基于改进投影寻踪法的农业气象灾情综合评价

针对气象灾害综合评价中客观存在的模糊性和多因素相互联系及相互制约性,提出运用改进投影寻踪法解决气象灾害综合评价问题,建立改进的投影寻踪综合评价模型。改进的投影寻踪法把每年的多维指标投影成一维的指标值,根据投影值的大小直接进行排序。通过对福建省近25a的农业气象灾害综合评价,结果表明：低温冻害对福建农业影响最大,按投影值将灾情划分为4级,福建1999年灾情最重,1984年灾情最轻,评价结果符合福建省的实际情况。     

基于WOFOST的东北地区玉米生育期气象条件适宜度评价

利用东北地区1981-2007年164个气象站逐日气象资料、玉米产量资料和30个农业气象试验站的玉米生育期资料,建立东北地区玉米生长发育期气象条件适宜程度诊断模型,计算玉米主要发育阶段(播种-出苗、出苗-拔节、拔节-开花、开花-乳熟、乳熟-成熟)的综合气象适宜度指数.应用WOFOST模型模拟玉米生物量,采用优化方法确定了基于模拟生物量(地上总干物重、穗重)的东北地区玉米不同发育阶段气象适宜程度诊断指标,动态、定量评价了玉米各生育阶段的气象适宜程度,并以2006年玉米全生育期气象适宜程度评价结果为例进行比较验证.结果表明,该方法的评价结果与利用综合气象适宜度指数得到的评价结果相比,等级完全相同和相差一个等级的占85％～90％,与研究区农业气象部门的监测公报也基本一致.表明该方法得到的评价结果可为玉米生产适应气候变化提供决策依据,相应的评价指标可在农业气象业务中推广应用.     

不同方法对保护性耕作的生态评价结果对比

应用生态经济学方法对农业生产技术进行综合评价是农业技术应用决策的重要参考,目前国际上存在各种不同的生态经济学评价方法,许多得到较为广泛的应用。但是不同方法的理论基础和评价侧重点不同、自成体系,应用单一方法难以全面系统评价农业技术。因此,该文基于农业技术评价的经济效益、生态功能以及环境影响3个方面的需求,选择目前国际上热门的能值、生态系统服务、生命周期评价3种生态经济评价方法对吉林省4种保护性耕作模式:玉米留茬垄侧种植技术(CT1)、玉米宽窄行交替休闲种植技术(CT2)、玉米留茬直播种植技术(CT3)和玉米灭高茬深松整地种植技术(CT4)的评价结果进行综合比较,探索吸收各种方法的优点用于系统综合评价农业生产技术的生态经济和环境影响效应的可行性。能值评价结果表明,4种模式的能值产出率高于对照模式9.6%,技术选择优先序是CT3CT4CT2CT1;生态服务价值评价结果表明,4种模式的生态服务价值是对照模式的2.1倍,技术排序是:CT2CT1CT3CT4;生命周期评价结果表明,4种模式的环境影响综合指数平均比对照模式低1.7%,技术排序为CT2CT3CT4CT1。研究结果表明3种方法的评价结果均显示了保护性耕作模式对于传统耕作模式在生态、经济和环境影响等方面都具有综合优势。但是,不同研究方法对于同一具体技术的评价结果有一定的差异。根据3种方法评价结果的排名平均计算,比较科学的综合排名结果应该是:CT2CT3CT4CT1。因此,采用单一方法难以全面系统评价某一具体的农业生产技术,在进行农业技术选择决策时,需要采取多方面、多方法进行综合评价,综合各种方法来选择合适的农业技术。     

贵州农业气象灾害综合风险评价与区划

为了明确贵州省不同区域内主要农业气象灾害类型以及综合研究农业气象灾害的风险,以县为基本评价单元,基于信息扩散理论、不确定性理论以及风险矩阵法,对贵州省8种主要农业气象灾害风险进行综合评价与区划。利用聚类分析将贵州省分为5类农业气象灾害风险区域,以不同聚类区域为研究对象进行灰色关联分析,求得每种灾害的关联度并据以确定不同聚类区域的主要灾害,分别为：春旱、秋绵雨灾害为主的区域;凝冻、倒春寒＼秋风灾害为主的区域;冬季低温＼夏旱灾害为主的区域;秋绵雨＼夏旱灾害为主的区域;夏旱＼暴雨洪涝灾害为主的区域。在灰色关联分析基础上建立了贵州省综合农业气象灾害风险评价模型,并计算了贵州省各县的综合农业气象灾害风险性,利用GIS空间分析进行综合农业气象灾害风险区划。区划结果表明：贵州农业气象灾害高风险区主要分布在西部及中部地区,低风险区域主要分布在南部地区以及东部地区。     

