Spatial and temporal changes of paddy rice ecosystem services in China during the period 1980–2014

The ecological systems services or multi-functionality of paddy rice cultivation are critical to the functioning of the Earth’s life-support system.We estimated the ecosystem services value(ESV)of paddy rice during 1980-2014 across China.The results indicated that the ESV of the paddy field in China showed an upward trend during this period.The share of ESV on CO_(2)sequestration was the highest,followed by ESV on temperature cooling and greenhouse gas(GHG)emission.The yield-scaled ESVs of ZonesⅡ(southern rice-upland crops rotation regions)andⅢ(southern double rice production regions)were similar and significantly higher than the ESVs of ZonesⅠ(northeastern single rice production regions)and IV(Southwest rice-upland crops rotation regions).Between 1980 and 2014,the ESV of each region increased to varying degrees,except for the ESVs of Guangxi,Zhejiang,Fujian,and Guangdong.Such effects suggest the existence of a significant spatial-temporal variation in the total amount,structure,and density of ESV of paddy fields in China,which can further guide the development of future options for the adaptation of healthy rice production in China.

Impacts of the north migration of China＇s rice production on its ecosystem service value during the last three decades (1980-2014)

The ecosystem services value （ESV） of rice system has received increasing attention in agricultural policy decision. Over the last three decades, China＇s rice production presented an obviously trend that moving towards north locations. However, the impacts of this migration on the ESV of rice production have not been well documented. In this paper, we analyzed the change of the ESV of rice production in China under ＂north migration＂ and ＂no migration＂ scenarios during 1980-2014 based on long-term historical data. The results showed that both the positive and negative ESVs of rice production were lower under ＂north migration＂ than under ＂no migration＂ scenarios. The total ESV during 1980-2014 was reduced by 15.8%. ＂North migration＂ significantly reduced the area-scaled ESV since the early 1990s; while its impact on yield-scaled ESV was not significant. The effects of＂north migration＂ on ESV showed great spatial variation. The greatest reduction in total and area-scaled ESV was observed in south locations. While the yield-scaled ESVs of most south locations were enhanced under ＂north migration＂ scenario. These results indicated that ＂north migration＂ has generated adverse effects on the ESV of rice production. An adjustment in the spatial distribution is essential to protecting the non-production benefits of rice ecosystem.

Methane and Nitrous Oxide Emissions from Rice-Duck and Rice-Fish Complex Ecosystems and the Evaluation of Their Economic Significance

Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.

Value of Ecosystem Services in Conventional and Organic Rice Paddies:A Case Study in Wannian,Jiangxi,China

In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.

STUDY ON RESIDUES OF ^(14)C-CARBOFURAN IN MODEL RICE-FISH ECOSYSTEM

Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.

STUDY ON RESIDUES OF ^（14）C－FENITROTHION IN MODEL RICE－FISH ECOSYSTEM AND FIELD RICE－FISH ECOSYSTEM

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THE FATE OF ^(14)C-FENITROTHION IN RICE-FISH MODEL ECOSYSTEM

The fate of fenitrothion in rice- fish ecosystem was studied using C- fenitrothion (14C- F) labelled at methoxyl and two application rates. The fenitrothion in water disappeared quickly, only 8 and 11 ppb in two treatments at harvest were detected respectively. Most of 14C-F in soil existed in upper layer and that in plants appeared in shoots. The extractable residues in cargo rice were 0.36 and 0.58 ppm in two treatments respectively. 14C- residues (14C- R) were concentrated in bones, next viscera, meat and scales. Total 14C-R in meat were 0.92 and 1.77 ppm at harvest. Comparing two treatments, the residue dynamics of fenitrothion in water, soil, plants and fish were similar. 14C- R in water and soil after harvest affected the rice- fish ecosystem in the next season. However, the extractable 14C- R in cargo rice, soil and water were very low. Fenitrothion 14C- fenitrothion Rice- fish Model

