Balancing nitrogen use efficiency, losses and soil nitrogen depletion to evaluate agri-environmental performance across spatial scales over 40 years

Changes of nitrate concentrations in surface waters influenced by land use in the crystalline complex of the Czech Republic

Achieving sustainable agricultural development necessitates a careful balance between the competing demands of environmental sustainability and food security. While extensive research has examined the economic impacts of agricultural parks, studies focusing on their environmental effects—particularly fertilizer usage—remain limited. Addressing this gap, this study investigates the impact of China’s National Modern Agricultural Industrial Parks (NMAIP) construction on fertilizer application using county-level panel data from 2014 to 2022. By leveraging the staggered establishment of these parks as a quasi-natural experiment, we apply a multi-period Difference-in-Differences (DID) approach. The results indicate that NMAIP construction led to a significant reduction in fertilizer use, a finding robust to a series of tests including parallel trends and placebo analyses. Mechanism analysis reveals that the reduction was primarily driven by enhanced agricultural labor and technology productivity. Heterogeneity analysis further shows that the effects were more pronounced in regions with high-level fertilizer consumption, in non-major grain-producing or wheat-producing areas, and in specialized or single-function parks. Importantly, this reduction in fertilizer use did not compromise grain output; instead, it was accompanied by stable or even increased production, thereby supporting food security. Our findings demonstrate that the NMAIP policy can achieve a “win-win” outcome by simultaneously promoting fertilizer reduction and safeguarding food security, offering a viable pathway toward sustainable agricultural development and food system resilience.

The Educational Collaborative on Sustainable Environmental and Agricultural Management (ECOSEAM) objective is to educate senior undergraduate and MS degree students on specific, high priority agricultural and rural environmental issues using a comprehensive systematic approach. Funded by a USDA Challenge Grant, ECOSEAM established a multi-university, multi-disciplinary team to develop four high-priority courses in sustainable agricultural and rural environmental management. Courses developed and offered beginning January 2009 are:

The paddy farmer’s performance and ability to improve productivity are driven by their level of farm management practices. Knowledge on the nature and level of sustainable farm management (SFM) practiced provides opportunities for supporting the competitive advantages of paddy farmers to sustainably break away from the poverty cycle. Little attention has been given to measuring the performance and impact of SFM on the improvement of paddy farmers livelihoods in Malaysia. Without understanding SFM, it is difficult to make policies and provide targeted, impactful support to paddy farmers. This study aims to evaluate the level of Sustainable Farming Management (SFM) among paddy farmers by applying the Sustainable Farm Management Index (SFMI), in accordance with the guidelines outlined in the Rice Check (RC) by the Department of Agriculture. Additionally, it seeks to analyze the key factors and their impact on enhancing paddy yield in Malaysia’s main granary areas. A set of structured questionnaire was designed to capture the eleven elements of farming practices based on the RC and was then distributed to 500 paddy farmers in Malaysia’s main granary areas, namely Muda Agriculture Development Authority (MADA), Kemubu Agriculture Development Authority (KADA), and Integrated Agriculture Development Authority Barat Laut Selangor (IAD-BLS). Each practice was given a score to determine whether the guidelines were followed. The index ranges from 0 to 100, with 0 being unsustainable and 100 being highly sustainable. A multiple regression analysis was employed as well to estimate the effects of SFM adoption on farmer livelihoods. The findings show that adopting SFM has a positive and significant effect on farmers’ livelihoods. The paper therefore recommends that farmers should be educated on the importance of sustainable farming practices, as this is essential for the sustainable livelihood development of the poor farmers who rely on government subsidies.

Quantifying and optimizing agroecosystem services in China's Taihu Lake Basin

Non-point source pollution in rivers is an important factor affecting water quality. Quantifying the load of non-point source pollutants in the water and implementing improvement measures are critical for guaranteeing drinking water quality. In this study, the Dan River watershed, which is an important water source for Beijing, was investigated. Through a combination of water sampling and numerical simulations, the temporal and spatial distributions of nitrate nitrogen (NO3--N) and ammoniacal nitrogen (NH4+-N) loads in the watershed were determined, and the effects of vegetation restoration and agricultural management on reducing nitrogen pollution in the river were predicted. The NO3--N and NH4+-N loads in the watershed were higher during the wet season (July-September), accounting for more than 50% of the annual nitrogen output. The Soil and Water Assessment Tool (SWAT) was used to simulate the nitrogen load in the watershed. Pollution from nitrogen loading was serious in the lower reaches of the river; however, vegetation restoration can reduce the nitrogen output. Through scenario simulations, we found that an increase in forestland in the watershed would reduce the NO3--N and NH4+-N loads. The nitrate and NH4+-N loads in the watershed also decreased with reduced fertilizer use and reduced irrigation application in the watershed. Thus, reasonable land planning and agricultural management measures can effectively reduce nitrogen loss, which is an effective way to control non-point source pollution in watersheds and ensure river water quality.

