整合分析中国农田腐秆剂施用对秸秆腐解和作物产量的影响

doi:10.3864/j.issn.0578-1752.2020.07.006

Abstract

Abstract: 【Objective】 Whether the application of straw decomposing microorganism inoculum (SDMI) in cropland could significantly promote returning straw decomposition and their nutrients releasing, and thus improve crop yield is still on debate. Therefore, it is very necessary to meta-analysis the effects of the SDMI on returning straw decomposition and crop yield on a national scale, as well as explore the variation of the effect under different climates, straw characteristics and returning conditions providing guidance for SDMI application. 【Method】The meta-analysis was performed involving 63 comparisons of straw decomposition and 207 comparisons of crop yield from 89 studies during 2001 and 2009 to identify site-specific factors, including regional climates, returning conditions, straw types, initial returning carbon-to-nitrogen ratio (C/N), soil pH, and soil organic matter (SOM). 【Result】 The results showed that SDMI application could significantly increase the decomposition rate of returning straw, except the study was designed at temperate continental climate areas (range of effect size was from -0.010 to 0.716, the same in below), or initial returning C/N was no more than 15 (-0.302 to 0.568), or tested soil was neutral (95% CI of effect size was from -1.01 to 0.475). In addition, the strength of SDMI application could be varied significantly under different returning conditions, straw types, and SOM. Similar to straw decomposition, SDMI application also could significantly increase the crop yield, except the study designed at neutral soil (-0.284 to 0.751). Regional climates, straw types, initial returning C/N, soil pH rather than returning conditions and SOM would regulate the increase rate of crop yield. Moreover, the linear fitting indicated the positive correlation between the rate of straw decomposition and crop yield (R²= 0.307, P<0.0001). 【Conclusion】 This study revealed that SDMI application in Chinese farmland could significantly promote returning straw decomposition and crop yield increasing, especially in temperate monsoon climate area with dryland, maize straw returning, initial returning C/N≥30 and acidic or alkaline soil.

Key words: straw returning, straw decomposing agent, straw decomposition, crop yield, meta-analysis

XinRun YANG,Bei XU,ZhiFeng HE,Jing WU,RuiHua ZHUANG,Chao MA,RuShan CHAI,Kianpoor Kalkhajeh Yusef,XinXin YE,Lin ZHU. Impacts of Decomposing Microorganism Inoculum on Straw Decomposition and Crop Yield in China: A Meta-Analysis[J].Scientia Agricultura Sinica, 2020, 53(7): 1359-1367.

