Virtual Issue

农业生态环境-气体排放和重金属Agro-ecosystem & Environment—Gas emission & heavy metals

Default Latest Most Read

Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Assessment of CH4 flux and its influencing drivers in the rice–wheat agroecosystem of the Huai River Basin, China Xiaolan Yu, Fangmin Zhang, Yanqiu Fang, Xiaohan Zhao, Kaidi Zhang, Yanyu Lu 2024, 23 (12): 4203-4215.   DOI: 10.1016/j.jia.2024.03.076 Abstract （90）      PDF in ScienceDirect       To understand the CH4 flux variations and their climatic drivers in the rice–wheat agroecosystem in the Huai River Basin of China, the CH4 flux was observed by using open-path eddy covariance at a typical rice–wheat rotation system in Anhui Province, China from November 2019 to October 2021.  The variations and their drivers were then analyzed with the Akaike information criterion method.  CH4 flux showed distinct diurnal variations with single peaks during 9:00–13:00 local time.  The highest peak was 2.15 µg m–2 s–1 which occurred at 11:00 in the vegetative growth stage in the rice growing season (RGS).  CH4 flux also showed significant seasonal variations.  The average CH4 flux in the vegetative growth stage in the RGS (193.8±74.2 mg m–2 d–1) was the highest among all growth stages.  The annual total CH4 flux in the non-rice growing season (3.2 g m–2) was relatively small compared to that in the RGS (23.9 g m–2).  CH4 flux increased significantly with increase in air temperature, soil temperature, and soil water content in both the RGS and the non-RGS, while it decreased significantly with increase in vapor pressure deficit in the RGS.  This study provided a comprehensive understanding of the CH4 flux and its drivers in the rice–wheat rotation agroecosystem in the Huai River Basin of China.  In addition, our findings will be helpful for the validation and adjustment of the CH4 models in this region. Reference | Related Articles | Metrics Select Mitigation of N2O emissions in water-saving paddy fields: Evaluating organic fertilizer substitution and microbial mechanisms Delei Kong, Xianduo Zhang, Qidong Yu, Yaguo Jin, Peikun Jiang, Shuang Wu, Shuwei Liu, Jianwen Zou 2024, 23 (9): 3159-3173.   DOI: 10.1016/j.jia.2024.03.047 Abstract （103）      PDF in ScienceDirect       Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields, but significantly stimulate nitrous oxide (N2O) emissions because of variations in soil oxygen level and redox potential.  However, the relationship linking soil N2O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.  Furthermore, the mitigation potential of organic fertilizer substitution on N2O emissions and the microbial mechanism in rice fields must be further elucidated.  Our study examined how soil N2O emissions were affected by related functional microorganisms (ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), nirS, nirK and nosZ) to various fertilization treatments in a rice field in southeast China over two years.  In this study, three fertilization regimes were applied to rice cultivation: a no nitrogen (N) (Control), an inorganic N (Ni), and an inorganic N with partial N substitution with organic manure (Ni+No).  Over two rice-growing seasons, cumulative N2O emissions averaged 0.47, 4.62 and 4.08 kg ha−1 for the Control, Ni and Ni+No treatments, respectively.  In comparison to the Ni treatment, the Ni+No fertilization regime considerably reduced soil N2O emissions by 11.6% while maintaining rice yield, with a lower N2O emission factor (EF) from fertilizer N of 0.95%.  Nitrogen fertilization considerably raised the AOB, nirS, nirK and nosZ gene abundances, in comparison to the Control treatment.  Moreover, the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.  The AOB responded to N fertilization more sensitively than the AOA.  Total N2O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.  In summary, we conclude that organic manure substitution for inorganic N fertilizer decreased soil N2O emissions primarily by changing the soil NO3−-N, pH and DOC levels, thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification, and strengthening N2O reduction in denitrification from water-saving rice paddies. Reference | Related Articles | Metrics Select Regulatory potential of soil available carbon, nitrogen, and functional genes on N2O emissions in two upland plantation systems Peng Xu, Mengdie Jiang, Imran Khan, Muhammad Shaaban, Hongtao Wu, Barthelemy Harerimana, Ronggui Hu 2024, 23 (8): 2792-2806.   