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1.
海南岛东北部红树林盐土的化学性质 总被引：1，自引：0，他引：1
廖金凤 《中山大学学报论丛》1990,(4)
研究结果表明,海南岛红树林盐土呈强酸性和酸性。其酸度与红树富硫有密切关系。土壤阳离子交换量随剖面深度而减少。土壤水溶性Cl~-与Na~+含量,SO_4~(2-)含量与 Ca~(2+)和Mg~(2+)合量紧密相关。土壤中磷在表层明显积累,钙、铁、锰在表层有所淋溶,钛、钾在剖面分布较均匀,硅、铝上下层多少不定。 相似文献
2.
本文采用等温吸附法研究了安徽省16种土壤对硅的吸附作用，研究了三种pH值条件下土壤对硅吸附特征，结果表明：土壤对硅的吸附与土壤活性铁、活性铝含量呈极明显正相关，相关系数分别为0.8572和0.6776。在加入硅溶剂pH值3-9范围内，平衡液硅浓度随溶液pH值升高而降低。 相似文献
3.
成土母质是影响土壤有效硅水平的主要因素,不同母质发育的水稻土有效硅平均含量顺序为：黄土性古河湖相沉积物＞近代黄泛＞淮河冲积＞石灰岩＞湖积物＞下蜀黄土＞长江冲积＞紫色砂页岩和第四纪红土＞板页岩和酸性结晶岩。土壤pH值和土壤有机质含量与土壤有效硅呈极显著正相关。安徽省水稻土有效硅含量不同地区差异很大,淮北平原＞江淮丘陵岗地＞沿江平原＞皖西山地＞皖南丘陵山地． 相似文献
4.
在农业生产中,如果没有掌握科学有效的施肥措施,会造成土壤中微量元素的有效性不高。通过以下三种措施可提高土壤中微量元素的有效性。一、调节土壤的酸碱度在强酸性土壤中容易造成铁的毒害和错的缺乏,可通过施用石灰的方法来解决。碱性土壤中可能缺乏铁、锰、锌和铝,施入能产生酸的肥料和硫磺可以解决。二、控制土壤水份因为土壤水份会影响土壤中微量元素的溶解度。改善酸性土壤的排水条件,能促进铁、锰由还原态向氧化态转化,从而减轻其毒性。石灰性土壤或碱性土壤,在湿润的条件下,可导致氧化态化合物的还原,使某些微量元素的有效… 相似文献
5.
土壤微团聚体与土壤有机质及有效氮、磷、钾的关系研究 总被引：5，自引：0，他引：5
通过对豫北地区壤质潮土与石灰性褐土的微团聚体及有机质、有效氮,磷、钾的测定结果表明土壤有机质含量与有效氮、磷、钾含量呈正相关,耕层增加的0.25～0.01mm的微团聚体的量与有机质含量呈正相关,同一土壤0～60cm土层0.25～0.01mm的微团聚体的量随着土层的加深呈逐渐增加的趋势. 相似文献
6.
土壤对磷的吸附与硅的吸附比较相似,吸附磷量多的土壤吸附硅的量也较多,但不同土壤吸附磷、硅的能力差异较大。两种吸附与Ｌａｎｇｍｕｉｒ等温吸附方程均达极显著相关。土壤吸附硅的能力远高于对磷的吸附能力,对硅的缓冲能力一般也高于对磷的缓冲能力,其对磷、硅的吸附能力主要受土壤物理性粘粒含量及土壤活性铁、活性铝的含量的影响。 相似文献
7.
本文采用等温吸附法研究了安徽省16种土壤对硅的吸附作用,研究了三种pH值条件下土壤对硅吸附特征,结果表明:土壤对硅的吸附与土壤活性铁、活性铝含量呈极明显正相关,相关系数分别为0.8572和0.6776.在加入硅溶液pH值3-9范围内,平衡液硅浓度随溶液pH值升高而降低. 相似文献
8.
通过室内土壤培养试验,初步研究了有机肥料对土壤硅素吸附的影响,结果表明：土壤对硅有较强的吸附性能,活性氧化铁、铝含量是影响土壤硅吸附性能的重要因素;添加有机肥料使土壤吸附硅量降低,其降低幅度受有机肥料种类的和土壤性质的影响;添加有机肥料后,土壤对硅的吸附也具等温吸附特征,其等温吸附曲线可用简单ｌａｎｇｍｕｉｒ 方程和Ｆｒｅｕｎｄｌｉｃｈ 方程描述。 相似文献
9.