0
/ / Recommend

Add to citation manager EndNote|Reference Manager|ProCite|BibTeX|RefWorks

URL: https://www.chinaagrisci.com/EN/10.3864/j.issn.0578-1752.2020.07.006

https://www.chinaagrisci.com/EN/Y2020/V53/I7/1359

Figures/Tables 4

Table 1

Fig. 1

Fig. 2

Fig. 3

References 43

[1]	石祖梁, 邵宇航, 王飞, 王久臣, 孙仁华, 宋成军, 李想. 我国秸秆综合利用面临形势与对策研究. 中国农业资源与区划, 2018, 39(10): 30-36.
	SHI Z L, SHAO Y H, WANG F, WANG J C, SUN R H, SONG C J, LI X.Study on the situation and countermeasures of straw comprehensive utilization in China. Journal of Chinese Agricultural Resources and Regional Planning, 2018, 39(10): 30-36. (in Chinese)
[2]	马超, 周静, 刘满强, 郑学博, 崔键, 李辉信, 康炳龙. 秸秆促腐还田对土壤养分及活性有机碳的影响. 土壤学报, 2013, 50(5): 915-921.
	MA C, ZHOU J, LIU M Q, ZHENG X B, CUI J, LI H X, KANG B L.Effects of incorportion of pre-treated straw into field on soil nutrients and labile organic carbon in Shajiang black soil.Acta Pedologica Sinica, 2013, 50(5): 915-921. (in Chinese)
[3]	马超, 周静, 郑学博, 刘满强, 李辉信, 姜中山, 王维国. 秸秆促腐还田对土壤养分和小麦产量的影响. 土壤, 2012, 44(1): 30-35.
	MA C, ZHOU J, ZHENG X B, LIU M Q, LI H X, JIANG Z S, WANG W G.Effects of returning rice straw into field on soil nutrients and wheat yields under promoting decay condition.Soils, 2012, 44(1): 30-35. (in Chinese)
[4]	马超, 周静, 朱远芃, 柴如山, 汪满照, 郜红建. 秸秆还田配伍腐秆剂对小麦生长发育和肥料利用率的影响. 安徽农业大学学报, 2018, 45(3): 532-537.
	MA C, ZHOU J, ZHU Y P, CHAI R S, WANG M Z, GAO H J.Effects of returning maize straw into field on the growth and nitrogen efficiency of winter wheat under promoting decay condition.Journal of Anhui Agricultural University, 2018, 45(3): 532-537. (in Chinese)
[5]	LI M H, TANG C G, CHEN X, HUANG S W, ZHAO W W, CAI D Q, WU Z Y, WU L F.High performance bacteria anchored by nanoclay to boost straw degradation. Materials, 2019, 12(7): 1148-1162.
[6]	张莹莹, 曹慧英. 秸秆腐熟剂对玉米秸秆腐解及下茬小麦生长的影响. 中国农技推广, 2019, 35(5): 57-59.
	ZHANG Y Y, CAO H Y. Effects of straw decomposition microorganism inoculum on decay of corn straw and the growth of next wheat. China Agricultural Technology Extension, 2019(5). (in Chinese)
[7]	杨春, 李刚, 吴永红. 不同秸秆腐熟剂品种在翻耕模式下使用效果研究. 现代农业科技, 2015(15): 214.
	YANG C, LI G, WU Y H.Studies of different straw decomposing microorganism inoculum under plough mode.Modern Agricultural Science and Technology, 2015(15): 214. (in Chinese)
[8]	杨光海, 张居菊, 杨光兰. 稻油两熟田应用秸秆腐熟剂的效果初探. 耕作与栽培, 2013(4): 20-22.
	YANG G H, ZHANG J J, YANG G L.Preliminary study on effect of straw decomposition additive in Rice/Rape pattern.Tillage and Cultivation, 2013(4): 20-22. (in Chinese)
[9]	李继福, 鲁剑巍, 李小坤, 任涛, 丛日环, 杨文兵, 鲁明星, 刘克芝. 麦秆还田配施不同腐秆剂对水稻产量、秸秆腐解和土壤养分的影响. 中国农学通报, 2013, 29(35): 270-276.
	LI J F, LU J W, LI X K, REN T, CONG R H, YANG W B, LU M X, LIU K Z.Effects of wheat straw returning with different organic matter-decomposing inoculants (OMIs) on the yield of rice.Chinese Agricultural Science Bulletin, 2013, 29(35): 270-276. (in Chinese)