基于农业灾情的东北粮食产量估算模型及灾损分析

利用1981-2010年东北三省农业灾情统计数据和粮食产量数据,应用多元回归方法分析粮食气候减产量与灾情的关系,并构建基于灾情数据的粮食产量估算模型;在粮食因灾减产量估算的基础上,应用灰色关联法评价干旱、洪涝、低温和风雹4种灾害在受灾率、成灾率及绝收率水平上对粮食减产量的影响。结果表明,东北三省粮食气候减产量与农业灾情统计数据存在极显著（P〈0.01）相关关系,回归模型决定系数（R2）分别为0.76（黑龙江省）、0.78（吉林省）和0.87（辽宁省）,各模型估算的粮食产量模拟值与实际值间的平均相对误差分别为-0.06%、-0.32%和-0.20%。可见在气象灾害发生时历史农业灾情统计资料对区域粮食灾损量和粮食产量具有较强的指示作用,能为以粮食作物为主的地区提供可靠的粮食产量估算和农业气象灾害评价依据。对粮食因灾减产量与灾情的灰色关联度的分析表明,在受灾水平上,干旱的关联度在三省均为最高;在成灾、绝收水平上,风雹的关联度均位列第1;低温灾害在受灾、成灾和绝收水平上的关联度都不是最高的。由此可见,造成东北三省粮食减产的主要气象灾害是以程度轻、范围广的干旱及程度重、局地性强的风雹为主,而东北地区作为气候变暖趋势最明显的地区之一,低温不再是当地首要的农业气象灾害。     

环境功能材料水肥保持性能的综合评价

保持水肥、提高水肥利用效率是我国,特别是西北地区土地利用过程中亟待解决的问题。环境功能材料的应用是农业生产和环境治理中水肥保持的新途径。目前对于不同环境功能材料应用效果的综合定量评价仍难以实现,阻碍了环境功能材料的推广及应用。本研究引入层次分析-模糊综合评价法,以土柱淋溶试验结果为例,对一种环境材料配方的保水性、保肥性及经济性进行综合评价。结果发现:当该复合材料中保水剂、沸石、腐殖酸的配比关系为1:10:1时,综合效果最好。配比方式最优的复合材料对水分的最优保持效果为空白对照的1.22倍,对氨态氮、硝态氮和尿素态氮的最优保持效果分别是空白对照的1.2、4.12和1.19倍。实验结果为环境功能材料的筛选及综合评价提供了一种行之有效的方法。     

华北地区冬小麦主要气象灾害风险评价

为了对华北地区冬小麦生育期内遇到的主要气象灾害(干旱和干热风)的综合风险进行评价,根据气象灾害发生机理及区域环境特征建立危险性、暴露性和脆弱性评价模型,并构建综合风险模型,具体分析各地区综合风险的大小及主导风险因子,该文利用华北地区48个农气站冬小麦发育期资料(1981-2010年)和气象资料(1961-2010年)以及近50 a产量资料,将冬小麦全生育期划分为前期(播种期-起身期)、中期(拔节期-开花期)、后期(灌浆期-成熟期)3个阶段,并充分考虑了底墒形成期(播种当年7-9月)内的降水,分别基于水分亏缺指数和加权干热风日数构建了干旱、干热风等级指数,对华北地区冬小麦干旱、干热风灾害以及综合气象灾害风险进行分析。结果表明:危险性、脆弱性和暴露性的权重分别为0.3272、0.3116和0.3612。华北地区冬小麦农业气象灾害风险值有2个高值中心,一个位于冀鲁豫交汇处,一个位于河北省泊头、黄骅等地,风险值由中心向四周逐渐降低。根据该文构建的综合风险评估模型,将华北冬小麦种植区划分为5个不同风险等级区。评价结果具有较强的针对性,可以为华北各地区农业气象灾害风险管理提供参考。     

