Reduce Fertilizer Use Research Articles

Genome-Wide Characterization of Class III Peroxidases and Their Expression Profile During Mycorrhizal Symbiosis and Phosphorus Deprivation in Lettuce (Lactuca sativa L.)

Lettuce cultivation requires high fertilizer inputs, which impact the environment and costs. Arbuscular mycorrhizal symbiosis (AMS) can reduce fertilizer use, enhance plant nutrition (especially phosphorus), and promote healthier plants. Class III peroxidases (PRXs) play crucial roles in various physiological processes and stress responses. However, their role in AMS and phosphorous (P) deficiency is still unclear. Our study identified 91 PRX genes in the lettuce genome (LsPRXs) and clustered them into eight subfamilies based on phylogenetic relationships. Evolutionary analysis indicated that tandem duplication was the main driver for LsPRX gene family expansion. Synteny analysis showed orthologous relationships of the PRX gene family between lettuce and potato, Arabidopsis, and maize, identifying 39, 28, and 3 shared PRXs, respectively. Transcriptomic data revealed that most LsPRX genes were more expressed in roots than in leaves and differentially expressed LsPRXs were found in response to AMS and P supply. Notably, 15% of LsPRX genes were differentially expressed in roots during mycorrhization. Gene expression network analysis highly correlated five LsPRXs (LsPRX17, LsPRX23, LsPRX24, LsPRX64, and LsPRX79) with genes involved in cell wall remodeling and reorganization during mycorrhization. Our results provide insights into the evolutionary history and functional roles of PRX genes in lettuce and identify candidate gene targets that may enhance the bio-stimulant effects of AMS and help to cope with P deficiency.

Spatial benefit difference of fertilizer reduction and substitution policy based on grid scale: A case study of the Heihe River Basin

Agriculture green development faces the challenge of balancing the application of both organic and chemical fertilizers. Formulating effective policies to harmonize these applications is essential for ensuring food security and environmental sustainability. However, there is a lack of studies investigating the economic and environmental benefits of policy implementation at the grid scale, and insufficient research has been conducted on the subsequent impacts these policies have on diverse crops. Therefore, this paper develops the SIMPLE-G-Heihe model to simulate the impacts of green agricultural policies on multiple crops planting in arid regions. This model addresses limitations found in the SIMPLE-G model, which supported a single crop and lacked organic fertilizer substitution simulation. The results show that: (1) Merely increasing subsidies for organic fertilizers is insufficient to significantly enhance yields, and improving the efficiency of fertilizer utilization should also be emphasized. (2) Combining improvements in fertilizer technology with subsidies for organic fertilizers can concurrently support economic advancement and environmental mitigation. Research indicates that integrating a 3% organic fertilizer subsidy with an 8% improvement in chemical fertilizer technology increases vegetable output value by 0.27% and reduces N2O emissions by 1.09%. (3) The upstream areas of the Heihe River Basin show a significant reduction in fertilizer use. Fertilizer input is mainly reduced for vegetables in the upstream areas, while for wheat and maize, the reduction is primarily in the midstream and upstream areas. The findings discuss the spatial heterogeneity and flexibility of policy impacts, providing valuable insights for the implementation of green agriculture strategies in China.

Use Efficiency, Reduction Potential, and Effects of Fertilizers on Carbon Emissions in China’s Major Citrus Regions

