, emphasizing the importance of participatory research approaches. In addition to circularity, the efficiency of nutrient use from secondary fertilizers must be enhanced, and the broader food system must evolve towards more nutrient-efficient practices. This transformation will likely require adopting a planetary health diet that promotes both sufficiency and sustainability in nutrient use. Therefore, policy measures need to provide a clear regulatory framework at supranational (e.g. European Union) or national level, targeting environmental and societal goals, while at the same time supporting locally adaptable interventions through economic incentives and innovation support.

Eco-toxicological impact of biologically synthesized FeONPs on rice plants and PGP bacteria

Nanoformulations of plant micronutrients can improve nutrient use efficiency and availability in plants compared to conventional fertilizers and, therefore, may prove helpful in addressing the widespread challenge of nutrient deficiency in agricultural soils. In this study, iron-oxide nanoparticles (FeONPs) were bio-synthesized using Aspergillus terreus cell-free extract and tested for bio-efficacy in rice (Oryza sativa L., ssp. japonica, T309) in situ. Physicochemical characteristics of biosynthesized FeONPs (B-FeONPs) were analyzed through UV-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX). Bio-efficacy was tested at both environmentally relevant concentrations (0-50 mg.kg−1) as well as supra-environmental concentrations (100 mg.kg−1). Germination, wet and dry biomass, root length, shoot length, chlorophyll and carotenoid content, and iron fortification in rice plants were evaluated under greenhouse conditions. Potential eco-toxic effects of B-FeONPs were investigated in multiple strains of plant growth-promoting (PGP) bacteria. A significant increment in plant growth parameters (p < 0.05), including wet biomass, dry biomass, root length, and chlorophyll and carotenoid content was observed in B-FeONPs treated rice plants as compared to those treated with bulk Fe-fertilizer FeSO4. B-FeONPs caused no oxidative stress and increased the % Fe content in the plants. Uptake and accumulation of the B-FeONPs were also confirmed in the roots and leaves of plants using TEM. The B-FeONPs did not demonstrate bactericidal activity against any of the tested strains of PGP bacteria at both environmentally relevant and supra-environmental concentrations. In conclusion, the data demonstrate that B-FeONPs exhibit significant potential in enhancing nutrient use efficiency and promoting growth in rice plants. These findings underscore the potential of B-FeONPs as sustainable alternatives to conventional Fe fertilizers, offering sustainable solutions for addressing nutrient deficiencies in agricultural soils.

Improving nutrient use efficiency (NtUE) in crops: an overview

Improving nutrient use efficiency (NtUE) in crops: an overview

Impacts of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on maize yields, nutrient use efficiency, and soil nutrient balance: Insights from a long-term diverse NPK omission experiment in the North China Plain

Context or problemSoil nutrient deficiency is one of the significant challenges in grain production, particularly nitrogen (N), phosphorus (P), and potassium (K). These deficiencies not only reduce crop yields but also cause associated environmental issues, such as soil structure deterioration and ecosystem services diminution. ObjectivesThis research aimed to investigate the long-term effects of NPK fertilizers on soil nutrient properties and maize phenology, further on the grain yield, and to evaluate the nutrient use efficiency and soil nutrient balance under different fertilization managements. MethodsA long-term field experiment was initiated in 1990 in a summer maize field in the North China Plain, including five fertilizer treatments: CK (control), NP, NK, PK, and NPK. The soil nutrient properties, maize yields, crop nutrient uptake amount, nutrient recovery efficiency (NRE), nutrient harvest index (NHI), and soil nutrient balance were annually evaluated from 2005 to 2022. ResultsSignificant improvements in maize yields were found under NPK (9081 kg ha−1), NP (6426 kg ha−1), and PK (2668 kg ha−1) compared with CK (1809 kg ha−1) and NK (1656 kg ha−1). The yield increase was mainly attributed to: (1) enhancing in soil nutrient properties, such as soil organic carbon, soil total N (TN), available N (AN), total P (TP), available P (AP), and available K (AK), and (2) the shortened vegetative period, leading to greater sunshine hours (SH) and accumulative growing degree days (GDD) during the reproductive period. Furthermore, a random forest analysis quantified their importance to grain yield, showing that the edaphic factors (mainly SOC, TN, AK, AN, TP, AP, C:N, and N:P) explained a much greater proportion of yield variation compared with phenological factors (mainly GDD during tasseling and physiological maturity stages, and SH during tasseling stage). Additionally, the significantly higher response ratio of both N and P to NRE and NHI implied that N and P fertilizers having a more pronounced impact on improving nutrient use efficiency than K fertilizer. In terms of soil nutrient balance, a most relative soil nutrient balance was detected under NPK treatment, avoiding either substantial nutrient depletion or accumulation under any nutrient deficiency conditions. ConclusionsSoil deficiencies in N and P had more severe impacts on maize yields and nutrient use efficiency compared with K deficiency. Additionally, a balanced NPK fertilizer regime effectively managed soil nutrient balance. Implications or significanceThese findings elucidate the roles of N, P, and K fertilizers in maize production and soil nutrient conditions from a long-term field experiment, which could provide valuable insights for optimizing fertilization management strategies.