Past, Present and Future Perspectives of Rice Production in Tanzania

Cultivated rice (Oryza sativa L. and Oryza. glaberrima) is one of the most important food crops in the world. World rice production has increased three times since the green revolution. However, climate change and global warming effects as well as ever increasing world population will require the world to produce more rice without increasing area under rice production in order to meet those demands. The best option to overcome these challenges includes adoption of climate-smart technologies and sustainable solutions to rice production. Rice was probably introduced in Tanzania over 1000 years ago by Asian traders during trade contacts between Asia and East Africa Coast through Indian Ocean. Rice cultivation had been restricted to coastal area until 19th century when it started spreading to interior areas of Tanzania. During colonial period (1880s-1960s), the emphasis was to produce cash crops as raw materials for industrialized world. After independence production of rice increased significantly. Currently, rice is the second most important food crop in Tanzania after maize and Tanzania is the leading producer of rice in East African countries. It ranks 4th and 22nd in Africa and World respectively in terms of rice production. In this paper, the rice history, ecosystems, challenges and future perspective for sustaining rice production in Tanzania is reviewed.

水稻生态系统碳密度空间分布及其影响因素研究

水稻生态系统是陆地生态系统的重要组成部分,在碳循环中起着十分重要的作用,且在小尺度区域中,碳密度空间分布上也会存在不小的差异,故本研究旨在区域尺度上分析水稻生态系统碳密度空间分布差异并探究造成差异的原因。通过实测临安区水稻地上部分、根系以及土壤的碳密度,同时结合临安区地理数据,使用空间自相关分析方法分析各乡镇碳密度空间分布差异,并对差异性作具体分析,探究其影响因素。结果表明,临安区水稻生态系统碳密度空间上呈现一定的自相关性及聚集性,临安中部地区水稻生态系统碳密度值较低,西部地区水稻土壤碳密度值较高且呈聚集性,东部地区水稻作物碳密度值较高且呈聚集性。究其原因,在区域尺度上地形因素对水稻生态系统的碳密度有一定影响;同时,由于中部地区的过度施氮肥导致土壤性质破坏,故土壤氮密度也是影响碳密度的一个重要因素。本研究对指导当地水稻农业生产以及促进水稻农业发展具有重要意义。

水稻生长季CO_(2)通量的时间动态和影响因子研究

为了明确长三角地区稻麦轮作生态系统中水稻生长季CO_(2)通量的多时间尺度变化特征,量化环境因子对农田CO_(2)通量变化的贡献度,拆分环境因子的直接影响和间接影响,该研究利用涡度相关观测系统进行了2年CO_(2)通量的连续观测,分析了辐射类、温度类、水汽类和风速对CO_(2)通量的影响。结果表明:稻麦轮作生态系统在水稻生长季是一个二氧化碳汇,2020、2021年水稻生长季的总固碳量分别为396.3、491.9 g/m^(2)(以C计);CO_(2)通量也有明显的日变化,呈现出“U形”和“V型”的单峰曲线,吸收峰值出现在第200~250天。在不同时间尺度上,影响CO_(2)通量的主控因子始终是光合有效辐射;但随时间尺度的增加,各个因子贡献度的差异逐渐减小。饱和水汽压差也是影响CO_(2)通量的重要因子,它与光合有效辐射的交互作用会抑制彼此对CO_(2)通量的直接贡献。