Enhancing the efficiency of fertilizer utilization and advancing fertilizer reduction efforts constitutes a pivotal initiative for augmenting the quality and productivity of the citrus industry; this constitutes an indispensable prerequisite for attaining green and sustainable development. Utilizing panel data from seven prominent mandarin-producing regions and seven prominent tangerine-producing regions in China spanning from 2002 to 2022, this study employed the stochastic frontier analysis (SFA) method to develop a translog production function model for precisely measuring the fertilizer use efficiency for mandarins and tangerines. Employing the calculated optimal fertilizer use rates, we further ascertained the fertilizer reduction potential for mandarin and tangerine; then, we estimated the associated carbon emission reduction potential within these key citrus regions. The research revealed the following findings: the overall level of citrus fertilizer use efficiency in China is comparatively low, with the mean values for mandarin and tangerine fertilizer use efficiency being merely 0.4403 and 0.3887, respectively, indicating substantial room for improvement by approximately 60%; substantial potential exists for decreasing fertilizer use in China’s citrus industry, with average reduction potentials of 66.27% for mandarins and 64.83% for tangerines, signifying a notable redundancy in fertilizer application within major citrus-producing areas. The magnitude of carbon emission reduction potential through the diminution of citrus fertilizer use is tremendous. When optimal fertilizer rates are applied, the average carbon emission reductions resulting from fertilizer reduction in mandarins and tangerines amount to 815.8681 kg/hm2 and 602.3551 kg/hm2, respectively. The average carbon reduction potential for mandarins and tangerines reach levels of 55.9673% and 61.1299%, respectively, both surpassing the threshold of 55%. Significant differences exist in the technical efficiency of fertilizer input, reduction potential, and carbon emission mitigation potential among major citrus-producing regions. Citrus orchards in Guangdong exhibit higher potential for fertilizer reduction but demonstrate a relatively low level of technical efficiency. In contrast, Hunan Province shows an opposite trend, necessitating the development of region-specific strategies. Therefore, to minimize citrus fertilizer use and augment the technical efficiency of citrus fertilizer, it is imperative to comprehensively integrate and promote the “three new” technologies aimed at reducing fertilizer use and enhancing its efficiency within the citrus industry; implement a regional coordinated development strategy for citrus fertilizer reduction; and intensify policy guidance, publicity, and training efforts related to citrus fertilizer reduction, efficiency enhancement, and carbon emissions reduction.

Nutrient and energy conservation through nano-fertilizers in maize

In the current scenario, achieving food security while conserving resources and energy is a significant challenge. Maize is a widely cultivated but nutrient-exhaustive crop. The adoption of nanotechnology-based nano-fertilizers offers a pathway to achieving sustainable yields while reducing fertilizer requirements and conserving energy. A field experiment was conducted during the Kharif season of 2021 to explore nutrient and energy conservation through nano-fertilizers in maize at the University of Agricultural Sciences, GKVK, Bengaluru. The experiment involved nine treatments comprising various combinations of the recommended dose of fertilizers (RDF) with nano-urea and nano Di-Ammonium Phosphate (DAP) under a Randomized Complete Block Design (RCBD). The results indicated that Treatment T5 - 75% of the Recommended Dose of Nitrogen (RDN) + Nano-N—achieved a higher yield (10.20% higher than the conventional practice, T1-RDF + Farmyard Manure (FYM)) and improved nutrient uptake at harvest [299.22, 55.56, and 208.26 kg of nitrogen (N), phosphorus (P), and potassium (K) per hectare, respectively]. This treatment also demonstrated greater physiological efficiency (36.11, 200.66, and 52.70 kg of maize per kg of N, P, and K, respectively), higher energy output (260,851 MJ ha?¹), improved energy use efficiency (16.93), enhanced energy productivity (0.627 kg MJ?¹), and better energy profitability (15.93). Using 75% of RDN + Nano-N increases yield while reducing fertilizer use and conserving energy.

