辽宁省东部山区5种森林植被类型水文生态效益综合评判   总被引：4，自引：0，他引：4       下载免费PDF全文

高人  周广柱 《中国生态农业学报》2003,11(2):122-125

利用层次分析与Fuzzy数学相结合方法,对辽宁省东部山区5种森林植被类型水源涵养能力进行了多目标综合评判。首先利用层次分析法确定了评价因子林冠截留、林冠蒸散、枯落物蓄水、土壤容重、非毛管孔隙度、初渗速率、稳渗速率、土壤总蓄水和土壤有效水的权重集为C=(0.0245,0.0051,0.1993,0.0109,0.0762,0.0565,0.2827,0.0573,0.2866),然后利用最大模糊熵原则确定了评价因子的隶属函数,最后利用Fuzzy综合评判得出油松、落叶松、红松、柞木林、杂木林评价结果模糊子集为B=(0.4686,0.3784,0.4145,0.6128,0.4808),结果表明阔叶林水源涵养效益高于针叶林,其中柞木林效益最佳。  相似文献   

Molecular characterization and PCR detection of a nitrogen-fixing Pseudomonas strain promoting rice growth     

M. Sajjad Mirza  Samina Mehnaz  Philippe Normand  Claire Prigent-Combaret  Yvan Moënne-Loccoz  René Bally  Kauser A. Malik 《Biology and Fertility of Soils》2006,43(2):163-170

Nitrogen-fixing plant growth-promoting rhizobacteria (PGPR) from the genus Pseudomonas have received little attention so far. In the present study, a nitrogen-fixing phytohormone-producing bacterial isolate from kallar grass (strain K1) was identified as Pseudomonas sp. by rrs (16S ribosomal RNA gene) sequence analysis. rrs identity level was high with an uncharacterized marine bacterium (99%), Pseudomonas sp. PCP2 (98%), uncultured bacteria (98%), and Pseudomonas alcaligenes (97%). Partial nifH gene amplified from strain K1 showed 93% and 91% sequence similarities to those of Azotobacter chroococcum and Pseudomonas stutzeri, respectively. The effect of Pseudomonas strain K1 on rice varieties Super Basmati and Basmati 385 was compared with those of three non-Pseudomonas nitrogen-fixing PGPR (Azospirillum brasilense strain Wb3, Azospirillum lipoferum strain N4 and Zoogloea strain Ky1) used as single-strain inoculants. Pseudomonas sp. K1 was detected in the rhizosphere of inoculated plants by enrichment culture in nitrogen-free growth medium, which was followed by observation under the microscope as well as by PCR using a rrs-specific primer. For both rice varieties, an increase in shoot biomass and/or grain yield over that of noninoculated control plants was recorded in each inoculated treatment. The effect of Pseudomonas strain K1 on grain yield was comparable to those of A. brasilense Wb3 and Zoogloea sp. Ky1 for both rice varieties. These results show that nitrogen-fixing pseudomonads deserve attention as potential PGPR inoculants for rice.  相似文献   

Genotypic variation in grain cadmium concentration of lowland rice   总被引：6，自引：0，他引：6  

Junyu He  Cheng Zhu  Yanfang Ren  Yuping Yan  Dean Jiang 《植物养料与土壤学杂志》2006,169(5):711-716

Cadmium (Cd) contamination of paddy rice soils is commonly observed in the Yangtse River Delta, China. Large Cd uptake by rice plants and its translocation into the grains can entail human‐health risks. Genotypic variations in Cd uptake and a differential Cd partitioning into grains will be the basis for developing a rice screening or breeding tool for low grain Cd. A field experiment, conducted at the experimental farm of Jiaxing, Zhejiang province from 2002 to 2004, compared 38 rice genotypes of different types (indica vs. japonica) collected from the Yangtse River Delta. The results showed large differences in Cd concentrations in straw, brown rice, and grain chaff among the rice genotypes grown on Cd‐contaminated soil. Concentrations in brown rice ranged from 0.06 to 0.99 mg Cd kg^–1. The total Cd uptake in brown rice varied between 0.96 and 28.58 μg plant ^{– 1}. In general, indica‐type cultivars accumulated significantly more Cd than the japonica‐type cultivars. The Cd concentration in straw was highly correlated with that in brown rice. While significant differences in the Cd‐partitioning ratio (% share of total Cd uptake found in brown rice) among rice genotypes were observed, these were not correlated with Cd concentration of brown rice. This indicates that the Cd accumulation in rice grains appears to be governed mainly by the Cd uptake by the plant and probably not by differential Cd partitioning. The large genotypic variation suggests the possibility to lower the Cd content of rice by genotype selection. The development of such breeding tools should focus on low Cd uptake rather than Cd partitioning between straw and grain.  相似文献   

长期定位施肥对无石灰性潮土酶活性的影响   总被引：7，自引：2，他引：7       下载免费PDF全文

秦韧  杨团结  刘树堂  王万志  韩晓日 《中国生态农业学报》2007,15(1):33-36

试验研究长期定位施肥对无石灰性潮土酶活性的影响结果表明,长期单施有机肥及其配施无机化肥均能显著增强土壤脲酶、蛋白酶、磷酸酶和蔗糖酶的活性。土壤脲酶活性、蛋白酶活性与土壤有机质、全N、碱解氮含量呈极显著正相关,磷酸酶活性与土壤有机质、有机磷、有效磷呈极显著正相关,蔗糖酶活性与土壤有机质呈极显著正相关。表明土壤酶活性与土壤肥力密切相关,可作为评价土壤肥力性状的生物学指标。  相似文献   