不同土地利用条件下土壤质量综合评价方法

针对传统的土壤质量评价方法难以满足现代农业发展的现状,提出了一种土壤质量指数法(SQI)综合评价土壤质量,旨在为农业生产、农产品产地选址、农业环境保护等提供理论支撑和参考依据。将方法在北京市郊区7种土地利用方式（粮田、林地、湿地、荒地、果园、菜地、草地）上进行了应用,并与常规方法进行了对比,结果表明：采用隶属度模型评价土壤肥力,肥力高低顺序为：湿地＞菜地＞粮田＞林地＞果园＞荒地＞草地;采用内梅罗污染指数评价了重金属污染状况,污染程度高低顺序为：湿地＞菜地＞荒地＞果园＞林地＞粮田＞草地;采用SQI指数评价土壤综合质量,其综合质量的高低顺序为：湿地＞粮田＞菜地＞果园＞林地＞荒地＞草地。此外还对评价模型的适用范围、评价结果的划分等一系列关键问题进行了探讨,得出：SQI指数评价方法的应用及结果的划分涵盖了不同的土地利用方式的农用地,体现了各种土壤属性的差异和变异特性,评价结果可实现土壤综合质量定性和定量化,能够反映土壤的关键信息,符合农业生产需要。     

基于遗传投影寻踪模型的农业水资源利用效率综合评价

针对农业水资源利用效率评价指标的不相容性问题,提出了农业水资源利用效率综合评价的遗传投影寻踪方法。该方法可以依据样本自身的数据特性寻求最佳投影方向,利用最佳投影方向可以判断各评价指标对综合评价目标的贡献大小和方向。通过最佳投影方向与评价指标的线性投影得到投影指标值,通过这一指标可以对样本进行统一评价和分类。利用该方法对甘肃省81个县域单元的农业水资源利用效率进行综合评价,评价结果很好的反映了各评价指标对综合评价目标的贡献大小和方向以及各评价单元综合利用效率。     

基于寒害过程的福建芒果种植气候风险区划

通过冬季寒害灾情调查、果园定位观测、地理移置和人工气候箱低温致灾试验4种渠道,收集芒果寒害的灾情样本39例,从而确定芒果寒害临界温度为2.0℃。在此基础上,筛选出福建芒果主产县市2001-2014年冬季28个寒害过程,通过将寒害过程温度、降水等气象因子与相对气象产量进行相关分析,确定芒果寒害致灾因子为过程极端最低气温、日最低气温≤2.0℃有害积寒、≤2.0℃寒害过程持续日数、≤2.0℃寒害过程降温幅度。利用主成分分析对4个致灾因子进行综合简化,得到芒果寒害评价的综合气候指标,结合相对气象产量确定了指标分级。根据寒害综合气候指标等级,应用GIS方法完成福建省芒果寒害种植气候风险区划,无寒害-轻度寒害的区域主要分布在沿海地区,是引种芒果优质品种寒害风险最低的区域。     

Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey

Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg^‐1 (mean 7.79 mg kg^‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg^‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg^‐1 (mean 166.5 mg kg^‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg^‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used.     

Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition

Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl₂)] and Se [0, 3, and 7 µM sodium selenite (Na₂SeO₃)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions.     

红壤区不同肥力水稻土根际硝化作用特征

通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。     

自由基在鸡肾病发生中的作用研究

肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据.     

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO₂ and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.     

Meta-analysis in the Selection of Groups in Varieties of Citrus

Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management.     

Effect of iron-quercetin complex on reduction of nitrite in in vitro and in vivo systems

This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions.     

旱地果园水肥管理模式研究进展

分析了旱地果园水肥管理模式的研究进展和存在问题,指出水肥胁迫尤其是水钾已成为旱区果树高产稳产优质化的主要限制因子。在系统探讨旱地果园水分管理、养分管理、综合管理以及果树叶营养综合诊断施肥标准的基础上,提出了旱地果园的高效水肥管理模式。     

Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs

The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance.     

北京市郊典型农田施肥研究与分析

通过问卷调查形式,对京郊粮田、菜田和果园3种农田施肥现状进行研究.结果表明,菜田和果园化肥施用量较高,氮、磷、钾肥均显著高于粮田.菜田和果园氮肥用量分别为1741.0和1172.8 kg/hm2,分别是粮田氮肥用量的4.5和3.0倍;磷肥用量分别为1375.1和996.4 kg/hm2,分别是粮田磷肥用量的15.5倍和11.2倍;钾肥用量分别为791.3和602.4 kg/hm2,分别是粮田钾肥用量的21.1和16.1倍.另外,3种利用方式的农田氮、磷和钾肥施用比例不同,粮田为75.4%、17.3%和7.3%;果园为42.3%、36.0%和21.7%;而菜田为44.6%、35.2%和20.3%.3种种植类型中均存在氮肥投入过量、钾肥不足的问题.