风光互补发电系统在西北山区农业发展中的应用

针对宁夏中卫兴仁地区的区域条件和气候条件,在西北干旱地区压砂地持续利用关键技术研究与示范项目中,引入了一套风光互补发电扬水系统,通过对该系统的流量测试以及对该系统所控制的瓜地产量的测定,得出该系统在西北山区农业发展中具有巨大的社会效益和经济效益。     

机械化助力硒砂瓜产业发展

中卫香山地区位于宁夏中部干旱带,多年来就有种植压砂西瓜的传统.2004年,中卫成立地级市以后,为解决当地经济发展问题,确定了3年之内在中部干旱带香山地区发展硒砂瓜产业66 666.67hm2(100万亩)的目标.截止2008年春,已完成硒砂瓜种植面积66 666.67 hm2的发展目标,并成功创立了"香山硒砂瓜"绿色无公害品牌,成为干旱带上经济发展和脱贫致富的龙头产业.     

黄土丘陵区沙棘水土保持薪炭林土地生产潜力研究

本文对黄土丘陵区主要灌木水土保持薪炭林树种——沙棘(Hippophae rhamnoides Lo)的土地生产潜力进行了研究。应用Thornthwait Memorial模型估算了其土地气候生产潜力，揭示了沙棘在该地区实际存在的气候条件下可能达到的理论产量；实测了当前技术经济管理水平条件下所能达到的最高产量——现实生产潜力，分析了目前林业的现实生产潜力与气候生产潜力之间的差距，预示了其发展前景；从合理利用气候资源和充分发挥土地生产潜力角度，提出了沙棘应为当地水土保持薪炭林优选的灌木树种。其结果对该地区培育坡地水土保持薪炭林具有重要的实践指导意义。     

水肥协同对压砂地枸杞叶绿素及光合作用的影响

为在宁夏中卫香山压砂地推广发展枸杞产业,通过大田试验,设置不同灌水定额、施肥量,研究水肥协同对压砂地枸杞叶绿素及光合作用的影响。结果表明:水肥协同对压砂地枸杞叶绿素及光合作用影响显著(P0.05),压砂地枸杞叶绿素含量、日均净光合速枸杞叶片蒸腾速率、枸杞气孔导度随着灌水定额的增加而增加。枸杞的胞间CO2浓度随着灌水定额和施肥量的增加而减小。     

不同种植年限对压砂地土壤盐分及西瓜产量的影响

通过大田试验,研究了宁夏环香山地区不同种植年限对压砂地土壤盐分以及西瓜产量的影响,以期为压砂地持续利用及西瓜生产力预估提供参考.结果表明:随着种植年限增加,压砂地0~80 cm土层内土壤盐分总值不断降低;在种植6,10,15 a后,盐碱性压砂地0~80 cm土层内盐分含量较3 a的分别降低了70.3%,21.4%和56.4%,非盐碱性压砂地0~80 cm土层内盐分分别降低了50.6%,62.4%和34.8%;随着土层深度增加,盐碱性与非盐碱性压砂地的土壤盐分含量均呈增大趋势;非盐碱性压砂地在0~80 cm土层内,pH值呈先减小后增大趋势;西瓜产量与盐分含量关系密切,盐碱性压砂地的西瓜产量随着盐分降低不断增大,西瓜产量随土壤盐分降低先增大后减小.     

