Changing land use to alternative crops: A rural landholder’s perspective

Alternative crops, combined with modern farming methods, are integral parts of the new agricultural model and dominant priorities of agricultural policy. The new conditions created in the internal and global markets of agricultural products indicate significant opportunities for growing alternative crops and for the introduction of modern farming practices and processing. The present study aims to assess the factors that determine the landholder’s decision to uptake an alternative crop. Primary data were gathered through a quantative survey (in-depth interviews) with landholders in two remote and less-favored prefectures of Northeastern Greece, and were analysed through a logistic regression model. The results indicate that the most significant determinants for adopting an alternative crop involve the scientific support to farmers, the development of product demand in the market, the creation of agricultural cooperatives, the development of promotional campaigns for the alternative products, the education and knowledge regarding alternative crops, and the landholder’s satisfaction with income. On the contrary, negative factors to their decision refer to exports development, product subsidies, landholder’s age, membership to a cooperative in its current form, and satisfaction with pesticides prices. Despite the dominance of conventional agriculture models and varieties, the new favorable investment conditions can spur the promotion of alternative crops.     

重庆市地表起伏度及其对农业生产的影响分析

重庆地貌复杂多样,地表起伏度大,通过对重庆各区县地表起伏度研究和计算,可定量了解重庆山水起伏骨架指数。以空间分辨率为30m、投影为WGS84_UTM的ASTER GDEM V2全球数字高程数据为基础,在ArcGIS10.1中利用投影面积比法计算重庆各区县地表起伏度指数,在此基础上分析了地表起伏度与2008~2013年各区县农业生产指标之间的相关性并建立系列模型。结果表明:1重庆西部较为平整,地表起伏度比中、东部地区低,地表起伏度最大的是东北部的城口、巫溪、巫山,最平整的是西部的荣昌、潼南、大足。2基于重庆市31个县域的统计分析,地表起伏度标准化指数每增加0.1,粮食单产减少约0.37t/hm~2,农林水支出占财政支出比例增加约1.1%。3地表起伏度对耕播面积比例影响力最大,其可决系数R~2达到0.8859。4农业产出不变时,农业投入随地表起伏度的增加而增加,地表起伏度与综合指标(农业产出投入比)所建指数模型的可决系数R~2为0.8296。     

The seed and agricultural biotechnology industries in India: An analysis of industry structure,competition, and policy options

Since the late 1980s, technological advances and policy reforms have created new opportunities for private-sector investment in India’s seed and agricultural biotechnology industries. These changes have had a significant impact on cotton yields and output in India, but less so for rice and wheat—the country’s main cereal staples—for which yield growth rates are tending toward stagnation. This analysis examines the structures of these industries, their potential effects on competition and innovation, and the policies that may improve both industry performance and the delivery of new productivity-enhancing technologies to India’s cereal production systems. Our findings suggest that more substantive policy reforms are needed to encourage further innovation, reduce regulatory uncertainty, and encourage firm- and industry-level growth, while continued public spending on agricultural research is needed to support technological change.     

Factors influencing adoption of genetically modified crops in Africa

The debate around genetically modified (GM) crops in Africa continues to grow especially among policy-makers, food manufacturers, farmer organisation and consumer advocacy groups and the general public. While other regions have taken a firm position on biotech crops, Africa remains largely ambivalent, with wide variation in GM policy across countries. The central objective of this paper is to analyse the factors that influence the adoption of GM crops in Africa. First we evaluate the current status of GM crop adoption in Africa. Second we identify the key enablers and hindrances to adoption of GM crops. The main factors include ministerial control of biosafety, peer country influence, stage of seed sector development, advocacy by key political figures, the media, activism, food security and technical capacity. We posit that, for most African countries, GM policy is guided by political rather than technological considerations with media and special interest groups playing a key role. Despite the numerous impediments, slow progress is being made in preparing the requisite enabling environment for biotechnology adoption in Africa.     

