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1.
湘西植烟土壤有机质和全氮时空变异特征研究 总被引:1,自引:0,他引:1
为揭示湖南省湘西州烟区土壤有机质(SOM)和全氮(TN)的时空变异特征和为合理施用有机肥和氮肥提供科学依据,采用经典统计学、地统计学和GIS等方法,对湘西州2000年和2015年植烟土壤SOM和TN时空变异特征进行了研究。结果表明:2015年SOM和TN平均含量较2000年分别增加了5.03g/kg和0.31g/kg,增幅分别达21.39%和21.99%,SOM和TN含量的最小值变小,变异系数、最大值和极差变大,Moran’sI指数标准化Z值下降,块金效应增加;SOM和TN含量"低""适宜"等级面积分别下降了3.42%、37.73%和2.04%、44.43%,"高""极高"等级面积分别增加了32.21%、8.94%和35.67%、10.80%。表明湘西植烟土壤SOM和TN含量和变异同时增加,SOM和TN空间自相关性减弱,随机变异性增强。植烟土壤SOM与TN含量表现出极显著的正线性相关,SOM的矿化释放是TN的一个主要来源。 相似文献
2.
湘西喀斯特区植烟土壤有效磷时空变异及风险评估 总被引:5,自引:1,他引:4
为揭示典型喀斯特烟区土壤有效磷的时空变异特征,为喀斯特地貌烟区合理施磷和控制磷素面源污染提供依据,以湘西州2000年和2014年耕地土壤有效磷含量为研究对象,利用空间自相关、半方差函数及分形维数等方法,对县域内土壤速效养分时空变异特征和环境风险进行了评价。结果表明,2014年土壤有效磷平均含量增加了30.89 mg/kg,增幅达425.48%;土壤有效磷Moran’s I指数标准化Z值下降,分形维数和块金效应增加,说明土壤有效磷空间结构减弱,随机变异性增强;土壤有效磷"极高"、"很高"和"高"等级面积显著增加,分别增加了28.36%、26.89%和25.94%;而"低"和"极低"等级面积分别下降了57.45%和27.12%;土壤有效磷含量与海拔、成土母质、土地利用类型、轮作模式及有机质含量关系密切;2014年湘西州有效磷含量超过风险临界值的概率大幅增加,很高风险(概率80%)、高风险(概率60%~80%)和中等风险(概率40%~60%)区域分别占研究区域面积的1.77%、5.40%和13.96%。其中,龙山县北部和永顺县东部应作为农业面源磷污染的重点控制区。 相似文献
3.
湘西植烟土壤pH时空变异及其主要驱动因素 总被引:2,自引:1,他引:1
4.
湖南郴州烟区土壤有机质和全氮时空变异及其影响因素研究 总被引:1,自引:0,他引:1
《土壤通报》2020,(3):686-693
为了探明湖南省郴州烟区土壤有机质和全氮的时空变化规律,从而为烟田有机物料投入和氮素养分管理提供科学依据,采用地统计学技术和地理信息技术相结合的方法,对该区2000年和2015年植烟土壤有机质和全氮时间和空间变异特征进行了研究。结果表明,2个年份有机质和全氮含量均十分丰富,2015年土壤有机质(SOM)和全氮(TN)平均含量较2000年分别增加了2.59 g kg~(-1)和0.04 g kg~(-1),变异系数基本稳定,极差变大,Moran's I下降,SOM块金效应基本稳定,TN块金效应显著增加;有机质"适宜"和"高"等级面积分别下降了12.07%和17.16%",极高"等级面积增加了29.47%;两个年份全氮含量"适宜"及以下的等级均缺失,2015年土壤全氮"高"等级面积下降了5.51%",极高"等级的面积增加了5.51%。上述结果表明郴州植烟土壤SOM和TN含量增加,极差变大,空间自相关性显著下降,而随机变异性增加。植烟土壤SOM与TN呈显著线性正相关。 相似文献
5.
为了研究龙山县植烟土壤有效硼分布状况及影响因素,以期为龙山县植烟土壤硼素的养分管理及特色优质烟叶开发提供理论依据;在龙山县采集植烟土壤样本294个,采用地统计学、多元统计学方法研究植烟土壤有效硼的空间分布及其影响因素,从描述性统计结果来看,龙山县植烟土壤有效硼含量总体丰富,平均值为0.792mg/kg,但变异较大,适宜样本比例为33.33%;从地统计分析结果来看,龙山县北部及东南部有效硼含量丰富,西部较为缺乏;影响因素研究的结果显示,随着海拔高度上升土壤有效硼呈先上升后下降的趋势;土壤有效硼与交换性钙及交换性镁呈极显著正相关关系;土壤有效硼含量随土壤有机质含量升高而升高;土壤有效硼含量随土壤pH值升高而升高。龙山县植烟土壤有效硼含量较为丰富,海拔高度、土壤质地和类型、有机质、pH值、交换性钙镁都影响土壤有效硼含量,土壤有效硼区域差异较大,建议在西部缺硼区域适当增施硼肥。 相似文献
6.
