水土保持边坡固化植草技术研究     

周利民  林新明  邓岚 《水土保持通报》2006,26(6):92-93,106

通过建立4种形式的边坡植草护坡处理试验小区,并对每种处理各设2组重复试验小区,对边坡防护效果及草籽出芽生长情况进行对比试验。研究结果表明,结合土壤固化剂和撒播草籽进行边坡表土处理后,草籽能够正常萌芽及生长,而且边坡表土层的抗冲刷能力明显增强,坡面侵蚀细沟显著减少。实践证明,边坡固化植草是一种行之有效的护坡绿化技术方法。  相似文献   

浙江省石灰土光谱特征及其自动识别分类技术研究   总被引：2，自引：1，他引：2  

王深法  蒋亨显  王人潮 《土壤学报》1994,31(3):312-321

本文通过石灰土专题调查，室内土壤光谱测定及其特定及其特征分析，并在此基础上进行土壤光谱自动识别分类方法的对比试验。明确了浙江省石灰土的四个土类，六个土属的光谱特征分异规律；提出了一种参数少，运算量小，精度高的光谱自动识别新方法－分层提取判别法。  相似文献   

β－转换生长因子对牛体外受精卵体外发育的影响     

蒋和生  卢克焕 《广西农业生物科学》1995,(2)

本研究主要检测ＴＧＦ－β对牛早期胚胎体外发育和移植后的成活率的影响。在试验１和试验２，添加０．３～７．０ｎｇ／ｍＬ的ＴＧＦ－β至无论是复杂培养液还是各成分已知的简单培养液中，囊胚中内细胞团细胞都不同程度地增长，比对照组的囊胚多０．５～１．０倍；此外在含有３．０～５．０ｎｇ／ｍＬ的ＴＧＦ－β的培养液中的囊胚，其孵化率显著地高于对照组。在试验３中，添加３．０ｎｇ／ｍＬ的ＴＧＦ－β显著地促进与不同细胞共同培养的囊胚内细胞团的细胞增长，在颗粒细胞或输卵管细胞及其两者组合当中的单层细胞上的囊胚表现突出。在试验４中，用ＴＧＦ－β培养所获得的囊胚移植于受体母牛，约４５～９０ｄ将受体屠宰检查中发现，ＴＧＦ－β的囊胚成活率高于无ＴＧＦ－β的囊胚．试验结果表明，ＴＧＦ－β可促进体外发育的囊胚内细胞团的细胞增长以及提高囊胚移植后的成活率。  相似文献   

西藏南迦巴瓦峰地区土壤地理分布规律的研究   总被引：3，自引：0，他引：3       下载免费PDF全文

彭补拙  濮励杰  蒋建军 《土壤学报》1995,32(3):278-283

西藏东南部的南迦巴瓦峰地区，面积约６．４３×１０＾４ｋｍ＾２。章探讨了土壤垂直带谱的性质和结构特点，土壤水平地带与垂直带的关系，土壤垂直带的结果类型；论述了湿润程度，逆温、人类活动对土壤垂直带影响，以及山体高度和大小与山地土壤分布的关系。  相似文献   

Gram-negative bacterial flora on the root surface of wheat (Triticum aestivum) grown under different soil conditions     

K. Sato  H. -Y. Jiang 《Biology and Fertility of Soils》1996,23(3):273-281

We identified 161 Gram-negative bacterial strains isolated from the root surface of wheat grown under different soil conditions. The strains were divided into seven groups based on major morphological and physiological properties. Taxonomic allocation of the groups was verified by guanine+cytosine contents of DNA. Except for one group, which may be assumed to include bacteria belonging to the genera Flavobacterium and Cytophaga, the various groups were taxonomically united. The distribution of the groups changed with soil improvement. Pseudomonads predominated in unimproved soil, but Flavobacterium and Cytophaga spp. were predominant in the most improved soil. As all the strains were non-fermentative by Hugh and Leifson's test, API 20NE identification was applied. However, many strains were misidentified by this system, especially in the Flavobacterium and Cytophaga spp. group. For ecological studies, the strains were classified to species level by the API 20 NE system and by the results of a combination of guanine+cytosine (mol%) and isoprenoid quinone data. The pattern of distribution of the bacteria on the root surface of wheat varied at species level within one genus depending on soil conditions.Dedicated to Professor J. C. G. Ottow on the occasion of his 60th birthday  相似文献   

