土壤侵蚀成因机制分析与模拟

本文对黄土丘陵沟壑区土壤侵蚀的成因机制与运动机理进行了深入探讨，分析了黄土地区高含沙火流通人的形成及其汇流过程，讨论了泥沙运动的基本模式。在此基础上对高含沙水流的运动机理及其挟沙力进行了力学模拟，分析了高含沙水流的流速分布及泥沙的垂线分布，构造了推移质泥沙的输沙模型。     

Rodent Control in India

Eighteen species of rodents are pests in agriculture, horticulture, forestry, animal and human dwellings and rural and urban storage facilities in India. Their habitat, distribution, abundance and economic significance varies in different crops, seasons and geographical regions of the country. Of these, Bandicota bengalensis is the most predominant and widespread pest of agriculture in wet and irrigated soils and has also established in houses and godowns in metropolitan cities like Bombay, Delhi and Calcutta. In dryland agriculture Tatera indica and Meriones hurrianae are the predominant rodent pests. Some species like Rattus meltada, Mus musculus and M. booduga occur in both wet and dry lands. Species like R. nitidus in north-eastern hill region and Gerbillus gleadowi in the Indian desert are important locally. The common commensal pests are Rattus rattus and M. musculus throughout the country including the islands. R. rattus along with squirrels Funambulus palmarum and F. tristriatus are serious pests of plantation crops such as coconut and oil palm in the southern peninsula. F. pennanti is abundant in orchards and gardens in the north and central plains and sub-mountain regions. Analysis of the information available on the damage and economic losses caused by rodents in rice, wheat, sugarcane, maize, pearl millet, sorghum, oil seed, legume and vegetable crop fields, horticulture and forestry, poultry farms, and rural and urban dwellings and storage facilities clearly shows that chronic damage ranging from 2% to 15% persists throughout the country and severe damage, sometimes even up to 100% loss of the field crop, is not rare. Several traditional and modern approaches and methods of rodent control are being used. The existing knowledge of the environmental, cultural, biological, mechanical and chemical methods of rodent control in India is reviewed. Considerable variations exist in the susceptibility of the pest species to different methods, particularly to rodenticides and trapping, their field applicability, efficacy and economics in different crops, seasons and geographical regions, behavioural responses of the pest species to these methods in different ecological conditions and their adoption by farmers in different regions of India. Environmental and cultural techniques, such as clean cultivation, proper soil tillage and crop scheduling, barriers, repellents and proofing which may reduce rodent harbourage, food sources and immigration have long lasting effects but are seldom adopted. However, their significance in relation to normal agricultural practices, intensification and diversification are discussed. Rodenticides, which provide an immediate solution to the rodent problem, form the major component of rodent control strategies in India. Poison baiting of rodents with zinc phosphide and burrow fumigation with aluminium phosphide are common in agricultural fields and recently Racumin (coumatetralyl) and bromadiolone have been introduced for the control of both agricultural and commensal rodent pests in India. Methods and timings of campaigns and successes and problems in implementation of rodent control are also reviewed.     

前期Nino 3.4 区海温变化与宁夏1、2月气温、降水的关系

通过对北半球极涡、亚洲极涡面积和强度指数、东亚大槽强度及位置指数的相关性年代际强弱分析、检验,在最强相关阶段对宁夏1、2月气温、降水影响进行相关性分析及显著性检验,通过检验的特征量与气温、降水在相应的阶段稳定性较好,作为预报预测的选取和参考因子具有一定的指示意义。对1961年以来Nino 3.4区12月海温监测状态与次年1、2月气温、降水进行相关性分析,得出前期Nino 3.4区12月海温自2000年以来在宁夏区域暖背景和厄尔尼诺-拉尼娜状态下,与次年1月气温、降水分别成正、负相关,系数较高;在厄尔尼诺状态下,与宁夏次年2月气温、降水的正、负相关性较高;在拉尼娜状态下,与次年2月降水的负相关较明显,上述相关均通过显著性水平检验,可作为短期气候预测中可确定因子的依据;海温在正常状态下与次年1、2月气温、降水均无明显相关。统计了1961-2010年共15次拉尼娜事件结束年对宁夏次年1、2月气温偏高、偏低、降水偏多、偏少影响的概率,并通过X²检验得出,拉尼娜事件与宁夏1、2月气温、降水无显著相关性。     