明清以来美洲作物的引种推广对经济社会发展的影响——以山东为例(1368-1949)

由于美洲作物具有耐旱、耐瘠薄、高产等特性决定其在中国北方旱作区得以大面积的快速推广。花生、烟草和棉花具有极高的商业价值，对我国传统的自然经济形成强大的冲击；甘薯、玉米和马铃薯等高产作物使得粮食单位面积产量和总产大幅度提高，引起饮食结构的巨大变化。在农业生产工具进步不大，农药、化肥没有出现的明清时期，美洲作物的引种推广是当时最为重要的科学技术手段，也是明清时期农业发展，人口迅速增加的主要原因。美洲作物的引种推广是明清时期生产力水平提高的标志，大土地所有者减少。小土地所有者增加，土地出现分散状态是其必然结果。     

美国作物品种改良技术在近代中国的引进与利用--以金陵大学农学院、中央大学农学院为中心的研究

近代以来，伴随着农业的资本主义化，美国农业出现了两次技术革命。由于农业革命而产生的先进的作物改良技术对近代中国的农业产生了极为深远的影响。作为中国最早成立农科以及第一所在华注册的美国教会大学的金陵大学和当时的全国教育重镇中央大学在近代中关两国的农业科技交流与合作中处于极其重要的地位。本文即以两校农学院为中心探讨美国的农作物改良技术在近代中国的引进和利用。     

我国转基因作物的发展现状及安全管理

转基因作物是当今世界各国现代生物技术产业研究的热点，中国的转基因生物技术发展迅速，由于科学界对转基因作物对人类及生态环境利与弊的争论，政府应制定相应的政策、措施对其进行安全管理。本文论述了转基因作物在国际国内的发展现状，分析了转基因作物对人类及生态环境的利与弊以及关于我国转基因作物安全管理的几点思考。     

农作物空间格局动态变化模拟模型(CROPS)构建

农作物空间格局指特定区域内农作物种植结构、空间分布等信息,是农业土地系统的核心内容之一,也是农业结构调整的重要依据。随着空间模拟技术的发展,农业土地系统的时空动态表达成为可能,但传统模型方法更多关注土地利用类型的转化,而忽视耕地内部农作物格局时空特征的表达。该研究基于CLUE-S土地利用变化模拟模型,进行了概念模型设计、框架和模块重建、参数本底化和校正,研究并提出一个适用于我国农作物空间格局动态变化模拟模型（CROPS,Crop Pattern Simulator）的可行架构,使其能够实现区域尺度土地利用变化与农作物空间格局变化的双层动态模拟。CROPS模型采用了两层次嵌套模拟的模型结构,第一个层次实现对耕地空间格局动态变化过程和状态的表达,第二层次基于第一层次的模拟输出的耕地空间格局,实现耕地内部的农作物空间格局动态变化的有效模拟。CROPS模型主要包括非空间和空间两个大模块,空间模块又包括空间模块I和空间模块II。CROPS模型在东北三省进行了区域应用,结果表明,模型总体模拟效果较好,能够科学合理的表达耕地空间格局和农作物空间格局的动态变化过程。     

基于多时相HJ卫星的渭干河-库车河绿洲主要农作物种植信息提取

在3S技术的支持下全面、快速、客观地监测农作物种植信息,对于正确的把握该区域的农业结构和布局,进行作物种植空间格局的调整和优化有着十分重要的意义.本文以渭干河-库车河洲绿洲为研究区,根据农作物的物候规律和季相节律的差异性特点,选取2012年的3景不同时相的HJ卫星CCD遥感数据,ENVI下基于CART算法的决策树规则自动提取主要农作物覆盖信息,然后以野外GPS调查点为依据,对决策树方法预分类结果进行修正,成功提取了研究区的玉米、棉花和小麦的种植面积,总体精度达到了91.73％.结果表明HJ卫星CCD影像可以很好地应用于农作物提取,而且CART算法的分类精度较高,能较好地反映作物的分布状况,可为该地区主要作物种植结构调整提供一定的依据.