某电解铝厂大气氟污染对区域土壤的影响探析 总被引：2，自引：0，他引：2
通过试验,对某铝厂周围土壤中的氟进行了测定。结果表明：0-20cm耕层土壤中水溶性氟的质量浓度值在6.76-7.64mg/kg之间,平均为（7.28±0.36mg/kg）;水溶性氟与总氟的比值为1.96%-2.38%,平均为2.23%,均高于当地的土壤背景值。针对土壤氟污染状况,提出了相关的对策和建议。 相似文献
10.
从翻译能力的构建出发,结合交际翻译和产出导向法相关理论,探讨了成人翻译能力自主培养模式,认为课外和课上有效自主学习的有机结合有助于成人英语教育阶段翻译能力自主培养远期目标的实现. 相似文献
11.
低分子量有机酸对土壤磷素的活化效应 总被引：3，自引：0，他引：3
用室内培养法试验了草酸 ,柠檬酸和酒石酸对土壤磷的活化作用。结果表明 :有机酸对土壤磷的活化作用明显 ,三种有机酸的活化作用草酸 >柠檬酸 >酒石酸。活化作用随有机酸浓度提高而增强 ,试验的两种土壤培养96小时 ,土壤有效磷释放便基本达到最大值。在潮土上 ,草酸、柠檬酸、酒石酸处理土壤磷素最大释放率分别为 15 0 .9%、97.6 %和 2 3 .3 %。 相似文献
12.
Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6～84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P＜0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P＜0.01). (3) Soil iodine value was 0.11～2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution. 相似文献
13.
本文对三门峡黄河滩地土壤进行了吸湿水含量、酸碱度、有效氮、有效磷和有机质含量分析。研究结果表明:河滩地种植黄豆可以改良土壤质地,调节PH值,增加土壤有效氮、有效磷和有机质含量,提高土壤肥力。 相似文献
14.
This study on the effect of land use on soil quality in relation to forms and toxicity of aluminum in red soils (Ultisol) in southeast China showed that in general, the extractable order for soil active aluminum by four extractants was: NaOH 0.5 mol/L > HCl 1 mol/L > NH4Ac 1 mol/L > KCl 1 mol/L . Different uses of the red soils, developed from Quarternary red clay with the similar hydrogeological environment, greatly affected the amount of active aluminum, especially the exchangeable Al3+. The order of exchangeable Al3+ (Al mg/kg) in the red soils with different land uses was: barren land (740) > tea garden (663) > peach garden (432) > citrus garden (234) > paddy soil (127). The content of water soluble aluminum in the red soils was highly sensitive to soil acidity. 相似文献
15.
B. Junge O. Deji R. Abaidoo D. Chikoye K. Stahr 《The Journal of Agricultural Education and Extension》2013,19(3):257-274
Abstract The main objective of this study was to determine the attitude of farmers towards erosion and the adoption of appropriate soil conservation technologies (SCTs). For the survey, farmers were selected from the communities Esa Oke, Elwure and Owode-Ede and Akoda in Osun State in Nigeria. In the first three communities farmers did receive training on soil conservation, in the fourth not. About 60 farmers were interviewed to obtain information on personal and socio-economic characteristics, awareness of environmental problems, attitude towards erosion control and experiences with SCTs. Statistical data analyses (analyses of frequencies, correlation, t-test, χ2-test) were made to examine possible relationships among parameters and the influence of factors on adoption. Most respondents were advanced in years, responsible for large households and characterized by low levels of income and literacy. Soil erosion was seen as a problem confronting agricultural production only to a small extent. The adoption rate of SCTs was low, as only mulching, cover cropping, contour tillage and cut-off drainage were practised and often rejected. Low labour-demand, the availability of common equipment, low costs of application, ease of practice and compatibility with the existing farming system influenced adoption. The observed positive correlation between level of education, knowledge of appropriate technologies, farming experience and the number of SCTs adopted emphasizes the importance for farmers of education and training. Strengthening agricultural extension agencies for capacity building is an important tool for improving soil conservation in Nigeria. The paper clarifies with specific examples the causes of the low rates of adoption of available technologies, with a reduced impact of research and of efforts to achieve food security and sustainable production at village level. 相似文献
16.
