The potential for mitigating greenhouse gas emissions and minimizing yield losses using the negative pressure irrigation system

Integrated nitrogen management enhances forage yield and quality while mitigating greenhouse gas emissions in legume-grass mixed grassland.

In order to explore the effective management measures of increasing yield and reducing non-CO2 greenhouse gas (CH4 and N2O) emission in the cold black soil paddy field, field experiments were carried out.This paper analyzed the impact of straw returning and different irrigation methods on rice field yield, greenhouse gas emissions, global warming potential (GWP) and greenhouse gas emission intensity (GHGI).The results showed that compared with the treatment without straw returning, the yield of straw returning treatment increased by 11.79% annually, CH4 emissions increased by 62.71% annually, N2O emissions decreased by 1.28% annually, GWP and GHGI increased by 60.90% and 45.58% annually, respectively.Compared with conventional flooding treatment, the yield of controlled irrigation treatment increased by 2.68% annually, the difference was not significant, CH4 emissions decreased by 56.42% annually, N2O emissions increased by 133.41%,GWP and GHGI decreased by 54.89% and 55.93% annually, respectively.Straw returning and controlled irrigation had significant interaction on GWP and GHGI, but not significant interaction on yield.The GHGI values of the four treatments were as follows: KFH0< KFHS< CFH0< CFHS.Therefore, controlled irrigation is an irrigation method with stable rice yield and good greenhouse gas emission reduction effect.Straw returning and controlled irrigation can achieve the double goals of increasing yield and reducing greenhouse gas emissions of rice fields in cold regions.

Enhancing resource use efficiency of alfalfa with appropriate irrigation and fertilization strategy mitigate greenhouse gases emissions in the arid region of Northwest China

Lowland rice cultivation is a major contributor to agricultural greenhouse gas (GHG) emissions. Managing water and fertilizer is important GHG emissions. This paper evaluated GHG emissions of rice production under contrasting water regimes, i.e., continuous flooding (CF) versus alternate wetting and drying (AWD), with six nitrogen fertilizer combinations: no nitrogen (F1), urea 175 kg ha-1 (F2), urea 350 kg ha-1 (F3), urea 262.5 kg ha⁻¹ + manure 3 tons ha-1 (F4), urea 525 kg ha⁻¹ + rice straw 3 tons ha-1 (F5), and urea 175 kg ha⁻¹ + manure 3 tons ha-1 + biochar 0.6 tons ha-1 (F6). The field experiments were conducted at Bogor Regency, West Java, Indonesia, using a randomized complete block design with three replications. Growth, yield components, and GHG emissions were observed in this study throughout the growing season. Results showed AWD reduced CH₄ emissions by 30% but increased N₂O by 43% compared to CF, yielding a net 23% lower global warming potential (GWP). Organic-amended treatments (F6) maintained yields equivalent to conventional fertilization while showing numerically lower GWP. The independent effect of the water regime and the nitrogen fertilizer combinations implies that the best level of biochar and manure combined with AWD has the most promising prospect of maintaining rice yield while reducing GHG emissions.

Mitigation of greenhouse gas emissions from beef production in western Canada – Evaluation using farm-based life cycle assessment

Integrated impacts of irrigation and nitrogen management for balancing winter wheat yield and greenhouse gas emissions

Environmental pollution and climate change have become nontraditional global security threats. As China's economy grows, the country faces an increasing number of challenges associated with improving atmospheric quality and reducing greenhouse gas emissions. Based on China's dynamic noncompetitive input-output tables and data on energy consumption and emissions from 1994 to 2016, a hybrid input-output model is constructed to identify high-energy-consuming sectors and to quantify the impact of industrial restructuring on the intensity of air pollutant and greenhouse gas emissions from these sectors. The empirical results indicate that the impact of industrial restructuring on the intensity of air pollutant and greenhouse gas emissions from high-energy-consuming sectors was nonlinear and has undergone a "promotion reduction" shift. This study also found that the impact of industrial restructuring is more significant on the intensity of greenhouse gas emissions than on the intensity of air pollutant emissions; furthermore, the reduction in greenhouse gas emission intensity achieved by industrial restructuring after 2008 began to show results. Based on the findings of this study, we make recommendations such as the need for the Chinese government to continue to promote supply-side structural reforms in the energy sector.

