整建制全要素全链条农业面源污染综合防治的思考及实践

加强农业面源污染综合防治是加快推进中国农业发展全面绿色转型,实现乡村全面振兴的重要任务。近年来,在多方的共同努力下,中国生态环境改善取得了一定成效,但重点流域的农业面源污染问题仍然突出。该研究在分析中国农业面源污染现状的基础上,通过资料收集、现场调研、专家座谈等多种方式梳理和分析了农业面源污染综合防治在治理主体、投入要素、技术体系与产业链条方面的瓶颈,解析了整建制全要素全链条农业面源污染综合防治的内涵,阐述了国家农业绿色发展先行区浙江平湖在践行整建制全要素全链条农业面源污染综合防治方面的先进做法及应用效果。总结了典型案例在网格化健全污染综合防治“整建制”、特色化延伸综合防治“全链条”、以及全方位保障污染综合防治“全要素”三个方面开展的相关工作,以期为探索形成农业面源污染综合防治整体解决方案,示范带动农业发展全面绿色转型提供支撑。     

离心式高速玉米精量排种器T形槽型孔设计与试验

针对离心式高速玉米精量排种器双粒种子并排填充导致重播严重的问题,该研究提出利用型孔槽对称凸台结构降低玉米种子并排填充概率的方法,设计了一种T形槽型孔。通过构建充种阶段玉米种子的力学模型,并结合玉米种子的形状特征确定了T形槽型孔基本结构参数。借助EDEM离散元仿真软件,以型孔槽前端长度、型孔槽后端面倾斜角以及型孔槽底部倾斜角为因素,以合格指数、重播指数与漏播指数为评价指标,设计二次正交旋转回归组合仿真试验。仿真试验结果表明：在作业速度18 km/h条件下,型孔槽前端长度为9.31 mm,型孔槽后端面倾斜角为43.37°与型孔槽底部倾斜角为70.5°时,排种质量最优,排种合格指数、重播指数与漏播指数分别为94.03%、1.72%与4.25%。台架验证试验结果表明：作业速度18 km/h时,T形槽型孔的合格指数为94.54%,与仿真试验结果的相对误差为0.54%,仿真优化试验结果可靠;作业速度为15 km/h时,排种器作业性能最佳,合格指数为95.16%,重播指数为1.42%,漏播指数为3.42%,满足高速精量播种要求;作业速度范围在12 ～ 21 km/h内时,T形槽型孔相较于矩形槽型孔的合格指数提升2.1个百分点以上,重播指数降低2.1个百分点以上,相较于蹄形槽型孔的合格指数提升1.4个百分点以上,重播指数降低2.1个百分点以上。该研究可为离心式高速玉米精量排种器优化提供参考。     

Spatial distribution of weeds in arable crops: are current sampling and analytical methods appropriate?

This paper reviews the literature concerning the spatial distribution of weeds; highlighting the limitations of our current sampling and analytical methodologies, and suggesting how these inadequacies can be addressed. Most research studies have used discrete sampling, i.e. weeds are counted within a quadrat, on a grid basis. Few have mapped weeds at a whole-field scale, either with a resolution appropriate to spraying operations or key ecological processes. Statistical analyses used to describe the data can be divided into two main types, spatially implicit (also at the scale of the sampling unit) or spatially explicit, in which the location of individuals is included in the analyses. Spatially implicit methods can be strongly affected by quadrat size and mean density and are of doubtful benefit. More attention is required to address sampling resolution issues for spatially explicit methods. Our understanding of the formation and dynamics of spatial pattern, as well as predicting the consequences of site-specific management, can be improved with models. Unfortunately, most models consider only newly expanding patches and appear incapable of predicting spatial distributions when an area has been fully invaded. More detailed biological information is required if models are to become more realistic and informative. We also need to ensure that we understand the spatial processes in the context of the whole field environment, to optimize the success of site-specific weed management in the longer term.     