After the Second World War, technological advancements helped to develop agriculture and meet urgent food needs. The green revolution was based on the cultivation of new high-yielding varieties, the adoption of plant protection measures, and synthetic fertilizer use. Today, agriculture is called upon to recover its productivity in environmentally friendly terms and to face challenges such as climate change and international political–military events that threaten global sufficiency in agricultural products. The objective of the study is to evaluate the function that crop-protection technologies play in ensuring the continuity of agricultural output. The research was conducted by the use of a questionnaire in a sample of 250 farmers in Northern Greece. Specifically, through descriptive and regression analysis, the roles of biological crop protection, chemical crop-protection techniques, and mechanical crop-protection techniques were explored, and it was found that they either have a positive effect or a significant relationship with sustainable agricultural productivity. In order to meet the current environmental, economic, and political challenges, the agriculture sector at the global and local level should improve and further adopt existing technologies, consolidate the use of integrated pest-management strategies, and fully introduce innovations, combined with digital transformation, into agricultural management and production.

Effective nitrogen (N) management measures are required to control environmental problems caused by N fertilizer use in intensive maize production systems. Soil N losses associated with high precipitation and over-fertilization in maize production can cause substantial environmental problems, whereas there is a lack of quantitative data and effective study countermeasures. A 2-year field study was conducted in the subtropical maize production system in Southwest China to quantify N leaching under varying N application rates of 0, 90, 180, 270 and 360 kg N ha-1 yr-1 . The results indicated that N leaching accounted for 16-38% of N fertilizer input. For farmer practice treatment (360 kg N ha-1 yr-1 ), N leaching loss was high at 110 kg N ha-1 yr-1 and accounted for 31% of the N applied. As an indicator of the ambient water quality pollution, the grey water footprint across all treatments ranged from 376 to 1092 m3 Mg-1 , with an average of 695 m3 Mg-1 . Reducing N rate to agronomically optimized treatment (180 kg N ha-1 yr-1 ) significantly decreased N leaching by 77%, and maintained high grain yield of 8.1Mg ha-1 . The grey water footprint was reduced by 52-63% with N rates from 270 or 360 kg N ha-1 yr-1 to 180 kg N ha-1 yr-1 . Nitrogen surplus (applied N rate minus N uptake by maize) resulted in higher soil residual nitrate concentration and consequently high N leaching. High precipitation and low soil pH were the main ecological factors leading to high N leaching. © 2021 Society of Chemical Industry.

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).

This article describes a behavioral model of the Flumen‐Monegros irrigation area (Spain) and presents the results from the model simulation under various policy scenarios. The model combines agronomic, economic and policy information in a framework built using linear programming and crop growth simulation techniques. An important feature of the model is the classification of crop acreage in various types of soils which have different productive potential. The objective function maximizes net margins of crops and includes direct payments of the Common Agricultural Policy (CAP). The crop activities covered in the model are the main crops cultivated in the area (fallow, wheat, barley, corn, sunflower, alfalfa, rice, other crops, and CAP set‐aside). To validate the model, the results on cropland utilization obtained from the model have been compared with actual cropland utilization, concluding that the model closely approximates the actual data. The model is used to characterize the behavior of the irrigation area under three scenarios which reflect likely changes in agricultural and environmental policies: removal of direct payments, increase in water prices, and reduction of fertilizer use. The results show the large impact of these three scenarios on farmers' production decisions: the elimination of direct payment reduces net margin almost by half; prices corresponding to full recovery of water costs reduce significantly the cultivated acreage; and the reduction in fertilizer use causes a fall of 23 percent in net margins.

The effects of nitrogen deposition reduction on nutrient loading in freshwaters have been widely studied, especially in remote regions. However, understanding of the ecological effects is still rather limited. Herein, we re-estimated nitrogen deposition, both of wet and dry deposition, in Lake Taihu with monthly monitoring data from 2010 to 2021. Our results showed that the atmospheric deposition of reactive nitrogen (namely NH4+ and NO3-) in Lake Taihu was 4.94-11.49 kton/yr, which equaled 13.9%-27.3% of the riverine loading. Dry deposition of NH4+ and NO3- contributed 53.1% of the bulk deposition in Lake Taihu. Ammonium was the main component of both wet and dry deposition, which may have been due to the strong agriculture-related activities around Lake Taihu. Nitrogen deposition explained 24.9% of the variation in phytoplankton community succession from 2010 to 2021 and was the highest among all the environmental factors. Atmospheric deposition offset the effects of external nitrogen reduction during the early years and delayed the emergence of nitrogen-fixing cyanobacterial dominance in Lake Taihu. Our results implied that a decrease in nitrogen deposition due to a reduction in fertilizer use, especially a decrease in NH4+ deposition, could limit diatoms and promote non-nitrogen-fixing cyanobacterial dominance, followed by nitrogen-fixing taxa. This result was also applied to other shallow eutrophic lakes around the middle and lower reaches of the Yangtze River, where significant reduction of fertilizer use recorded during the last decades.