[10]	TAOVA S.GetData digitizing program code: description, testing, training. International Nuclear Data Committee, International Atomic Energy Agency, Vienna, 2013.
[11]	HEDGES L V, GUREVITCH J, CURTIS P S.The meta-analysis of response ratios in experimental ecology. Ecology, 1999, 80(4): 1150-1156.
[12]	任凤玲, 张旭博, 孙楠, 徐明岗, 柳开楼. 施用有机肥对中国农田土壤微生物量影响的整合分析. 中国农业科学, 2018, 51(1): 119-128.
	REN F L, ZHANG X B, SUN N, XU M G, LIU K L.A meta-analysis of manure application impact on soil microbial biomass across China’s croplands.Scientia Agricultura Sinica, 2018, 51(1): 119-128. (in Chinese)
[13]	EGGER M, SMITH G D, SCHNEIDER M, MINDER C.Bias in meta-analysis detected by a simple, graphical test.British Medical Journal, 1997, 315(7109): 629-634.
[14]	ROSENTHAL R.The file-drawer problem and tolerance of null result. Psychological Bulletin, 1979, 86(3): 638-641.
[15]	ROSENBERG M S, ADAMS D C, GUREVITCH J.Metawin: Statistical Software for Meta-Analysis with Resampling Tests. America: Sinauer Associates Inc, 1997.
[16]	MA C, LI S P, PU Z C, TIAN J Q, LIU M Q, ZHOU J, LI H X, JIANG L.Different effects of invader-native phylogenetic relatedness on invasion success and impact: a meta-analysis of Darwin’s naturalization hypothesis.Proceedings of the Royal of Society B-Biological Sciences, 2016, 283(1838): 20160663.
[17]	曾廷廷, 蔡泽江, 王小利, 梁文君, 周世伟, 徐明岗. 酸性土壤施用石灰提高作物产量的整合分析. 中国农业科学, 2017, 50(13): 2519-2527.
	ZENG T T, CAI Z J, WANG X L, LIANG W J, ZHOU S W, XU M G.Integrated analysis of liming for increasing crop yield in acidic soils.Scientia Agricultura Sinica, 2017, 50(13): 2519-2527. (in Chinese)
[18]	于建光, 常志州, 黄红英, 叶小梅, 马艳, 钱玉婷. 秸秆腐熟剂对土壤微生物及养分的影响. 农业环境科学学报, 2010, 29(3): 563-570.
	YU J G, CHANG Z Z, HUANG H Y, YE X M, MA Y, QIAN Y T.Effect of microbial inoculants for straw decomposing on soil microorganisms and the nutrients.Journal of Agro-Environment Science, 2010, 29(3): 563-570. (in Chinese)
[19]	张经廷, 张丽华, 吕丽华, 董志强, 姚艳荣, 金欣欣, 姚海坡, 贾秀领. 还田作物秸秆腐解及其养分释放特征概述. 核农学报, 2018, 32(11): 2274-2280.
	ZHANG J T, ZHANG L H, LV L H, DONG Z Q, YAO Y R, JIN X X, YAO H P, JIA X L.Overview of the characteristics of crop straw decomposition and nutrients release of returned field crops.Journal of Nuclear Agricultural Sciences, 2018, 32(11): 2274-2280. (in Chinese)
[20]	丁文成, 李书田, 黄绍敏. 氮肥管理和秸秆腐熟剂对¹⁵N标记玉米秸秆氮有效性与去向的影响. 中国农业科学, 2016, 49(14): 2725-2736.
	DING W C, LI S T, HUANG S M.Bioavailability and fate of nitrogen from ¹⁵N-labeled corn straw as affected by nitrogen management and straw microbial inoculants.Scientia Agricultura Sinica, 2016, 49(14): 2725-2736. (in Chinese)
[21]	董志新, 孙波, 殷士学. 气候条件和作物对黑土和潮土固氮微生物群落多样性的影响. 土壤学报, 2012, 49(1): 130-138.
	DONG Z X, SUN B, YIN S X.Impacts of climate and cropping on community diversity of diazotrophs in pachic udic agriboroll and fluventic ustochrept.Acta Pedologica Sinica, 2012, 49(1): 130-138. (in Chinese)
