气象因子对鹤望兰产量的影响因素

采用滑移相关和斜交因子分析方法,得出影响成都地区鹤望兰产量的气象因子是温度、光照和相对湿度,且有显著的超前性.冬季的增温、增光和降低湿度是增加春季产量的重要管理环节,而秋季的增光、降低湿度是提高秋、冬季产量的重要措施.     

野生和栽培粗毛淫羊藿苷含量变化分析

目的：寻找淫羊藿苷在野生及人工种植的粗毛淫羊藿地上、地下各部位及夏、秋、冬三季的动态分布规律，指导栽培和收获。方法：分别在6月、9月、12月中旬取样测定苷在叶片、地上茎、地下根状茎及须根中的含量，分析分布规律。结果表明，淫羊藿苷在叶片中含量最高，在地上茎中最低，栽培上要注意提高叶片及须根产量。     

江苏省废无机酸的产生及处置现状

江苏省废无机酸的产生总量大,且逐年增加。废无机酸具有腐蚀性、毒性、不稳定性等危险特性,如不进行合理处置便排入环境中,危害极大。江苏省废无机酸的产量与城市区域分布、产业布局有着密切的关系。废无机酸处置及利用企业与废无机酸的产生情况有较密切的关联。针对不同特性的废无机酸,适合采用不同的处置或利用工艺。废无机酸作为危险废物可采用中和法实现无害化处置或采用浓缩回收法等工艺进行资源化利用。     

石油污染物生物降解试验研究

在用人工方法改变微生物所处的环境条件下进行了生物降解试验研究,以三种不同水平的碳氮比、含油量及投菌量进行了三因素、三水平正交实验。实验结果表明,在相同温度下,温度小于或等于30 ℃时,固体菌的降解效果优于液体菌;在不同温度下,30 ℃时,固体菌的降解效果最好。最终确定出石油污染物生物降解的最佳工艺条件:温度小于或等于30 ℃,接种量为10:1,碳氧比为100:10。     

观秋

<正>秋,总是伴随着一场淅沥的雨而来。这场雨过后,夏的燥热几乎在一夜间悄然隐退了。阳光,虽然明亮,却敛去了光芒,褪去了锐气,渐次温和平淡,于是早晚便有了凉意。秋凉如水。秋的凉,如同岁月在一个人身上,打磨掉浮躁后的沉淀,没有了火急火燎。秋的凉,是一种静美。尤其是落日的黄昏或晚饭后,手捧一杯香茗,一握黄卷,静坐阳台,听秋虫在窗下的草丛中低吟,自有一番滋味。     

整草免浸泡栽培鸡腿菇的技术要点

选场配料:①场地,室内、大田、大棚、葡萄架下、果树间套作均可。②配料,按20ｍ2。③配方,稻草或麦草400ｋｇ、石灰粉20ｋｇ。④菌种选择,矮壮一号、ＥＣ05。⑤用种量,母种1支或栽培种40ｋｇ。⑥栽培季节,春、秋、冬三季。原料处理:用3%石灰水浇泼在配料上,用羊角叉叉取草...     

碳中和背景下中国钢铁行业低碳发展路径

钢铁行业的低碳转型对于我国实现碳达峰碳中和目标具有至关重要的作用,有必要提前研究"双碳"目标下中国钢铁行业的发展路径及技术路线图。本文回顾了中国钢铁行业发展的历史趋势;归纳了钢铁行业实现低碳发展的主要技术选择;基于文献调研汇总了近年来关于中国钢铁行业低碳发展路径的相关研究,并总结了不同研究对钢铁未来低碳路径中关键参数的判断,包括粗钢产量、废钢资源量、电炉炼钢比例、低碳技术应用、能耗强度、二氧化碳排放等,同时分析了不同研究得出的普遍认识和主要差异。在研究中我们也简要分析了中国钢铁转型路径与全球钢铁转型路径之间的异同。基于上述分析,本文提出了"双碳"目标下中国钢铁行业发展路径的研究需求。     