喀斯特地区植烟土壤有效硼含量分布及其影响因素—— 以湘西州烟区为例 总被引:6,自引:1,他引:5
采集湘西州488个植烟土壤样本,采用传统统计学和地统计学方法分析了湘西州植烟土壤有效硼含量分布及其影响因素。结果表明:①湘西州植烟土壤有效硼含量总体上略偏高,平均值为0.728 mg/kg,变幅在0.05?~?2.21 mg/kg,变异系数为53.46%,处于适宜范围内的样本占30.00%。②植烟土壤有效硼含量在空间分布上呈斑块状分布态势,永顺县的西部为一个低值区,东部为一个高值区。③蔬菜和油菜前茬的土壤有效硼含量相对较高;黄棕壤土壤的有效硼含量极显著地高于红灰土和红壤土类型。④有效硼含量有随海拔、pH、土壤有机质含量升高而升高的趋势。 相似文献
7.
湘西植烟土壤pH和主要养分特征及其相互关系 总被引:8,自引:1,他引:7
为了解湘西烟区植烟土壤pH和主要养分特征及其相互关系,于2015年采集烟区1 242个土壤样本,研究了植烟土壤pH、有机质、碱解氮、有效磷和速效钾的适宜性分布、县域分布以及pH与这些养分指标的量化关系。结果表明:1湘西烟区植烟土壤pH平均值为6.12,有20.77%样品偏酸和18.20%的样品偏碱;有机质和碱解氮含量的平均值分别为28.42 g/kg和145.63 mg/kg,总体上处于适宜水平;有效磷含量的平均值为28.94 mg/kg,有近40%样品偏高;速效钾含量平均值为198.76 mg/kg,有近45%的样品偏低。2主产烟县植烟土壤pH和养分差异极显著。3土壤主要养分含量与pH之间呈现曲线关系;当pH5.5时或pH8.0时,随土壤pH变化,主要养分含量变化较大;当pH在5.5~8.0时,随土壤pH变化,主要养分含量变化平缓。当pH5.5时,随土壤pH升高,有机质、碱解氮、有效磷和速效钾含量快速下降;当pH在5.5~8.0时,随土壤pH升高,有机质、有效磷和速效钾含量缓慢升高,碱解氮含量缓慢下降;当pH8.0时,随土壤pH升高,有机质、碱解氮、有效磷含量快速下降,速效钾含量快速升高。 相似文献
8.
不同海拔高度植烟土壤有效钙镁的分布状况——以云南曲靖烟区为例 总被引:3,自引:3,他引:3
为探明不同海拔高度植烟土壤有效Ca、Mg的差异和分布状况,采集了2552个曲靖烟区1300~2300m海拔高度土壤样品,利用数理统计和地统计学方法对其有效Ca、Mg进行了研究。结果表明:曲靖烟区土壤有效Ca、Mg含量平均为2640.86mg/kg、314.26mg/kg。中海拔地区土壤有效Ca含量最高,低与较低海拔地区土壤有效Ca含量适宜,高与较高海拔地区土壤有效Ca含量处于低水平范围内。随着海拔高度的增加,土壤有效Mg含量递减。低与较低海拔地区土壤有效Mg含量过高,其他地区适宜。土壤有效Ca、Mg含量与海拔高度呈极显著负相关。较低和低海拔地区土壤Ca/Mg比值显著低于其他地区,中海拔地区Ca/Mg比值最大。土壤有效Ca与有效P呈极显著负相关,与其他土壤养分指标呈极显著正相关,有效Mg与碱解N、有效P呈显著负相关,与其他土壤养分呈极显著正相关。曲靖烟区土壤有效Ca含量从东往西逐渐下降,有效Mg则是南北高,中间低,Ca/Mg比值在东部地区较大,而南北部地区和西部地区较小。 相似文献
9.