DOI: 10.1016/j.jia.2024.01.005 Abstract （124）      PDF in ScienceDirect       Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions, and they play a vital role in regulating soil N2O emissions in rice-based cultivation.  It is imperative to understand the influences of different upland crop planting systems on soil N2O emissions.  In this study, we focused on two representative rotation systems in Central China: rapeseed–rice (RR) and wheat–rice (WR).  We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N2O emissions.  The results revealed that during the rapeseed-cultivated seasons in the RR rotation system, the average N2O emissions were 1.24±0.20 and 0.81±0.11 kg N ha–1 for the first and second seasons, respectively.  These values were comparable to the N2O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system (0.98±0.25 and 0.70±0.04 kg N ha–1, respectively).  This suggests that upland cultivation has minimal impacts on soil N2O emissions in the two rotation systems.  Strong positive correlations were found between N2O fluxes and soil ammonium (NH4+), nitrate (NO3–), microbial biomass nitrogen (MBN), and the ratio of soil dissolved organic carbon (DOC) to NO3– in both RR and WR rotation systems.  Moreover, the presence of the AOA-amoA and nirK genes were positively associated with soil N2O fluxes in the RR and WR systems, respectively.  This implies that these genes may have different potential roles in facilitating microbial N2O production in various upland plantation models.  By using a structural equation model, we found that soil moisture, mineral N, MBN, and the AOA-amoA gene accounted for over 50% of the effects on N2O emissions in the RR rotation system.  In the WR rotation system, soil moisture, mineral N, MBN, and the AOA-amoA and nirK genes had a combined impact of over 70% on N2O emissions.  These findings demonstrate the interactive effects of functional genes and soil factors, including soil physical characteristics, available carbon and nitrogen, and their ratio, on soil N2O emissions during upland cultivation seasons under rice-upland rotations. Reference | Related Articles | Metrics Select A combination of straw incorporation and polymer-coated urea offsets soil ammonia and nitrous oxide emissions in winter wheat fields Xiaoyun Wang, Yajie Tian, Qianhui Zhang, Zhengxin Zhao, Rui Wang, Huanjie Cai 2024, 23 (5): 1718-1736.   DOI: 10.1016/j.jia.2023.12.008 Abstract （67）      PDF in ScienceDirect       The combined effects of straw incorporation (SI) and polymer-coated urea (PCU) application on soil ammonia (NH3) and nitrous oxide (N2O) emissions from agricultural fields have not been comprehensively evaluated in Northwest China.  We conducted a two-year field experiment to assess the effects of combining SI with either uncoated urea (U) or PCU on soil NH3 emissions, N2O emissions, winter wheat yields, yield-scaled NH3 (INH3), and yield-scaled N2O (IN2O).  Five treatments were investigated, no nitrogen (N) fertilizer (N0), U application at 150 kg N ha–1 with and without SI (SI+U and S0+U), and PCU application at 150 kg N ha–1 with and without SI (SI+PCU and S0+PCU).  The results showed that the NH3 emissions increased by 20.98–34.35% following SI compared to straw removal, mainly due to increases in soil ammonium (NH4+-N) content and water-filled pore space (WFPS).  SI resulted in higher N2O emissions than under the S0 scenario by 13.31–49.23% due to increases in soil inorganic N (SIN) contents, WFPS, and soil microbial biomass.  In contrast, the PCU application reduced the SIN contents compared to the U application, reducing the NH3 and N2O emissions by 45.99–58.07 and 18.08–53.04%, respectively.  Moreover, no significant positive effects of the SI or PCU applications on the winter wheat yield were observed.  The lowest INH3 and IN2O values were observed under the S0+PCU and SI+PCU treatments.  