污泥减量化系统中营养盐优化比例研究

以石化污水处理厂为研究对象,考察不同磷源、氮源及碳源的不同比例对污泥产生的影响,特别是对剩余污泥产量的减量效果产生的影响。目的是确定最佳的营养盐比例,以最大程度减少剩余污泥产量而不影响污水处理厂的出水排放指标,同时减少营养盐的投加量,降低生产成本。     

龟蟾蚓同池养殖技术

乌龟、蟾蜍、蚯蚓同池养殖 ,既解决了春夏秋三季乌龟的饲料问题 ,又节省了饲料和劳动力 ,其经济效益高。现将龟蟾蚓同池养殖技术介绍于下 :池底铺 30ｃｍ厚的淤泥 ,池面养殖藻类、浮萍等 ,池边四周种植水浮莲 ,岸边种植水草 ,以利于乌龟、蟾蜍的栖息和遮荫。乌龟、蟾蜍对水质的要求相同 ,即水色以淡绿色、透明度30ｃｍ以上即可 ,透明度低则更换池水。水池进、出水口和池外四周必须用铁丝网或尼龙网封好 ,以防龟、蟾逃逸。蟾蜍穴居在泥土中 ,或栖于石下草间 ,白昼潜伏 ,晚间或雨天外出活动 ,不用人工饲喂 ,捕获蜗牛、蛞蝓、蚂蚁、蚊子等对乌…     

浙北平原土壤有效磷的农学-环境综合分级研究

通过调查试验,拟订了浙北土壤有效磷的农学-环境综合分级指标体系。按照不施磷对照处理产量占施磷肥处理产量的相对比例大小和土壤磷素发生明显流失时的土壤磷状况,把土壤有效磷由低至高分为低、较低、中、较高、高和环境危险等6级。其中,水稻生产的土壤有效磷分级标准依次为〈6、6～10、10～15、15～20、20～50和〉50mg·kg-1;蔬菜生产的土壤有效磷分级标准依次为〈10、10～20、20～28、28～40、40～50和〉50mg·kg^-1。提出了不同磷素状况的土壤管理看法：对当土壤有效磷超过15mg·kg^-1的水稻田或有效磷超过28mg·kg^-1的蔬菜地可实施＂减量、隔年施磷＂的施肥方法;当水稻田土壤有效磷超过20mg·kg^-1或蔬菜地土壤有效磷超过40mg·kg^-1时,应实施动态优化施磷方法,即减少磷肥施用量,保持施磷量相当或略高于作物吸磷量即可。在施用有机肥或长期施用一定量化学磷肥的条件下,可以不施用磷肥或少施用磷肥,充分发挥磷肥的后效特性。     

河南省主要粮食作物波动分析

为了减少粮食生产波动给粮食安全带来的不良影响,采用剩余法对改革开放以来河南省主要粮食作物的波动特征进行了分析。结果表明,河南省的粮食总产和三大粮食作物产量在今后一段时间内都将保持增长趋势,粮食产量的增加主要得益于单产的增加,主要粮食作物波动属古典型波动,波动剧烈。河南省粮食总产的波动指数和三大粮食作物产量波动指数的相关性基本相当,说明河南省粮食总产的波动受三大粮食作物的影响基本相等,提出了河南省粮食生产的建议。     

APPLICATION OF CROP YIELD FUNCTIONS IN RESERVOIR OPERATION1

ABSTRACT: A model is developed for real-time operation of an irrigation reservoir with the objective of maximizing the value of multiple crop yields during a growing season. The model employs monthly additive and product forms of crop yield functions for dry matter and grain crops, respectively. The resulting nonlinear optimization model uses a log transform to reduce nonlinearities in the model. An application of the proposed model is compared to a common operating rule used in simulation models. The proposed model results were better in terms of net benefits from crop yields. The model uses GAMS (General Algebraic Modeling System) language. It requires an IBM-compatible microcomputer and is suitable for use by a reservoir manager.     

