遥感信息结合光合特性研究作物光合产量估测模型

从遥感信息参数和植物生理生态参数出发 ,建立了遥感-光合作物产量机理模型(RSPCYM) ,其中包括直接以遥感信息获取吸收光合有效辐射 (APAR),将用以完整表示作物生育期中光合时间的作物光合同化势 (CPAP)引入到遥感-光合作物产量模型中,同时利用遥感信息求算作物光合速率 ,进而建立遥感-光合作物产量模型。将建立的模型用于典型区域的冬小麦作物产量估测研究中 ,表明发展的模型有可比的精度。     

The carbon sequestration potential of tree crop plantations

Carbon (C) conservation and sequestration in many developing countries needs to be accompanied by socio-economic improvements. Tree crop plantations can be a potential path for coupling climate change mitigation and economic development by providing C sequestration and supplying wood and non-wood products to meet domestic and international market requirements at the same time. Financial compensation for such plantations could potentially be covered by the Clean Development Mechanism under the United Nations Framework Convention on Climate Change (FCCC) Kyoto Protocol, but its suitability has also been suggested for integration into REDD?+?(reducing emissions from deforestation, forest degradation and enhancement of forest C stocks) currently being negotiated under the United Nations FCCC. We assess the aboveground C sequestration potential of four major plantation crops – cocoa (Theobroma cacao), oil palm (Elaeis guineensis), rubber (Hevea brasiliensis), and orange (Citrus sinesis) – cultivated in the tropics. Measurements were conducted in Ghana and allometric equations were applied to estimate biomass. The largest C potential was found in the rubber plantations (214 tC/ha). Cocoa (65 tC/ha) and orange (76 tC/ha) plantations have a much lower C content, and oil palm (45 tC/ha) has the lowest C potential, assuming that the yield is not used as biofuel. There is considerable C sequestration potential in plantations if they are established on land with modest C content such as degraded forest or agricultural land, and not on land with old-growth forest. We also show that simple C assessment methods can give reliable results, which makes it easier for developing countries to partake in REDD?+ or other payment schemes.     

Conservation and sustainable use of crop wild relatives

Conservation of crop wild relatives (CWRs) is a complex interdisciplinary process that is being addressed by various national and international initiatives, including two Global Environment Facility projects (‘In situ Conservation of Crop Wild Relatives through Enhanced Information Management and Field Application’ and ‘Design, Testing and Evaluation of Best Practices for in situ Conservation of Economically Important Wild Species’), the European Community-funded project ‘European Crop Wild Relative Diversity Assessment and Conservation Forum (PGR Forum)’ and the European ‘In situ and On Farm Network’. The key issues that have arisen are: (1) the definition of what constitutes a CWR, (2) the need for national and regional information systems and a global system, (3) development and application of priority-determining mechanisms, (4) the incorporation of the conservation of CWRs into existing national, regional and international PGR programmes, (5) assessment of the effectiveness of conservation actions, (6) awareness of the importance of CWRs in agricultural development at local, national and international levels both for the scientific and lay communities and (7) policy development and legal framework. The above issues are illustrated by work on the conservation of a group of legumes known as grasspea chicklings, vetchlings, and horticultural ornamental peas (Lathyrus spp.) in their European and Mediterranean centre of diversity.     

Relation of baseflow to row crop intensity in Iowa

Increasing baseflow and baseflow percentage over the second half of the 20th century in Iowa has contributed to increasing nitrate-nitrogen concentrations measured in Iowa rivers because nitrate is primarily delivered to streams as baseflow and tile drainage. The relation of baseflow and baseflow percentage to row crop land use was evaluated for 11 Iowa rivers and their watersheds for their period of streamflow record (58–73 years period). Results indicated increasing baseflow in Iowa’s rivers is significantly related to increasing row crop intensity. A 13–52% increase in row crop percentage in many Iowa watersheds has contributed to an increase of 33–135 mm increase in baseflow and 7–31% increase in baseflow percentage. Limited historical water quality data from two larger Iowa rivers (Cedar and Raccoon rivers) suggest that increasing row crop land use over the 20th century has produced more baseflow and contributed to increasing nitrate concentrations in Iowa’s rivers.     