Influence of Organic Nutrient Sources on Nutrient, Quality and Yield Parameters of Vegetable Cluster Bean

Aim: The experiment was taken up to study the influence of various organic nutrient sources on soil nutrient availability and their uptake and also on quality parameters of vegetable cluster bean. Place and Duration of Study: the study was conducted at irrigated wetland farms, TNAU, Coimbatore during the year 2018. Methodology: The RBD (randomized complete block design) design was adopted and replicated thrice. The total number of treatments were 12 with various basal applications of organic manures namely farm yard manure, vermicompost, humic acid, ghanjeevamrutham and also foliar spray combinations namely panchagavya and banana pseudo stem sap. The standard recommended cultural practices of organic farming were followed for all treatments except fertilizer application and synthetic chemical use. Results: The data revealed that soil chemical properties viz., pH, EC and organic carbon were not significantly influenced by various organic nutrient sources. Significantly, higher values of N, P and K availability in soil and their uptake by cluster bean crop and crude protein content, crude fiber, ascorbic acid, moistures percentage in cluster bean pods were recorded with 100 % recommended dose of fertilizer and 2% foliar spray of TNAU pulse wonder. However, organic treatments were on par with inorganic treatments for all the nutrient, quality and yield parameters. Conclusion: Organic treatments like organic farmers practice and FYM along with Panchagavya were recommended to improve nutrient use efficiency and quality of yield, eventually to benefit farmers and complete agricultural ecosystem in terms of profit and sustainability, respectively.

Assessing impact of elevated CO2 on heavy metal accumulation in crops: meta-analysis and implications for food security

Human activities led to elevation in carbon dioxide (CO2) concentrations in atmosphere. While such increase per se may be beneficial for the growth of some crops, it comes with a caveat of affecting crop nutritional status. Here, we present a comprehensive analysis of changes in concentration of essential (Cu, Fe, Mn, Zn, Mo, Ni) and non-essential (Ba, Cd, Cr, Hg, Pb, and Sr) heavy metals in response to elevated CO2, drawing on a meta-analysis of 1216 paired observations. The major findings are as follows: (1) Elevated CO2 leads to reduced concentrations of Cu, Fe, Mn, and Zn in crops; (2) the extent of above reduction varies among plants species and is most pronounced in cereals and then in legumes and vegetables; (3) reduction in accumulation of non-essential (toxic) metals is less pronounced, potentially leading to an unfavorable essential/non-essential metal ratio in plants; (4) the above effects will come with significant implication to human health, exacerbating effects of the “hidden hunger” caused by the lack of Fe and Zn in the human diets. The paper also analyses the mechanistic basis of nutrient acquisition (both at physiological and molecular levels) and calls for the changes in the governmental policies to increase efforts of plant breeders to create genotypes with improved nutrient use efficiency for essential micronutrients while uncoupling their transport from non-essential (toxic) heavy metals.

Inductive cum targeted yield model-based integrated fertilizer prescription for sweet corn (Zea mays L. Saccharata) on Alfisols of Southern India.