Effect of different forms and sources of arsenic on crop yield and arsenic concentration     

Qing Qiao Jiang  Bal Ram Singh 《Water, air, and soil pollution》1994,74(3-4):321-343

Two greenhouse experiments were conducted to investigate the effects of different sources of As application on the yield of ryegrass (Lolium perenne L.) and barley (Hordeum vulgare L.) and the arsenic concentration in crop tissue. The soils used were a sand and a loam soil. In the first experiment (3 yr), As was applied either as sodium arsenite or as disodium hydrogen arsenate at the rate of 0, 2, 10, 50, and 250 mg As kg^?1 soil in year 1. In years 2 and 3, only the residual effect of As applied in year 1 was investigated. In the second experiment (5 yr), a NPK(16-7-12) fertilizer containing 10, 100 and 3000 mg As kg^?1 as sodium arsenite was applied at rates of 750 and 600 mg kg^?1 to ryegrass and barley, respectively, with lime and without lime. Arsenite had more inhibitory effect on crop yield than arsenate. Although the residual effect persisted up to year 3, it was found to be dependent on As application rate, soil type, and crop species. Only minor differences in As concentration in crops between arsenite and arsenate sources were observed. The yield reduction and the increase of As concentration in crops was highly related to As application rates. The As rates of 50 and 250 mg As kg^?1 resulted in significant yield reduction and marked increase of As concentration in both crops and these rates could be considered as critical for both crops. The application of As containing fertilizer had little or no effect on crop yield. The As concentration in both crops was little affected by the fertilizer containing up to 100 mg As kg^?1 but the concentration increased several folds when the fertilizer containing 3000 mg As kg^?1 was applied. The application of additional P to the treatment containing 3000 mg As kg^?1 fertilizer only slightly increased crop yields but it increased As concentration in ryegrass markedly. The repeated application of As containing fertilizer up to a period of 5 yr, even at 3000 mg As kg^?1 level, generally did not affect either the yields or the As concentration in both crops although a slight increase of As concentration in barley grain over the years was observed. In both experiments, the yield reduction and the increase in As concentration in crop tissue were lower in the loam soil than in the sand and barley straw cointained much higher As than barley grains, indicating that greater proportion of the As taken up by this crop was retained in the vegetative organs.  相似文献   

Fatty acid composition and squalene content of the marine microalga Schizochytrium mangrovei     

Jiang Y  Fan KW  Wong RT  Chen F 《Journal of agricultural and food chemistry》2004,52(5):1196-1200

Certain species of thraustochytrids are being explored as potential producer of polyunsaturated fatty acids for nutritional enrichment of food products and use as feed additives in aquaculture. The fatty acid composition and squalene content were determined in the thraustochytrid, Schizochytrium mangrovei that was newly isolated from decaying Kandelia candel leaves in Hong Kong mangrove habitat. The major fatty acid constituents identified in all three S. mangrovei strains were tetradeanoic acid (C14:0), hexadecanoic acid (C16:0), docosapentaenoic acid (C22:5 n-6, DPA) and docosahexaenoic acid (C22:6 n-3, DHA). DHA was the most predominant polyunsaturated fatty acid, and the percentage of DHA (of total fatty acids) in all these strains varied from 32.29 to 39.14%. Only slight changes were observed in fatty acid composition of the S. mangrovei strains harvested at their early (day 3) and late stationary (day 5) phases. In contrast, the cellular squalene content was affected significantly by the culture time; the largest decrease of squalene content from 0.162 mg/g to 0.035 mg/g was found in S. mangrovei FB1 as the culture aged.  相似文献   

