共查询到20条相似文献，搜索用时 31 毫秒
1.
土壤动物在土壤有机质形成中的作用 总被引：2，自引：1，他引：2
作为土壤生态系统重要组成部分的土壤动物,在土壤元素循环转化和迁移过程中发挥着重要的作用。土壤动物是凋落物分解的"微型粉碎机",通过体内"特殊转换器",影响土壤有机质的转化、腐殖质的形成。本文从土壤动物对地表枯落物分解入手,分析了影响土壤动物对凋落物分解的因素,土壤动物通过刺激土壤酶活性,与土壤微生物群落一起,加快土壤有机物的分解,促进土壤腐殖质的转化。旨在拓宽土壤动物生态功能,丰富土壤腐殖质形成机理学说,对保护土壤生物多样性、提高土壤地力、保障粮食安全具有重要的科学意义。 相似文献
2.
关于我国“数字土壤”建设若干问题的思考 总被引：1，自引：0，他引：1
对"数字土壤"的渊源、定义、功能以及如何建设我国的"数字土壤"进行了讨论。"数字土壤"渊源于"数字地球",是土壤学科发展的产物、是土壤科学与现代信息技术和计算机技术相融合的必然趋势,是一种进行土壤科学研究的现代技术体系;"数字土壤"具有管理与提供土壤科学数据、进行空间分析、制作士壤专题图、指导土壤调查、查询与传播土壤信息、构建运用模型、土壤质量预警等功能;历史土壤调查资料是研制我国"数字土壤"的骨干材料;中国需要同时研制不同精度的"数字土壤";"联合共建",是建设我国"数字土壤"的好途径。 相似文献
3.
磺胺类兽药对土壤生化功能及氮素的影响 总被引：3，自引：0，他引：3
研究了磺胺类药物对土壤呼吸作用、硝化作用、氨化作用、铵态氮、硝态氮、亚硝态氮及全氮的影响。结果表明,相对较低浓度药物残留(10 mg/kg土)对土壤呼吸作用的影响呈现"激活-抑制"循环的规律,而相对较高浓度药物残留(50 mg/kg土)对土壤呼吸作用的影响则呈现"抑制-激活-抑制"的规律,因此,磺胺类药物残留会抑制土壤呼吸作用。相对较低浓度药物残留(10 mg/kg土)对土壤硝化作用、氨化作用呈现"激活-恢复"的规律,而相对较高浓度药物残留(50 mg/kg土)对土壤硝化作用、氨化作用则一直呈现"激活"的状态,因此,磺胺类药物残留会刺激土壤的硝化作用与氨化作用。土壤氮素是生物圈内氮循环的重要指标,磺胺类药物残留对土壤氮素有一定的抑制作用,若长期保持着较高残留水平,则会破坏土壤的氮循环。 相似文献
4.
城市土壤研究进展与中国城市土壤生态保护研究 总被引：17，自引：0，他引：17
加速城市化发展已成为我国经济、社会发展的必然,但随着城市化的发展,城市土壤环境质量急剧恶化,城市土壤已成为中国土壤学和城市化问题研究中亟需关注的领域。在城市化进程中大规模的工程建设、大量废弃物的排放和频繁的交通运输等多种因素的综合作用下,城市土壤结构被破坏,土壤剖面层次混乱,土壤化学性质变异加大,土壤生物多样性降低,土壤肥力水平下降。为减缓城市活动施加于土壤生态系统的负面影响,当前的城市土壤研究应首先在样点城市通过"城-郊-乡"生态样带来开展城市化土壤环境效应的定量研究,重点进行城市土壤基础信息数据库的构建和城市土壤的分类与制图,加强城市土壤环境修复技术和城市废弃物处理技术的研究及应用。同时,积极运用景观生态学原理,进行合理规划,构建城市绿色空间网络体系。为从根本上实现城市土壤资源的有效保护和持续利用,应加强宣传有关土壤知识,使广大公众积极参与城市土壤的保护,尤其使城市管理者相信在城市建筑和规划活动中有必要利用土壤学研究成果。 相似文献
5.