[22]	SCHIMEL J P, GULLEDGE J M, CLEIN-CURLEY J S, LINDSTROM J E, BRADDOCK J F. Moisture effects on microbial activity and community structure in decomposing birch litter in the Alaskan taiga.Soil Biology and Biochemistry, 1999, 31(6): 831-838.
[23]	李昌明, 王晓玥, 孙波. 不同气候和土壤条件下秸秆腐解过程中养分的释放特征及其影响因素. 土壤学报, 2017, 54(5): 1206-1217.
	LI C M, WANG X Y, SUN B.Characteristics of nutrient release and its affecting factors during plant residue decomposition under different climate and soil conditions.Acta Pedologica Sinica, 2017, 54(5): 1206-1217. (in Chinese)
[24]	ZHAO M X, XUE K, WANG F, LIU S S, BAI S J, SUN B, ZHOU J Z, YANG Y F.Microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping.The ISME Journal, 2014, 8(10): 2045-2055.
[25]	VERBURG P S J, DAM D V, HEFTING M M, TIETEMA A. Microbial transformations of C and N in a boreal forest floor as affected by temperature.Plant and Soil, 1999, 208(2): 187-197.
[26]	BERGER T W, DUBOC O, DJUKIC I, TATZBER M, GERZABEK M H, ZEHETNER F. Decomposition of beech(Fagus sylvatica)and pine(Pinusnigra) litter along an Alpine elevation gradient:Decay and nutrient release.Geoderma, 2015, 251/252: 92-104.
[27]	LIU S, WANG F, XUE K, SUN B, ZHANG Y G, HE Z L, VAN NOSTRAND J, ZHOU J Z, YANG Y F.The interactive effects of soil transplant into colder regions and cropping on soil microbiology and biogeochemistry.Environmental Microbiology, 2015, 17(3): 566-576.
[28]	AGEHARA S, WARNCKE D D.Soil moisture and temperature effects on nitrogen release from organic nitrogen sources.Soil Science Society of America Journal, 2005, 69(6): 1844-1855.
[29]	王景. 厌氧和好气条件下作物秸秆的腐解特征研究[D]. 合肥: 安徽农业大学, 2015.
	WANG J.Study on the decomposition characteristics of crop straw under anaerobic and aerobic conditions[D]. Hefei: Anhui Agricultural University, 2015. (in Chinese)
[30]	代文才, 高明, 兰木羚, 黄容, 王金柱, 王子芳, 韩晓飞. 不同作物秸秆在旱地和水田中的腐解特性及养分释放规律. 中国生态农业学报, 2017, 25(2): 188-199.
	DAI W C, GAO M, LAN M L, HUANG R, WANG J Z, WANG Z F, HAN X F.Nutrient release patterns and decomposition characteristics of different crop straws in drylands and paddy fields.Chinese Journal of Eco-Agriculture, 2017, 25(2): 188-199. (in Chinese)
[31]	马瑞霞, 刘秀芬, 袁光林, 孙思恩. 小麦根区微生物分解小麦残体产生的化感物质及其生物活性的研究. 生态学报, 1996, 16(6): 632-639.
	MA R X, LIU X F, YUAN G L, SUN S E.Study on allelochemicals in the process of decomposition of wheat straw by microorganisms and their bioactivity.Acta Ecologica Sinica, 1996, 16(6): 632-639. (in Chinese)
[32]	宋芳芳. 主要粮食作物秸秆降解菌剂的制备及应用研究[D]. 郑州: 河南农业大学, 2015.
	SONG F F.Studies on the stalk-degradable microbial preparation in main food crops and its application[D]. Zhengzhou: Henan Agricultural University, 2015. (in Chinese)
[33]	宋大利, 侯胜鹏, 王秀斌, 梁国庆, 周卫. 中国秸秆养分资源数量及替代化肥潜力. 植物营养与肥料学报, 2018, 24(1): 1-21.