Temporal and spatial analysis of fertilizer application intensity and its environmental risks in China from 1978 to 2022

Fertilizers are an essential input in agriculture as they can enhance crop yields. However, their use also poses significant environmental risks. To thoroughly explore the intensity of fertilizer use and its potential threats to the ecological environment, this study analyzed the environmental risks of fertilizer use from a temporal and spatial perspective based on fertilizer application data in China from 1978 to 2022. Additionally, the contribution of fertilizer application in Chinese farmland to greenhouse gas N2O emissions was quantified using IPCC emission factor methodology. The results indicated that fertilizer application intensity and N2O emissions in China initially increased and then decreased from 1978 to 2022. Despite the implementation of various fertilizer control measures at the policy level, such as the Zero Growth of Fertilizer Action in 2015 and the Efficiency-Increasing Action for Reducing Fertilizer Use in 2022, the intensity of fertilizer application in China still exceeded international safety standards by 1.33-fold in 2022, reaching 298.79 kg/hm2. Furthermore, N2O emissions amounted to 50.17 × 104t, accounting for 16% of China's total agricultural greenhouse gas emissions that year. Correlation and regression analyses demonstrated that with increasing fertilizer application, crop production exhibits an inverted U-shaped growth trend, indicating limited effectiveness of high-intensity fertilizer use in increasing crop yields. These findings highlight the profound greenhouse effect resulting from the use of agricultural nitrogen fertilizer. Therefore, this study proposed technical and policy-level mitigation measures to address the issues caused by excessive fertilizer application, aiming to provide insights for controlling agricultural non-point source pollution and preserving the agroecological environment.

Strategic Management of Eco-Innovation and Emerging Technologies for Sustainability in Agro-Based Industries

Eco-innovation and emerging technologies are increasingly central to driving sustainability in agro-based industries. This study examines the impact of technological advancements on sustainable agricultural practices, focusing on innovations that reduce environmental impacts while enhancing productivity. According to the USDA, precision agriculture systems implemented in the Midwest show a 15-20% reduction in fertilizer use and a 10-15% increase in crop yields. Furthermore, the adoption of renewable energy solutions, such as solar-powered irrigation in India, has led to a 30% decrease in energy costs and a 25% reduction in greenhouse gas emissions (GHGs), as reported by the International Renewable Energy Agency (IRENA). Biotechnology applications, such as genetically modified drought-resistant crops, have reduced pesticide use by up to 37% while increasing crop resilience, according to a study published in Nature. This paper also explores the socio-environmental implications of these technologies, emphasizing the need for balanced development that integrates technological progress with ecological sustainability. Case studies from Brazil, India, and Kenya provide further insights into the successful implementation of these innovations. The findings suggest that leveraging emerging technologies in agro-based industries can significantly enhance sustainability, contributing to a more resilient and equitable human-environment relationship.

Evaluation of Nitrogen Fertilizer Supply and Soil Nitrate Thresholds for High Yields of Foxtail Millet

Foxtail millet is an important cereal crop in the North China Plain. However, excessive nitrogen fertilizer application over the years has led to declining yield and soil quality. This study investigated nutrient management strategies for foxtail millet based on crop yield levels and soil nutrient availability. In a field where targeted fertilization was conducted over six seasons, nitrogen fertilization effects and the dynamics of soil-available nitrogen were monitored continuously for two consecutive years (2022–2023) across five different foxtail millet varieties with varying yield levels. The study aimed to determine the optimal nitrogen application rate for achieving a high yield of foxtail millet, the minimum soil nitrate threshold required to maintain soil fertility, and the effective nitrogen application rate range for sustaining soil-available nitrate levels. Results showed that fertilization significantly affected dry matter weight during flowering, while variety affected dry matter weight at maturity. The average nitrogen application rate for achieving high yield across all five millet varieties was 141.3 kg·ha−1. Specifically, the average nitrogen application rate of nitrogen-efficient varieties achieving high yield (5607.32–5637.19 kg·ha−1) was 151.5 kg·ha−1, while the average nitrogen application rate of nitrogen-inefficient varieties achieving high yield (4749.77–4847.74 kg·ha−1) was 134.5 kg·ha−1. Soil NH4+-N and NO3−-N content increased when nitrogen application rate exceeded 360 kg·ha−1, posing environmental risks. To achieve high yield, soil nitrate levels would be maintained at an average of 17.23 mg·kg−1 (before sowing) and 9.75 mg·kg−1 (at maturity). A relationship between soil nitrate and nitrogen application rate was established: y = 867.5 − 50z (where y represents the optimal nitrogen application rate for high yield (kg·ha−1), and z represents soil NO3−-N content in the 0–20 cm layer before sowing, ranging from 10.0 to 17.35 mg·kg−1), which provided a practical method for nitrogen fertilization to achieve high yield of foxtail millet. In this study, the fertilization strategy was optimized according to soil nutrient level and yield targets, and the nitrogen application rate was controlled within 360 kg·ha−1 based on the soil nitrate nitrogen content, which will be instructive for reducing fertilizer use, maximizing fertilizer efficiency, and increasing yield.