Striking the right nutrient balance is essential for sustainable farming and ecosystem health. In this regard, field experiments were conducted in three phases viz., fertility gradient experiment, main experiment and validation experiment through a soil test crop response approach to develop and validate fertilizer prescription equations for sweet corn in comparison with general recommended dose and soil fertility rating approach. The soil data, fresh cob yield, and NPK uptake were used for establishing four important basic parameters, viz., nutrient requirement (kg t-1), contribution of nutrients from fertilizers, soil, and organic manure. The results revealed that nutrients required to produce one tonne of fresh cob yield (NR) were 5.85 kg, 0.87 kg and 4.31kg for N, P and K, respectively under the STCR NPK alone approach and 6.07 kg, 0.92 kg and 4.33 kg for N, P and K, respectively under STCR NPK+FYM approach. In the validation experiment, STCR NPK+FYM approach for the targeted yield of 25 t ha-1 recorded higher fresh cob yield (23.38 t ha-1) and dry stover yield (35.07 t ha-1) which were significantly higher compared to general recommended dose and soil fertility rating approach. The developed STCR equations for the aforesaid crop are valid as the percent deviation of cob yield from the targeted yield was within ±10%. Similarly, highest nutrient use efficiency was achieved with the STCR approach, specifically when targeting a lower yield through an NPK+FYM mode. Thus, implementation of the STCR approach of fertilizer prescription, with or without FYM, at targeted yields of 25 and 22 t ha-1, not only surpassed the effects of the other fertilizer recommendation approach in terms of cob yields, but also increased NPK uptake, improved nutrient use efficiency and greater economic returns.

The role of mycorrhizal fungi in enhancing fertiliser efficiency in agriculture

The study was conducted to evaluate the impact of mycorrhizal fungi on the yield, biomass and quality of cereals (wheat and maize) in the South of Ukraine. For the experiment, control and experimental plots were selected where mycorrhizal fungi were used to improve plant nutrient uptake. The research process included detailed measurements of yields, biomass and uptake of nutrients such as phosphorus, nitrogen and potassium at different stages of the growing season. The results showed that the use of mycorrhizal fungi increased wheat yields by 15% and corn yields by 18% in the experimental plots compared to the control plots, which was achieved through increased nutrient uptake from deeper soil layers. Wheat biomass increased by 12% and corn biomass by 14%, indicating a positive impact of mycorrhiza on plant development. Phosphorus uptake at a depth of 20-30 cm increased by 50%, which contributed to better root development and the supply of available elements to plants. In addition, we recorded a 7% increase in protein content in wheat grain and a 9% increase in corn, which indicates an improvement in the nutritional and feed value of the products. The analysis also showed a 4% increase in the oil content of corn grain, which increases its economic value. Another important result was a 15% reduction in mineral fertiliser costs due to improved nutrient use efficiency, which reduces the need for additional fertiliser. The results confirm that the use of mycorrhizal fungi is an effective method for increasing yields, product quality and economic efficiency of agricultural production

Influence of fertigation on soil-plant nutrition and crop productivity of shade grown Robusta coffee (Coffea canephora) in India

Coffee in Western Ghats grown under shade, soils are enriched with all the nutrients except phosphorus. The areas receive high rainfall, which leads to leaching loss and surface runoff of applied nutrients causing low fertilizer use efficiency. Improved agronomic practices are essential to address these issues. Fertigation is one such practice, having the potential to reduce extra chemical load by improving nutrient use efficiency. Hence, an attempt was made to study the impact of long-term fertigation on soil-plant nutrition and productivity of Robusta coffee. The trial was laid out in randomized complete block design (RCBD) with six treatments and four replications. Data on yield parameters and coffee yield indicated that significantly higher total number of nodes/branches, number of bearing nodes/branches, number of fruits/branches and coffee yield (49.1, 35.0, 758, and 2117 kg ha−1, respectively) were recorded in fertigation block supplied with 100% recommended dose of fertilizer (RDF) as water soluble fertilizer (WSF) which were statistically on par with 75% RDF (44.1, 29.4, 679, and 1821 kg ha−1, respectively). Similarly, higher major, secondary, and micro-nutrient content were noticed in leaf with fertigation at 75 and 100% RDF and also it was observed that, leaf Nitrogen (N), Phosphorus (P), and Potassium (K) content played a highly significant role in increasing coffee yield. The study results revealed that the quantum of N, P, and K fertilizer requirement could be brought down to the tune of 25% through fertigation as compared to the conventional soil application.