土壤动物与土壤健康息息相关,土壤动物多样性和功能能够灵敏反映人类活动和气候变化引起的土壤扰动。同时,土壤动物还通过与生物和非生物组分间的相互作用对地上生态系统产生反馈作用。当前土壤动物在土壤健康评价体系中的应用相对较少,主要集中在土壤线虫、节肢动物和蚯蚓等类群,仍缺乏基于土壤动物的系统性评价指标。因此,本文围绕土壤动物在指示土壤健康方面的潜力,系统总结了现有基于土壤动物的土壤健康评价指标,强调未来应建立和完善土壤动物基因组信息数据库,挖掘土壤动物的功能性状,加强土壤食物网结构和生态功能的研究,建立集成土壤动物物种多样性、功能性状和土壤食物网的指标体系,从而促进土壤健康和生态系统的可持续发展。 相似文献
6.
《土壤通报》2020,(1):241-244
第4届瓦赫宁根土壤会议于2019年8月27日至30日在荷兰瓦赫宁根大学及研究中心召开,有来自世界各国的300余名科研工作者参加。此次会议在"认识土壤功能"主题框架下,按土壤质量研究的基本逻辑,设置了土壤功能与社会、衡量土壤功能的创新方法、跨尺度的土壤功能建模与制图、土壤功能协同与权衡等4个议题,从土壤功能的视角,展示了以欧洲研究团队成果为主的土壤质量研究最新进展。本文对其内容与组织进行了介绍和评述,得到了以下思考与启示:(1)土壤功能分解与表达已成为土壤质量研究的热点问题;(2)应重视模型与专家系统在土壤质量评价中的综合运用;(3)工作坊、大师课等新型学术会议办会形式值得借鉴与发展。 相似文献
7.
中国土壤地理学发展的回顾与展望 总被引：9，自引：2，他引：7
基础土壤地理学的核心内容是土壤在时间和空间中的变化,目标是预测土壤在生态系统中的行为以及在自然和人为影响下的演变、实现土壤资源的有效管理。我国土壤地理学的发展经历了几个重要阶段,20世纪50年代区域和全国性的土壤调查和综合考察奠定了我国土壤地理学的发展基础;20世纪80年代随着全国第二次土壤普查的开始和科学研究恢复,土壤地理学重新复兴,包括土壤发生、土壤分类、土壤制图、土壤遥感等各个分支学科在内的土壤地理学得以迅速发展,这其中1984年开始的"中国土壤系统分类"研究贯穿了此后20多年的发展历程并推动了相关学科的进步;20世纪90年代以后,以3S技术为代表的新技术和新方法全面促进了土壤地理研究的现代化,土壤空间变化描述的内容、方式、应用等都发生了重大变化。未来的土壤地理学研究将面对我国土壤资源制约的国情,重点应该围绕变化中的自然条件和强烈的人为干扰下土壤质量与功能的演变、以土系为主体的土壤基层分类体系、以信息技术和模型模拟相结合的土壤资源数字化表达与管理系统等中心内容,为我国土壤资源的可持续管理、环境保护以及应对全球环境变化服务。 相似文献
8.
土壤质量与土壤可持续管理 总被引：4，自引：0，他引：4
土壤是农业生存之本,土壤质量是联系土壤管理与可持续农业的桥梁与纽带。介绍了土壤质量的概念及其发展,在客观地分析我国土壤质量现状的基础上,提出土壤管理必须建立在土壤质量的基础上并兼顾土壤的生产性、稳定性、持续性、生存性及社会的可接受性,才能实现农业的可持续发展。 相似文献
9.
土壤种子库是植被更新和恢复的物质基础,对地面植被恢复有着重要意义。以江西省兴国县飞播马尾松林为研究对象,通过标准地调查、土壤理化性状测定及土壤种子库萌发试验,分析土壤种子库的萌发特征及其与土壤因子的关系。结果表明:土壤种子库有23种植物,隶属于17个科,0~10 cm土层种子密度为9.8×102粒m~(-2)。不同坡位土壤种子达到萌发最高峰的时间、萌发平缓期持续的时间相差不大,但单子叶植物与双子叶植物间达到萌发峰值点的时间有所差异;萌发种子数与时间关系呈双"S"型曲线,表现出"平缓-上升-平缓-上升-平缓"的变化过程。采用主成分分析提取非毛管孔隙、土壤含水量、全N、全P、有机质5个变量进行冗余分析,得出对土壤种子库影响较大的是非毛管孔隙度与土壤含水量。 相似文献
10.