This study evaluates the effectiveness of the Khamari Mobile App, a geospatially enabled crop production advisory tool aimed to improve productivity and profitability in Bangladesh’s agricultural sector. Field-level demonstration trials were conducted for 14 major non-rice crops during the Rabi and Kharif-I seasons of 2022–23 and 2024–25 across diverse Agro-Ecological Zones (AEZs). Fertilizer recommendations generated by the Khamari app were evaluated in terms of fertilizer-use efficiency, crop yield, and economic returns, and compared with farmers’ conventional practices. The results indicate that app-based recommendations significantly reduced fertilizer use by 10–78% while increasing crop yields by 0.84–26.33%, resulting in higher net economic returns. Statistical analysis using a t-test at the 5% significance level confirmed that differences in fertilizer costs and yields between the two practices were statistically significant. These findings demonstrate the potential of Khamari app, as a geospatial decision-support tools, to enhance resource-use efficiency, farm profitability, and sustainability in Bangladesh’s agricultural systems, while also providing policy-relevant insights for reducing excessive fertilizer use and associated subsidy burdens.

We explored the relationships between synthetic fertilizer use, yield, and ecosystem services in a coffee agroecosystem in the Tarrazú region in the central highlands of Costa Rica. Working in nine farms ranging from 0.3 to 2.7 ha in the CoopeTarrazú farmers' cooperative, we focused on two important indicators of ecosystem services: biological control agents and mycorrhizal fungi. Biological control agents (especially parasitoid wasps) are essential for population regulation of herbivorous arthropods that reside in coffee agroecosystems. Mycorrhizal fungi contribute to plant nutrition and disease resistance and produce a highly stable protein, glomalin, which is critical for soil aggregation. Soil aggregates hedge against erosion, particularly in sloping soils, by improving porosity. Slopes in this study ranged from 4% to 66%. We manipulated synthetic fertilizer levels in experimental plots ranging from 6.9% increase to 53.3% decrease in total N relative to control plots that received a standard amount of fertilizer. The effects on coffee yields, soil glomalin production by mycorrhizal fungi, and wasp diversity were examined. Yield and glomalin decreased, but parasitoid diversity increased with greater reductions in fertilizer application six months after application. Reducing fertilizer use may bolster biological control assemblages, while glomalin is more directly dependent on plant production.

Nitrification tend to reduce the agronomic fertilizer use efficiency in cropping systems because nitrate, the end product of nitrification, has high potential to loss from soil environment due to denitrification and leaching. The population characteristics of ammonia oxidizing and nitrite oxidizing microorganisms carrying out nitrification in soils may affect the effectiveness of approaches taken to suppress nitrification. A study was conducted to assess the activity and abundance of nitrifiers in soils of intensively vegetable grown regions in Sri Lanka. Soil samples were collected from 72 locations across Nuwara Eliya, Marassana, Kalpitiya and Gannoruwa representing vegetable cultivated fields managed conventionally (<em>n</em>=45) and organically (<em>n</em>=9), and uncultivated areas (<em>n</em>=18). Basic soil characteristics were determined using standard procedures. Potential nitrification rate (PNR) and the abundance of ammonia oxidizers and nitrite oxidizers were estimated. Chemical characteristics of soils varied widely with pH, EC and organic C% ranging from 3.8 to 8.5, 0.04 to 0.94 dS/m and 0.9% to 4.5%, respectively. The PNR of the studied soils ranged from 0.18 to 15.80 NO3--N/kg/h. The abundance of ammonia oxidizers and nitrite oxidizers ranged from 1.96 to 5.97 log10CFU g-1 and 1.36 to 5.63 log10CFU g-1, respectively. The potential activity of nitrifiers did not correlate with the abundance of ammonia oxidizers or nitrite oxidizers. Thus, the functional and compositional diversities of nitrifying communities may be different across the soils. PNR values for studied soils are higher compared to reported values in literature. Hence, appropriate measures need to be taken to suppress nitrification as high nitrification rates could lead to reduce fertilizer use efficiency and increase risk of groundwater contamination with nitrate.

Mapping agriculture's impact by combining farm management handbooks, life-cycle assessment and search engine science