Greenhouse gas emissions and nutrient use efficiency assessment of 6 New York organic dairies

Improving nutrient use efficiency and reducing GHG emissions are important environmental priorities for organic-certified dairy operations. The objectives of this research were to quantify annual nutrient use and GHG emissions in 6 organic New York dairy farms. Farm-gate nutrient mass balances (NMB) were estimated with the Cornell NMB calculator. Whole-farm GHG emissions were estimated using the Cool Farm Tool (CFT) and COMET. Farm-gate NMB were low, ranging from -6.5 to 19 kg N/ha for N1 (without legume N fixation), 26 to 71 kg N/ha for N2 (including N fixation), -2.4 to 8.2 kg P/ha for P, and 1.1 to 19.8 kg K/ha for K. Additional nutrient imports, coupled with nutrient management planning, adequate legume stands, and diet balancing may help improve P balances and ensure no N deficiencies in the system. Estimates of annual GHG emissions intensity ranged from 0.98 to 2.10 kg of CO2-equivalents (CO2-eq) per kilogram of fat- and protein-corrected milk (FPCM) estimated by CFT, and from 0.69 to 2.48 kg CO2-eq/kg FPCM estimated by COMET. Enteric fermentation, feed production, and fuel and energy use represented the largest sources of GHG. For farms with liquid manure storages, manure management was also a significant source. Estimates of soil carbon (C) stock changes from CFT were in agreement with or smaller than previous studies, and estimates from COMET were in agreement or greater. Variability and uncertainty in the results for soil C stock change indicate that more research and new protocols are needed. The effects of individual management changes on GHG emissions intensity were small, ranging from -8 to +7% in CFT, and -8% to +8% in COMET. The management changes that resulted in the largest reductions in GHG emissions intensity included increasing individual cow productivity and ratio of milk to total feed, and implementation of manure treatment systems.

Increasing Hybrid Rice Yield, Water Productivity, and Nitrogen Use Efficiency: Optimization Strategies for Irrigation and Fertilizer Management.

Water and fertilizer are crucial in rice growth, with irrigation and fertilizer management exhibiting synergies. In a two-year field study conducted in Yiyang City, Hunan Province, we examined the impact of three irrigation strategies-wet-shallow irrigation (W1), flooding irrigation (W2), and the "thin, shallow, wet, dry irrigation" method (W3)-in combination with distinct fertilizer treatments (labeled F1, F2, F3, and F4, with nitrogen application rates of 0, 180, 225, and 270 kg ha-1, respectively) on rice yield generation and water-fertilizer utilization patterns. The study employed Hybrid Rice Xin Xiang Liang you 1751 (XXLY1751) and Yue Liang you Mei Xiang Xin Zhan (YLYMXXZ) as representative rice cultivars. Key findings from the research include water, fertilizer, variety, and year treatments, which all significantly influenced the yield components of rice. Compared to W2, W1 in 2022 reduced the amount of irrigation water by 35.2%, resulting in a 42.0~42.8% increase in irrigation water productivity and a 25.7~25.9% increase in total water productivity. In 2023, similar improvements were seen. Specifically, compared with other treatments, the W1F3 treatment increased nitrogen uptake and harvest index by 1.4-7.7% and 5.9-7.7%, respectively. Phosphorus and potassium uptake also improved. The W1 treatment enhanced the uptake, accumulation, and translocation of nitrogen, phosphorus, and potassium nutrients throughout the rice growth cycle, increasing nutrient levels in the grains. When paired with the F3 fertilization approach, W1 treatment boosted yields and improved nutrient use efficiency. Consequently, combining W1 and F3 treatment emerged as this study's optimal water-fertilizer management approach. By harnessing the combined effects of water and fertilizer management, we can ensure efficient resource utilization and maximize the productive potential of rice.

