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951.
952.
攀西烟区紫色土pH值与土壤养分的相关分析 总被引:5,自引:1,他引:5
对四川攀西烟区有代表性的30个紫色土样品的pH值、有机质及有效养分含量进行了测定。结果表明,攀西烟区紫色土的pH值在5.13~8.14范围内,有半数左右的土壤偏碱性;有机质、碱解氮、有效锌和有效锰的含量均随pH值的升高而降低,交换性钙的含量随pH值的升高而升高,而pH值与速效磷、速效钾、交换性镁、速效铜、速效硼间的相关性则不显著。烟区紫色土的有机质和碱解氮含量偏低,速效磷、速效钾含量中等,交换性钙、交换性镁含量丰富;部分pH值较高的土壤可能会缺乏铜、锌等微量元素;在不同pH值的土壤上硼营养均严重亏缺,建议生产中增施硼肥。 相似文献
953.
秸秆及生物质炭对砖红壤酸度及交换性能的影响 总被引:6,自引:1,他引:6
为合理运用秸秆材料改良热带地区砖红壤,采用室内培养试验研究了玉米秸秆及其制备的生物质炭对海南花岗岩母质发育的砖红壤的酸度和交换性能的影响。试验设单施生物质炭(B)、生物质炭和秸秆混合施用(BCS)、单施秸秆(CS)及对照(CK)共4个处理。结果表明,添加生物质炭和秸秆显著提高土壤p H、CEC、交换性盐基总量和盐基饱和度。秸秆和生物质炭可降低土壤交换性酸,尤其是交换性酸中交换性铝含量更是显著降低,表明生物碳和秸秆施用能够有效降低砖红壤酸度,提高交换性能。不同处理改良效果的大小顺序为CSBCSB。 相似文献
954.
T. KARAK R. Kumar PAUL R. Kumar BORUAH I. SONAR B. BORDOLOI A. K. DUTTA B. BORKOTOKY 《土壤圈》2015,25(2):316-328
Major chemical properties of tea-growing soils are of paramount importance for better management in a sustainable fashion.Therefore,this study was carried out to understand the major soil chemical properties of major tea(Camellia sinensis L.)-growing areas,Dibrugarh and Tinsukia districts,in the state of Assam,India.A total of 991 surface soil samples were collected from 15 large tea estates(TEs) for analysis of their major chemical properties.Soil pH ranged from 3.61 to 6.81.Total organic carbon and total nitrogen ranged from 2.4 to 47.3 and 0.24 to 3.60 g kg-1,respectively.All soils were sufficiently rich in plant-available potassium(as K2O),which ranged from 127.71 to 252.33 mg kg-1,exceeding the amount prescribed for optimum tea yield of > 100 mg kg-1.Plant-available sulfur among soil samples widely varied from 4 to 129 mg kg-1.Results of hierarchical clustering analysis for homogenous grouping of the 15 TEs based on soil chemical properties showed that the 15 TEs could be classified into three distinct groups which consisted of6,8 and 1 TEs,respectively.Based on the Kolmogorov-Smirnov(K-S) test,the best fitted theoretical probability distributions were found out for different soil chemical properties.It could be concluded that a balanced fertilizer application would be needed as a part of tea improvement program using soil chemical test. 相似文献
955.
Yoshitake Hayashi Keitaro Tanoi Hiroyuki Nishiyama Tomoko M. Nakanishi 《Soil Science and Plant Nutrition》2005,51(5):729-731
To study the mechanisms of Al tolerance in rice, we focused on the change of rhizosphere pH. The 4-d seedlings were treated with Al solution (0, 10, 50 mM) for 24 h. Then each sample was put on an agarose gel including bromocresol green, so that the color of the gel indicated pH change. During 2-h contact, the pH of rhizosphere was decreased gradually, especially for Al-treated samples, showing the specific pH profiles along the root axis. Pretreatment of sample plants with a decoupling reagent 2,4-dinitrophenol (DNP) or a plasma membrane H+ -ATPase inhibitor Na3 VO4 did not decrease rhizosphere pH. Therefore, it was suggested that the H+ secretion activity was involved with Al-tolerant mechanisms of rice. 相似文献
956.