Enhancing Maize Yield and Nutrient Utilization through Improved Soil Quality under Reduced Fertilizer Use: The Efficacy of Organic–Inorganic Compound Fertilizer

Objectives: The substitution of chemical fertilizers with organic alternatives presents a viable strategy for enhancing soil quality and boosting agricultural productivity. However, the question remains whether organic–inorganic compound fertilizers (COIFs) can sustain improved soil quality and crop yields while reducing chemical fertilizer use. The underlying mechanisms of COIF’s impact still warrant further exploration. Methods: In this study, a long-term fertilization trial was conducted from 2020 to 2023 at two sites with different soil textures and types in the Huang-Huai-Hai Plain, China. The experiment involved three fertilization treatments, each replicated three times: (1) LCF (conventional fertilizer treatment); (2) COIF1 (COIF applied at 90% of the recommended rate); and (3) COIF2 (COIF applied at 80% of the recommended rate). The objective was to assess the effects of COIF on summer maize growth, grain yield, nutrient uptake and utilization, and soil quality. Results: Compared to LCF, COIF1 in Yantai and Dezhou increased biomass by 6.4% and 8.1%, grain yield by 5.9% and 4.12%, PFP (N, P, and K) by 17.6% and 15.7%, and soil quality by 563.6% and 462.5%, respectively. No significant differences in biomass and grain yield were observed between COIF2 and LCF, yet COIF1 in Yantai and Dezhou enhanced PFP (N, P, and K) by 19.7% and 18.6%, and soil quality by 109.1% and 175.0%, respectively. In conclusion, COIF improved soil quality by enhancing soil organic matter (SOM), available nutrients, pH, and other soil indices. It promoted summer maize growth, increased grain yield, and improved nutrient utilization. COIF was a practical and effective measure to reduce chemical fertilizer use, enhance field soil quality, and ultimately increase maize yield and nutrient utilization.

Adoption of Fertilizer-Reduction and Efficiency-Increasing Technologies in China: The Role of Information Acquisition Ability

Reducing fertilizer use and increasing its efficiency will improve the quality of farmland and resource conservation. These are necessary steps to achieving green development in agriculture. Nevertheless, fertilizer-reduction and efficiency-increasing technologies (FREITs) remain limited. To improve the situation, 538 farmers in Jiangsu and Hubei Provinces were surveyed with the goal of measuring the information acquisition ability (IAA) of farmers using an Item Response Theory (IRT) model. A model of improved technology selection was employed in conjunction with an IV-probit model to examine the impacts of IAA on farmers’ adoption of FREITs. The results showed that 34.76% of the surveyed farmers had adopted FREITs, with 12.45% and 26.02% having adopted Soil Testing and Formula Fertilization Technology (STFFT) and Organic Fertilizer Replacement Technology (OFRT), respectively. Second, farmers who used more information access channels had greater IAA, which significantly improved their adoption of FREITs. Third, participation in technical training and an increased degree of technical understanding increased the probability of farmers adopting FREITs. The results remained robust after accounting for endogeneity and correlation. Consequently, enhancing farmers’ IAA, organizing technical training, and improving technical publicity will promote the adoption of FREITs.