Impact of lifestyle, human diet and nutrient use efficiency in food production on eutrophication of global aquifers and surface waters

A spatially explicit (0.5 degree resolution) analysis is presented of the impact of human lifestyle, diet and nutrient use efficiency in food production and wastewater treatment on exceedance of threshold concentrations for nitrate in groundwater, and total N and total P concentrations in surface water, as well as criteria for their ratio. This analysis starts from the middle-of-the-road (SSP2) and the sustainability (SSP1) Shared Socio-economic Pathways (SSP), focusing on the year 2050. The scenarios with changed lifestyle assume a reduction of food wastage and a low-meat diet for all world inhabitants, implying large reductions of meat and milk consumption and production in industrialized countries. Scenarios with improved nutrient use efficiencies assume maximum achievable efficiencies under practical conditions. The SSP2 scenario combined with assumptions on lifestyle and human diet leads to improvement in industrialized countries only, and increased levels in many other regions. A strong improvement is achieved in SSP1, but not in many developing countries, and SSP1 combined with changed lifestyle leads to improvement of groundwater and surface water quality in industrialized countries only. Therefore, changed lifestyle needs to be combined with efforts to improve the efficiency in food production systems and wastewater treatment to achieve reductions of the area affected by groundwater contamination and eutrophication of surface waters. Reduction strategies need to find a balance between N and P, since it is easier to reduce N in rivers to levels below the threshold than P.

Exploring the Impact of Organic-inorganic Coupling on Nutrient Use Efficiency and Cane Yield in Calcareous Soils of the Indo-gangetic Plains of India

Improving nutrient use efficiency beyond its typical ceiling of 50% is imperative for enhancing sugarcane production and juice quality, while concurrently reducing reliance on synthetic fertilizers and mitigating environmental impact. To address this challenge, a field experiment was conducted during the year 2021–2022 at the Kalyanpur research farm of Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar. The study aimed to evaluate the effects of integrated nutrient management on sugarcane yield and nutrient utilization efficiency in spring-planted crops like sugarcane. Employing the randomized block design with three replications, the experiment utilized the sugarcane variety CoP-112. Although various treatments exhibited no significant influence on parameters such as germination percentage, plant height, cane length, diameter and individual cane weight, the combination of the recommended dose of fertilizers (RDF) with vermicompost and biofertilizer (Azotobacter + PSB) at a rate of 4 kg/ha resulted in the highest millable cane (125.4×103/ha) and cane yield (94.0 t/ha). This combination led to an increase of 78% and 24% over the sole prescribed dose of fertilizer and the absolute control, respectively. No substantial differences were observed in juice quality among treatments. The maximum agronomic use efficiency was achieved in plots treated with RDF + vermicompost + Azotobacter + PSB, exhibiting a 75% improvement over plots receiving only the recommended dose of fertilizer. The findings underscore the efficacy of integrated nutrient management as the optimal approach for fostering sustainable sugarcane production.

Combined Application of Leguminous Green Manure and Straw Determined Grain Yield and Nutrient Use Efficiency in Wheat-Maize-Sunflower Rotations System in Northwest China.

Leguminous green manure (LGM) has a reputation for improving crop productivity. However, little is known about the beneficial interactions with straw on crop yield and nutrient (N, P, K) use efficiency. Herein, a 9-year field experiment (from 2015 to 2023) containing three treatments-(1) chemical fertilizer as the control (CK), (2) NPK + straw return (Straw) and (3) NPK + straw return with LGM (Straw + LGM)-was conducted to investigate whether the combined application of LGM and straw can increase productivity and nutrient use efficiency in the wheat-maize-sunflower diversified cropping rotation. The results showed that in the third rotation (2021-2023), Straw + LGM significantly increased wheat yield by 10.2% and maize yield by 19.9% compared to CK. The total equivalent yield under Straw + LGM was the highest (26.09 Mg ha-1), exceeding Straw and CK treatments by 2.7% and 12.3%, respectively. For each 2 Mg ha-1 increase in straw returned to the field, sunflower yield increased by 0.2 Mg ha-1, whereas for each 1 Mg ha-1 increase in LGM yield from the previous crop, sunflower yield increased by 0.45 Mg ha-1. Compared to CK, the co-application of LGM and straw increased the N use efficiency of maize in the first and third rotation cycle by 70.6% and 55.8%, respectively, and the P use efficiency by 147.8% in the third rotation cycle. Moreover, Straw treatment led to an increase of net income from wheat and sunflower by 14.5% and 44.6%, while Straw + LGM increased the net income from maize by 15.8% in the third rotation cycle. Combining leguminous green manure with a diversified cropping rotation has greater potential to improve nutrient use efficiency, crop productivity and net income, which can be recommended as a sustainable agronomic practice in the Hetao District, Northwest China.

