施用稀土使大棚蔬菜增产     

科信 《内江科技》2002,(3):37-37

稀土微肥,可以促进光合作用,增强植株抗逆性,提高秧苗对棚内低温、高温、弱光等不良环境的适应能力,从而促进蔬菜的优质、早熟和高产。不同作物应采用不同的施用方法:  相似文献   

从速溶肥料、缓释肥料到智能化肥料--中科院沈阳生态所武志杰科研团队的孜孜追求     

姚敏 《科学中国人》2005,(12):41-43

在现代农业生产中化肥的决定作用毋庸置疑。化肥的发展从低含量、低质量、单质，到高浓度、高质量、复合养分及目前大力发展的缓／控释肥料．经历了一个半世纪的时间，在发展历程的每一阶段，都有新种类产生．都凝聚着科技发展的最新成果．但到目前为止．每种新产品的诞生都有其自身的缺陷。开发缓／控释肥料可以大幅度降低肥料的损失，然而目前研究最多的缓／控释肥料存在着养分释放不能完全符合作物需肥规律的问题。因此．为实现肥料的高效利用．要求肥料养分释放智能化．解决肥料利用率低及对环境污染问题，是建立节约型社会和实现科学发展观的必然选择。  相似文献   

黄河三角洲及渤海莱州湾滨海区土壤资源及其合理开发利用   总被引：6，自引：0，他引：6  

郭洪海赵树慧史立本林守宗刘兆辉 《资源科学》1994,16(3):12-19

黄河三角洲及渤海莱州湾滨海区土壤含盐量高和肥力低为其突出特点。干旱的气候、黄河尾闾河道的摆动、咸水的侵染、风暴潮的侵袭等自然条件和人类活动决定着土壤发生与发展的总趋势。生物与工种措施相结合综合治理旱、涝、盐、咸、瘦、农、林、牧、渔、盐综合发展，是合理开发4黄河三角洲、土壤资源、土壤盐  相似文献   

一种典型的南方山区变电站接地网设计     

吴浩浪  靳盛玉 《中国科技信息》2006,(2):137

结合110KV武夷山仙店变电所工程,对其接地网的设计过程进行了分析总结。主要内容有:设计资料的收集及现场勘察,接地网敷设方案,接地计算等。  相似文献   

小小垃圾清洁工     

张波 《大科技．科学之谜》2004,(1):52-53

生活垃圾给人们带来的困扰越来越大,尤其是城市垃圾。随着城市的扩大和人口的增加,有不少城市居民已经与垃圾山为邻了。垃圾污染环境是人所共知的事实,在高温下分解产生的有毒气体甚至会直接危及人的生命。目前,普遍采用的处理垃圾的方法有四种:一是填埋;二是焚烧;三是堆肥;四是回收再利用。然而,这些方法都并不理想,各有各的缺点。填埋方法的永久性占地面积大,潜在的污染危险大,在有些国家甚至出现过垃圾填埋几十年后造成污染的事件;堆肥方式可使垃圾变成有机肥,但是这种垃圾肥的肥效低,销路有限,发展余地不大;焚烧垃圾具有回收热能和清除…  相似文献   

锦州市市区交通干线周边土壤及植物体中铅污染状况的研究     

丛孚奇  曲蛟  丛俏 《中国科技信息》2007,(20):17-18

以锦州市交通要道两旁的土壤以及银杏树叶为研究对象,采集土壤以及对应的植物样品60份,背景土壤及植物样品10份。利用火焰原子吸收分光光度法分别测定植物样品以及土壤样品中铅的含量,得到锦州市市区土壤中Pb的平均含量为58.0738mg/kg,银杏叶片中Pb的平均含量为4.7206mg/kg。采用Muller地积指数法进行土壤Pb污染评价,土壤污染程度为无污染-轻度污染级别。银杏叶对土壤中Pb富集系数普遍较低。  相似文献   

渍害土壤肥力综合评价研究   总被引：12，自引：0，他引：12  

李方敏周治安艾天成  原雄人 《资源科学》2002,24(1):25-29

利用因子分析、相关分析和模糊数学原理，针对渍害土壤的10项肥力指标进行了土壤肥力的综合评价。根据S型或抛物线型作物效应曲线建立各项肥力指标的隶属度函数，计算出隶属度值，并按各肥力指标的公因子方差、相关系数确定其权重系数，从而求得各渍害类型土壤肥力综合指标值（IFI),检验两种方法的IFI与其对应的水稻产量间的相关性，表明均达极显著水平（r=0.7521),说明综合评价结果能较好地反映出土壤的肥力。  相似文献   

Potential production simulation and optimal nutrient management of two hybrid rice varieties in Jinhua,Zhejiang Province,China     

Xie WX  Wang GH  Zhang QC 《Journal of Zhejiang University. Science. B》2007,8(7):486-492

Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST. Parameters of the rice growth in WOFOST were calibrated through field experiments from 1999 to 2002 in Jinhua. The potential yield simulated with WOFOST was about 12 t/ha for Shanyou63 and 10 t/ha for Xieyou46, which are in good agreement with the highest recorded yield obtained in this area. Under farmers practice, current yield is about 7.5 t/ha for Shanyou63 and 6.5 t/ha for Xieyou46. There is a gap between the actual rice yield and the potential yield for these two hybrid rice varieties grown in this area. The attainable target yields were set to 70% to 75% of their potential yields for the two varieties. A recently developed software ＂Nutrient Decision Support System （NuDSS）＂ for irrigated rice was used to optimize nutrient management for these two rice varieties. According to NuDSS, the optimal fertilizer N requirement for the target yields was about 150 kg/ha for Shanyou63 and about 120 kg/ha for Xieyou46, which were only about 70% of the fertilizer N application under current farmers＇ practice. Comparing with farmers＇ practice, there is great potential to increase actual rice yields and to reduce fertilizer N use rates by improving rice crop management practice in Jinhua.  相似文献   

<Emphasis Type="Italic">Mrakia psychrophila</Emphasis> sp. nov., a new species isolated from Antarctic soil     

Xin MX  Zhou PJ 《Journal of Zhejiang University. Science. B》2007,8(4):260-265

The yeast strain （Y18） was isolated from a soil sample collected from Fildes Peninsula, Antarctica. The strain is a psychrophilic yeast with optimum and maximum growth temperatures of 10 ℃ and 18 ℃, respectively. Teliospores were formed after 7 d on malt agar, when the germination of teliospores was observed. Both inositol and D-glucuronate were assimilated. Positive results of the DBB （diazonium blue B） color reaction, urease test, and starch formation were observed. The major CoQ is Qs. All results indicated that Y18 belongs to the genes of Mrakia. The 18S rDNA sequence analyses showed that Y18 is closely related to Mrakiafrigida. DNA-DNA relatedness study, and some biochemistry characteristics indicated that Y18 represents a new species for which Mrakia psychrophila sp. nov. is proposed.  相似文献   

耕耘生命的土壤——同课异构活动之后“问读”《生命 生命》(人教版课标教科书四年级下)     

廖纪元 《辽宁教育》2011,(Z1)

在一次同课异构的片区教研活动中,三位教师都执教了《生命生命》一课。讨论会上,听课教师有一个共同疑惑:如此人文性浓厚的课文,为何对学生的熏陶却显得有点苍白无力?于是,我把评课变成了另一种方式的读课  相似文献