[目的] 针对水力侵蚀对土壤碳循环"源汇"效应争议,综述水力侵蚀对土壤有机碳矿化作用和土壤微生物多样性的影响机制,提出未来定量研究的方向与注意事项。[方法] 在提出水力侵蚀对土壤碳循环"源"汇"效应概念和理论的基础上,分析现阶段研究中水力侵蚀对土壤碳循环"源汇"效应争议的核心问题,进而探讨水力侵蚀导致不同种类土壤微生物多样性变化的差异及其作用机制。[结果] 水力侵蚀过程导致土壤有机碳矿化作用形成碳循环中的"源"效应,而沉积过程导致有机碳迁移至低洼处固存形成碳循环中的"汇"效应,微生物的呼吸和分解作用可能解释土壤碳循环中消失的碳"汇"问题;水力侵蚀过程削弱细菌群落结构复杂性,而沉积过程可增加细菌群落结构的复杂性,但侵蚀和沉积过程都可能降低土壤真菌的α多样性和群落结构复杂性;水力侵蚀过程通过影响土壤有机碳含量、植被覆盖度和土壤pH等因素间接影响土壤微生物多样性。[结论] 未来研究应强化不同尺度水力侵蚀过程对土壤碳循环的影响机制、水力侵蚀过程与土壤微生物多样性的相互作用机制及水力侵蚀过程中土壤微生物对碳循环的影响机制相关量化研究。 相似文献
11.
通过田间小区试验研究了不同N、K肥料配比对酸性和碱性土壤上两个莴笋品种(科兴 3 号和双尖莴笋)产量及品质的影响.结果表明,不同土壤上施用不同N、K配比肥料对双尖莴笋和科兴 3 号的产量影响不同.在酸性土壤上,对照(N15K10)是适宜两种莴笋高产的最佳N、K肥配比处理.在碱性土壤上种植双尖莴笋时,可以考虑在对照基础上适当地降低N肥用量.在碱性土壤上两种莴笋的产量均高于酸性土壤.减N和增K处理有利于降低莴笋的硝酸盐含量.在酸性土壤上莴笋中的硝酸盐含量高于碱性土壤.莴笋采收后期茎的硝酸盐含量高于叶片.不同施肥处理对两种土壤上科兴3号和双尖莴笋营养品质的作用不一致.在酸性土壤上增施K肥或提高N肥的用量对莴笋营养品质的改善更有效果.莴笋的Vc含量以叶片＞茎,且酸性土壤＞碱性土壤.除双尖莴笋在增K处理(N15K15、N20K15)中茎的可溶性糖含量表现为酸性土＜碱性土以外,其他处理莴笋茎叶中的可溶性糖均为酸性土＞碱性土.不同处理莴笋的氨基酸含量均表现为茎＞叶. 相似文献
12.
衡阳盆地紫色土丘陵坡地土壤水分变化动态研究 总被引：16，自引：0，他引：16
2007年对衡阳盆地紫色土丘陵坡地0-50 cm土壤进行研究.结果表明:(1)在同一水平空间位置上,土壤平均含水量总的变化趋势是阴坡>阳坡.而土壤水分变异系数则呈现出相反的变化规律;(2)在同一垂直空间位置上,阴坡与阳坡不同坡位的土壤含水量的变化规律均为:下坡>中坡>上坡.阳坡的土壤水分变异系数的大小顺序是:阳坡上坡>阳坡中坡>阳坡下坡;而阴坡则呈现出相反的变化趋势;(3)土壤含水量的消长与同期的降雨量有关,1-6月为雨季水分补偿期,7-12月属于旱季水分亏缺期;(4)在同一水平空间,不同坡向土壤含水量剖面变化明显.随着土层深度的增加,土壤含水量增加.从土壤水分的变异系数来看,阳坡土壤水分的变异系数随土壤的加深而变大,阴坡土壤水分的变异系数随土壤深度的加深而变小,土壤水分的最稳定层均出现在10-30 cm处. 相似文献
13.