Enhancing emission reductions in South African agriculture: The crucial role of carbon credits in incentivizing climate-smart farming practices

Agriculture faces environmental threats caused by climate change, exacerbated by greenhouse gas emissions (GHG). As a result, climate change is a pressing issue for agriculture, necessitating strategies like carbon credits to mitigate emissions and enhance productivity. Carbon credits are recognized as a prominent avenue for reducing emissions, as highlighted in the 2023 Climate Change Conference (COP28). However, research on carbon credit targeting non-CO2 emissions from agriculture is limited. Thus, this study employed stochastic frontier analysis (SFA) to examine panel data from 1991 to 2020, focusing on the effectiveness of climate-smart agriculture in reducing South African agricultural GHG emissions. The data included non-mechanical agricultural emissions sources, paying attention to emissions from crops and livestock. The findings supported the hypothesis, suggesting that increasing incentives, specifically carbon credits, can raise agricultural productivity while reducing emissions. The study also found that inefficiencies in agriculture significantly impact farm output and emissions. The results indicate that offering GHG carbon credits for agriculture promotes sustainable practices, as methane and nitrous oxide emissions are short-lived and can help reduce climate change impact through carbon sequestration. Prioritizing on-farm emissions, soil fertility improvement, reduced fertilizer use, and better livestock management can lead to positive change through climate-smart farming practices. Therefore, promoting customized GHG credits for agriculture mechanisms can lead to positive change through climate-smart farming practices. Thus, it is necessary to enhance mitigation strategies, policies, and farm practices. Finally, the study emphasizes the significance of evidence-based GHG credits for agriculture mechanisms policies and the need for future research into ways to persuade farmers to participate in the carbon credit market.

Effect of AMF Inoculation on Reducing Excessive Fertilizer Use.

Excessive use of chemical fertilizer is a global concern. Arbuscular mycorrhizal fungi (AMF) are considered a potential solution due to their symbiotic association with crops. This study assessed AMF's effects on maize yield, fertilizer efficiency, plant traits, and soil nutrients under different reduced-fertilizer regimes in medium-low fertility fields. We found that phosphorus supplementation after a 30% fertilizer reduction enhanced AMF's positive impact on grain yield, increasing it by 3.47% with pure chemical fertilizers and 6.65% with mixed fertilizers. The AMF inoculation did not significantly affect the nitrogen and phosphorus fertilizer use efficiency, but significantly increased root colonization and soil mycelium density. Mixed fertilizer treatments with phosphorus supplementation after fertilizer reduction showed greater mycorrhizal effects on plant traits and soil nutrient contents compared to chemical fertilizer treatments. This study highlights that AMF inoculation, closely linked to fertilization regimes, can effectively reduce fertilizer use while sustaining or enhancing maize yields.

Enriching NPK Mineral Fertilizer with Plant-Stimulating Peptides Increases Soilless Tomato Production, Grower Profit, and Environmental Sustainability.

The need to increase agricultural production to feed a steadily growing population may clash with the more environmentally friendly but less efficient production methods required. Therefore, it is important to try to reduce the use of chemical inputs without compromising production. In this scenario, natural biostimulants have become one of the most sought-after and researched technologies. In the present study, the results of a greenhouse experiment on hydroponic tomatoes (Solanum lycopersicum L.) are presented, which involved comparing the use of ordinary NPK fertilizer (Cerbero®) with the use of NPK fertilizers enriched with 0.5% protein hydrolysate of plant origin (Cerbero Green®) at both standard (100%) and reduced (70%) fertilization rates. The results highlight how the use of Cerbero Green® fertilizers improves the production performance of tomatoes. More specifically, they show that the use of Cerbero Green® leads to higher marketable yields, especially under reducing fertilizer use, ensuring a positive net change in profit for the grower. In addition, carbon footprint analysis has revealed that the use of Cerbero Green® reduces the environmental impact of hydroponic tomato growing practices by up to 8%. The observed higher yield of hydroponically grown tomatoes even with reduced fertilization rates underlines once again the key role of natural biostimulants in increasing both the economic and environmental sustainability of horticultural production.