Improving Human Diets and Welfare through Using Herbivore-Based Foods: 2. Environmental Consequences and Mitigations.

Animal-sourced foods are important for human nutrition and health, but they can have a negative impact on the environment. These impacts can result in land use tensions associated with population growth and the loss of native forests and wetlands during agricultural expansion. Increased greenhouse gas emissions, and high water use but poor water quality outcomes can also be associated. Life cycle analysis from cradle-to-distribution has shown that novel plant-based meat alternatives can have an environmental footprint lower than that of beef finished in feedlots, but higher than for beef raised on well-managed grazed pastures. However, several technologies and practices can be used to mitigate impacts. These include ensuring that grazing occurs when feed quality is high, the use of dietary additives, breeding of animals with higher growth rates and increased fecundity, rumen microbial manipulations through the use of vaccines, soil management to reduce nitrous oxide emission, management systems to improve carbon sequestration, improved nutrient use efficacy throughout the food chain, incorporating maize silage along with grasslands, use of cover crops, low-emission composting barns, covered manure storages, and direct injection of animal slurry into soil. The technologies and systems that help mitigate or actually provide solutions to the environmental impact are under constant refinement to enable ever-more efficient production systems to allow for the provision of animal-sourced foods to an ever-increasing population.

Zinc and silicon fertilizers in conventional and nano‐forms: Mitigating salinity effects in maize (Zea mays L.)

AbstractBackgroundSalinity stress, an escalating concern in the realm of agriculture, significantly hampers crop productivity worldwide. In recent years, nano‐fertilizers have been identified as an innovative and promising avenue for improving nutrient use efficiency and mitigating salt stress in plants.AimsThis study delves into the comparative efficacy of nano‐fertilizers (Zn and Si) and their conventional sources in bolstering maize's resilience against salt stress.MethodsThe hydroponic experiment was conducted to test maize plants under salt stress along with Zn and Si nanoparticles (NPs) application. The analysis extends to their impacts on ionic homeostasis, specifically focusing on potassium and sodium concentrations, K/Na ratio, stomatal conductance, chlorophyll content, and the osmotic potential (OP) within the shoots and roots of maize.ResultsNanoparticles relatively helped plants better under stress, compared to their respective bulk mode of applications. Nano‐Zn treatment considerably boosts the K+ concentration and enhanced K/Na ratio, as a key physiological trait in salt‐resistant species, while nano‐Si demonstrates a prominent role in modulating OP and limiting Na+ accumulation along with higher Zn and Si accumulation in plants. The salt tolerance index confirmed the contribution of these ionic and osmotic adjustments in helping maize plant against salt stress.ConclusionsOur findings confirm that the application of nutrients as nano‐fertilizers, particularly nano‐Zn, enhanced K/Na ratio and improved nutrient availability and uptake of the plant. Si nanoparticles are also attributed to better osmotic adjustment and facilitating water movement, thus highlighting the potential of nano‐fertilizers in improving overall agricultural productivity and related environmental issues.

Validation of a delivery strategy for reducing nutrient inputs and improving nutrient use efficiency in greenhouse-grown sub-irrigated pot chrysanthemums

Two experiments were conducted in a naturally lit research greenhouse to validate our modified strategy for delivering nutrients to sub-irrigated chrysanthemum plants. A split-plot design was used with four blocks arranged randomly, three nutrient rates as the main plot, and two contrasting cultivars as the subplot. The entire nutrient supply was removed at bud break and markedly reduced during vegetative growth, compared to common commercial fertilizer formulations, without adversely affecting tissue nutrient levels and plant/inflorescence quality, indicating that the plants were functioning in the low nutrient sufficiency zone. Specific nutrients (Nt) were more likely to exhibit improved uptake efficiency (shoot Nt content/Nt supply) than improved utilization efficiency (inflorescence DM/shoot Nt content) with decreasing nutrient supply. Thus, the common practice of delivering superfluous nutrient levels to greenhouse-grown chrysanthemum has little scientific merit in terms of nutrient accumulation and plant longevity. Applying a low‐input nutrient delivery strategy to the cultivation of indoor-grown, potted ornamental plants would improve the overall sustainability of the Canadian floricultural industry.