540年来宁夏旱涝分区及演变趋势的诊断分析

应用近500年的旱涝史料和现代降水量资料,对宁夏引黄灌区、中部干旱带和南部山区三个区域进行时段为百年的旱涝特征及演变趋势的诊断分析;通过11年旱涝等级序列滑动平均来探讨其周期变化规律及变化趋势,采用交叉谱分析方法,得到了太阳活动对宁夏地区旱涝的影响尺度、幅度及响应时间,以说明旱涝变化与这些因素的相关程度;并采用功率谱分...     

近50年西峰气候变化特征分析

根据西峰1951~2001年51 a系列的降水和气温实测资料对气候变化进行了分析。分析表明,1976年以前,年降水量有增加趋势,1976年以后,年降水量呈下降趋势,年均气温和年最低气温呈线性升高趋势。利用年降水量和年均气温距平百分比累计分析表明,西峰气候变化可以分为凉干期、凉湿期、暖湿期和暖干期等四个阶段。不同月份逐年气候变化分析结果表明,冬季和初春降水量增加,7、8、9三个月的降水量呈下降趋势。各月平均气温和最低气温均呈增加趋势。从气温变化季节特征分析,冬季暖湿化趋势明显,在初春季节最高气温下降,在降水较多的夏秋季节,气候显示为暖干化趋势。     

低氮环境下燕麦与箭豌豆间混作与刈割时间对饲草产量及质量特性的影响

对北京市延庆县旱作低N土壤环境下燕麦与箭豌豆间混播6种方式与比例对饲草产量与质量特性影响进行了研究。结果表明,在低N环境下,与燕麦单作相比,箭豌豆与燕麦间混播不仅可增加饲草中干物质产量,饲草N产量也可增加30%~130%;而且燕麦与箭豌豆间混作对饲草质量也有显著影响(P<0.01)。间混作能够降低饲草中ADF与NDF含量,提高燕麦开花后饲草RFV值。4种间混作处理在饲草产量与饲草品质方面各有优点,也各有不足。在低N环境下,如果以饲草产量和饲草N产量为主要追求目标,则燕麦与箭豌豆1∶1邻行间作方式为最佳播种模式,其次依次分别是燕麦与箭豌豆1∶1同行混播、燕麦与箭豌豆1∶2同行混播、燕麦与箭豌豆2∶1同行混播。燕麦与箭豌豆间混播最佳刈割期为燕麦乳熟期 箭豌豆满荚期,因为此时混合饲草产量最高,饲草N产量与RFV较高,而ADF与NDF较低。     

陕西省农业和农村生态环境补偿机制研究

建立健全农业和农村生态环境补偿机制,既是农业和农村经济工作贯彻落实科学发展观、坚持走可持续发展道路的具体体现,也是加强陕西省农业和农村生态环境建设的重要环节。本文评析了陕西省农业和农村生态环境建设与保护的现状,总结探讨了陕西省农业和农村生态环境补偿机制的做法及经验,并提出建立健全陕西省农业和农村生态环境补偿机制的对策与建议。     