Are there real endogeic species in temperate forest mites? 总被引:3,自引:0,他引:3
The determinants of mite diversity in soil and the reasons why so many species co-exist are poorly understood. There is evidence that niche differentiation (i.e. microhabitat complexity) in the litter layers of forest floors is important, however, little is known for deeper horizons since mite density and diversity in deeper soil layers have been rarely studied. In order to address this dearth of information, we collected microarthropods from both the forest floor and the mineral soil to a depth of 1 m in two deciduous forest locations. The density exceeded 8×105 microarthropods m−2 in one location, and a number of individuals were collected from deep in the soil. No species was exclusively living in mineral horizons. Measurements of porosity spectrum, pH, water content, total C and total N were made at each depth and related to mite diversity and species richness. Meso- and microporosity were strongly correlated with species distribution while macroporosity and pH were correlated to density and species richness. 相似文献
957.
958.
Quantitative analyses of the snail assemblages of four a priori defined categories of grassland sites, characterized by soil moisture, land use and management, were conducted in SW Germany. Topsoil pH and calcium content were determined for each of 39 sites. The objectives were to study the effects of these habitat characteristics on snail density, species richness and quantitative structure of the land snail assemblages. With one exception, no significant relationships between soil pH (as a proxy for Ca supply) and the total numbers of individuals and species at the four site categories were observed. Snail density and species richness on groundwater soils, represented by rarely mown sedge stands and regularly mown meadows, were clearly higher than on intermediate moisture soils (as defined by the climatic water balance) of regularly mown meadows, indicating that soil moisture was the most important factor accounting for these differences. Furthermore, we observed specific conditions associated with the presence of trees in the category of meadow orchards on intermediate moisture soils. There, numbers of individuals and species were significantly higher than in the meadows on intermediate moisture soils. A posteriori cluster analysis of quantitative similarity of all snail assemblages showed that soil moisture accounts for the major differences between the site categories with respect to snail density, species richness and quantitative composition of the grassland snail assemblages. As these results are in contrast to the findings of many woodland studies, we suggest that the occurrence or abundance of certain species in the site categories are explained by land management, especially by frequent disturbances at the soil surface caused by mowing. 相似文献
959.
960.
Effects of resident rhizobial communities and soil type on the effective nodulation of pulse legumes
Communities of resident rhizobia capable of effective nodulation of pulse crops were found to vary considerably over a range of soil environments. These populations from soils at 50 sites in Southern Australia were evaluated for nitrogen fixing effectiveness in association with Pisum sativum, Vicia faba, Lens culinaris, Vicia sativa, Cicer arietinum and Lupinus angustifolius. The values for nitrogen fixing effectiveness could be related to soil pH as determined by soil type and location. It was found that 33% of paddocks had sufficient resident populations of Rhizobium leguminosarum bv viciae for effective nodulation of faba bean, 54% for lentils, 55% for field pea and 66% for the effective nodulation of the vetch host plant. Mesorhizobium cicer populations were very low with only 7% of paddocks surveyed having sufficient resident populations for effective nodulation. Low resident rhizobial populations (<10 rhizobia g−1 soil) of R. leguminosarum bv viciae and M. cicer were found in acid soil conditions. In contrast, Bradyrhizobium populations increased as soil pH decreased. Inoculation increased faba bean yields from 0.34 to 4.4 t ha−1 and from 0.47 to 2.37 t ha−1 for chickpeas on acid soils. On alkaline soils, where resident populations were large there was no consistent response to inoculation. Observations at experimental field sites confirmed the findings from the survey data, stressing the importance of rhizobial inoculation, especially on the acid soils in south-eastern Australia. 相似文献