作物植株残体还田土壤对除草剂的截留作用

加入成熟作物植株残体还田的土壤（简称秸秆还田土壤）与自然土壤的土柱淋洗对比实验，研究了玉米秸秆还田土壤对除草剂乙草胺和阿特拉津的截留作用以及水稻秸秆还田土壤对丁草胺的截留作用。结果表明，作物秸秆还田土壤对所研究的三种除草剂有明显的截留作用，在土桩的最上部10cm内，秸秆还田土壤对乙草胺、丁草胺和阿特拉津的截留量分别是自然土壤对其截留量的1.33、1.77和1.88倍。     

农作物秸秆综合利用新技术——工业化生产羧甲基纤维素

从农作物秸秆引起的污染问题着手 ,论述了农作物秸秆的各项综合利用技术 ;在实验室研究的基础上 ,提出了工业化生产羧甲基纤维素的综合利用技术 ,不仅可以解决农作物秸秆焚烧引起的污染问题 ,还可以创造可观的经济效益     

盐肥耦合对农作物生长影响的研究现状

土壤盐渍化是制约现代农业发展的重要因素之一,作物耐盐度既受自身遗传性状的影响,也与土壤环境、化肥施用等方面有关。因此在改良盐碱地的基础上,制定适宜的农田施肥管理制度,成为当前盐渍土合理利用及提高农作物产量的重要环节。文章就盐肥耦合对一些作物生长影响方面的研究现状做一综述。     

Studies on crop growth modelling and simulation models in China

There is a close relationship between agricultural production and environmental meteorological conditions. In the study of the correlation between them, the simulation models are paid more attention to the crop growth. In this paper the development of the studies on the crop growth dynamic simulation model in China is briefly reviewed. The relationships between meteorological conditions and each process of crop growth (such as photosynthesis, respiration, accumulation and distribution of assimilation products and growth of leaf area) are studied and simulated basing on the results from field experiments. Preliminary models for rice, wheat, maize and soybean have been developed, and some investigations about modelling methods, procedures and parameters in simulation models are made.     

Cover crop effects on nitrous oxide emission from a manure-treated Mollisol

Agriculture contributes 40–60% of the total annual N₂O emissions to the atmosphere. Development of management practices to reduce these emissions would have a significant impact on greenhouse gas levels. Non-leguminous cover crops are efficient scavengers of residual soil NO₃, thereby reducing leaching losses. However, the effect of a grass cover crop on N₂O emissions from soil receiving liquid swine manure has not been evaluated. This study investigated: (i) the temporal patterns of N₂O emissions following addition of swine manure slurry in a laboratory setting under fluctuating soil moisture regimes; (ii) assessed the potential of a rye (Secale cereale L.) cover crop to decrease N₂O emissions under these conditions; and (iii) quantified field N₂O emissions in response to either spring applied urea ammonium nitrate (UAN) or different rates of fall-applied liquid swine manure, in the presence or absence of a rye/oat winter cover crop. Laboratory experiments investigating cover crop effects N₂O emissions were performed in a controlled environment chamber programmed for a 14 h light period, 18 °C day temperature, and 15 °C night temperature. Treatments with or without a living rye cover crop were treated with either: (i) no manure; (ii) a phosphorus-based manure application rate (low manure): or (iii) a nitrogen-based manure application rate (high manure). We observed a significant reduction in N₂O emissions in the presence of the rye cover crop. Field experiments were performed on a fine-loamy soil in Central Iowa from October 12, 2005 to October 2, 2006. We observed no significant effect of the cover crop on cumulative N₂O emissions in the field. The primary factor influencing N₂O emission was N application rate, regardless of form or timing. The response of N₂O emission to N additions was non-linear, with progressively more N₂O emitted with increasing N application. These results indicate that while cover crops have the potential to reduce N₂O emissions, N application rate may be the overriding factor.     

用ALMANAC作物生长模型模拟冬小麦生长

冬小麦是黄淮海地区的主要农作物。精确模拟冬小麦产量能够帮助生产者获得更好的经济效益。根据实验资料调整了ALMANAC作物生长模型部分参数后,用其对该地区的冬小麦生长进行了模拟,结果显示ALMANAC模型能够较好地模拟冬小麦的叶面积指数和产量。叶面积指数的模拟结果与实测结果的比值为1.0552,可决系数R2为0.7021;生物量模拟的最大误差为-6.01%,经济产量模拟的最大误差为-5.41%。模型还可以揭示影响冬小麦生长的主要胁迫因素。     

结合态氚在作物生态系统中的形成动态

采用模拟污染物的同位素示踪技术研究了氚水在玉米、大豆和水稻中结合态氚形成的动态过程,并探讨了结合态氚形成的机理.结果表明,土壤(或水)中的氚水通过作物根系吸收进入作物体内,并在作物各部位形成结合态氚;作物体中结合态氚的比活度随时间呈增加趋势;作物籽粒中的结合态氚的比活度约为2～3Bq/g,玉米籽和稻谷中结合态氚的比活度高于其余部位,而大豆籽则与其他部位相当.对3种作物中结合态氚比活度的变化动态进行指数回归分析得:玉米、大豆和水稻中的比活度分别为C_m(t)=1.14(1-e^-0.0509t)、C_s(t)=1.65(^1-e-0.0595t)和C_r>(t)=1.29(^1-e-0.1027t),经方差分析表明,各拟合方程较好地反映了氚水在玉米、大豆和水稻中结合态氚形成的动态.     

