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。     

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。     

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.     

How would compliance with dietary recommendations affect revenues for agricultural producers?

Nutritionists and other health experts have recommended a range of dietary plans, and these often differ significantly. Although the USDA food guides have been the most visible in the United States, other dietary plans now are achieving greater public recognition. Our analysis extracts the nutrient recommendations for seven dietary plans and models the recommendations as shifts in demand for the nutrients. Demand shifts for nutrients are combined with nutrient composition shares to simulate the revenue implications in selected agricultural markets. Based on current consumption patterns in the United States, we find that compliance with Harvard’s Healthy Eating Pyramid would generate the greatest revenue gains for specialty crop producers in California.