Our results suggest that single PCU applications and their combination with straw are the optimal agricultural strategies for mitigating gaseous N emissions and maintaining optimal winter wheat yields in Northwest China. Reference | Related Articles | Metrics Select Derivation and validation of soil total and extractable cadmium criteria for safe vegetable production LI Li-jun, LI Kun, JIANG Bao, LI Ju-mei, MA Yi-bing 2023, 22 (12): 3792-3803.   DOI: 10.1016/j.jia.2023.05.008 Abstract （113）      PDF in ScienceDirect       Determining the appropriate soil cadmium (Cd) criteria for vegetable production is important for ensuring that the Cd concentrations of the vegetables meet food safety standards. The soil extractable Cd criteria for vegetable production are also essential for both food safety and environmental management, especially in areas with a high natural background level. In the present study, soil total and extractable Cd criteria were derived using the approach of species sensitivity distribution integrated with soil aging and bioavailability as affected by soil properties. A dataset of 90 vegetable species planted in different soils was compiled by screening the published in literature in five bibliographic databases using designated search strings. The empirical soil–plant transfer model was applied to normalize the bioaccumulation data. After normalization, the intra-species variability was reduced by 18.3 to 84.4%. The soil Cd concentration that would protect 95% (HC5) of the species was estimated by species sensitivity distribution curves that were fitted by the Burr III function. The soil Cd criteria derived from the added approach for risk assessment were proposed as continuous criteria based on a combination of organic carbon and pH in the soil. Criteria for total Cd and EDTA-extractable Cd in the soil ranged from 0.23 to 0.61 mg kg–1 and from 0.09 to 0.25 mg kg–1, respectively. Field experimental data were used to validate the applicability and validity of these criteria. Most of the predicted HC5 values in the field experimental sites were below the 1:1 line. These results provide a scientific basis for soil Cd criteria for vegetable production that will ensure food safety. Reference | Related Articles | Metrics Select Assessment of the crucial factors influencing the responses of ammonia and nitrous oxide emissions to controlled release nitrogen fertilizer: A meta-analysis LÜ Hui-dan, WANG Xi-ya, PAN Zhao-long, ZHAO Shi-cheng 2023, 22 (11): 3549-3559.   DOI: 10.1016/j.jia.2023.07.008 Abstract （151）      PDF in ScienceDirect       Reducing ammonia (NH3) and nitrous oxide (N2O) emissions have great effects on mitigating nitrogen (N) nutrient loss and greenhouse gas emissions.  Controlled release urea (CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea (CU).  However, the crucial factors influencing the responses of NH3 and N2O emissions to CRU relative to CU are still unclear.  In this study, we evaluated the responses of NH3 and N2O emissions to CRU based on collected field data with a meta-analysis.  CRU reduced the NH3 and N2O emissions by 32.7 and 25.0% compared with CU, respectively.  According to subgroup analysis, CRU presented better mitigation of NH3 and N2O emissions in soils with pH 6.5–7.5 (–47.9 and –23.7%) relative to either pH<6.5 (–28.5 and –21.4%) or pH>7.5 (–29.3 and –17.3%), and in the rice season (–34.8 and –29.1%) relative to the wheat season (–19.8 and –22.8%).  The responses of NH3 and N2O emissions to CRU increased from rainfed (–30.5 and –17.0%) to irrigated (–32.5 and –22.9%), and then to paddy (–34.8 and –29.1%) systems.  In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen (TN); however, soil TN did not significantly affect the response of NH3 volatilization.  The reduction in NH3 emission was greater in sandy-textured soil (–57.7%) relative to loam-textured (–32.9%) and clay-textured (–32.3%) soils, whereas soil texture did not affect N2O emission.  Overall, CRU was a good option for reducing the NH3 and N2O emissions relative to CU in agricultural production.  