基于ANFIS的陕西省参考作物蒸散量计算

为有效提高陕西省参考作物蒸散量（ET₀）的计算精度,选取陕西省6个气象站点57 a（1960—2016年）每日气象资料,构建8种基于自适应神经模糊推理系统（ANFIS）的ET₀计算模型,将其与Hargreaves-Samani、Makkink和Iramk等三种在陕西省ET₀计算精度较高的模型进行比较。结果表明：ANFIS模型能较好地反映气象因子与ET₀之间的复杂非线性关系,在仅有气温数据时,ANFIS模型具有足够的精度（平均R²=0.894,平均R_MSE=0.558 mm/d,平均MRE=18.258%）,ANFIS模型的精度随着气象因子数量的增加而增加;在相同气象条件下,ANFIS模型模拟效果最好;ANFIS模型具有较强的泛化能力,基于不同站点也有较高的精度（平均R²=0.974,平均R_MSE=0.276 mm/d,平均MRE=8.608%）,具有很好的可移植性。因此,在缺少气象数据时,ANFIS可以作为陕西省ET₀的计算模型,为农业用水管理及水资源优化配置提供帮助。     

两种常用兽药对作物发芽的生态毒性效应

采用室内生长箱培养的试验方法,研究了2种常用兽药磺胺嘧啶钠、环丙沙星对小麦、白菜和番茄种子发芽、根伸长、芽伸长的影响,分析了兽药和作物生长之间的剂量.效应关系,比较分析了小麦,白菜和番茄对2种兽药胁迫的敏感性.结果表明,根长抑制率和芽长抑制率与兽药浓度显著相关(p<0.05);种子发芽抑制率与2种兽药浓度不相关(p>0.05).2种兽药对根伸长和芽伸长的抑制明显强于对种子发芽的抑制.3种作物对磺胺嘧啶钠胁迫的敏感性依次为小麦＞白菜＞番茄;对环丙沙星胁迫的敏感性依次为白菜＞番茄＞小麦;磺胺嘧啶钠对3种作物的毒性效应明显强于环丙沙星.     

Impact of prolonged rainy seasons on food crop production in Cameroon

This study set out to examine why agricultural production in differing agro-ecological zones of the same country responds differently to a common environmental event (an extension of the rainy season). We find that the heavy reliance of farmers in the drier agro-ecological zones on seasonal cycles make them more vulnerable to an extension of the rainy season than those in regions where rainfall is less relied on. Effects in these vulnerable regions include significant damage to crops as well as a shortage in local markets, which raises prices of basic food commodities. The difference between prices in low and high food producing periods is low for crops that can easily be preserved during rains (such as cassava at 58% from an average of 20% in previous years and yams at 82% from 65%). Crops that depend on sunshine for preservation experience greater differences between low and high periods (maize at 92% from an average of 31% in previous years, sorghum at 180% from 53%, and beans at 68% from 42%). In zones with a history of unreliable dry seasons, farmers are more adapted to coping with an extension of the rainy season and possess technology and skills which can be made available to others in vulnerable zones through inter-regional knowledge transfer of knowledge and skills. This study further reinforces the understanding that isolated climate shocks could be important in understanding and managing vulnerability. Also, vulnerability is quite variable even among communities in the same country, in which people practice the same economic activity and are exposed to the same shock.     

种植绿肥对作物产量和细菌群落稳定性的影响

为深入研究青海高原地区长期种植绿肥,减施化肥条件下小麦/油菜产量及土壤理化性状及微生物群落的变化,通过2011年建立的定位试验,设GF0（毛苕子作为绿肥,不施用化肥）、GF60（毛叶苕子配施60%化肥）、GF70（毛叶苕子配施70%化肥）、GF80（毛叶苕子配施80%化肥）、GF90（毛叶苕子配施90%化肥）、GF100（毛叶苕子配施100%化肥）、F0（休耕并且不施化肥）、F100（休耕并且施用100%化肥）共8个处理,利用高通量测序等技术,研究了种植利用绿肥减施化肥条件下小麦和油菜的产量、土壤性质和微生物群落结构的变化特征.结果表明,在保证小麦、油菜不减产的基础上,种植绿肥后茬作物减施化肥达到30%左右.绿肥配施减量化肥对土壤肥力有显著的提升作用,特别是土壤有机碳和全氮含量有明显的提高,分别提高1.34%~7.46%、2.16%~7.48%.化肥与绿肥配施增强了土壤微生物群落多样性,其中酸杆菌门和变形菌门是本研究土壤中的优势菌群.共生网络分析表明,绿肥处理提高了细菌群落的稳定性和抗干扰能力,同时绿肥应用增加了细菌群落中的关键物种.本研究表明,不同土壤微生物丰度受种植模式、施肥量影响很大,长期种植绿肥、减施化肥提高了土壤微生物丰度和多样性,增强微生物群落的稳定性.种植绿肥条件下化肥减肥量30%左右保证作物稳产可为当地的施肥管理提供参考.     