A framework to assess regional environmental impacts of dedicated energy crop production

Numerous studies have evaluated air quality and greenhouse gas mitigation benefits of biomass energy systems, but the potential environmental impacts associated with large-scale changes in land-use patterns needed to produce energy crops have not been quantified. This paper presents a framework to assess the potential soil, water, and biodiversity impacts that may result from the large-scale production of dedicated energy crops. The framework incorporates producer economic decision models with environmental models to assess changes in land use patterns and to quantify the consequent environmental impacts. Economic and policy issues that will affect decisions to produce energy crops are discussed. The framework is used to evaluate erosion and chemical runoff in two Tennessee regions. The analysis shows that production of dedicated energy crops in place of conventional crops will significantly reduce erosion and chemical runoff.     

GMOs and Global Justice: Applying Global Justice Theory to the Case of Genetically Modified Crops and Food

Proponents of using genetically modified (GM) crops and food in the developing world often claim that it is unjust not to use GMOs (genetically modified organisms) to alleviate hunger and malnutrition in developing countries. In reply, the critics of GMOs claim that while GMOs may be useful as a technological means to increase yields and crop quality, stable and efficient institutions are required in order to provide the benefits from GMO technology. In this debate, the GMO proponents tend to rely on a simple utilitarian type of calculus that highlights the benefits of GMOs to the poor, but that overlooks the complex institutional requirements necessary for GMO production. The critics, recognizing the importance of institutional conditions, focus primarily on the negative impacts of institutional deficiencies, thereby overlooking the basically Rawlsian claim that institutions per se may generate claims to justice. This article investigates how GMOs might generate claims to global justice and what type of justice is involved. The paper argues that the debate on GMOs and global justice can be categorized into three views, i.e., the cosmopolitan, the pluralist, and the sceptic. The cosmopolitan holds that GMOs can and should be used for alleviating global hunger, whereas the sceptic rejects this course of action. I will argue here for a moderately cosmopolitan approach, relying on the pluralist view of institutions and the need to exploit the benefits of GMOs. This argument rests on the premise that global cooperation on GMO production provides the relevant basis for assessing the use of GMOs by the standard of global distributive justice.     

Economics and energetics of organic and conventional farming

The use of organic farming technologies has certain advantages in some situations and for certain crops such as maize; however, with other crops such as vegetables and fruits, yields under organic production may be substantially reduced compared with conventional production. In most cases, the use of organic technologies requires higher labor inputs than conventional technologies. Some major advantages of organic production are the conservation of soil and water resources and the effective recycling of livestock wastes when they are available.     

Cost-effectiveness of tillage methods to reduce phosphorus loss from agricultural land

In this paper, we estimate the cost-effectiveness of tillage methods as a measure to reduce phosphorus loss. The study was based on real-world information on costs. Data on phosphorus loss for different soil tillage methods were modelled. The cost-effectiveness of various soil tillage methods were related to autumn ploughing. The results showed large variation in cost-effectiveness related to erosion risk. Furthermore, spring harrowing was the most cost-effective method to reduce phosphorus loss, followed by autumn harrowing and spring ploughing in spring cereals. Implementation of changed tillage methods showed lower costs for spring cereals compared to winter wheat. The differences in costs between areas were most evident for spring tillage due to differences in yields and agronomic management. Cost-effectiveness is an important criterion in selecting mitigation methods, but due to large variations in the effect of changed tillage, these should be locally adapted to the high risk areas of erosion.     