黑果枸杞茎叶生长及其生态化学计量特征对灌水施肥的响应

在石羊河中游田间条件下,通过灌水和施肥调节黑果枸杞生长。测定不同时期黑果枸杞茎、叶生长量及其化学计量学特征变化,分析器官水平生长速率与化学计量学特征的关系,验证生态化学计量学理论"生长速率假说"。灌水施肥显著促进了茎长、基径和叶片长、宽及叶干重的生长(P<0.05),而茎长、基径、叶面积和叶干重的相对生长速率与对照之间无显著差异。各处理下黑果枸杞新梢C含量及C∶N、C∶P随生育期进程呈增加趋势,而N、P及N∶P呈降低趋势;灌水和施肥处理后茎C含量及C∶N、C∶P、N∶P低于对照,茎N、P含量高于对照。各处理叶片C、N、P含量在生育期内呈降低趋势,而C∶N、C∶P及N∶P呈增加趋势;灌水和施肥后叶片C含量及C∶N、C∶P、N∶P低于对照,叶片N、P含量高于对照。茎C含量及C∶N、C∶P显著高于叶片(P<0.05),而N、P含量及N∶P显著低于叶片(P<0.05)。生长速率假说认为,生物个体的生长速率与体内的N∶P、C∶P具有负相关关系,与N、P含量呈显著的正相关关系。各处理黑果枸杞茎、叶的生长速率与其N、P含量及C∶P、N∶P总体相关性不显著。表明施肥灌水调节下黑果枸杞茎叶生长及化学计量学特征不支持生长速率假说。     

农作物病虫害防治农药速查系统构建与应用

为了让农户能够直观了解及掌握常见病虫害的防治信息,帮助农户通过智能手机在农田、果园和茶园等现场方便快捷地获取作物病虫害图文识别要点与科学防治方法,为农户提供在线植保技术服务,本研究采用RESTful Web 服务架构设计,运用HTML5移动Web开发技术,借助微信平台作为用户访问入口,开发了一款跨平台 (android/iOS) 的农药速查软件系统,实现了农药信息查询、病虫害图谱查询及后台数据管理等功能。通过建立农药与病虫害间的关联关系,实现了从农药名称和病虫害名称两个途径查询农药信息;所构建的数据库涵盖了蔬菜、果树、水稻、茶叶及烟草等共30种福建省常规种植作物上的重要病虫害农药防治技术。初步运用验证结果表明,该系统整体实用性和稳定性较好,适合在农村基层推广应用。基于微信平台的农药速查系统能够满足植保新技术普及和应用的需求,可为农户提供简单便捷、对症下药的在线植保科技服务,对提高用户安全施药和科学防控能力、推进农药的增效减量均具有重要意义。     

黄河流域历史文化名城名镇名村的空间分异与影响因素分析

文中结合建设部和国家文物局发布的七个批次的国家级历史文化村镇数据和历史文化名城数据,综合利用最近邻指数法、GIS空间分析、地理探测器等分析方法,得出以下结论:1)全国尺度上,历史文化名城数量东西差异大,而历史文化村镇数量南北差异大.2)黄河流域历史文化名城分布比较均匀,而历史文化村镇属于集聚分布.3)因子影响程度上,人...     

宁夏草原蝗虫多样性及其对环境因子的响应

为明确宁夏四类主要草原的蝗虫物种组成、多样性和对天敌、植被、土壤及其气候等生物和非生物因子的响应,2019-2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠四类草原对蝗虫及天敌物种进行了调查采集,通过物种数、个体数、多样性指数、优势度指数、丰富度指数及均匀性指数分析蝗虫、天敌和昆虫的多样性,并就草原蝗虫优势种和多样性对天敌、植被、土壤及气候等生物和非生物因子的响应进行分析。结果表明,共采集鉴定草原蝗虫和天敌个体数分别有743头和3592头,物种数分别有27种和24种;温性草原上发生的蝗虫和天敌物种和数量均最多,蝗虫和天敌的物种分别为23种和21种,数量分别为432头和1682头;温性草原化荒漠上发生的蝗虫和天敌物种和数量均最少,蝗虫和天敌的物种分别为8种和7种,数量分别为34头和132头。蝗虫优势种有白纹雏蝗Chorthippus albonemus、短星翅蝗Calliptamus abbreviatus和亚洲小车蝗Oedaleus asiaticus三种,天敌优势种有直角通缘步甲Pterostichus gebleri、麻步甲Carabus brandti和短翅伪葬步甲Pseudotaphoxenus brevipennis三种。温性草原无论是在草原蝗虫群落中,还是整个昆虫和天敌群落中,其丰富度指数均显著高于其他三类草原;草原蝗虫多样性指数和丰富度指数与天敌多样性指数和丰富度指数间均存在极显著正相关关系,与天敌优势度指数间存在极显著负相关关系;短星翅蝗和亚洲小车蝗发生均与天敌直角通缘步甲呈显著正相关关系,白纹雏蝗与禾本科植被盖度、高度、生物量,菊科植被盖度、生物量、频度、高度、土壤饱和持水量、毛管持水量、田间持水量、毛管孔隙度、总孔隙度、有机质、碱解氮、海拔和降水量间均呈显著正相关关系,与土壤容重、pH、平均气温和最高气温间均呈极显著负相关关系。     