《Journal of plant nutrition》2013,36(10-11):2093-2110
Abstract Field observations have indicated that Fe deficiency chlorosis symptoms in peanut are more severe and widespread in monoculture than intercropped with maize in calcareous soils of northern China. Here we report a pot experiment that investigated the mechanisms underlying the marked improvement in Fe nutrition of peanut grown in mixture with maize. Iron deficiency chlorosis occurred in the young leaves of peanut in monoculture and was particularly obvious at the flowering stage, while the young leaves of peanut grown in mixture with maize remained green throughout the experiment. The chlorophyll and HCl‐extractable Fe concentrations in young leaves of peanut grown in mixture were much higher than those in monoculture, indicating that maize may have markedly improved the peanut Fe nutrition. Growth in mixture was associated with greatly altered root morphology and microbial populations in the rhizosphere of peanut. Visual observation of peanut roots in monoculture showed that they were larger in diameter and shorter than those in mixture. Moreover, peanut roots in mixture with maize produced more lateral roots and had increased root length compared with plants in monoculture. Peanut grown together with maize showed obvious rhizodermal transfer cells in the subapical root zone, but cells with cell wall ingrowths were poorly developed in peanut in monoculture. Mixed culture resulted in a significantly decreased abundance of bacteria in the rhizosphere of peanut compared with monoculture, and electron microscope observations indicated that this was associated with a thicker mucigel layer on the root surface of peanut in mixture with maize. Several root morphological and rhizosphere microbial factors may thus have contributed to the improvement in Fe nutrition of peanut in mixed culture. 相似文献
14.
近30年江西省耕地土壤全氮含量时空变化特征 总被引：12，自引：0，他引：12
以第二次土壤普查和测土配方施肥项目采集的大量土壤样品为基础,以GIS为技术工具,对江西省耕地土壤全氮的时空变化特征进行分析。研究结果表明:1985年和2012年江西省耕地土壤全氮含量在各设区市以及不同土壤类型之间均存在有较大的空间差异。1985年耕地土壤全氮含量最高的为萍乡市,最低的为九江市,空间变异最大为赣州市;2012年耕地土壤全氮含量较1985年整体提高了1个等级,全氮含量最高的为新余市,最低的为九江市,空间变异最大的为九江市。2012年水稻土全氮平均含量较1985年提高了7.24%;无论是在1985年还是2012年,水稻土全氮含量最高的为萍乡市,1985年水稻土全氮含量较低的三个设区市分别为吉安、赣州和九江,2012年则分别为九江、鹰潭和赣州。2012年旱地土壤全氮平均含量较1985年增加了43.88%,其中丰富级水平的土壤面积比例由1985年的7.38%提高至2012年的88.16%。 相似文献
15.
Hironori Heinai Masahiko Saigusa Kazuo Yoshida Hitoshi Okazaki 《Soil Science and Plant Nutrition》2005,51(7):961-966
The effect of the application of acidified porous hydrate calcium silicate (APS) in nursery bed soil and porous hydrate calcium silicate (PS) in paddy fields on the growth of rice plants ( Oryza sativa L. cv. Hitomebore) was examined in 2002 and 2003. The results revealed the following: 1) Shoot dry weight of rice seedlings increased by APS treatment in nursery bed soil. The tiller number of rice plants after transplanting in both years also increased by APS treatment in nursery bed soil, and in 2003, the tiller number in the treatment with a combination of APS in nursery bed soil and PS in paddy fields was significantly higher than that in the other treatments until the maximum tiller number stage. Furthermore, the root length of rice plants 14 d after transplanting increased by APS treatment in nursery bed soil. 2) Silicon concentration in the soil solution significantly increased by PS treatment in paddy fields, and the concentration of dissolved carbon oxide increased by APS treatment in nursery bed soil. 3) Only in the APS treatment the rice yield was 341 g m−2 , while 400 and 450 g m−2 in the PS and both APS and PS treatments, respectively, in 2003. Percentages of ripened grains in the plots without PS treatment ranged from 57 to 63%, respectively, while, those in the PS treated plots were 82%. The numbers of panicles and ripened grains in both APS and PS treatments were the highest among the treatments. Based on the above results, we concluded that both APS in nursery bed soil and PS in paddy field treatments were effective in improving the silicon nutrition and growth of rice plants, and that this effect was enhanced by a combination of treatments with the two. 相似文献
16.
