Labour Control in the Tobacco Agro‐spaces: Migrant Agricultural Workers in South‐Western Ontario

International labour migration programs provide a vulnerable workforce that services various sectors in developed economies. The agriculture sector is one arena in which the employment of migrant workers has become more pervasive. Annually, approximately 30,000 workers are employed in the Canadian agriculture sector through the Seasonal Agricultural Workers Program (SAWP). In this paper, I focus on the SAWP workers in tobacco farming, and investigate the ways that labour control is achieved on two small‐scale farms. I draw upon original empirical evidence from interviews with three Mexican and nine Jamaican workers, two union representatives, and two farm owners in South‐Western Ontario, Canada. My findings show that various factors at multiple scales shape the labour control regime and significantly advantage farm owners over workers. Based on my findings, I argue that the labour control regime is conditioned exogenously by multi‐scalar factors and generated endogenously at the point of production.     

Re-evaluating the history of the wheat domestication gene NAM-B1 using historical plant material

The development of agriculture is closely associated with the domestication of wheat, one of the earliest crop species. During domestication key genes underlying traits important to Neolithic agriculture were targeted by selection. One gene believed to be such a domestication gene is NAM-B1, affecting both nutritional quality and yield but with opposite effects. A null mutation, first arisen in emmer wheat, decreases the nutritional quality but delays maturity and increases grain size; previously the ancestral allele was believed lost during the domestication of durum and bread wheat by indirect selection for larger grain. By genotyping 63 historical seed samples originating from the 1862 International Exhibition in London, we found that the ancestral allele was present in two spelt wheat and two bread wheat cultivars widely cultivated at the time. This suggests that fixation of the mutated allele of NAM-B1 in bread wheat, if at all, occurred during modern crop improvement rather than during domestication. We also discuss the value of using archaeological and historical plant material to further the understanding of the development of agriculture.     

韩国经济地理学研究现状和趋势

至今在我国国内,有关评介韩国地理学研究状况的文章甚少。虽然韩国地理学研究历史较短,但有些领域的研究已走到了我们的前面。本文将系统地介绍韩国农业地理学、工业地理学、商业流通地理学、交通地理学的研究状况,并指出目前在经济地理学研究中所存在的一些问题和今后的发展趋势。     

新形势下青海省农牧区改革发展的态势分析

积极推进农牧区改革发展,是全面建设小康社会和实现现代化的重大战略任务。本文围绕总体目标任务,应用态势分析方法,对新形势下青海省农牧区改革发展的内部条件和外部环境进行分析,提出了促进青海农牧区改革发展的策略。     

贵州省农艺作物的品种改良与农业发展（1938-1949）

受抗战大后方垦殖督导活动带动,以粮食、纤维、油料等农作物和经济作物品种改良、各级农技培养与服务体系建设为主的贵州省农业技术推广运动,在1938年前后开始得到积极实施,掀起了黔省自清代中期移民开发以来的农业发展又一高潮。尽管新一轮的农业开发历时较短,但当时贵州省稻、麦等农业作物和棉花、桐油等经济作物品种得到较大规模的改良、引进及推广,在20世纪40年代中期显现出良好经济效益,同时也对地区社会和生态等产生了深刻影响。本文就此做出梳理,并进一步分析和探讨此轮物种变化带来的贵州地区农业经济和生态区域变化及其特征。     

Stratigraphy and geochronology of La Playa archaeological site,Sonora, Mexico

La Playa archaeological site in northern Sonora, Mexico contains a long record of human activity that includes the Paleoindian period (terminal Pleistocene) and much of the Holocene. The size and complexity of La Playa has discouraged a systematic characterization of its stratigraphy and geochronology, a deficiency we redress in the study. We distinguished seven stratigraphic units ranging in age from >44,570 to 400 cal yr B.P. using ¹⁴C dates from charcoal and terrestrial gastropods found mostly in archaeological features. All of the buried (in situ) cultural remains are contained in Units B (4690–1580 cal yr B.P.) and C (1010–400 cal yr B.P.) and represent overbank deposition from the nearby Rio Boquillas. Occupation at the site peaks in Units B₄ and B₅, corresponding to the Cienega phase (2800–1800 cal yr B.P.) of the Early Agricultural period. This period coincides with the growth of early agricultural villages in the region and is marked at La Playa by thousands of archaeological features including roasting pits, human burials, and extensive canal irrigation systems. The presence of semi-aquatic and aquatic snails demonstrates that water was present year round in the canal systems constructed during this period. Stable and radiometric isotopic evidence suggests that early agriculturalists diverted ground water over several kilometers from the nearby Rio Boquillas. The extensive Cienega phase occupation ended after about 1700 cal yr B.P. with deep erosion of the site, an event also visible in alluvial records in southern Arizona that marked the end of the Early Agricultural period and significant changes in settlement organization in the region.     

Latitudinal variation in a photoperiod response gene in European barley: insight into the dynamics of agricultural spread from ‘historic’ specimens

Between ca. 6000 BC and ca. 500 BC, barley cultivation spread across the continent of Europe from the extreme south to the extreme north. Carbon-dating would suggest that this spread, and indeed the spread of crop cultivation generally, varied in its pace, with ‘delays’ at certain points along its route. Such delays in the spread of agriculture have been explained as resulting from the slow assimilation of agricultural practices by existing indigenous human populations or as the time taken for the crops to adapt to novel climatic conditions, such as altered temperature regimes and day-lengths. A mutant form of the photoperiod response gene, Ppd-H1, causes barley to be non-responsive to long days, while the wild-type responsive form allows plants to flower in response to long days. We sequenced this gene in 65 ‘historic’ barley accessions, from the late 19th and early 20th centuries, in order to explore the potential role of environmental adaptation in the spread of agriculture. We chose to use ‘historic’ material, to complement the richer patterns in extant genetic lines, by spreading the data range in both time and space. Our ‘historic’ barley data shows a latitudinal divide in the Ppd-H1 gene similar to that found in extant lines, but with clearer geographical resolution, and extending northwards into the Arctic Circle. We discuss the implications of our results in relation to the dynamics of agricultural spread across Europe.     

清代陕西的农业开发与生态环境的破坏

清代陕西地区,在人口日益增长的压力之下,由于不顾后果的过度垦殖,森林、草原等天然植被遭到严重破坏,水土流失严重,并进而导致了干旱和水涝等自然灾害的日益频繁,耕地面积也随之减少。所以,尽管有广大农民的勤奋开发,农业生产也曾一度繁荣,但由于违反了自然规律,终难逃脱衰落的命运。     

对推行农业循环经济问题的探讨

农业循环经济的主要内容是发展生态农业。生态农业我国古已有之,如珠江三角洲的“桑基鱼塘”,是农业人工生态系统,在解放前就已出现。实现农业现代化,要把生态农业规模扩大。当前要推行生态农业村、生态农业户,这是切实可行的措施,有现实性和可操作性。     

发达国家的农业现代化对我国农业发展的启示

本文系统地分析了发达国家农业现代化的特点,从发达国家农业现代化与我国农业生产现状的结合点上,探讨了今后我国农业发展的途径与策略。