基于激光图像的苹果品质分析与模型   总被引：2，自引：2，他引：2  

陈育彦  屠康  任珂  邵兴锋  董庆利  潘磊庆 《农业工程学报》2007,23(4):166-171

该试验利用波长650 nm，功率25 mW的半导体激光及计算机视觉技术，初步探讨了激光图像的影响因素以及利用激光图像对苹果(嘎拉、红富士)品质进行无损检测的可行性。分别测定贮藏期间苹果的硬度、固酸比、果面底色、果型等品质指标，并获取图像参数及其像素个数(S1、S2、S3、S4)。试验结果显示，苹果的向阳面和背阳面对获取的激光图像的像素个数有显著的影响，而果型大小对其无显著影响。其中图像参数S3与各品质指标的皮尔逊相关系数最高。逐步回归表明，引入变量S3后模型的解释率最好(最高R²为0.99)，且都为极显著水平(P≤0.01)。试验的结果为利用小功率激光图像对苹果品质进行无损检测提供了理论依据。  相似文献   

广东惠阳水稻种植中耕牛与小型拖拉机使用的能值比较     

白瑜  陆宏芳  何江华  任海 《农业工程学报》2007,23(5):105-110

以能值理论方法为手段，从资源的投入和输出结构角度，对广东省惠州市惠阳区典型水稻种植户的耕牛和小型拖拉机这两种典型的农业驱动力产出系统的转化与生产效率，环境负载和可持续性进行比较分析与评价。研究表明：耕牛系统在单位面积水稻田上消耗的不可更新资源量是拖拉机系统的4.57倍；人力能值消耗是拖拉机系统的6.14倍。相对于拖拉机动力，耕牛产出动力处于较低的能量等级，其环境负载率(ELR)仅是拖拉机系统的24%，可持续能值指标(ESI)是拖拉机系统的4.25倍，但有巨大的优化空间和可能。而广东小型拖拉机系统产出驱动力的使用效率则稍高于典型65 kW拖拉机系统。从提高能值效率角度分析，减少耕牛系统生产过程中过多的人力投入，着力提高耕牛系统产出驱动力的利用效率比发展小型拖拉机系统更有潜力。生产过程中的人力投入和使用过程中的维护投入是农机驱动力产出系统不可忽视的能值投入项。  相似文献   

Capillary electrophoresis and high-performance liquid chromatography determination of polyglutamyl 5-methyltetrahydrofolate forms in citrus products   总被引：2，自引：0，他引：2  

Matella NJ  Braddock RJ  Gregory JF  Goodrich RM 《Journal of agricultural and food chemistry》2005,53(6):2268-2274

The 5-methyltetrahydrofolate (5mTHF) polyglutamates in citrus products were analyzed by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). Folate species were purified from citrus products and concentrated from 2- to 100-fold using combined folate-affinity chromatography and C18 extraction. Seven polyglutamyl 5mTHFs were found in most not-from-concentrate (NFC) orange juices (OJ) in total amounts of approximately 1 nmol/mL, with varying distributions of individual polyglutamates. Folate amounts and distributions were also measured in orange fractions, single-strength OJ from concentrate, NFC grapefruit juice, and citrus peel molasses. Models containing ascorbic acid had folate thermal degradation rates one-seventh that of models without ascorbic acid. Pasteurization studies demonstrated that folate loss was <2% for commercial OJ pasteurization conditions (i.e., 93 degrees C for 5 s, 88 degrees C for 15 s, and 82 degrees C for 30 s). Both methods were precise, reproducible, and potentially faster than traditional analytical procedures requiring enzymatic deconjugation and microbial assays.  相似文献   

基于GIS的地下水资源可持续性评价   总被引：6，自引：1，他引：6  

张久川  任树梅  马明  刘洪禄  杨培岭 《农业工程学报》2005,21(8):35-39

该文根据区域水资源评价工作的特点和GIS技术强大的空间分析功能,探讨了GIS技术在区域水资源可持续性评价中的可行性,并将其应用到北京市通州区潞城镇地下水资源可持续性评价中。根据GIS技术与动态均衡法的结合,评价得出自1988年以来,潞城镇地下水储量一直处于亏损状态,16年累计亏损1715.577万m³,地下水位平均每年下降0.12 m。表明今后该区域地下水应采取相应措施来缓解地下水的压力。  相似文献   

无线传感器网络在农业中的应用   总被引：8，自引：0，他引：8  

乔晓军  张馨  王成  任东  何秀红 《农业工程学报》2005,21(Z2):232-234

无线传感器网络集传感器技术、微机电系统(MEMS)技术、无线通信技术、嵌入式计算技术和分布式信息处理技术于一体,是多学科高度交叉的、知识高度集中的热点研究领域,因其广阔的应用前景而备受关注.该文综述了无线传感器网络的节点构成、体系结构、研究热点,以及在农业中的应用研究现状,针对性地提出在温室、节水灌溉、畜牧等农业领域应用无线传感器网络的方案与思路,为无线传感器网络在农业中的应用拓宽思路,争取早日将无线传感器网络投入到农业应用领域.  相似文献   

土壤—植物系统中重金属污染的治理途径及其研究展望   总被引：77，自引：2，他引：77  

顾继光  林秋奇  胡韧  诸葛玉平  周启星 《土壤通报》2005,36(1):128-133

由于工业“三废”的排放,使农田遭受不同程度重金属的污染,重金属通过在作物体内富集进入食物链,对人畜健康构成了威胁。文章对土壤重金属的污染现状、治理途径及其原理、优缺点、可行性作了简要的回顾,对土壤重金属污染植物修复技术类型、原理、特点以及基因工程等现代生物技术在重金属污染植物修复技术中的应用前景作了进一步的展望,为实现对重金属污染土壤进行有效的生态整治与安全高效益的利用提供了新的技术途径。  相似文献