Ridge culture is a special conservation tillage method, but the long-term influence of this tillage system on soil aggregate-size stability in paddy fields is largely unknown in southwest of China. The paper is to evaluate soil aggregate stability and to determine the relationship between soil organic carbon （SOC） and soil aggregate stability. Soil samples at 0 cm-20 cm layer were adopted from a long-term （16 a） field experiment including conventional tillage： plain culture, summer rice crop and winter upland crop under drained conditions （PUR-r）; and conservation tillage： ridge culture without tillage, summer rice and winter fallow with floodwater layer annually （NTR-f）, winter upland crop under drained conditions （NTR-r）, and wide ridge culture without tillage, summer rice crop and winter upland crop under conditions （NTRw-r）, respectively. Different pretreatments, such as slaking in fast wetting, wetting and subsequent slaking, were applied to simulate the breakdown mechanisms of aggregates in paddy soil. The results show that soil particles contents were mainly consisted of silt （0.050 mm to 1.000 mm） in fraction of 42.9% to 51.2%, sand （0.050 mm to 0.001 mm） in fraction of 28.0% to 31.8%, and clay （〈0.001 mm） in fraction of 17.9% to 25.4%. The amount of aggregate-size was greatly observed in fraction of 2.000 mm-6.720 mm under ridge culture in paddy soil （more than 50$） under slaking and wetting pretreatment. The proportion of soil macro-aggregates （〉0.250 mm） in conservation tillage was greatly higher than that in conventional tillage under subsequent fast slaking treatment. Minimal differences of aggregate stability between slaking in fast wetting and wetting were observed, while significant differences were found between ridge culture and plain culture. The aggregate stability under slaking treatment ranked in the order of NTR-r〉NTRw-r〉 NTR-f 〉 PUR-r, while under wetting was NTRw-r 〉 NTR-r 〉 NTR-f 〉PUR-r. There was a positive correlation between the aggregate stability and SOC concentration under wetting, and a low correlation was observed under slaking pretreatment. Soil exposure with tillage and lack of rice/rape-seed stubble inputs caused declines in aggregation and organic carbon, both of which make soil susceptible to water erosion. Adoption of ridge culture with no-tillage integrated with crop rotation and stubble mulch significantly altered soil organic concentration. It was a valuable conservation practice for soil aggregation and soil organic carbon sequestration on paddy soil. 相似文献
17.
五种蕨类植物抗旱生理指标研究 总被引：2，自引：0，他引：2
采用人工盆栽控水,研究在干旱胁迫条件下,五种蕨类植物银脉凤尾蕨、蜈蚣蕨、肾蕨、普通铁线蕨、狭翅巢蕨和阔叶鳞盖蕨的一些生理指标的变化和抗旱能力。结果表明：五种蕨类的生理指标随着干旱胁迫的加强,叶片的相对含水量和叶绿素含量均呈下降变化,相对电导率、脯氨酸含量、可溶性总糖含量和过氧化物酶活性都呈上升趋势。 相似文献
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19.
研究了钛铁试剂分光光度法测定土壤中铁的方法,探讨了方法的最佳条件。结果表明,以钛铁试剂为显色剂,可于560nm处测定土壤中铁的含量,铁含量在0-3mg／L范围内服从比尔定律,线性回归方程为Y=0．0889x,相关系数1=0．9984,表观摩尔吸光系数为K560=5．12×10^4L·mol^-1·cm^-1。该方法简便,选择性好,灵敏度高。此法用于土壤中铁的测定,结果与磺基水杨酸法相符。样品标准加入回收率分别为95．6％～99．9％,相对标准偏差为0．34％-0．53％（n=6）。 相似文献
20.
Field investigation on effects of wheat-straw/corn-stalk mulch on ecological environment of upland crop farmland 总被引：2，自引：0，他引：2
This work systematically investigates the effects of wheat-straw/corn-stalk mulch on the ecological environment in upland crops (winter wheat, summer corn) field from 1997 to 1998. With and without mulch soil moisture distribution, water demand, day and night variation of soil temperature, weeds control, crop yields, water and soil conservation, as well as improvement of soil texture were experimentally investigated. The optimal mulch rate for both water saving and yield-increase was determined. Ineffective interplant evaporation can be turned into effective transpiration of leaf by application of wheat-straw/corn-stalk mulch, which enhances the utility factor of soil moisture and reduces irrigation norm, and may also regulate soil temperature, increase soil fertility, and improve soil texture after being returned to the field. Wheat-straw/corn-stalk mulch inhibits evaporation of moisture so that accumulation of salinity near the soil surface is prevented, and thus ameliorates salinization of land. In the region of severe soil erosion, mulch is used to cover land so as to forestall hydraulic and wind erosion of the soil. 相似文献