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作物根系研究室的设计 总被引:3,自引:0,他引:3
根据作物根系研究的需要,设计和建造了华南农业大学作物根系研究室。为此,从根室的采光、通风、保温等几方面阐述了作物根室的设计思想,并结合科学家对根系的研究特性,着重介绍了两种种植槽的结构及设计特点。 相似文献
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夏季填闲作物及秸秆还田对日光温室黄瓜连作土壤养分和微生物的影响 总被引:4,自引:2,他引:2
选用已进行4 a温室夏季种植甜玉米、菜豆及其秸秆还田试验的温室黄瓜连作土壤,于2009年继续进行相同的处理,研究了温室夏季填闲作物及秸杆还田对黄瓜连作土壤养分和微生物代谢功能的影响。结果表明,种植甜玉米秸秆还田处理能减小土壤容重,改善土壤通透性。夏季填闲及秸秆还田处理对土壤养分和微生物的影响在秋冬茬表现较明显,能增加土壤中有效磷含量,种植菜豆处理(秸秆还田和不还田)能增加土壤有效钾含量。填闲作物及秸秆还田处理还能提高土壤微生物代谢活性,改变土壤微生物对单一碳源的利用能力。 相似文献
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根据南方经济林生产现状,分析了南方经济林生产与管理中存在的问题,结合国内外市场对经济林产品需求,提出了保障南方经济林健康,稳定,持续发展的经营管理策略。 相似文献
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我国农作物秸秆人造板技术与产业化问题探讨 总被引:1,自引:0,他引:1
就农作物秸秆人造板技术与产业化问题,从国内外发展现状入手,分析了在产业化过程中亟待解决的难点问题,提出了加速农作物秸秆人造板技术与产业化的改革建议。认为应当实事求是地面对开发秸秆人造板的有利和不利条件,脚踏实地解决好技术、市场和应用环境等问题。 相似文献
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Farmers in the North Central region of the United States often are reluctant to use shelterbelts because of inadequate information clearly showing their benefits. We developed a computer model, called SBELTS for ShelterBELT and Soybeans, that simulates the influence of a shelterbelt on soybean (Glycine max L.) production across an agricultural field in the midwestern United States. Objectives of this study were to 1) describe the structure of SBELTS, 2) present model simulations, and 3) discuss model limitations. SBELTS is composed of three submodels. The first submodel produces characteristics of a shelterbelt that are passed to the second submodel that estimates daily windrun at user-specified distances leeward (away from the prevailing wind) of the shelterbelt. Estimated daily windruns are merged with other microclimatic information to produce weather files for each specified distance. Finally, the third submodel uses a soybean growth/yield model to estimate soybean yield at specified distances, and the yields are averaged. Data collection was not a part of the present project, so SBELTS was evaluated by comparing predicted results with published information. SBELTS was used to predict soybean yield across a field leeward of a 7.6 m tall shelterbelt, and the predicted yield curve compared well with published yield curves. The sensitivity of SBELTS to variation in rainfall was evaluated by predicting yields for 3.8 m tall and 7.6 m tall shelterbelts in wet, normal, and dry years. Results showed no shelterbelt influence in wet years, some influence in normal years, and a sizable influence in dry years. Results showed that the 7.6 m shelterbelt had more influence than the 3.8 m shelterbelt. Although SBELTS has limited use, it is the first step in the development of more advanced models that will be able to simulate production of soybeans and other crops under the influence of shelterbelts on a variety of soil types.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
90.
Development and ecology of bottomland hardwood sites 总被引:3,自引:0,他引:3
John D. Hodges 《Forest Ecology and Management》1997,90(2-3):117-125
A basic knowledge of the origin, development, and ecology of bottomland hardwood sites is important for assessing harvesting impacts on those sites. This paper presents an overview of the geologic origin and development of hardwood sites, species-site relationships and the natural patterns of ecological succession on those sites, and the implications of that information for forest management. Bottomland hardwoods occur on floodplain sites primarily in the Atlantic and Gulf Coastal Plains. Past geologic events led to the formation of broad stream valleys in those areas because of the erodible, sedimentary geologic materials. Natural patterns of ecological succession on floodplain sites are influenced by autogenic and allogenic processes in that the sites may undergo constant change because of deposition. Three natural patterns of succession are recognized for floodplain sites of major river bottoms—those occurring on permanently flooded sites, those on low elevation wet sites, and those on higher elevation, better drained sites. Floristic composition and successional patterns are strongly influenced by the hydrologic events on the sites and particularly by rates and types of deposition. 相似文献