The legacy effect of long-term nitrogen fertilization on nitrous oxide emissions.

The primary driver of increasing atmospheric concentrations of nitrous oxide (NO) is the use of organic and synthetic fertilizer to increase agricultural crop production. Current global estimates are based on IPCC NO emission factor (EF) calculations, although there are shortcomings as many of the NO EFs are derived from measurements during the cropping season. These neglect the fallow season, and do not adequately account for double or even triple cropping systems or legacy effects on soil NO emissions in the following year.

Reducing the environmental impact of rice production in subtropical India by minimising reactive nitrogen loss.

The future of reactive nitrogen (N) for subtropical lowland rice to be characterised under diverse N-management to develop adequate sustainable practices. It is a challenge to increase the efficiency of N use in lowland rice, as N can be lost in various ways, e.g.

Are single global warming potential impact assessments adequate for carbon footprints of agri-food systems?

The vast majority of agri-food climate-based sustainability analyses use global warming potential (GWP) as an impact assessment, usually in isolation; however, in recent years, discussions have criticised the 'across-the-board' application of GWP in Life Cycle Assessments (LCAs), particularly of food systems which generate large amounts of methane (CH) and considered whether reporting additional and/or alternative metrics may be more applicable to certain circumstances or research questions (e.g. Global Temperature Change Potential (GTP)).

Assessing the Occurrence and Distribution of Microplastics in Surface Freshwater and Wastewaters of Latvia and Lithuania.

Microplastic concentrations in surface water and wastewater collected from Daugavpils and Liepaja cities in Latvia, as well as Klaipeda and Siauliai cities in Lithuania, were measured in July and December 2021. Using optical microscopy, polymer composition was characterized using micro-Raman spectroscopy. The average abundance of microplastics in surface water and wastewater samples was 16.

Using nitrification inhibitors and deep placement to tackle the trade-offs between NH and N O emissions in global croplands.

Ammonia (NH ) and nitrous oxide (N O) are two important air pollutants that have major impacts on climate change and biodiversity losses. Agriculture represents their largest source and effective mitigation measures of individual gases have been well studied. However, the interactions and trade-offs between NH and N O emissions remain uncertain.

Effects of pharmaceuticals on the nitrogen cycle in water and soil: a review.

The effects of pharmaceuticals on the nitrogen cycle in water and soil have recently become an increasingly important issue for environmental research. However, a few studies have investigated the direct effects of pharmaceuticals on the nitrogen cycle in water and soil. Pharmaceuticals can contribute to inhibition and stimulation of nitrogen cycle processes in the environment.

Predicting field NO emissions from crop residues based on their biochemical composition: A meta-analytical approach.

Crop residue incorporation is a common practice to increase or restore organic matter stocks in agricultural soils. However, this practice often increases emissions of the powerful greenhouse gas nitrous oxide (NO). Previous meta-analyses have linked various biochemical properties of crop residues to NO emissions, but the relationships between these properties have been overlooked, hampering our ability to predict NO emissions from specific residues.

Soil oxygen depletion and corresponding nitrous oxide production at hot moments in an agricultural soil.

Hot moments of nitrous oxide (NO) emissions induced by interactions between weather and management make a major contribution to annual NO budgets in agricultural soils. The causes of NO production during hot moments are not well understood under field conditions, but emerging evidence suggests that short-term fluctuations in soil oxygen (O) concentration can be critically important. We conducted high time-resolution field observations of O and NO concentrations during hot moments in a dryland agricultural soil in Northern China.

Cropping system design can improve nitrogen use efficiency in intensively managed agriculture.

New agronomic and management approaches are urgently required to meet the challenges of improving resource use efficiency and crop yields in intensive agricultural systems. Here we report the fertilizer N use efficiency (FNUE), fate of fertilizer N and N budgets in newly designed cropping systems as compared with conventional winter wheat-summer maize double cropping (Con. W/M) in the North China Plain.

Reducing NO emissions with enhanced efficiency nitrogen fertilizers (EENFs) in a high-yielding spring maize system.

Enhanced efficiency nitrogen fertilizers (EENFs), including nitrification inhibitors (NIs) and slow-release fertilizer (SRF), are considered promising approaches for mitigating nitrous oxide (NO) emissions while improving crop yield. This study investigated the combined application of EENFs with improved water and fertilizer management in an intensively irrigated spring maize rotation over five years in Northwestern China. High-frequency measurements of NO fluxes were made throughout each year (both during crop growth and the fallow season) in five treatments: no N fertilizer as a control (CK), conventional N fertilization and irrigation (Con), optimum N fertilization and irrigation (Opt, 33% reduction in N fertilizer and 25% reduction of irrigation water), optimum N fertilization and irrigation with nitrification inhibitor (Opt + NI), and optimum N fertilization and irrigation with slow-release fertilizer (Opt-SRF).

Using milk vetch (Astragalus sinicus L.) to promote rice straw decomposition by regulating enzyme activity and bacterial community.