This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3 and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE. Reference | Related Articles | Metrics Select Soil conditioners improve Cd-contaminated farmland soil microbial communities to inhibit Cd accumulation in rice ZHAO Jun-yang, LU Hua-ming, QIN Shu-tao, PAN Peng, TANG Shi-de, CHEN Li-hong, WANG Xue-li, TANG Fang-yu, TAN Zheng-long, WEN Rong-hui, HE Bing 2023, 22 (8): 2521-2535.   DOI: 10.1016/j.jia.2023.02.023 Abstract （210）      PDF in ScienceDirect       The addition of silicon (Si) and organic fertilizers to soil conditioners can inhibit the transfer of heavy metal ions from soil to crops. However, it is not clear how Si and organic fertilizers affect soil properties and the micro-ecological environment and thereby reduce cadmium (Cd) accumulation in rice. In this study, the effects of L-type soil conditioners containing Si and organic fertilizers on bacterial and fungal community diversity, soil pH, organic matter, and available Si were analyzed with field experiments at two sites in Liuzhou City and Hezhou City, respectively, in Guangxi, China. With the increase of Si and organic fertilizer content in soil conditioner, rice yield respectively increased by 16.8–25.8 and 6.8–13.1%, and rice Cd content decreased significantly by 8.2–21.1 and 10.8–40.6%, respectively, at the two experimental sites. Soil microbiome analysis showed that the increase in abundance of Firmicutes and Actinobacteriota bacteria associated with Cd adsorption and sequestration, and Basidiomycota fungal populations associated with degradation of macromolecules favored the inhibition of soil Cd activity (soil exchangeable Cd decreased by 14.4–14.8 and 18.1–20.6%). This was associated with an increase in organic matter and Si content caused by applying soil conditioners. In conclusion, L-type soil conditioners, rich in Si and organic fertilizer, can reduce soil Cd bioavailability by regulating the dominant Cd passivating flora in the soil and ultimately reduce Cd accumulation in rice. Reference | Related Articles | Metrics Select Linking atmospheric emission and deposition to accumulation of soil cadmium in the Middle-Lower Yangtze Plain, China TANG Li-li, FU Bo-min, WU Yang, CAI Fu-chen, MA Yi-bing 2023, 22 (10): 3170-3181.   DOI: 10.1016/j.jia.2023.05.016 Abstract （196）      PDF in ScienceDirect       Cadmium (Cd) is one of the most toxic heavy metals in the environment.  Atmospheric deposition has been found to be the main source of Cd pollution of soil on a large scale in China, and identification of the relationships between anthropogenic emission, atmospheric deposition, and Cd accumulation in soil is important for developing ways to mitigate Cd non-point pollution.  In this study, the relationship between atmospheric emission, atmospheric deposition, and soil Cd accumulation in the Middle-Lower Yangtze Plain in China was investigated using datasets of atmospheric emission, deposition, and soil accumulation from the literatures published between 2000 and 2020.  The results showed that the soil Cd accumulation rate in the study area exceeded the national average (4.0 μg kg–1 yr–1) and continued to accumulate in recent decades, although the average accumulation rate decreased from 9.45 μg kg–1 yr–1 (2000–2010 period) to 8.86 μg kg–1 yr–1 (2010–2020 period).  The contribution of atmospheric deposition flux to Cd increment in the soil was in the range of 22–29%, with the atmospheric deposition flux decreasing from 0.54 mg m–2 yr–1 (2000–2010) to 0.48 mg m–2 yr–1 (2010–2020), both values being greater than the national average.  Atmospheric Cd deposition and emission were highly correlated in a provincial administrative region, which is close to a ratio of 1.0.  Emission factors may be in a state of dynamic change due to the influences of new Cd emission control technologies and environmental policies.  As the main sources of Cd emissions, dust, and smoke emissions per ton of non-ferrous metal production decreased by 64.7% between the 2000–2010 and 2010–2020 periods.  Although new environmental policies have been instigated, atmospheric emission of Cd is still excessive.  