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李世成 《农业机械化与电气化》2007,(2):33-34
保护性耕作技术是对农田实行免耕、少耕,尽可能减少土壤耕作,并用作物秸秆、残茬覆盖地表,保护土壤,减少水土风失、水蚀,提高土壤肥力和抗旱能力的一项先进农业耕作技术,在美国、澳大利亚等国家已大面积应用。近年来,我国把保护性耕作列为农业可持续发展和保护生态环境的重大项目来抓,并在河 相似文献
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机械化深松在保护性耕作中的作用及效益浅析 总被引：1，自引：0，他引：1
结合山西省潞城市机械化保护性耕作技术的实践，论述了深松技术的操作方法、技术原理、作业要求。阐述了深松技术是替代传统耕作方式的一种新型土壤耕作技术。 相似文献
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保护性耕作技术是对农田实行免耕、少耕，尽可能减少土壤耕作，并保证播种后地表用不低于30％的作物秸秆、残茬粉碎覆盖，或保留高留茬秸秆30％以上及作物残留物覆盖率不低于30％的耕作技术。它可减少土壤风蚀、水蚀，减少土壤流失和抑制农田扬尘，提高土壤肥力和抗旱能力； 相似文献
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国外逾半个世纪的应用证明，保护性耕作是当今世界上普遍采用的一项旱地农业耕作技术。我国的实践也证明，保护性耕作相对于传统精耕细作农艺，可以减少风蚀、水蚀、提高土壤蓄水保墒能力、增加土壤有机质、培肥地力、降低农业生产成本、增加农机收入。 相似文献
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保护性耕作实践中存在的问题 总被引：1，自引：0，他引：1
近年来，各地实践证明，推广保护性耕作可减少土壤耕作，能有效保护农田、改善生态环境、促进农业可持续发展。但在保护性耕作技术越来越被重视的今天，各地推广实践中尚存在诸多问题，需要认真对待。 相似文献
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保护性耕作技术是对农田实行免耕、少耕,尽可能减少土壤耕作．并保证播种后地表不低于30％的作物秸秆、残茬粉碎覆盖,或保留高留茬秸秆30％以上及作物残留物覆盖率不低于30％的耕作技术。它可减少土壤风蚀、水蚀,减少土壤流失和抑制农田扬尘,提高土壤肥力和抗旱能力;能明显提高旱区粮食产量、降低农业生产成本、改善生态环境、促进农业可持续发展等。 相似文献
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1.农机农艺结合是实施保护性耕作的客观要求
保护性耕作是在满足农艺要求条件下,不翻耕土壤,尽可能减少土壤耕作,用作物残茬覆盖地表,利用非翻耕方法控制杂草和病虫害的一种农业耕作技术。由于它有利于保水保土，所以称为保护性耕作。 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性，认为在缺水不可避免的情况下，对供水进行优化调度可以减小缺水带来的损失，产生较好的减灾效益，特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性，提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献