	SONG D L, HOU S P, WANG X B, LIANG G Q, ZHOU W.Nutrient resource quantity of crop straw and its potential of substituting.Journal of Plant Nutrition and Fertilizer, 2018, 24(1): 1-21. (in Chinese)
[34]	南雄雄, 田霄鸿, 张琳, 游东海, 吴玉红, 曹玉贤. 小麦和玉米秸秆腐解特点及对土壤中碳、氮含量的影响. 植物营养与肥料学报, 2010, 16(3): 626-633.
	NAN X X, TIAN X H, ZHANG L, YOU D H, WU Y H, CAO Y X.Decomposition characteristics of wheat and maize straw and their effects on soil carbon and nitrogen content.Journal of Plant Nutrition and Fertilizer, 2010, 16(3): 626-633. (in Chinese)
[35]	YANNI S F, WHALEN J K, SIMPSON M J, JANZEN H H.Plant lignin and nitrogen contents control carbon dioxide production and nitrogen mineralization in soils incubated with Bt and non-Bt corn residues.Soil Biology and Biochemistry, 2011, 43(1): 63-69.
[36]	FANG M, MOTAVALLI P P, KREMER R J, NELSON K A.Assessing changes in soil microbial communities and carbon mineralization in Bt and non-Bt corn residue-amended soils.Applied Soil Ecology, 2007, 37(1/2): 150-160.
[37]	SINGH B, RENGEL Z.The role of crop residues in improving soil fertility//Marschner P, Rengel Z. Nutrient Cycling in Terrestrial Ecosystems. Berlin Heidelberg: Springer, 2007: 183-214.
[38]	李涛, 何春娥, 葛晓颖, 欧阳竹. 秸秆还田施氮调节碳氮比对土壤无机氮、酶活性及作物产量的影响. 中国生态农业学报, 2016, 24(12): 1633-1642.
	LI T, HE C E, GE X Y, OUYANG Z.Responses of soil mineral N contents, enzyme activities and crop yield to different C/N ratio mediated by straw retention and N fertilization.Chinese Journal of Eco-Agriculture, 2016, 24(12): 1633-1642. (in Chinese)
[39]	李飞, 张文丽, 刘菊, 夏会娟, 王建柱. 三峡水库泄水期消落带土壤微生物活性. 生态学杂志, 2013, 32(04): 968-974.
	LI F, ZHANG W L, LIU J, XIA H J, WANG J Z.Soil microbial activities in the water-level-fluctuating zone of Three Gorges Reservoir area during discharging period.Chinese Journal of Ecology, 2013, 32(04): 968-974. (in Chinese)
[40]	XIONG W, GUO S, JOUSSET A, ZHAO Q Y, WU H S, LI R, KOWALCHUK G A, SHEN Q R.Bio-fertilizer application induces soil suppressiveness against Fusarium wilt disease by reshaping the soil microbiome.Soil Biology Biochemistry, 2017, 114: 238-247.
[41]	史央. 红壤中秸秆降解的微生物演替及应用研究[D]. 南京: 南京师范大学. 2003.
	SHI Y.Microbial succession and application of straw degradation in red soil[D]. Nanjing: Nanjing Normal University, 2003. (in Chinese)
[42]	刘秉儒. 贺兰山东坡典型植物群落土壤微生物量碳、氮沿海拔梯度的变化特征. 生态环境学报, 2010, 19(4): 883-888.
	LIU B R.Changes in soil microbial biomass carbon and nitrogen under typical plant communities along an altitudinal gradient in east side of Helan Mountain.Ecology and Environment Sciences, 2010, 19(4): 883-888. (in Chinese)
[43]	黄靖宇, 宋长春, 张金波, 郭跃东, 廖玉静. 凋落物输入对三江平原弃耕农田土壤基础呼吸和活性碳组分的影响. 生态学报, 2008, 28(7): 3417-3424.
	HUANG J Y, SONG C C, ZHANG J B, GUO Y D, LIAO Y J.Influence of litter importation on basal respiration and labile carbon in restored farmland in Sanjiang Plain.Acta Ecologica Sinica, 2008, 28(7): 3417-3424. (in Chinese)