压砂地土壤盐分、土壤水分及坡向对西瓜产量的影响

通过田间调查及取样的方法,研究了宁夏环香山地区土壤盐分本底值、土壤水分及坡地坡向对压砂地西瓜产量的影响,并采用独立样本T-检验的统计方法对数据进行了分析,以期为不同压砂地西瓜生产力评价提供参考依据。研究结果表明:在种植管理相同前提下,土壤盐分含量高压砂地西瓜产量比盐分含量低的增加了50.4%;土壤水分含量高压砂地的西瓜产量比土壤水分含量低增加了12.6%;旱地阴坡土壤含水率显著大于阳坡(P0.05),但阴坡的西瓜产量在数值上高于阳坡,差异不显著。压砂措施具有良好的压盐作用,表现为压砂地0~80cm土壤盐分含量随深度增加而逐渐增大。     

压砂砾石水-岩作用下元素释放规律

为了解压砂砾石在干湿交替和冻融循环这两种水-岩作用过程中的元素释放规律,以宁夏中卫地区一种主要压砂砾石为研究对象,对该种压砂砾石本身元素组成及其干湿交替和冻融循环模拟试验条件下元素累积过程做了检测分析.发现绿色板岩压砂砾石共由O,Si,Fe等25种元素组成,其中包含了多种植物生长所需要且能溶于水的矿质元素.这种压砂砾石在干湿交替和冻融循环处理过程中能够释放N,Ca,K等多种植物生长所需要的大量元素、微量元素和有益元素,50次干湿交替和冻融循环处理条件下,各类元素累积释放量分别为786.90,958.18 mg.明确了宁夏中卫地区一种主要压砂砾石的元素组成,摸清了干湿交替和冻融循环过程中压砂砾石成矿元素的释放规律,对维护当地土壤健康、提高农作物品质具有重要意义.     

宁夏压沙地西瓜自然降水生产力及障碍因子分析

在水资源缺乏状况下,通过降水模拟对比试验,分析宁夏各压沙地类型在不同自然降水水平下的生产力及主要障碍因子对产量影响度。研究表明,西瓜自然降水生产力大小排序依次为丰水年>平水年>枯水年,新沙地>中沙地>老沙地;障碍因子影响程度为水文条件>压沙类型>肥力水平,为当地压沙地西瓜生产提供科学指导依据。     

基于PI模型的压砂地生产力评价指标体系研究

以宁夏中部干旱地区为研究区域,研究基于PI指数模型的压砂地生产力评价指标体系。压砂地生产力评价指标体系主要是考虑土壤自然状态下对压砂地生产力的影响,采用FAO提出的PI指数模型作为压砂地生产力评价的指标模型,选取10个指标,分别为有机质含量、速效磷含量、速效钾含量、全氮含量、土壤机械构成、土壤有效厚度、地面坡度、土壤酸碱度、光热条件、和水分供应能力等。通过分析得出,西瓜产量Y和评价指数PI之间存在线性相关关系:Y=1 440 PI+407.72,即PI指数模型能较好的对压砂地生产力进行评价。     

老压砂地西瓜水肥效应研究

针对宁夏中部干旱带压砂地随着压砂年限的增加生产力下降问题,从补水定额、施肥水平和补水次数方面入手,探索影响老压砂地生产力的主要因素,提出解决制约老压砂地生产的水肥方案。于2009年和2010年在宁夏中卫市香山乡红圈子村采用正交方法进行了桶栽试验研究,结果表明:桶栽条件下的最佳组合为补水定额37.5m3/hm2;施有机肥1 200kg/hm2,二铵91.5kg/hm2,尿素157.5kg/hm2,硫酸钾94.5kg/hm2;补水次数7次。经方差分析可知,补水定额对产量的影响效果极为显著,施肥水平和补水次数对产量的影响效果不显著,对试验结果影响不显著的因子可以依经济、方便为原则任选一水平。     