Adoption of improved fallow technology for soil fertility management in Zambia: Empirical studies and emerging issues

In the subsistence-agricultural region of eastern Zambia, less than 10% of the households have adequate supply of maize (Zea mays L.), the staple food, throughout the year. A major constraint to increasing crop production in the region is poor fertility status of the soil. In order to address this problem, improved fallow has been introduced as a technology for improving soil fertility within a short span of two to three years. Farmers have been testing the technology and a number of empirical studies have been undertaken over the years to identify the factors influencing farmers' decision to adopt the technology. This paper presents a synthesis of the results of adoption studies and highlights generic issues on the adoption of improved fallows in Zambia. The synthesis indicates that farmers' decision on technology adoption does not have a simple directed relationship of some technological characteristics only, but constitutes a matrix of factors including household characteristics, community level factors, socioeconomic constraints and incentives that farmers face, access to information, local institutional arrangements and macro policies on agriculture. The adoption of improved fallows is not strictly speaking a binary choice problem but a continuous process in which farmers occupy a position along a continuum in the adoption path. Further, adoption of improved fallows may not take place in a policy vacuum but needs to be facilitated by appropriate and conducive policy and institutional incentives. Several questions and issues that require further study emerge from the synthesis. These include determination of the relative importance of the factors in the adoption matrix, identification of the conditions under which farmers use a combination of inputs and their profitability under changing price scenarios, exact definition to delineate between `non-adopters', `testers' and `adopters' of agroforestry technologies, and understanding the impact of cash crop farming in farmers' adoption decisions of improved fallows (where off farm opportunities exist). Further, there is a need to determine the inter-relationship between household poverty, labor availability and the adoption of improved fallows and, to evaluate a combination of policy interventions at both national and local level to promote the adoption of agroforestry-based soil fertility management. This revised version was published online in June 2006 with corrections to the Cover Date.     

农村秸秆产量的测算与影响因素分析——基于构建低碳农业经济的视角

在阐述我国秸秆的产量状况及利用发展趋势的基础上,选取秸秆产量、耕种面积、化肥用量、有效灌溉面积4个指标,依据1991～2008年《中国统计年鉴》相关数据,利用线性回归模型测算了我国农村秸秆产量,剖析了影响秸秆产量的因素,指出化肥的使用量是影响秸秆产量的重要因素。在此基础上,从低碳农业经济的角度,从改善化肥依赖性、开发秸秆再利用技术、积极推行秸秆气化技术以及提高农民低碳意识4个方面提出了秸秆综合利用的建议,以期能为决策者提供理论参考。     

决策树在精准农业中的应用现状与发展趋势

决策树算法是一种重要的分类方法,是数据挖掘领域研究热点之一.现介绍了决策树算法当前的研究状况.从土壤质量等级划分、自然灾害分析、遥感影像分类及耕地质量分析等方面介绍决策树算法在精准农业中的应用现状,对决策树算法在精准农业中的应用前景进行了展望.     

日光温室环境控制系统应用推广探析

结合农业物联网技术在北京市日光温室智能控制的推广工作,介绍与椰糠基质栽培高品质番茄生产相结合的日光温室环境智能集成控制技术体系,包括软件集成和硬件配置,并提出了农业物联网技术推广中存在的问题和建议,希望为日光温室环境控制系统的应用推广提供参考模式。      

基于生态学技术的农牧混合管理应用研究

为进一步促进我国农牧业的发展,提高农牧种养的综合效率,针对农牧混合管理应用展开了研究。在单一农作物种植的基础上,基于生态学的规律与特性,建立相应的生态学模型,融入物联网、无线通信等智能管控技术,形成功能完整、布局合理、实用科学的农牧混合管理系统。展开该理念下的应用试验,结果表明:以生态学技术为平台理念,较单一培养模式而言,农牧混合管理系统下的综合培养效率可提高至90%以上,作物生长良好率和畜牧产率均提升5%以上,系统运行平稳高效,可为促进生态农业的循环发展提供一定的思路。     

农业及生物类网络免费电子书对农业院校图书馆产生的影响及图书馆应采取的对策

详细分析了目前网络免费农业及生物类电子书在数量、分布、出版、利用方面的特点。及其对农业院校图书馆在资源理念、资源建设和馆员素质方面产生的积极影响及农业院校图书馆应采取的对策     

江苏外向农业发展的现状及对策

外向农业是现代农业的重要内涵,发展外向农业是江苏实现农业现代化的重要突破口.入世以来,江苏省委、省政府高度重视外向农业的发展,先后出台了加快发展外向型农业的政策和措施,并采取一系列步骤加以推进,确保江苏省外向农业取得较快发展,并逐步跃进全国先进行列,农业国际竞争力得到日益提升.然而,如何在建设现代农业中更好地发挥外向农业的作用,这是每一个外向农业工作者必须思考的课题.本文分析了江苏农业利用外资、农产品出口、农业对外经济技术合作以及农业对外交流等现状,研究了近5年江苏外向农业发展较快的内外因素,比较了江苏省与发达国家或地区以及山东、广东和浙江等省的差距及其原因,并就发展中存在的主要问题提出了对策建议.