1978-2011年呼图壁河径流的变化趋势          下载免费PDF全文

王岚  刘志辉  姚俊强  张文娜  王元 《水土保持通报》2015,35(3):62-67

[目的]分析新疆维吾尔自治区呼图壁河径流变化特征与长期变化趋势,为制定科学合理的呼图壁地区水资源供需平衡发展战略提供理论支撑。[方法]采用变差系数法、距平累积法、Mann-Kendall非参数秩次相关检验法及Morlet连续复小波变换对呼图壁河石门水文站1978—2011年实测日流量资料进行分析。[结果]呼图壁河径流的年内变化主要受降水与气温的影响,其主要径流产生于5—9月,汛期为6—8月,径流量占全年径流量的69.4%,枯水期为12月至次年3月。呼图壁河的Cv平均值为0.149。近34a来径流量整体呈现出不显著的增加趋势,径流量的年际变化小,年际间持续枯水与持续丰水的时间几乎相同。此外,呼图壁河年径流存在4个较为显著的周期波动,其中18和29a分别为径流量年际变化的第Ⅰ、第Ⅱ主周期。[结论]呼图壁河近34a来径流量呈增加趋势,径流量的年际变化呈现出较为显著的周期性,径流量的年内分配很不均匀。  相似文献   

县级农村能源建设模拟研究   总被引：2，自引：0，他引：2       下载免费PDF全文

张衍林  邹岚 《农业工程学报》2001,17(2):123-125

以宜昌县为例，在系统分析该县农村能源、农村经济和环境之间的关系及农村能源建设现状的基础上，建立了该县能源生态工程建设系统的结构模型及系统动力学模型，经过DYNAMO语言反复的仿真试验，研究该能源生态工程建设系统在当今市场经济的条件下未来30年的发展趋势，观察系统状态的动态变化。模拟结果表明：通过大力发展小水电、沼气和努力提高热效率，30年后，该县薪柴和秸秆的供能比例从54.73%下降到34.03%，土壤有机质从1.2 g/kg增加到2.0646 g/kg，森林覆盖率从32.3%提高到60.6%，实现了能源、生态效益同步增长。  相似文献   

Impact of epistasis and QTL × environmental interaction on the oil filling rate of soybean seed at different developmental stages     

Zhenfeng Jiang  Binbin Zhang  Weili Teng  Yingpeng Han  Xue Zhao  Desheng Sun  Zhongchen Zhang  Wenbin Li 《Euphytica》2011,177(3):431-442

The oil accumulation in the developing soybean seed has been shown to be a dynamic process with different rates and activities at different phases affected by both genotype and environment. The objective of the present study was to investigate additive, epistatic and quantitative trait loci (QTL) × environment interaction (QE) effects of the QTL controlling oil filling rate in soybean seed. A total of 143 recombinant inbred lines (RILs) derived from the cross of Charleston and Dongnong 594 were used in this study to obtain 2 years of field data (2004 and 2005). A total of 26 QTL with significantly unconditional and conditional additive (a) effect and/or additive × environment interaction (ae) effect at different filling stages were identified on 14 linkage groups. Among the QTL with significant a effects, 18 QTL showed positive effects and 6 QTL had negative effects on seed filling rate of oil content during seed development. A total of 29 epistatic pairwise QTL underlying seed filling rate were identified at different filling stages. About 28 pairs of the QTL showed additive × additive epistatic (aa) effects and 14 pairs of the QTL showed aa × environment interaction (aae) effects at different filling stages. QTL with aa and aae (additive × additive × environment) effects appeared to vary at different filling stages. Our results demonstrated that oil filling rate in soybean seed were under genetic, developmental and environmental control.  相似文献