Marine Plant Growth Promoting Bacteria (PGPB) inoculation technology: Testing the effectiveness of different application methods to improve tomato plants tolerance against acute heat wave stress

Regenerative agriculture aims to boost native biodiversity and ensure sustainable production. Plant Growth Promoting Bacteria (PGPB) enhance crop yield through improved nutrient use efficiency or stress tolerance. Utilizing synthetic bacterial communities (SynCom) tailored to specific challenges holds promise for enhancing plant resilience. However, challenges include designing microbial consortia and selecting SynCom application techniques. This study tested four PGPB SynCom application methods on tomato plants to evaluate their effectiveness in promoting plant resistance and recovery from short extreme heat waves. Non-invasive phenotyping techniques were used to assess plant responses to three delivery methods (watering, foliar spray, and alginate spheres immobilization) under heat stress. Plants treated with the marine PGPB SynCom through methods like leaf spraying or encapsulation in alginate spheres exhibited improved resilience in terms of Kautsky curve intensity and shape, indicating better photochemical apparatus function. These techniques also facilitated post-stress recovery. Deep photochemical analysis revealed SynCom-induced improvements in the plant's photochemical apparatus, particularly the PS II donor side. Moreover, it was also possible to observe that upon stress relief these two techniques, alongside the plants inoculated throughout watering were able to recover their photochemical profiles. Analysing the Fv/Fm values, plants inoculated through watering, alginate beads and leaf spray can be considered heat-tolerant, a characteristic conserved throughout the three sampling moments. Heat-wave exposure led to an increase in the energy absorbed by the non-inoculated plants as a counteractive measure to overcome the low energy use efficiency observed (low trapping and transported energy fluxes). The reduction in stress impact was attributed to SynCom's ACC-deaminase production, which lowered ethylene accumulation, promoting growth and photosynthetic efficiency. The study also noted reduced energy dissipation under stress relief, indicating efficient heat dissipation mechanisms due to SynCom application. Statistical models generated with the attained photochemical data allowed depicting specific fluorescence signatures of each thermal and inoculation treatment with a very high degree of accuracy, reinforcing that these different inoculation treatments have in fact different impacts on plant photochemistry but also provide a tool for future phenotyping assessments using the proposed inoculation techniques. Alginate bead based PGPB release emerged as an efficient, scalable technique with continuous benefits for plant growth and stress response.

Interaction of Zinc Mineral Nutrition and Plant Growth-Promoting Bacteria in Tropical Agricultural Systems: A Review.

The relationship between zinc mineral nutrition and plant growth-promoting bacteria (PGPB) is pivotal in enhancing agricultural productivity, especially in tropical regions characterized by diverse climatic conditions and soil variability. This review synthesizes and critically evaluates current knowledge regarding the synergistic interaction between zinc mineral nutrition and PGPB in tropical agricultural systems. Zinc is an essential and fundamental micronutrient for various physiological and biochemical processes in plants. Its deficiency affects plant growth and development, decreasing yields and nutritional quality. In tropical regions, where soil zinc availability is often limited or imbalanced, the PGPB, through different mechanisms such as Zn solubilization; siderophore production; and phytohormone synthesis, supports Zn uptake and assimilation, thereby facilitating the adverse effects of zinc deficiency in plants. This review outlines the impacts of Zn-PGPB interactions on plant growth, root architecture, and productivity in tropical agricultural systems. The positive relationship between PGPB and plants facilitates Zn uptake and improves nutrient use efficiency, overall crop performance, and agronomic biofortification. In addition, this review highlights the importance of considering indigenous PGPB strains for specific tropical agroecosystems, acknowledging their adaptability to local conditions and their potential in sustainable agricultural practices. It is concluded that Zn fertilizer and PGPBs have synergistic interactions and can offer promising avenues for sustainable agriculture, addressing nutritional deficiencies, improving crop resilience, and ensuring food security.