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51.
日本设施栽培土壤热水消毒技术的发展现状 总被引:5,自引:0,他引:5
简要说明了土壤物理消毒技术的基本方法和原理,着重介绍了日本土壤热水消毒法的发展过程,土壤热水消毒的主要设备、基本作业步骤、土壤热水消毒的功效。 相似文献
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依据大量的实测试验资料,论证了土壤水分对小麦、玉米、棉花生长发育的影响及不同土壤水分与作物产量的关系,分析确定了三种作物高产的适宜土壤水分上、下限指标,为实现高产及节水灌溉提供了依据。 相似文献
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如何认识、正确处理野生动物的保护与利用之间的关系是极为重要的。与中国传统医药发展息息相关的黑熊养殖业,在中国已经存在20多年了。目前已完成了自野外捕获向自我繁殖以维持种群发展的关键转折,实现了养殖技术的升级、取胆技术的革新、养殖规模呈现集约化发展趋势。本文概述了中国野生黑熊分布和种群数量,为保护黑熊所采取的各种措施和成效,以及黑熊养殖业的历史和发展现状。介绍了国内与黑熊保护和驯养有关的法律和政策,在此基础上,详细分析了野生黑熊保护与黑熊养殖业的关系,揭示二者间即保护与可持续利用的内在关联,并对黑熊养殖业涉及的问题进行了解析。以化解黑熊保护与利用之间的矛盾,引导黑熊养殖业迈向健康发展之路。 相似文献
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连续两年在慈利县研究了不同耕作方式(翻耕和免耕)和不同油菜秸秆覆盖量(全量、半量、0)对三北2号玉米产量和主要农艺性状的影响,以评价和筛选适合当地的耕作模式。结果表明,与免耕处理相比,翻耕各处理玉米平均产量增加了2.36%~9.11%,且在高温干旱年份(2013年)比雨水较多年份(2014年)增幅大。玉米单产均是秸秆全量覆盖处理半量覆盖处理不覆盖处理。翻耕+秸秆全量覆盖在连续两年的试验中产量均为最高,可在慈利县推广。 相似文献
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Large‐scale inoculation with arbuscular mycorrhizal fungi (AMF) is generally impractical in most regions and we have little understanding of the factors that determine inoculation success. Nevertheless, the ability to take full advantage of indigenous AMF for sustainable production needs to be developed within cropping systems. We used part of a long‐term field experiment to understand the influence of tillage and the preceding crop on AMF colonization over the growing season. Arbuscular mycorrhiza colonization rate was more affected by treatment (tillage or the combination of crop and preceding crop) than by the total number of AMF spores in the soil. Conventional tillage (CT) had a statistically significant negative effect (P ≤ 0.05) on spore numbers isolated from the soil, but only in the first year of study. However, the AMF colonization rate was significantly reduced by CT, and the roots of wheat, Triticum aestivum, L, cv. Coa after sunflower, Helianthus annuus L., were less well colonized than were those of triticale, X Triticosecale Wittmack, cv. Alter after wheat, but the affect of tillage was more pronounced than was the effect of crop combination. Under no‐till there was a significant increase in AMF colonization rate throughout the sampling period in both wheat and triticale, indicating that the extraradical mycelium previously produced acted as a source of inoculum. In general, triticale showed greater AMF colonization than wheat, despite the preceding crop being less mycotrophic. Under these experimental conditions, typical of Mediterranean agricultural systems, AMF colonization responded more strongly to tillage practices than to the combination of crop and preceding crop. 相似文献
58.
《Scandinavian Journal of Forest Research》2012,27(4):445-454
In Finland, Norway and Sweden forest management is presently changing towards a more nature-orientated management. In this study the European Forest Information SCENario (EFISCEN) model was applied to determine how this change might affect the potential for wood production in the three countries. Three different management regimes, traditional, traditional with nature conservation (''conservation''), and longer rotations with nature conservation (''conservation +''), were combined with two alternative felling levels. The results show that conserving 6.1-8.8% of the older forests in the southern regions had no limiting effects on production levels, as foreseen by the European Timber Trend Studies V by the UN-ECE for Finland and Sweden. Under the conservation + scenario, maximum sustainable felling levels decreased to 84, 79 and 72% of the present levels in Finland, Norway and Sweden, respectively. Increasing the rotation length put more pressure on the older age classes and thus did not increase the average age of the forest. If the consumption of wood increases as quickly as indicated by other studies, it will be hard to fulfil that demand and at the same time conserve considerable areas of forest in the southern regions of the countries. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(12):1415-1421
Reduced tillage and no-tillage systems provide shallow incorporation of surface applied materials at best. Due to concern of over-liming the surface of agricultural soils, producers either reduce lime rates (and apply more often) or perform some sort of soil inversion to mix the lime deeper into the soil profile. The objective of the authors in this field study was to evaluate the effects of tillage, lime rate, and time of limestone application on corn and soybean growth, and assess the changes in soil acidity to an already acidic soil. Treatments consisted of a no lime check, two no-tillage systems with either a 4.5 ton ha?1 lime application every two years or an annual application of 450 kg pelleted lime ha?1, a continuous annual chisel tillage system with a 9.0 ton ha?1 lime application every four years, and two inversion systems utilizing a rotary tiller (Howard Rotovator) where 9.0 ton lime ha?1 was mixed into the soil followed by either continuous chisel tillage or continuous no-tillage. Inversions occurred in 1999, 2003, and 2007. Soil samples were collected annually in increments of 5 cm to a 30 cm depth for pH determinations. After 10 years, the continuous chisel system increased soil pH in the top 20 cm and had grain yields comparable to the no-tillage system, but not different than the no lime treatment. The no-tillage system increased the pH in the surface 15 cm of soil. The inversion treatments after soybean mixed the lime more thoroughly in the top 15 cm than inversion after corn and also increased the pH to a deeper depth. The pelleted lime had no effect on soil acidity. Soybean yields were affected by lime treatment with the no lime and pelleted lime having the lowest yields. This is most likely due to manganese (Mn) toxicity with these treatments. There was no perceived benefit of inversion of the soil with no-till or chisel systems. 相似文献