The study of the effects of different fertilization treatments on soil methane (CH4) and nitrous oxide (N2O) emissions in rice-vegetable rotation systems is of great significance to supplement the research gap on greenhouse gas emissions in tropical regions of China. In this study, four fertilization treatments were set up during the pepper season:phosphorus and potassium fertilizer application (PK); nitrogen, phosphorus, and potassium (NPK) application; half application of nitrogen, phosphorus, and potassium plus half application of organic fertilizer (NPK+M); and application of organic fertilizer (M). There was no fertilizer application during the following early rice season. The objective of our study was to investigate the rules of CH4 and N2O emissions under different fertilization treatments in the pepper growth season, and the effects of different fertilization treatments in the pepper growth season on rice yield, and CH4 and N2O emissions in the following early rice growth season. The close static chamber-gas chromatography method was applied to determine soil CH4 and N2O emissions. We measured crop yield, estimated global warming potential (GWP), and calculated greenhouse gas emission intensity (GHGI). Our results showed that:① the cumulative CH4 emission under the four fertilization treatments ranged between 0.9 kg·hm-2 to 2.7 kg·hm-2 during the pepper growth season and between 5.5 kg·hm-2 to 8.4 kg·hm-2 during the early rice growth season. Compared with NPK, NPK+M and M reduced the cumulative CH4 emission in the pepper growth season by 35.3% and 7.6%, respectively; however, NPK+M and M increased the cumulative CH4 emission in the early rice season by 37.5% and 55.1%, respectively. There was a significant difference in cumulative CH4 emission between M and NPK in the early rice growth season. ② The cumulative N2O emission under the four fertilization treatments varied from 0.5 kg·hm-2 to 3.0 kg·hm-2 in the pepper growth season and from 0.3 kg·hm-2 to 0.5 kg·hm-2 in the early rice growth season. The cumulative N2O emission was significantly decreased by 33.7% in NPK+M and by 16.0% in M, compared with that in NPK. In the early rice growth season, the cumulative N2O emission was decreased by 23.5% by NPK+M but was increased by 9.1% by M. There was no significant difference in the cumulative N2O emission among the four fertilization treatments. ③ The yields of pepper and early rice under the four fertilization treatments were 3055.6-37722.5 kg·hm-2 and 5850.9-6994.4 kg·hm-2, respectively. Compared with that in NPK, NPK+M and M significantly increased pepper yield. The GWP under the four fertilization treatments in the pepper-early rice rotation system varied from 508.0 kg·hm-2 to 1864.4 kg·hm-2. Compared with NPK, NPK+M significantly decreased GWP by 25.7% and M insignificantly decreased GWP by 5.7%. The pepper growth season with the four fertilization treatments contributed to 69.2%-78.1% of the total GWP, and N2O contributed to 77.3%-85.3% of the total GWP. The GHGI ranged between 0.03 kg·kg-1 and 0.09 kg·kg-1 in the pepper growth season and between 0.04 kg·kg-1 and 0.24 kg·kg-1 in the early rice growth season. Compared with that in NPK, both M and NPK+M significantly reduced the GHGI by 71.5% and 54.7%, respectively, in the pepper growth season. In the early rice season, NPK+M significantly decreased the GHGI by 44.0%, but M non-significantly decreased the GHGI by 20.8%. The peak in N2O emission in the tropical pepper-early rice rotation system appeared after fertilization, and N2O emissions primarily occurred in the pepper growth season. However, CH4 emission was mainly concentrated in the early rice season. Considering the overall enhancing effects on crop yield and mitigation of greenhouse gas emissions, the co-application of chemical and organic fertilizers (NPK+M) can be recommended as an optimal fertilization practice to mitigate greenhouse gas emissions and maintain crop yield in pepper-rice rotation systems of Hainan, China.

Optimizing irrigation management sustained grain yield, crop water productivity, and mitigated greenhouse gas emissions from the winter wheat field in North China Plain

Combination of organic fertilizer and slow-release fertilizer increases pineapple yields, agronomic efficiency and reduces greenhouse gas emissions under reduced fertilization conditions in tropical areas

Wolfberry production has become a major agro-industry on the Qinghai–Tibetan Plateau, causing increased nitrogen (N) pollution and greenhouse gas (GHG) emissions. Appropriate N fertilizer rate and nitrification inhibitors may mitigate GHG emissions and improve N use efficiency. A 2-year field experiment was conducted to measure the effects of N application rate and nitrapyrin on GHG emissions, to reduce GHG emissions and N pollution. We used eight treatments: Control (CK), 667 kg·ha−1 N (Con), 400 kg·ha−1 N (N400), 267 kg·ha−1 N (N267), 133 kg·ha−1 N (N133), 400 kg·ha−1 N plus 2.00 kg·ha−1 nitrapyrin (N400I2.00), 267 kg·ha−1 N plus 1.33 kg·ha−1 nitrapyrin (N267I1.33) and 133 kg·ha−1 N plus 0.67 kg·ha−1 nitrapyrin (N133I0.67). Compared with Con treatment, N400 maintained fruit yield and increased net income, but saved 40% of N fertilizer and decreased the cumulative N2O emission by 14–16%. Compared to N400, N267 and N133 treatments, the cumulative N2O emission of N400I2.00, N267I1.33 and N133I0.67 treatments was reduced by 28.5–45.1%, 26.6–29.9% and 33.8–45.9%, respectively. Furthermore, N400I2.00 resulted in the highest wolfberry yield and net income. The emissions of CH4 and CO2 were not significantly different among treatments. Moreover, the global warming potential (GWP) and the greenhouse gas emission intensity (GHGI) of N400I2.00 declined by 45.6% and 48.6% compared to Con treatment. Therefore, 400 kg·ha−1 N combined with 2.00 kg·ha−1 nitrapyrin was shown to be a promising management technique for maintaining wolfberry yield while minimizing GWP and GHGI.