基于TOP-RICE模型嘧菌酯·噻呋酰胺4%展膜油剂稻田水溢出对水生生态系统风险评估研究

为评估嘧菌酯·噻呋酰胺4%展膜油剂在我国稻田水溢出对水生生态系统的风险,本研究依据中华人民共和国农业行业标准NY/T 2882.2—2016《农药登记环境风险评估指南第2部分:水生生态系统》,采用TOP-RICE暴露模型分别单独评估了嘧菌酯和噻呋酰胺2种有效成分稻田滴撒方式应用时水溢出对水生生态系统的风险。其中,TOP-RICE初级暴露模型中有我国连平和南昌2个水稻-地下水暴露场景,每个场景都对分蘖期和拔节期进行分别评估。分析结果显示,嘧菌酯·噻呋酰胺4%展膜油剂中的嘧菌酯按照申请的良好农业规范(GAP)使用,生物富集风险可接受,初级风险评估对无脊椎动物(急性)和无脊椎动物(慢性)风险不可接受,但经中宇宙研究后,在连平和南昌2个场景点,均为拔节期用药对无脊椎动物的风险可接受,但分蘖期用药对无脊椎动物的风险不可接受;嘧菌酯·噻呋酰胺4%展膜油剂中的噻呋酰胺按照申请的GAP使用,生物富集带来的风险可以接受,经初级风险评估风险均可接受。在忽略2种有效成分相互间作用时,初步认为嘧菌酯·噻呋酰胺4%展膜油剂在我国稻田拔节期按照GAP要求施用时水溢出对水生生态系统的风险可接受,但应避免在分蘖期用药,以免其中的有效成分嘧菌酯对水生无脊椎动物产生不良影响。

水稻种植环境治理对乡村生态系统的影响与可持续发展策略

水稻种植是全球粮食安全的关键环节,其环境治理和可持续发展策略对保障国家粮食安全、应对气候变化挑战至关重要。合理的水稻种植环境治理措施有助于减少农业生产对自然生态环境的负面影响,提高农业生产效率、增加农民收入,促进乡村生态系统的可持续发展。从种植技术、废弃物利用、生态补偿、经济发展四个层面提出了水稻种植环境治理的可持续发展策略,为乡村振兴战略的实施提供了科学依据和实践指导。

Seasonal and Interannual Variations of Carbon Exchange over a Rice–Wheat Rotation System on the North China Plain

Rice-wheat （R-W） rotation systems are ubiquitous in South and East Asia, and play an important role in modulating the carbon cycle and climate. Long-term, continuous flux measurements help in better understanding the seasonal and interannual variation of the carbon budget over R-W rotation systems. In this study, measurements of CO2 fluxes and meteorological variables over an R-W rotation system on the North China Plain from 2007 to 2010 were analyzed. To analyze the abiotic factors regulating Net Ecosystem Exchange （NEE）, NEE was partitioned into gross primary production （GPP） and ecosystem respiration. Nighttime NEE or ecosystem respiration was controlled primarily by soil temperature, while daytime NEE was mainly determined by photosythetically active radiation （PAR）. The responses of nighttime NEE to soil temperature and daytime NEE to light were closely associated with crop development and photosynthetic activity, respectively. Moreover, the interannual variation in GPP and NEE mainly depended on precipitation and PAR. Overall, NEE was negative on the annual scale and the rotation system behaved as a carbon sink of 982 g C m 2 per year over the three years. The winter wheat field took up more CO2 than the rice paddy during the longer growing season, while the daily NEE for wheat and rice were -2.35 and -3.96 g C m-2, respectively. After the grain harvest was subtracted from the NEE, the winter wheat field became a moderately strong carbon sink of 251-334 g C m-2 per season, whereas the rice paddy switched to a weak carbon sink of 107-132 per season.