降雨强度对三峡库区坡耕地土壤氮、磷流失主要形态的影响 总被引：11，自引：1，他引：11
揭示紫色土坡耕地在不同降雨条件下对土壤养分流失及其环境效益的影响,对于保护三峡库区水环境具有重要意义。通过径流场试验分析2010年5月1日-7月10日6次降雨过程中紫色土坡耕地的氮、磷流失特征。结果表明:大雨时产生的径流量分别为中雨和小雨时的2.34,7.59倍,同时大雨产生的径流中TN、TP含量高于小雨和中雨时,大雨导致的氮、磷流失远远超过中雨与小雨。大雨时产生的累积泥沙量分别是中雨和小雨的8.34,111.38倍。紫色土坡耕地径流中TN、TP的主要形式是有泥沙携带的颗粒态氮、磷,降雨量越大,颗粒态氮、磷的比例越高。中雨产生的径流中颗粒态氮占TN的74.9%～75.9%,大雨产生的径流中颗粒态氮占TN的比例更高,达到85.0%～92.6%。颗粒态磷是径流中磷的主要形态,大雨、中雨、小雨产生的径流中颗粒态磷占TP的比例分别为96.6%～97.7%,93.9%～96.2%,90.5%～94.4%。紫色土坡耕地氮、磷流失主要是以泥沙为载体,这在降雨量较大时表现得尤为明显。控制坡耕地氮、磷流失应着重考虑控制降雨量较大时的氮、磷流失。 相似文献
17.
Hui Ming Luo Toshihiro Watanabe Takuro Shinano Toshiaki Tadano 《Soil Science and Plant Nutrition》2013,59(4):897-907
Aluminum (Al) tolerance and phosphate absorption in rape and tomato were compared under water culture and field conditions. The relative growth rate in the Al treatment compared with -A1 treatment was similar in the two crops under water culture conditions, while under field conditions, the growth rate was 2- to 3-fold higher in rape than in tomato in spite of the higher Al concentration in the soil solution than in the culture solution. The relative amount of phosphate absorbed in the Al treatment compared with - Al was not appreciably different between rape and tomato under water culture conditions, while under field conditions, it was 3- to 6-fold larger in rape than in tomato. The exudation rate of citric acid by roots was much higher in rape than in tomato. The plant growth, root elongation, and amount of phosphate absorbed in rape were inhibited in the 150 µM Al in the culture solution. However, the inhibition was alleviated by the addition of 200 µM citric acid or 500 µM malic acid. The P concentration in the culture solution decreased by the presence of Al as aluminum phosphate. However, addition of citric and malic acids increased the amount of phosphate released from the precipitated aluminum phosphate. In conclusion, one of the mechanisms for the higher Al tolerance and larger phosphate absorption in rape than in tomato under field conditions was ascribed to the higher concentration of exuded citric acid by Al in the rhizosphere. It was suggested that the exudation of citric acid might contribute to the detoxification of Al and to the increase phosphate availability in the rhizosphere in rape. 相似文献
18.