Flood Risk Reduction from Agricultural Best Management Practices

Best management practices (BMPs) play an important role in improving impaired water quality from conventional row crop agriculture. In addition to reducing nutrient and sediment loads, BMPs such as fertilizer management, reduced tillage, and cover crops could alter the hydrology of agricultural systems and reduce surface water runoff. While attention is devoted to the water quality benefits of BMPs, the potential co‐benefits of flood loss reduction are often overlooked. This study quantifies the effects of selected commonly applied BMPs on expected flood loss to agricultural and urban areas in four Iowa watersheds. The analysis combines a watershed hydrologic model, hydraulic model outputs, and a loss estimation model to determine relationships between hydrologic changes from BMP implementations and annual economic flood loss. The results indicate a modest reduction in peak discharge and economic loss, although loss reduction is substantial when urban centers or other high‐value assets are located downstream in the watershed. Among the BMPs, wetlands, and cover crops reduce losses the most. The research demonstrates that watershed‐scale implementation of agricultural BMPs could provide benefits of flood loss reduction in addition to water quality improvements.     

Commercialization of Perennial GE Crops: Looming Challenges for Regulatory Frameworks

Overall, the deregulation of genetically engineered (GE) crops for commercial cultivation in North America has been a success story. In several cases, however, GE crops have sparked concerns and disagreements among the stakeholders and there are incidences of court lawsuits, including a recent one on glyphosate resistant (GR) alfalfa (Medicago sativa, L.). While GE crops can provide operational benefits to farmers, challenges are looming from commercialization of perennial GE crops. The unique ecology and biology of these crops and GE alfalfa in particular can facilitate adventitious presence (AP) of GE traits and it makes more visible that economic risks for conventional growers and food/feed producers have not been adequately addressed by the GE regulatory system in the United States (US). Asynchronous market approvals and the existence of a number of GE sensitive export markets create uncertainties among the exporters. Policy development in these fields may be helpful for ensuring a broader acceptance and market success of GE agriculture in general. The analysis is focusing on the US, although many diagnosed problems are also relevant to other jurisdictions—in particular if no co-existence policy is in place.     

Human urine as a source of alternative natural fertilizer in agriculture: A flight of fancy or an achievable reality

Organically agricultural products are gaining popularities through out the world as it gives the consumer satisfaction with a basket of safer and better trusted foods. It is also well established that intensive conventional agricultural practices can introduce contaminants into the food chain with adverse affect on environment. However, organic agricultural practices give an alternative environmental friendly sustainable agriculture among the farmers. Beside this fact, organic crops contain fewer nitrates, nitrites, pesticide residues and trace elements than conventional crops. Even though, in organic systems generally have 20% lower yields than conventionally produced crops. One of the major constrains of organic farming is decrease of raw organic matters to prepare compost. Therefore, scientists are looking forward for different organic sources which are plenty in nature and available at little-to-no cost. Human urine is one of them, and has been gaining popularities as a raw material for organic cultivation. However, several important merits and demerits of application of human urine are needed to be addressed in agriculture.     

Forests and competing land uses in Kenya

Indigenous forests in Kenya, as in other developing countries, are under heavy pressure from competing agricultural land uses and from unsustainable cutting. The problem in Kenya is compounded by high population growth rates and an agriculturally based economy, which, even with efforts to control birth rates and industrialize, will persist into the next century. Both ecological and economic consequences of these pressures need to be considered in land-use decision making for land and forest management to be effective. This paper presents one way to combine ecological and economic considerations. The status of principal forest areas in Kenya is summarized and competing land uses compared on the basis of ecological functions and economic analysis. Replacement uses do not match the ecological functions of forest, although established stands of tree crops (forest plantations, fuel wood, tea) can have roughly comparable effects on soil and water resources. Indigenous forests have high, although difficult to estimate, economic benefits from tourism and protection of downstream agricultural productivity. Economic returns from competing land uses range widely, with tea having the highest and fuel wood plantations having returns comparable to some annual crops and dairying. Consideration of ecological and economic factors together suggests some trade-offs for improving land allocation decisions and several management opportunities for increasing benefits or reducing costs from particular land uses. The evaluation also suggests a general strategy for forest land management in Kenya.The views and interpretations expressed in this article are those of the authors and should not be attributed to the World Bank, its affiliated organizations, or any individual acting on their behalf.