烟-稻轮作区不同种植模式碳汇效应及经济效益评价

【背景和目的】植烟土壤碳汇效应近年来颇受关注,生态效应与经济效益双赢的烤烟与其他作物轮作模式也有待探索。本研究旨在评价分析皖南烟田不同种植模式生态系统碳汇效应及经济效益。【方法】采用大田试验,设置烤烟-水稻→小麦-中稻(TWR)、烤烟-水稻→紫云英-再生稻(TRR)两类种植模式,定量评价两种模式的碳汇效应以及作物产量和经济效益。【结果】与传统的TWR模式相比,TRR模式生产成本显著降低8.8%,经济收益显著增加8.9%,净碳汇显著提高47.3%,表明TRR是一种经济收益高且温室气体排放强度低的种植模式。在TRR系统中,水稻的碳吸收和碳排放均最高,紫云英呈现高碳吸收、低碳排放的特点,而烤烟则是低碳吸收、高碳排放。TRR系统净碳汇贡献的大小顺序表现为紫云英>头季稻>烟后晚稻>再生稻>烤烟,碳足迹主要来自于CH4(44.6%)、N_(2)O(20.2%)和化肥(16.5%),紫云英绿肥和再生稻是该模式重要的碳汇作物。烤烟碳足迹主要来源为肥料、N_(2)O和农膜,占总排放的比例均超过20%。种植紫云英和再生稻有利于TRR模式作物高产和碳汇增效。【结论】TRR模式是一种经济收益高且温室气体排放强度低的种植模式,其碳汇潜力的进一步提高的关键是减少稻季CH4排放和提高烤烟季肥料利用率。本研究为烟-稻轮作生态系统温室气体减排及其高效、绿色、低碳农业生产提供了理论依据。

Nitrogen Fertilizer Optimization and Cultivar Selection for Rice Grown near Mountainous Slopes in Orissa,India—A Field Experiment and Simulation Model Study

Degradation of the natural resource base has led to decline in crop yields or stagnation that caused food shortages at varying degrees among mountain families. Rice, the major staple food in Asia,is suffering from lack of suitable cultivar and N fertilizer management, when grown near mountainous slopes under rain-fed agro-ecosystem.An investigation through a field experiment and simulation study was conducted at United Nations University, Tokyo to select suitable rice cultivars and N fertilizer level for the rice grown near mountainous slopes in Orissa, India. The field experiment was conducted during wet season (June to November) of 2001 at Kasiadihi village of Dhenkanal district, Orissa,India with eight popular rice cultivars of medium (120～130 d) and long duration (135～150 d) group and Ranjit of long duration group followed by 4,730group, across N levels. CERES-Rice model was used to simulated grain yield of these two selected cultivars using historical weather data of the past 18years (1983～2000). Long duration cultivar Ranjit registered higher yield with lower stability as compared medium duration cultivar Mahamaya over the past 18 years. An optimum N fertilizer level of 80rain-fed ecosystem near mountainous slopes in Orissa,India to attain optimum yield potential of cultivar.

2018-2020年松嫩平原长岭盐碱稻田碳水通量观测数据集

与其他陆地生态系统相比,农田生态系统与大气间的CO_(2)和H2O交换的过程具有多变性与复杂性,其交换过程不仅受到环境因子的影响,还受作物类型、种植模式、管理方式等因素的共同作用。作为中国东北松嫩平原盐碱地改良过程中最有效的治理措施之一,洗盐种稻具有较强的区域代表性,在气候调节、水分利用、碳汇功能等方面都亟待研究,需要实地监测数据作为支撑。基于微气象学理论的涡度协方差技术,可以对农田生态系统与大气间CO_(2)和水热通量交换进行直接测量。本数据集为长岭盐碱稻田2018–2020年通量观测结果,该结果经ChinaFLUX技术标准体系进行质量控制与插补处理。数据集的时间尺度含半小时、日、月和年,数据指标具体包括观测期间的大气温度(Ta)、空气相对湿度(RH)、水汽压(e)、饱和水汽压(es)、土壤温度(Ts)、土壤水分(SWC)、净辐射(Rn)、光合有效辐射(PAR)、降雨量(P)、风速(Ws)、风向(Wd)、显热通量(Hs)、潜热通量(LE)、蒸散量(ET)、二氧化碳净交换量(NEE)、生态系统呼吸(Re)、总生态系统交换量(GEE)等。建立和共享本数据集可为农田生态系统与大气间能量与物质交换提供本底资料,为区域生态系统评估提供数据支持和理论参考。