Shigeyuki Tajima Michihiko Yatazawa Yukio Yamamoto 《Soil Science and Plant Nutrition》2013,59(2):225-235
A remarkable accumulation and utilization of allantoin are observed in soybean plant bearing modules (Glycine max variety A62-1). To study ita physiological role, changes in activities and distribution of the enzymes concerning the purine catabolism (i.e., xanthine oxidase, uricase, allantoinase and allantoicase) were measured during development. Uricase activity was found in the radicles in the early stage of seedling development, and no difference of the enzyme activity was detected between the radicles of the nodulating variety (A62-) and non-nodulating variety (A62-2). On maturation the activity disappeared rapidly in radicles and appeared in leaves, pods and nodules. The activity in nodules was much higher than that in the leaves and the pods throughout the culture period. Xanthine oxidase activity was found in the radicles and nodules. Allantoinase activity was present in all regions of both varieties, and the specific activity in the nodules Was 2-10 times that in other regions. Allantoicase activity was detected in the leaves, but not in the nodules. The distribution of these enzymes suggested that allantoin is formed in the nodules and utilized mainly in the leaves after translocation. Changes in the allantoin concentration and in the activities of uricase and allantoicase were studied in non-nodulating soybean (A62-2) grown in a culture solution containing various nitrogenous compounds. The allantoin concentration in the leaves increased as the plants were cultured in the solution containing 100 ppm of nitrate-N, urea-N or allantoin-N, whereas no uricase activity in the root was detected. The specific activity of uricase decreased in the process of plant development in all cultures. Allantoicase activity increased in the roots and leaves when the plants were cultured in this solution containing 100 ppm of urea-N or allantoin-N, indicating that allantoin is utilized easily in the soybean plants. Intracellular localization of uricase in the nodules was studied by the method of linear sucrose density gradient centrifugation. The uricase activity was associated with the bacteroids, density 1.25. The uricase activity peak was coincident with the peak of fonnic dehydrogenase activity (bacteria type), and not with peaks of catalase activity, cytochrome oxidase activity and absorbance at 280 nm. This evidence together with the observation by electron microscopy suggested that at uricase is associated with bacteroids. 相似文献
19.
Distribution and Solubility of Boron in Different Organs of Sunflower Plants in Relation to the Boron Concentration of the Nutrient Solution The distribution of boron in different plant organs and its solubility in various extractants was investigated in sunflowers supplied with different concentrations of boron in the nutrient solution. 1. The distribution of boron within the plant differs depending on boron supply. Under deficiency conditions the boron content of younger tissues is decreased (compared with older tissues) while under conditions of boron toxicity an accumulation in the older leaves results. 2. A cell in need of B takes the B from the solutions continuum of its surroundings. Under conditions of poor B supply almost all the B is converted to a form which is not soluble in water. A large part of this B is soluble in chloroform; a similar amount is chloroform-extractable from chloroplasts. The remainder is neither soluble in chloroform nor in inorganic extractants. 3. Surplus boron is not accumulated in all cells. It remains in the solutions-continuum until it is deposited at the end of the transpiration stream. Here it remains soluble in water or unspecifically occluded and is soluble in soda or acids. The distribution of surplus boron follows the pattern of a toxification. 4. In a plant adequately supplied with B only the boron in the transport pathways seems to be soluble in water. 相似文献
20.
磷是重要的生命元素,其循环与转化在食物链中起着至关重要的作用。研究通过整理统计资料和文献数据,利用NUFER模型(Nutrient flows in Food chain,Environment and Resources use,NUFER),分析长春地区1993—2013年食物链磷素流动趋势特征,揭示其存在的问题并提出策略,为该地区食物链磷素的优化管理提供依据。结果表明,1993年长春地区食物链磷素总输入量为32.6 Gg,至2013年增长至113.9 Gg。食品生产方面,动物性食品磷素养分生产量由1993年的0.7 Gg提高到2013年的2.7 Gg,而植物性食品则由1993年的16.1Gg降低至2013年的15.7 Gg。食品消费方面,动物性食品磷素消耗量由1993年的0.5 Gg提高到2013年的1.1Gg,植物性食品则由1993年的5.0 Gg降低至2013年的4.4 Gg。20年间,长春地区食物链以废物形式累积的磷素量上升了15个百分点,通过径流、淋洗及侵蚀方式损失掉的磷素增加了17.6 Gg。至2013年,食物链中磷素的损失率达到20.2%。食物链各环节的磷素利用效率均呈下降趋势,其中作物生产和畜禽生产系统磷素利用效率分别由94.2%和4.1%降至49.3%和3.8%。整个食物链的磷素利用效率降低了20.3个百分点。同时,磷素的循环再利用效率也在逐渐降低。20年间,长春地区食物链磷素流动呈现出"投入量大、累积量多、损失量高、利用效率和循环再利用率低"的形式。因此,该地区的食物链中应控制磷素养分的投入,注意畜禽系统中废弃物的磷素循环利用,减少磷素损失从而提高磷素的利用效率。 相似文献