茶树对茶橙瘿螨抗性机制的研究

作者分析了对茶橙瘿螨抗性和感性的两组无性系茶树新梢叶片下表面形态特征、叶片组织结构和新梢内含物含量。结果表明,抗性品种的叶片下表面茸毛密度、新梢咖啡碱和氨基酸的含量显著高于感性品种;叶片下表面气孔密度和新梢还原糖含量则相反。叶片组织结构、新梢茶多酚和可溶蛋白的含量抗、感品种间无显著差异。在氨基酸的组份中,以茶树特有氨基酸茶氨酸的含量差异最显著,其次是谷氨酸、丙氨酸、甘氨酸、天门冬氨酸、缬氨酸和丝氨酸。采用反渗叶盘法测定了多种氨基酸、咖啡碱、葡萄糖对该螨生物学的影响,明确了咖啡碱和多种氨基酸具有增加该螨活动时间、抑制其取食,从而影响其生长、繁殖的生理效应;葡萄糖有助于该螨的取食和繁殖。据此表明,茶树新梢叶片下表面多茸毛、低气孔密度的形态学抗螨机制和新梢高氨基酸、咖啡碱含量和低还原糖含量的生化抗螨机制。     

药液表面张力和黏度对草甘膦药效的影响及其机理研究

通过添加有机硅助剂和丙三醇调节草甘膦药液的表面张力和黏度,测定其对草甘膦药液液滴的物理性状及生物活性的影响。结果表明：降低药液的表面张力,雾滴的铺展直径增加,干燥时间缩短,药液的黏度以及在杂草叶片表面的最大稳定持留量没有显著性变化;草甘膦对杂草的防效表现为先升高后降低,对阔叶杂草最高目测防效和鲜重防效可提高42%和41%,对禾本科杂草防效可提高37%和37%。增加草甘膦的药液黏度,药液在杂草叶片上的最大稳定持留量增加,表面张力降低,对雾滴的干燥时间和铺展直径影响很小;草甘膦对阔叶杂草最高目测防效和鲜重防效可提高42%和41%,对禾本科杂草的防效可提高42%和42%。适当降低草甘膦药液的表面张力或增加其黏度均可提高其对杂草的防除效果。     

干旱胁迫及复水对豌豆苗期保护酶活性及膜脂过氧化的影响

采用盆栽控水试验法,研究了干旱胁迫及复水对豌豆苗期叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性及丙二醛(MDA)含量、质膜相对透性(RC)的影响,对豌豆苗期抗氧化能力进行了综合评价。结果表明:干旱胁迫降低了SOD活性,随胁迫程度加重和历时延长降幅增大。轻度干旱胁迫10 d或重度干旱胁迫提高了POD和CAT活性,随胁迫程度加重和历时延长增幅加大。复水5 d对CAT、SOD活性产生部分补偿效应,对POD活性产生等量补偿效应。复水10 d对SOD活性产生等量补偿效应,对CAT、POD活性产生等量或超补偿效应;干旱胁迫增加了MDA含量,随胁迫程度加重增幅加大、胁迫历时延长增幅减少。复水5 d、10 d对干旱胁迫5 d豌豆叶片MDA含量分别产生部分和等量补偿效应。干旱胁迫导致膜脂透性增大,随胁迫程度加重和历时延长增幅加大。复水5 d、10 d可分别产生部分和等量补偿效应。     