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed

Comments

Recommended 0

No Suggested Reading articles found!

气候类型<break/>Climate type	还田环境<break/>Returning condition	秸秆类型<break/>Straw type	还田初始碳氮比<break/>Initial returning C/N	土壤酸碱性<break/>Soil pH	土壤有机质<break/>Soil OM (g·kg^-1)
温带大陆气候NTC (14)	水田Paddy field (215)	玉米Maize (26)	≤15 (66)	≤6.5 (72)	≤15 (30)
温带季风气候NTM (31)	旱地<break/>Dry land (55)	小麦Wheat (65)	15-30 (70)	6.5-7.5 (35)	>15 (167)
亚热带季风气候STM (224)	旱地<break/>Dry land (55)	水稻Rice (155)	>30 (25)	>7.5 (32)	>15 (167)

Impacts of Decomposing Microorganism Inoculum on Straw Decomposition and Crop Yield in China: A Meta-Analysis

RichHTML

PDF

Abstract

Cite this article

share this article

Figures/Tables 4

References 43

Related Articles 15

Metrics

Comments

Recommended 0

[1]	ZHAO ZhengXin,WANG XiaoYun,TIAN YaJie,WANG Rui,PENG Qing,CAI HuanJie. Effects of Straw Returning and Nitrogen Fertilizer Types on Summer Maize Yield and Soil Ammonia Volatilization Under Future Climate Change [J]. Scientia Agricultura Sinica, 2023, 56(1): 104-117.
[2]	LIAO Ping,MENG Yi,WENG WenAn,HUANG Shan,ZENG YongJun,ZHANG HongCheng. Effects of Hybrid Rice on Grain Yield and Nitrogen Use Efficiency: A Meta-Analysis [J]. Scientia Agricultura Sinica, 2022, 55(8): 1546-1556.
[3]	QIN YuQing,CHENG HongBo,CHAI YuWei,MA JianTao,LI Rui,LI YaWei,CHANG Lei,CHAI ShouXi. Increasing Effects of Wheat Yield Under Mulching Cultivation in Northern of China: A Meta-Analysis [J]. Scientia Agricultura Sinica, 2022, 55(6): 1095-1109.
[4]	LIU ShuJun,LI DongChu,HUANG Jing,LIU LiSheng,WU Ding,LI ZhaoQuan,WU YuanFan,ZHANG HuiMin. Effects of Straw Returning and Potassium Fertilizer on Soil Aggregate and Potassium Distribution Under Rapeseed-Rice Rotation [J]. Scientia Agricultura Sinica, 2022, 55(23): 4651-4663.
[5]	LI YuHao,WANG HongYe,CUI ZhenLing,YING Hao,QU XiaoLin,ZHANG JunDa,WANG XinYu. Spatial-Temporal Variation of Cultivated Land Soil Basic Productivity for Main Food Crops in China [J]. Scientia Agricultura Sinica, 2022, 55(20): 3960-3969.
[6]	WANG Liang,LIU YuanYuan,QIAN Xin,ZHANG Hui,DAI HongCui,LIU KaiChang,GAO YingBo,FANG ZhiJun,LIU ShuTang,LI ZongXin. The Single Season Wheat Straw Returning to Promote the Synergistic Improvement of Carbon Efficiency and Economic Benefit in Wheat- Maize Double Cropping System [J]. Scientia Agricultura Sinica, 2022, 55(2): 350-364.
[7]	Chao MA,YuBao WANG,Gang WU,Hong WANG,JianFei WANG,Lin ZHU,JiaJia LI,XiaoJing MA,RuShan CHAI. Research Progress of Direct Straw Return in Anhui Province over the Last Decade [J]. Scientia Agricultura Sinica, 2022, 55(18): 3584-3599.
[8]	ZHONG JiaLin,XU ZiYan,ZHANG YiYun,LI Jie,LIU XiaoYu,LI LianQing,PAN GenXing. Effects of Feedstock, Pyrolyzing Temperature and Biochar Components on the Growth of Chinese Cabbage [J]. Scientia Agricultura Sinica, 2022, 55(14): 2775-2785.
[9]	MENG Yi,WENG WenAn,CHEN Le,HU Qun,XING ZhiPeng,WEI HaiYan,GAO Hui,HUANG Shan,LIAO Ping,ZHANG HongCheng. Effects of Water-Saving Irrigation on Grain Yield and Quality: A Meta-Analysis [J]. Scientia Agricultura Sinica, 2022, 55(11): 2121-2134.
[10]	MA LiXiao,LI Jing,ZOU ZhiChao,CAI AnDong,ZHANG AiPing,LI GuiChun,DU ZhangLiu. Effects of No-Tillage and Straw Returning on Soil C-Cycling Enzyme Activities in China: Meta-Analysis [J]. Scientia Agricultura Sinica, 2021, 54(9): 1913-1925.
[11]	JIN YuTing,LIU YunFeng,HU HongXiang,MU Jing,GAO MengYao,LI XianFan,XUE ZhongJun,GONG JingJing. Effects of Continuous Straw Returning with Chemical Fertilizer on Annual Runoff Loss of Nitrogen and Phosphorus in Rice-Rape Rotation [J]. Scientia Agricultura Sinica, 2021, 54(9): 1937-1951.
[12]	Xu LI,WeiLing DONG,ALin SONG,YanLing LI,YuQiu LU,EnZhao WANG,XiongDuo LIU,Meng WANG,FenLiang FAN. Effects of Straw Addition on Soil Biological N₂-Fixation Rate and Diazotroph Community Properties [J]. Scientia Agricultura Sinica, 2021, 54(5): 980-991.
[13]	WANG XinYuan,ZHAO SiDa,ZHENG XianFeng,WANG ZhaoHui,HE Gang. Effects of Straw Returning and Nitrogen Application Rate on Grain Yield and Nitrogen Utilization of Winter Wheat [J]. Scientia Agricultura Sinica, 2021, 54(23): 5043-5053.
[14]	DENG LiJuan,JIAO XiaoQiang. A Meta-Analysis of Effects of Nitrogen Management on Winter Wheat Yield and Quality [J]. Scientia Agricultura Sinica, 2021, 54(11): 2355-2365.
[15]	YaLin LI,XuBo ZHANG,FengLing REN,Nan SUN,Meng XU,MingGang XU. A Meta-Analysis of Long-Term Fertilization Impact on Soil Dissolved Organic Carbon and Nitrogen Across Chinese Cropland [J]. Scientia Agricultura Sinica, 2020, 53(6): 1224-1233.