Long-term cover crop monocultures and mixtures improve soil multifunctionality and shift microbial communities and functions

Long-term cover crops are an emerging approach for achieving sustainable agriculture by reducing fertilizer use and enhancing soil quality. However, soil microbial communities, multifunctionality (i.e., the ability of soil ecosystems to simultaneously provide and maintain multiple ecological functions), and their relationships in cover crops remain poorly understood, especially in cover crop mixtures. To address these issues, here, we conducted a 15-year field experiment under different cover crop deployments (one legume and one brassica grown in monoculture or in mixture) in Carya cathayensis plantations. We found that cover crops significantly increased soil microbial diversity and multifunctionality, especially in mixtures. The bacterial and fungal compositions was significantly affected by cover crops. Interestingly, some taxa may serve as potential indicator species for nutrient status (i.e., bacterial Subgroup_2, Subgroup_6 and Subgroup_17). Cover crops significantly increased beneficial microbial functions (e.g., nitrogen fixation) but decreased pathogen-related functions (e.g., pathotroph). Bacterial and fungal community assemblages under cover crops were dominated by stochastic processes. Cover crops, especially mixtures, had a higher habitat niche breadth (Bcom). In addition, cover crops have more complex and stable bacterial and fungal networks. Partial least squares path modeling further confirmed that the variations in soil multifunctionality were largely related to nutrient resources. Importantly, the relative abundance of rare microbial taxa was also highly correlated with soil multifunctionality. Overall, our study illustrates that the use of cover crops in the long term can foster soil microbial specific taxa and contribute to improved soil multifunctionality. Our study provides support for the benefits of a legume-brassica mixture over monocultures of either and a theoretical basis for exploring cover crops as an ecological management model.

Response of nutrient accumulation, remobilization and yield to combined application of nitrogen and potassium in waxy maize

Unbalanced fertilizers supply with highly intensity and excessive nitrogen (N) and less potassium (K), lead to the decrease of soil fertility year by year. Balanced fertilization is one of the most effective measures to reduce fertilizer use while improving maize yield and efficiency. Two N levels (180 and 225 kg N ha−1, abbreviated N12 and N15) and four K treatments (0, 75, 150, and 75+75 kg K2O ha−1, abbreviated K0, K5, K10, and K5+5) were set to study the effects of combined application of N and K on the biomass and nutrient accumulation and remobilization characteristics in waxy maize. The results demonstrated that grain yield increased when higher amounts of K were applied at constant N levels, showing an average increase of 1,254.8 kg ha−1 (2020) and 727.3 kg ha−1 (2021) compared with K0. Under same N and K application, K5+5 increased grain yield by increasing kernel weight. Under K5+5 treatment, the biomass and nutrient accumulation had no significant difference between N12 and N15. Compared with K10, K5+5 not only enhanced the average remobilization amount (RBA) of biomass, but also increased RBA of N, phosphorus (P) and K. In addition, the average remobilization efficiency (RBE) of biomass, N, P and K in K5+5 were increased 3.3, 4.6, 10.6 and 4.2%, respectively. Furthermore, topdressing K improved the apparent contribution to grain (AC) of biomass, N, P and K, which promoted more nutrient to grains, and significantly increased nutrient harvest index. Considering yield and fertilizer use efficiency, we recommend optimized K application (basal and topdressing 75 kg ha−1) and moderately reduced N application (from 225 to 180 kg ha−1) in the production of spring-sown waxy maize in southern China.

How do price (risk) changes influence farmers’ preferences to reduce fertilizer application?