噁霉灵水稻田施用下的水生生态系统风险评估

为了明确噁霉灵制剂产品水稻苗床用药对水生生态系统的风险,根据噁霉灵的理化性质、环境归趋数据和产品GAP施药信息,结合产品用药的特点对施药信息进行处理,根据降解半衰期折算噁霉灵施药量,采用TOP-Rice模型预测叶发育期、分蘖期用药后水体中噁霉灵的暴露浓度,结合噁霉灵毒性数据评估其对水生态系统的环境暴露风险。结果表明:噁霉灵苗床用药移栽前直接进入水体,对脊椎动物急性和无脊椎动物急性、慢性风险不可接受,对脊椎动物慢性、初级生产者风险可接受,移栽后噁霉灵制剂产品所有场景施用对水生态系统风险均可接受,噁霉灵水稻苗床用药移栽后对水生态系统较为安全,但应密切重视苗床土壤和用药后移栽前剩余秧苗的管理,严禁丢弃至水田、池塘及河水中,同时应开发适合的模型用于水稻苗床用药对水生态系统的评估,避免不适当的评估加大产品风险,给企业造成负担,同时也要避免低估风险给生态系统产生危害。

稻田系统养分循环利用对土壤肥力和可持续生产力的影响

基于12a田间定位试验结果,研究了在不同化肥配施条件下,有机养分循环利用对亚热带红壤稻田生产力和土壤肥力的影响。结果表明:①施用化肥是实现水稻高产的必要条件。在连续不施肥情况下,水稻产量维持在5.6t·hm-2的水平,投入化肥N(229kg·hm-2)、N-P(39kg·hm-2)和N-P-K(162kg·hm-2)之后,产量分别提高到了6.6、7.9和9.0t·hm-2。农田系统有机养分循环利用能进一步提高水稻产量,但产量增益随NPK配施程度提高而降低。②在不施肥或只施N肥的情况下,有机物循环利用能显著降低水稻产量的年际变异系数,而在NP或NPK配施基础上的有机物循环利用则不能显著提高水稻的稳产性能,说明适量和平衡地提供水稻所需的营养元素是水稻稳产的物质基础,至于这些养分是来自化肥或有机肥源并不重要。红壤稻田早稻的稳产性受施肥模式的影响较大,施磷肥是降低早稻产量波动、提高稳产性能的最重要条件。③连续12a不施肥对土壤有机质含量没有显著影响,施化肥NPK处理的土壤有机质含量呈现出不稳定的上升趋势,而有机物循环利用能显著提高土壤有机质含量和土壤养分的生物有效性。通过有机物养分资源的循环利用,可有效降低当前稻田化肥的高投入水平,减轻环境污染压力,实现农田生态系统生产力的高效可持续发展。

4种生态类型稻区节肢动物群落的基本组成与结构特征分析

根据在浙江富阳、河南郑州、江苏句容和湖南长沙的连续田间调查，稻田节肢动物群落的组成依生态学上的营养关系分为植食类（害虫）、捕食类和寄生类（天敌）、以及腐生类和水生类（与水稻关系不甚密切，但可作为天敌的猎物）等。进一步分析显示，不同稻区的节肢动物群落的种－丰盛度关系适于用对数正态分布（Ｌｏｇｎｏｒｍａｌｄｉｓｔｒｉｂｕｔｉｏｎ）模型描述，单一作物生长季节中取样总计少于１０个个体的物种所占比例为４３．７６％－７１．９１％。不同类群的相对丰盛度因地而异，且可是水生类的摇蚊（富阳早稻田）、白背飞虱和褐飞虱（富阳晚稻、句容、长沙）、黑尾叶蝉（郑州）或腐生类的弹尾虫（句容）。多样性（以Ｎ＿１表示）的高低顺序为郑州（２８．５６）＞富阳晚稻（２２．４３）＞句容９１（１１．０８）＞富阳早稻（６．４３），句容９２（６．８０），和长沙（６．７２）。极丰盛种所包括的个体数占总个体数量的比例在６９％－８０％之间，具有普遍性的丰盛种有猎物类的褐飞虱、白背飞虱、蚊类、弹尾虫以及捕食类的狼蛛、黑肩绿盲蝽和尖钩宽蝽等，构成了稻田节肢动物群落组成及功能作用的主体。