腐植酸在旱地农业土壤改良和水肥增效中的作用研究

腐植酸是农田土壤有机质的重要组成成分，是土壤生命最具活力的核心物质。针对旱地农业发展中土壤结构退化、水肥利用效率低和作物低产低效等核心问题，总结了我国生物腐植酸和煤基腐植酸等腐植酸资源及其行业发展进展，分析了腐植酸组成特点及其在改良土壤结构和维持土壤酸碱平衡、提高肥料利用效率、刺激作物生长、增强作物抗逆、改善作物品质和降低重金属污染等方面的作用原理，开展了腐植酸在酸化地、盐碱地土壤改良和在废弃地土壤结构改良以及水肥保持中应用的研究，对研发的腐植酸保水肥剂、腐植酸土壤改良剂和重金属污染地治理的材料及其应用效果进行介绍。针对我国旱地农业发展态势和腐植酸在旱区土壤改良应用中存在的问题，指出腐植酸产品研发和应用技术在旱地农业中的发展方向。     

新疆工业化和城镇化协调发展研究

工业化和城镇化是推动区域经济社会发展的主要动力,实现工业化和城镇化的协调发展是促进新疆经济社会跨越式发展重要途径之一。文中运用钱纳里发展模型,并通过计算工业化和城镇化协调指数,论述了工业化和城镇化协调发展关系,结合城镇人口与农业劳动力人口指标,分析了新疆工业化进程与城镇化进程的互动关系,并对省域层面工业化和城镇化区域协调发展状况进行了初步探讨。认为新疆工业化和城镇化之间的发展存在显著不协调状况,总体发展水平低、城镇化滞后工业化发展态势明显;在省域85个县市中,协调发展区域尚处于低度协调水平,为提升新疆区域经济社会发展水平,必须打破当前发展模式,实现由"协调发展-交互发展-更高层次协调发展"模式的转变。     

The return and loss of litter phosphorus in different types of sand dunes in Horqin Sandy Land, northeastern China

Litter phosphorus(P) return is important to maintain the P cycle and balance in the sandy land of arid areas.In this study,we determined the loss and return of litter P in sand dune areas and elucidated their relationship.We investigated litter production and litter P amount,and simulated leaf litter moving dynamics to understand the relationships between the loss of litter P and the total litter P,and between the return of litter P and the total litter P in active(AD),semi-stabilized(SSD) and stabilized(SD) dunes in Inner Mongolia,northeastern China.The vegetation litter P was 12.6,94.5,and 201.6 mg P/m2 in AD,SSD,and SD,respectively.A significant movement and loss of leaf litter P with time occurred on the three types of sand dunes.As a result,the loss of P was 7.4,46.9,and 69.8 mg P/m2 and the return of P was 5.5,47.6,and 131.8 mg P/m2 in AD,SSD,and SD,respectively.The relationship between both loss and return of P and total litter P in AD,SSD,and SD was revealed by linear regression.The slope of the regression line indicated the rate of loss or return of litter P.From AD to SD,the loss rate showed a declining slope(0.52,0.32,and 0.17 for AD,SSD,and SD,respectively),and the return rate showed a rising slope(0.48,0.67,and 0.83 for AD,SSD,and SD,respectively).The loss of litter P should be regarded in the local management of vegetation and land in sand dune areas.Improved vegetation restoration measures are necessary to decrease litter P loss to maintain the stability of ecosystems in sand dune areas.     

阜新露天煤矿排土场边坡土壤团聚体稳定性及分形特征

露天煤矿排土场边坡水土流失严重.以阜新露天煤矿排土场为对象,探究不同坡位、坡向和恢复年限间土壤团聚体稳定性及分形维数的差异,为排土场边坡生态恢复提供理论依据.选取自然恢复5 a和10 a排土场边坡,分析坡上、坡中和坡下以及阴坡与阳坡间土壤团聚体的平均质量直径(MMD)、几何平均直径(GMD)、分形维数(D)和破坏率(P...     