Role of farmers' attitudes in adoption of irrigation in Saskatchewan

Adoption of a new technology, such as irrigation, is a complex phenomenon. Several factors of economic and social nature contribute to the farm-level decisions affecting adoption. In this study, the role played by attitudes of potential adopters towards irrigation and its subsequent adoption on their farm unit was estimated. Two models were estimated, one incorporating only adopters' socio-economic characteristics, and the other, only their attitudes towards irrigation. Results suggest that adopters' attitude, particularly with respect to economic and environmental effects of irrigation, were significant determinants of their decision to proceed with adoption of irrigation, and have a role to play in adoption of irrigation over and above that explained by socio-economic characteristics. In particular, these results suggest that negative perceptions with respect to economics of irrigation and those related to its detrimental impacts on environmental quality, particularly through soil salinity, may be significant deterrents for adoption of irrigation. The study suggests that planning of large scale water development projects, particularly those involving irrigation, must be cognizant of attitudes of potential adopters. Furthermore, during the planning stages, more attention should be paid to the development of proper educational programs, as well as extension packages, to ensure that potential adopters formulate correct attitudes towards the new technology.     

饮料中柠檬黄含量测定的不确定度分析

对饮料中的柠檬黄含量进行了测定和不确定度分析,通过对各影响因素的不确定度评定,试验重复性对饮料中合成着色剂的测量结果不确定度的影响最大,其次是样品处理回收率和标准曲线拟合引入的不确定度对试验结果也有较大的影响。结果表明:饮料中柠檬黄的含量为（103.5?3.5）mgkg,k＝2。      

技工院校数学教学中培养学生应用能力的对策分析

数学作为一门基础性学科，在学生的各个学习阶段都起到了不可替代的作用，在工科院校中数学教学的重要性更是升到了一个新的高度。通过数学的学习，可以培养学生的应用能力和探究思维，通过对数学知识的学习和灵活运用，学生的综合能力会得到系统性的提高。对于数学的教学工作，应当做到有针对性、有目标，在教学工作中，充分做到对症下药、有的放矢，让学生通过对数学的学习，提高自身的综合能力，更好地为社会建设贡献力量。     

沼气在冬季温室生产中的应用

本试验通过沼气燃烧,提高冬季温室温度,促进西红柿生长发育.试验结果表明:增温可有效提高冬季温室温度,为西红柿越冬生产提供良好条件,有利于西红柿植株茎粗增加及果实膨大速率提高;可使西红柿坐果期提前10天左右,采收期延长20天左右,并提早上市.同时,增温可显著提高西红柿产量,亩增产800kg.     

Advances in application of climate prediction in agriculture

Agricultural ecosystems and their associated business and government systems are diverse and varied. They range from farms, to input supply businesses, to marketing and government policy systems, among others. These systems are dynamic and responsive to fluctuations in climate. Skill in climate prediction offers considerable opportunities to managers via its potential to realise system improvements (i.e. increased food production and profit and/or reduced risks). Realising these opportunities, however, is not straightforward as the forecasting skill is imperfect and approaches to applying the existing skill to management issues have not been developed and tested extensively. While there has been much written about impacts of climate variability, there has been relatively little done in relation to applying knowledge of climate predictions to modify actions ahead of likely impacts. However, a considerable body of effort in various parts of the world is now being focused on this issue of applying climate predictions to improve agricultural systems.

In this paper, we outline the basis for climate prediction, with emphasis on the El Niño-Southern Oscillation phenomenon, and catalogue experiences at field, national and global scales in applying climate predictions to agriculture. These diverse experiences are synthesised to derive general lessons about approaches to applying climate prediction in agriculture. The case studies have been selected to represent a diversity of agricultural systems and scales of operation. They also represent the on-going activities of some of the key research and development groups in this field around the world. The case studies include applications at field/farm scale to dryland cropping systems in Australia, Zimbabwe, and Argentina. This spectrum covers resource-rich and resource-poor farming with motivations ranging from profit to food security. At national and global scale we consider possible applications of climate prediction in commodity forecasting (wheat in Australia) and examine implications on global wheat trade and price associated with global consequences of climate prediction.

In cataloguing these experiences we note some general lessons. Foremost is the value of an interdisciplinary systems approach in connecting disciplinary knowledge in a manner most suited to decision-makers. This approach often includes scenario analysis based on simulation with credible models as a key aspect of the learning process. Interaction among researchers, analysts and decision-makers is vital in the development of effective applications — all of the players learn. Issues associated with balance between information demand and supply as well as appreciation of awareness limitations of decision-makers, analysts, and scientists are highlighted. It is argued that understanding and communicating decision risks is one of the keys to successful applications of climate prediction.