AbstractThe decision of farmers to reduce fertilizer applications and, thus, the achievement of agri‐environmental policy goals interacts with market price developments. In this study, we analyze how changes in price levels and volatility over time (i.e., 1991–2006 vs. 2007–2022) affected farmers’ preferences to reduce fertilizer application using statistical inferences of stochastic dominances. The analysis considers two cropping systems and fertilizer reduction measures: (i) grassland‐based milk production and the use of legumes and (ii) wheat production and the use of variable rate application. We show that the economic value of reducing fertilizer increased over time in both grassland‐based milk and wheat production. However, only in the case of wheat production was the reduction in fertilizer application observed as more risk‐reducing over time. In contrast, in grassland‐based milk production, the co‐movement of fertilizer and milk prices canceled out the increase in risk reduction. We conclude that changes in market price, along with agri‐environmental subsidies, can increasingly incentivize the reduction of fertilizer use.

Plant Growth-Promoting Rhizobacteria as Tools to Improve the Growth of Kohlrabi (Brassica oleracea var. gongylodes) Plants in an Aquaponics System.

The use of nitrogen as a fertilizer can be highly risky when used excessively, and it is therefore necessary to find novel techniques to reduce its use. Aquaponics reduces the use of synthetic fertilizers and water, and the leaching of nitrate into the environment. One way to avoid problems due to a reduction in nitrogen availability could be the use of plant growth promoting rhizobacteria (PGPR). This study examines the effect of PGPR on kohlrabi plants grown with a traditional nutrient solution (100S), in combination with "fish water" (50F/50D), or with a supplement of synthetic fertilizers (50F/50D + S). Two formulations were used: T1 (Azospirillum brasilense and Pantoea dispersa) and T2 (Azotobacter salinestris). Irrigation with 50F/50D caused a reduction in several of the measured parameters. The combined application of 50F/50D with T1 attenuated the negative effects. T2 did not present significant effects on the parameters measured. The results obtained with 50F/50D + S hardly showed differences with the 100S. Thus, by irrigating with 50F/50D + S, we were able to maintain the yields while reducing fertilizer use and water. The combined use of T1 and 50F/50D was also positive; however, it would be necessary to continue adjusting the amount of nitrate supplied to maintain production.

Soil Moisture Conservation through Crop Diversification and Related Ecosystem Services in a Blown-Sand Area with High Drought Hazard.

Soil moisture reserves are a key factor in maintaining soil fertility and all other related ecosystem services (including carbon sequestration, soil biodiversity, and soil erosion control). In semiarid blown-sand areas under aridification, water preservation is a particularly crucial task for agriculture. The international Diverfarming project (2017-2022), within the EU Horizon 2020 Program, focused on the impacts of crop diversification and low-input practices in all pedoclimatic regions of Europe. In this three-year experiment conducted in the Pannonian region, the impact of intercropping asparagus with different herbs on some provisioning and regulating ecosystem services was evaluated in the Kiskunság sand regions. Relying on findings based on a range of measured physical and chemical soil parameters and on crop yields and qualitative properties, advice was formulated for farmers. The message drawn from the experiment is somewhat ambiguous. The local farmers agree that crop diversification improves soil quality, but deny that it would directly influence farm competitiveness, which primarily depends on cultivation costs (such as fertilization, plant protection, and labour). Further analyses are needed to prove the long-term benefits of diversification through enriching soil microbial life and through the possible reduction of fertilizer use, while water demand is kept at a low level and the same crop-quality is ensured.