Target site insensitivity mutations in the AChE and LdVssc1 confer resistance to pyrethroids and carbamates in Leptinotarsa decemlineata in northern Xinjiang Uygur autonomous region

A survey of resistance to five conventional insecticides was conducted in 2009 and 2010 for the first generation 4th-instar larvae of Leptinotarsa decemlineata from Urumqi, Changji, Qitai and Qapqal. Compared with the Tekes population, a reference susceptible population, the Changji and Qapqal populations exhibited very high to moderate levels of resistance to cyhalothrin and deltamethrin, moderate to high levels of resistance to carbosulfan and carbofuran, and low levels of resistance to azinphosmethyl. Moreover, the Urumqi and the Qitai populations reached a high and a moderate level of resistance to carbosulfan, respectively. Synergistic effects of triphenyl phosphate, diethylmeleate, and piperonyl butoxide on cyhalothrin and carbosulfan in Changji population revealed that cytochrome P450s were involved in the resistance to cyhalothrin but not carbosulfan. A modified bi-PASA was developed to simultaneously detect point mutations of S291G in the AChE and L1014F in the LdVssc1 genes. The former mutation resulted in the resistance to carbamates and the latter in the resistance to pyrethroids. The rates of homozygous and heterozygous resistant individuals to carbamates (S291G mutation) were 17.6% and 14.7%, 50.6% and 42.2%, 49.9% and 41.7%, 51.3% and 41.4%, and 44.8% and 47.4%; to pyrethroids (L1014F mutation) were 5.8% and 8.7%, 36.1% and 27.0%, 41.8% and 24.8%, 12.2% and 9.7%, and 7.9% and 10.6%, respectively, in samples from Tekes, Changji, Qapqal, Urumqi and Qitai. I392T point mutation in the AChE was detected by RT-PCR among 18 individuals from Changji, Qapqal, Urumqi and Qitai. These results demonstrated that point mutations of S291G in the AChE and L1014F in the LdVscc1 are responsible for, at least partially, the resistance to carbamates and pyrethroids in L. decemlineata in some field populations in northern Xinjiang Uygur autonomous region.     

Characteristics of soil organic carbon and total nitrogen under various grassland types along a transect in a mountain-basin system in Xinjiang,China

Soil organic carbon(SOC) and soil total nitrogen(STN) in arid regions are important components of global C and the N cycles, and their response to climate change will have important implications for both ecosystem processes and global climate feedbacks. Grassland ecosystems of Funyun County in the southern foot of the Altay Mountains are characterized by complex topography, suggesting large variability in the spatial distribution of SOC and STN. However, there has been little investigation of SOC and STN on grasslands in arid regions with a mountain-basin structure. Therefore, we investigated the characteristics of SOC and STN in different grassland types in a mountain-basin system at the southern foot of the Altai Mountains, north of the Junggar Basin in China, and explored their potential influencing factors and relationships with meteorological factors and soil properties. We found that the concentrations and storages of SOC and STN varied significantly with grassland type, and showed a decreasing trend along a decreasing elevation gradient in alpine meadow, mountain meadow, temperate typical steppe, temperate steppe desert, and temperate steppe desert. In addition, the SOC and STN concentrations decreased with depth, except in the temperate desert steppe. According to Pearson's correlation values and redundancy analysis, the mean annual precipitation, soil moisture content and soil available N concentration were significantly positively correlated with the SOC and STN concentrations. In contrast, the mean annual temperature, p H, and soil bulk density were significantly and negatively correlated with the SOC and STN concentrations. The mean annual precipitation and mean annual temperature were the primary factors related to the SOC and STN concentrations. The distributions of the SOC and STN concentrations were highly regulated by the elevation-induced differences in meteorological factors. Mean annual precipitation and mean annual temperature together explained 97.85% and 98.38% of the overall variations in the SOC and STN concentrations, respectively, at soil depth of 0–40 cm, with precipitation making the greatest contribution. Our results provide a basis for estimating and predicting SOC and STN concentrations in grasslands in arid regions with a mountain-basin structure.