Balancing crop production and greenhouse gas (GHG) emissions from agriculture soil requires a better understanding and quantification of crop GHG emissions intensity, a measure of GHG emissions per unit crop production. Here we conduct a state-of-the-art estimate of the spatial-temporal variability of GHG emissions intensities for wheat, maize, and rice in China from 1949 to 2012 using an improved agricultural ecosystem model (Dynamic Land Ecosystem Model-Agriculture Version 2.0) and meta-analysis covering 172 field-GHG emissions experiments. The results show that the GHG emissions intensities of these croplands from 1949 to 2012, on average, were 0.10-1.31kgCO2 -eq/kg, with a significant increase rate of 1.84-3.58×10-3 kgCO2 -eqkg-1 year-1 . Nitrogen fertilizer was the dominant factor contributing to the increase in GHG emissions intensity in northern China and increased its impact in southern China in the 2000s. Increasing GHG emissions intensity implies that excessive fertilizer failed to markedly stimulate crop yield increase in China but still exacerbated soil GHG emissions. This study found that overfertilization of more than 60% was mainly located in the winter wheat-summer maize rotation systems in the North China Plain, the winter wheat-rice rotation systems in the middle and lower reaches of the Yangtze River and southwest China, and most of the double rice systems in the South. Our simulations suggest that roughly a one-third reduction in the current N fertilizer application level over these "overfertilization" regions would not significantly influence crop yield but decrease soil GHG emissions by 29.60%-32.50% and GHG emissions intensity by 0.13-0.25kgCO2 -eq/kg. This reduction is about 29% and 5% of total agricultural soil GHG emissions in China and the world, respectively. This study suggests that improving nitrogen use efficiency would be an effective strategy to mitigate GHG emissions and sustain China's food security.

This article explores therelationship among farm‐level productivity growth, scale, and greenhouse gas (GHG) emission intensity during a time period of significant agricultural policy change affecting Ireland's dairy industry. Specifically, we focus on the 2015 EU milk quota abolition, which initiated major dairy expansion in Ireland. We use a representative sample of Irish dairy farms from 2000 to 2017, that includes data on farm specific GHG emissions. Based on this detailed farm level panel data set, we estimate productivity with a control function approach. We then apply fixed effects and dynamic panel data methods to explore the implications of productivity and scale on GHG emission intensity. Our findings indicate that increased productivity is negatively associated with GHG emission intensity, which changes with distinct milk quota abolition phases. Overall, our findings are important for understanding the relationship between policy reforms and GHG emissions in agriculture, and how to improve agricultural mitigation strategies.

Constructed wetlands (CWs) have emerged as a green solution for wastewater treatment in many regions. However, their efficacy can be impacted by temperature fluctuations, and the potential emission of greenhouse gases may offset their environmental and ecological benefits. This study focuses on the effluent of one wastewater treatment plant in the cold temperate zone of northern China. It investigates the supplemental treatment effects of CWs on effluents from conventional sewage treatment plants using three plant species: Phragmites australis, Scirpus validus, and Typha orientalis for phytoremediation. Under 15°C, CWs showed moderate removal efficiencies for COD (35.71-40.28%) and TN (28.79-33.59%), with relatively low CO2 emission flux (43.56-176.56 mg/m2/h) and global warming potential (GWP,2.815-6.613 mg/m2/h). Among the plants, Scirpus validus demonstrated superior pollutant removal and lower greenhouse gas (GHG) emissions, making it a prime candidate for future use. Additionally, it explores the incorporation of biochar into CW substrates to simultaneously enhance water quality (+9.99% for COD and +22.13% for TN) and mitigate GHG emissions (-9%). The conclusions provide insights into the potential of CWs as complementary measures for conventional wastewater treatment, particularly in reducing GHG emissions and improving water quality in cold temperate regions. These findings contribute to understanding sustainable wastewater management practices in environmentally sensitive areas.

Climate change mitigation in rice fields: A global synthesis of agronomic interventions.