We consider that advances of the future will be made by better connecting agricultural scientists and practitioners with the science of climate prediction. Professions involved in decision making must take a proactive role in the development of climate forecasts if the design and use of climate predictions are to reach their full potential.     

四川简阳地区砂岩层中水分利用研究

分析了四川简阳地区砂岩和土壤中的水分运动特性和砂岩中储存的水分对土壤水分补给量的多少。对当地的砂岩和土壤进行了水分特征曲线的测定试验、入渗试验和蒸发试验,并采用研究中常用模型对试验结果进行了拟合,通过对拟合结果的分析,得出了当地土壤和砂岩的水分特性,总结出了该地区表面土层在缺水时水分很容易被下部砂岩层补给,砂岩中的水分是作物利用的重要水资源的结论。这对于充分利用当地水资源,合理确定类似地质条件地区灌溉定额,解决无灌溉条件丘陵区作物缺水问题,实现农业节水灌溉有一定的参考价值。     

Fate and transport of atrazine in a sandy soil in the presence of antibiotics in poultry manures

Pesticides degrade principally through biodegradation processes, whereas antibiotics kill microorganisms or inhibit their growth in soils and thus may affect the fate of pesticides. In this study, the impact of antibiotics on the degradation of atrazine in a sandy soil is investigated in lysimeters over a ninety-day period. Four treatments, monensin, narasin, salinomycin and non-antibiotic, were assigned in triplicate to twelve PVC lysimeters. Both soil and leachate samples were collected and analyzed at predetermined time intervals. In all treatments, atrazine was found to leach down through the soil profiles with the concentration level decreasing with depth, and only trace amounts of atrazine were found in the leachate. However, the statistical analysis of the results showed that all the three antibiotic treatments yielded a significantly slower dissipation of the atrazine level as compared to the non-antibiotic treatment; the mass balance analysis indicated an increased half-life of atrazine in the presence of antibiotics.     

北京典型灌区土壤和农产品多氯联苯污染风险评估

为明确北京东南郊灌区表层土壤和农作物多氯联苯(PCBs)含量和污染水平以及人体健康风险,2015年在该灌区采集了20个土壤样品和28个作物样品,利用气相色谱-质谱联用仪分析了样品中7大类PCBs含量。研究结果表明,灌区表层土壤PCBs质量比为ND(低于检出限)到0.711 776μg/kg,均值为0.43μg/kg,总体上土壤PCBs含量随污灌历史年限增加而增加。本研究区表层土壤PCBs含量处于较低水平,土壤未受到PCBs污染且其生态风险概率均小于10%。灌区采集的冬小麦籽粒、大葱、茄子、梨、白薯、芥蓝PCBs含量均低于实验检出限,未检出;夏玉米籽粒、菜心和油菜PCBs总量分别为0.17~0.47μg/kg、1.63μg/kg和5.91μg/kg。不同污灌历史年限并未显著影响夏玉米籽粒PCBs含量。本研究区农产品PCBs含量处于较低水平,均低于美国卫生及公共服务部建议限量。采集的土壤和农产品样品仅四氯联苯含量高于实验检出限,能检测出;一氯联苯到三氯联苯和五氯联苯到七氯联苯均低于实验检出限,未检出。本研究中成人和儿童PCBs致癌风险分别为8.49×10-7和4.66×10-7,非致癌风险分别为1.41×10-1和3.88×10-1,均低于US EPA规定限值,说明PCBs未对人群产生明显的健康危害。致癌危害和非致癌危害均以口-作物(玉米和蔬菜)为主,其对人体健康所造成的风险占总个人年风险的比例分别为99.79%~99.95%和99.81%~99.94%。