Controls on in-stream nitrogen loss in western Lake Erie tributaries

Management efforts to reduce cyanobacterial harmful algal blooms (cHABs) in the Great Lakes have focused on decreasing tributary inputs of phosphorus (P). Recent research has indicated that reduction of both P and nitrogen (N) can lessen cHABs severity. Microbially mediated N cycling in streambed sediment may reduce N riverine loads, yet little is known about in-stream N processing rates in the Maumee River Basin, a major source of nutrients to Lake Erie. During summer of 2019 and 2021, we sampled streambed sediment to measure potential nitrification and denitrification rates using the acetylene block method at 78 sites throughout the Maumee River network. We used structural equation models to identify indirect and direct drivers of denitrification. Precipitation was greater in 2019, resulting in a 67 % increase in mean discharge, 41 % of farm fields to be fallow, and a 50 % reduction in fertilizer use. During summer field surveys, median stream-water nitrate concentrations were not different between 2019 and 2021. Median denitrification rates were 13.3 mg N/m2/h and 31.2 mg N/m2/h, respectively, indicating high potential to remove N. Nitrate concentrations and nitrification rates were strong direct drivers of denitrification, especially in 2019 when coupled nitrification–denitrification sustained denitrification. Nitrate concentrations varied with land use. Notably, nitrate concentrations increased with the area of fallow land, which may indicate the presence of a legacy N source. These findings indicate that promoting streambed denitrification could reduce N loads to Lake Erie, but legacy N currently stored in the system may mask N reduction efforts.

Can high-yielding maize system decrease greenhouse gas emissions largely while simultaneously enhancing economic and ecosystem benefits through the “Rhizobiont” concept? Evidence from field

Ensuring high grain yields while minimizing environmental costs is a pressing imperative aligned with the Sustainable Development Goals (SDGs). In this study, we sought to establish a high-yielding maize system (HYMS) by implementing the innovative “Rhizobiont” concept for nutrient management, while substantially reducing greenhouse gas emissions. A 2-yr field study was conducted in a station of China Agriculture University (Wuqiao) with six treatments. The HYMS was established to achieve a harmonious equilibrium among genetic factors, environmental conditions, and management practices. HYMS demonstrated a significant boost in grain yield, averaging 12,706.6 kg ha−1 in 2021 and 13,676.4 kg ha−1 in 2022. These represented substantial increases of 25.6 % and 25.5 %, respectively, when compared to the current farmers practices (CP). More importantly, the N rate in HYMS was optimized to 148.2 kg ha−1 in 2021 and 138.0 kg ha−1 in 2022 with the implementation of the “Rhizobiont” concept. This represented a remarkable reduction of 35.5 % to 39.9 % in N application compared to CP. As a direct consequence, the measured cumulative emissions of greenhouse gases such as CO2, N2O, and CH4 in HYMS were notably decreased, showing reductions of 24.1 %, 36.0 %, and 7.0 %, respectively, compared to CP. Furthermore, the carbon intensity in HYMS was significantly reduced by 43.7 %. These considerable reductions in fertilizer use translated into tangible economic benefits (EB) and ecosystem economic benefit (EEB) in HYMS. EB was found to be 90.9 % higher, while EEB was 117.9 % higher than CP. These findings underscore the vast potential of HYMS and the “Rhizobiont” concept in promoting sustainable agriculture, with far-reaching implications for global food security and the well-being of smallholder farmers.

Treated waste water reuse in agriculture: An Overview

The reuse of treated wastewater in agriculture is a promising solution to the water scarcity challenge faced by many regions worldwide. This review paper provides an overview of the current state of knowledge on treated wastewater reuse in agriculture, highlighting its potential benefits and challenges. The paper begins by discussing the importance of treating wastewater before reuse and the potential it offers. The benefits of using treated wastewater in agriculture are discussed, including increased water availability, improved soil fertility and reduced fertilizer use. The risks associated with the use of treated wastewater, such as the accumulation of pollutants and the potential for pathogen transmission, are also discussed. The review paper then presents some examples of reuse projects for irrigation and their success criteria. The current regulations governing the use of treated wastewater in agriculture are examined, and their evolution presented. The paper concludes with a discussion of future research needed to address the remaining challenges surrounding the use of treated wastewater in agriculture. Overall, the review paper emphasizes the importance of careful management and regulation of treated wastewater reuse in agriculture to ensure safety and sustainability to meet the growing demand for water in agriculture.