The present study determined the dynamic changes of enzyme activity and bacterial community in rice straw (RS) and milk vetch (MV) co-decomposing process. Results showed that mixing RS and MV promoted decomposition. The mixture enhanced β-glucosidase and β-cellobiohydrolase activities relative to its monospecific residue during the mid-late stage of decomposition.

Global Research Alliance N O chamber methodology guidelines: Flux calculations.

A critical step in determining soil-to-atmosphere nitrous oxide (N O) exchange using non-steady-state chambers is converting collected gas concentration versus time data to flux values using a flux calculation (FC) scheme. It is well documented that different FC schemes can produce different flux estimates for a given set of data. Available schemes differ in their theoretical basis, computational requirements, and performance in terms of both accuracy and precision.

Global Research Alliance N O chamber methodology guidelines: Considerations for automated flux measurement.

Nitrous oxide (N O) emissions are highly episodic in response to nitrogen additions and changes in soil moisture. Automated gas sampling provides the necessary high temporal frequency to capture these emission events in real time, ensuring the development of accurate N O inventories and effective mitigation strategies to reduce global warming. This paper outlines the design and operational considerations of automated chamber systems including chamber design and deployment, frequency of gas sampling, and options in terms of the analysis of gas samples.

Oxygen Regulates Nitrous Oxide Production Directly in Agricultural Soils.

Oxygen (O) plays a critical and yet poorly understood role in regulating nitrous oxide (NO) production in well-structured agricultural soils. We investigated the effects of O dynamics on NO production in a typical intensively managed Chinese cropping system under a range of environmental conditions (temperature, moisture, ammonium, nitrate, dissolved organic carbon, and so forth). Climate and management (fertilization, irrigation, precipitation, and temperature), and their interactions significantly affected soil O and NO concentrations ( < 0.

Characterising the biophysical, economic and social impacts of soil carbon sequestration as a greenhouse gas removal technology.

To limit warming to well below 2°C, most scenario projections rely on greenhouse gas removal technologies (GGRTs); one such GGRT uses soil carbon sequestration (SCS) in agricultural land. In addition to their role in mitigating climate change, SCS practices play a role in delivering agroecosystem resilience, climate change adaptability and food security. Environmental heterogeneity and differences in agricultural practices challenge the practical implementation of SCS, and our analysis addresses the associated knowledge gap.

Weakened growth of cropland-N O emissions in China associated with nationwide policy interventions.

China has experienced rapid agricultural development over recent decades, accompanied by increased fertilizer consumption in croplands; yet, the trend and drivers of the associated nitrous oxide (N O) emissions remain uncertain. The primary sources of this uncertainty are the coarse spatial variation of activity data and the incomplete model representation of N O emissions in response to agricultural management. Here, we provide new data-driven estimates of cropland-N O emissions across China in 1990-2014, compiled using a global cropland-N O flux observation dataset, nationwide survey-based reconstruction of N-fertilization and irrigation, and an updated nonlinear model.

Just the tonic! Legume biorefining for alcohol has the potential to reduce Europe's protein deficit and mitigate climate change.

Industrialised agriculture is heavily reliant upon synthetic nitrogen fertilisers and imported protein feeds, posing environmental and food security challenges. Increasing the cultivation of leguminous crops that biologically fix nitrogen and provide high protein feed and food could help to address these challenges. We report on the innovative use of an important leguminous crop, pea (Pisum sativum L.

A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity.

Cover crops play an increasingly important role in improving soil quality, reducing agricultural inputs and improving environmental sustainability. The main objectives of this critical global review and systematic analysis were to assess cover crop practices in the context of their impacts on nitrogen leaching, net greenhouse gas balances (NGHGB) and crop productivity. Only studies that investigated the impacts of cover crops and measured one or a combination of nitrogen leaching, soil organic carbon (SOC), nitrous oxide (N O), grain yield and nitrogen in grain of primary crop, and had a control treatment were included in the analysis.

Gross N transformation rates and related NO emissions in Chinese and UK agricultural soils.

The properties of agricultural soils in various regions of the world are variable and can have a significant but poorly understood impact on soil nitrogen (N) transformations and nitrous oxide (NO) emissions. For this reason, we undertook a study of gross N transformations and related NO emissions in contrasting agricultural soils from China and the UK. Seven Chinese and three UK agricultural soils were collected for study using a N tracing approach.

Nitrous Oxide Emissions Increase Exponentially When Optimum Nitrogen Fertilizer Rates Are Exceeded in the North China Plain.

The IPCC assume a linear relationship between nitrogen (N) application rate and nitrous oxide (NO) emissions in inventory reporting, however, a growing number of studies show a nonlinear relationship under specific soil-climatic conditions. In the North China plain, a global hotspot of NO emissions, covering a land as large as Germany, the correlation between N rate and NO emissions remains unclear. We have therefore specifically investigated the NO response to N applications by conducting field experiments with five N rates, and high-frequency measurements of NO emissions across contrasting climatic years.