Ozone distribution in central Italy and its effect on crop productivity

The focus of the present study was to assess the ozone levels in a typical area of the Mediterranean basin, viz. Tuscany (central Italy). Eighty-thousand hourly mean ozone concentrations were recorded by 10 automatic analysers in the districts of Florence, Pisa, Lucca and Prato, from May to September 1995 to 1997. The highest daily mean concentrations were reached in Florence, with a maximum hourly average of 197 ppb. In Lucca and Pisa, the peaks were close to 100 ppb. Data from Prato were much lower. Long-term critical levels for vegetation, as set by United Nations Economic Commission for Europe (UNECE), were constantly exceeded in Florence and Pisa, occasionally in Lucca, never in Prato. The results were used to fit exposure/yield response relationships proposed by UNECE and US National Crop Loss Assessment Network for some important crops. The estimated yield losses varied in Florence from 8% for corn and alfalfa to 27% for soybean, in Pisa from 5% for corn to 24% for soybean, in Lucca from 3% for corn to 17% for soybean. A preliminary economic estimate for corn, wheat, barley, soybean, tomato and alfalfa, calculated annual damage to be 4.6 M Euro in Florence, 0.5 M Euro in Lucca and 3 M Euro in Pisa. The picture must be regarded as only partial, as exposure/yield response relationships for important Italian crops (such as grapevine and vegetables) are not available.     

秸秆焚烧影响南京空气质量的成因探讨

综合利用卫星遥感的火点和云覆盖信息,结合气团后向轨迹分析,探讨了由秸秆焚烧造成的空气污染物的区域尺度输送和本地源对城市空气质量的影响.结果表明,在一定气象条件下,污染物可以发生区域尺度的输送,上风火点与下风城市的污染有明显的相关,将空气污染分为局地型(如,2006年5月31日、2009年11月8日)、区域型(如,2008年10月28日),以及局地区域相结合型(如,2006年6月14日、2007年6月5日、2008年6月2日)3种.应用本文的方法,在有云时,可以通过部分火点和气团后向轨迹分析推测污染物源地.空气污染气象条件分析表明,秸秆焚烧若伴随高空(500hPa)有槽(或位于槽前),低空存在弱切变,气流由周边向中心辐合;同时,若在均压场控制下,等压线稀疏,风速较小或静风,污染物则易积聚而不易输送;逆温层的形成将污染物禁锢在混合层以下,不利于垂直扩散;再加上较大的相对湿度,有利于霾的形成,造成严重空气污染.     

Dairy manure as a potential source of crop nutrients and environmental contaminants

Although animal manure is applied to agricultural fields for its nutrient value, it may also contain potential contaminants. To determine the variability in such contaminants as well as in valuable nutrients, nine uncomposted manure samples from Idaho dairies collected during 2.5 years were analyzed for macro- and micro-nutrients, hormones, phytoestrogens, antibiotics, veterinary drugs, antibiotic resistance genes, and genetic elements involved in the spread of antibiotic resistance. Total N ranged from 6.8 to 30.7 (C:N of 10 to 21), P from 2.4 to 9.0, and K from 10.2 to 47.7 g/kg manure. Zn (103 – 348 mg/kg) was more abundant than Cu (56 – 127 mg/kg) in all samples. Phytoestrogens were the most prevalent contaminants detected, with concentrations fluctuating over time, reflecting animal diets. This is the first study to document the presence of flunixin, a non-steroidal anti-inflammatory drug, in solid stacked manure from regular dairy operations. Monensin was the most frequently detected antibiotic. Progesterones and sulfonamides were regularly detected. We also investigated the relative abundance of several types of plasmids involved in the spread of antibiotic resistance in clinical settings. Plasmids belonging to the IncI, IncP, and IncQ1 incompatibility groups were found in almost all manure samples. IncQ1 plasmids, class 1 integrons, and sulfonamide resistance genes were the most widespread and abundant genetic element surveyed, emphasizing their potential role in the spread of antibiotic resistance. The benefits associated with amending agricultural soils with dairy manure must be carefully weighed against the potential negative consequences of any manure contaminants.