It was hoped that the findings of this work would provide a scientific basis for the rational control of atmospheric emissions and Cd pollution of soil. Reference | Related Articles | Metrics Select Significant reduction of ammonia emissions while increasing crop yields using the 4R nutrient stewardship in an intensive cropping system ZHANG Chong, WANG Dan-dan, ZHAO Yong-jian, XIAO Yu-lin, CHEN Huan-xuan, LIU He-pu, FENG Li-yuan, YU Chang-hao, JU Xiao-tang 2023, 22 (6): 1883-1895.   DOI: 10.1016/j.jia.2022.12.008 Abstract （160）      PDF in ScienceDirect       Ammonia (NH3) emissions should be mitigated to improve environmental quality.  Croplands are one of the largest NH3 sources, they must be managed properly to reduce their emissions while achieving the target yields.  Herein, we report the NH3 emissions, crop yield and changes in soil fertility in a long-term trial with various fertilization regimes, to explore whether NH3 emissions can be significantly reduced using the 4R nutrient stewardship (4Rs), and its interaction with the organic amendments (i.e., manure and straw) in a wheat–maize rotation.  Implementing the 4Rs significantly reduced NH3 emissions to 6 kg N ha–1 yr–1 and the emission factor to 1.72%, without compromising grain yield (12.37 Mg ha–1 yr–1) and soil fertility (soil organic carbon of 7.58 g kg–1) compared to the conventional chemical N management.  When using the 4R plus manure, NH3 emissions (7 kg N ha–1 yr–1) and the emission factor (1.74%) were as low as 4Rs, and grain yield and soil organic carbon increased to 14.79 Mg ha–1 yr–1 and 10.09 g kg–1, respectively.  Partial manure substitution not only significantly reduced NH3 emissions but also increased crop yields and improved soil fertility, compared to conventional chemical N management.  Straw return exerted a minor effect on NH3 emissions.  These results highlight that 4R plus manure, which couples nitrogen and carbon management can help achieve both high yields and low environmental costs. Reference | Related Articles | Metrics Select Reduction of N2O emissions by DMPP depends on interaction of nitrogen source (digestate vs. urea) with soil properties LI Hao-ruo, SONG Xiao-tong, Lars R. BAKKEN, JU Xiao-tang 2023, 22 (1): 251-264.   DOI: 10.1016/j.jia.2022.08.009 Abstract （247）      PDF in ScienceDirect       The inhibition of nitrification by mixing nitrification inhibitors (NI) with fertilizers is emerging as an effective method to reduce fertilizer-induced nitrous oxide (N2O) emissions.  The additive 3,4-dimethylpyrazole phosphate (DMPP) apparently inhibits ammonia oxidizing bacteria (AOB) more than ammonia oxidizing archaea (AOA), which dominate the nitrification in alkaline and acid soil, respectively.  However, the efficacy of DMPP in terms of nitrogen sources interacting with soil properties remains unclear.  We therefore conducted a microcosm experiment using three typical Chinese agricultural soils with contrasting pH values (fluvo-aquic soil, black soil and red soil), which were fertilized with either digestate or urea in conjunction with a range of DMPP concentrations.  In the alkaline fluvo-aquic soil, fertilization with either urea or digestate induced a peak in N2O emission (60 μg N kg–1 d–1) coinciding with the rapid nitrification within 3 d following fertilization.  DMPP almost eliminated this peak in N2O emission, reducing it by nearly 90%, despite the fact that the nitrification rate was only reduced by 50%.  In the acid black soil, only the digestate induced an N2O emission that increased gradually, reaching its maximum (20 μg N kg–1 d–1) after 5–7 d.  The nitrification rate and N2O emission were both marginally reduced by DMPP in the black soil, and the N2O yield (N2O-N per NO2–+NO3–-N produced) was exceptionally high at 3.5%, suggesting that the digestate induced heterotrophic denitrification.  In the acid red soil, the N2O emission spiked in the digestate and urea treatments at 50 and 10 μg N kg–1 d–1, respectively, and DMPP reduced the rates substantially by nearly 70%.  Compared with 0.5% DMPP, the higher concentrations of DMPP (1.0 to 1.5%) did not exert a significantly (P<0.05) better inhibition effect on the N2O emissions in these soils (either with digestate or urea).  This study highlights the importance of matching the nitrogen sources, soil properties and NIs to achieve a high efficiency of N2O emission reduction. Reference | Related Articles | Metrics