不同海拔高度植烟土壤pH值分布情况及其与土壤养分的关系——以云南省曲靖市为例 总被引:5,自引:1,他引:4
《土壤通报》2015,(1):105-110
分析了云南省曲靖不同海拔高度烟区3690个植烟土壤样本的p H和养分状况。研究表明:曲靖烟区土壤p H为6.3±0.9,变异系数为13.75%;p H处于适宜烤烟生长的5.0~7.0的土壤样本占到68.58%;该烟区海拔介于1322~2380 m,变化较大,土壤p H随海拔高度的增加而下降;将不同海拔高度进行分组后,呈现出土壤p H与土壤养分之间的相关性随海拔高度的变化而变化;按土壤p H进行分组后,土壤养分含量在组间存在极显著差异,在土壤p H为5.5~6.5时,土壤有机质、全氮、速效磷、有效钙、有效镁、有效铜、有效锰、有效硫含量均很丰富,土壤碱解氮、速效钾含量适中,土壤全磷、全钾、有效硼含量偏低。 相似文献
10.
【目的】研究云南大理烟区土壤有效磷的时空变异特征及分区,为优质烟草生产中磷素管理和面源污染控制提供科学依据。【方法】试验在云南大理开展,该区年均烤烟种植面积3.23万hm2左右,分别于1999、2012、2018和2022年选取5个典型植烟片区的代表性烟田256、633、1244和2332块,测定土壤有效磷含量,利用地统计学及GIS技术分析近40年5个时间段(1982、1999、2012、2018和2022年)大理5个植烟县域土壤有效磷时空变异特征,依据土壤有效磷含量现状进行合理施磷分区。【结果】烟区土壤有效磷含量呈逐渐升高趋势,1982—2022年有效磷含量由8.09 mg/kg升高到43.92 mg/kg,升高了4.42倍。1982年有效磷含量均处“低”等级(<20 mg/kg),1999—2022年以“中等”为主(20~40 mg/kg),面积占比50%以上。近40年土壤有效磷块金效应由<25%上升至41.45%,表明地形等自然因素影响减弱,施肥等人为因素影响增强。根据当前有效磷含量,高磷区和极高磷区面积占比34.21%,主要分布于弥渡北部、祥云西部及宾川西南和东北。... 相似文献
11.
天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:13,自引:1,他引:12
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
12.
天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:3,自引:0,他引:3
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
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14.
Sediment denitrification in waterways in a rice-paddy-dominated watershed in eastern China 总被引:1,自引:0,他引:1
Xiaobo Li Yongqiu Xia Yuefei Li Todd M. Kana Sonoko D. Kimura Masanori Saito Xiaoyuan Yan 《Journal of Soils and Sediments》2013,13(4):783-792
Purpose
Rice-paddy-dominated watersheds in eastern China are intensively cultivated, and lands with two crops receive as much as 550–600 kg?ha–1?year–1 of nitrogen (N), mainly through the addition of N-based fertilizers. However, stream N concentrations have been found to be relatively low. Waterways in the watersheds are assumed to be effective “sinks” for N, minimizing its downstream movement. We directly measured net sediment denitrification rates in three types of waterways (ponds, streams/rivers, and a reservoir) and determined the key factors that control net sediment denitrification. Such information is essential for evaluating the impact of the agricultural N cycle on the quality of surface water.Materials and methods
The pond–stream–reservoir continuum was sampled every 2 months at nine sites in an agricultural watershed between November 2010 and December 2011. Net sediment N2 fluxes/net sediment denitrification rates were determined by membrane inlet mass spectrometry and the N2/Ar technique. A suite of parameters known to influence denitrification were also measured.Results and discussion
Net denitrification rates ranged between 28.2?±?18.2 and 674.3?±?314.5 μmol N2–N?m–2?h–1 for the streams, 23.7?±?23.9 and 121.2?±?38.7 μmol N2–N?m–2?h–1 for the ponds, and 41.8?±?17.7 and 239.3?±?49.8 μmol N2–N?m–2?h–1 for the reservoir. The mean net denitrification rate of the stream sites (173.2?±?248.4 μmol N2–N?m–2?h–1) was significantly higher (p?<?0.001) than that of the pond sites (48.3?±?44.5 μmol N2–N?m–2?h–1), and the three types of waterways all had significantly higher (p?<?0.01) mean net denitrification rates in summer than in other seasons. Linear regression and linear mixed effect model analysis showed that nitrate (NO3 ?–N) concentration in surface water was the primary controlling factor for net sediment denitrification, followed by water temperature. Using monitoring data on NO3 ?–N concentrations and temperature of the surface water of waterways and an established linear mixed effect model, total N removed through net sediment denitrification in the pond–stream–reservoir continuum was estimated at 46.8?±?24.0 t?year–1 from July 2007 to June 2009, which was comparable with earlier estimates based on the mass balance method (34.3?±?12.7 t?year–1), and accounted for 83.4 % of the total aquatic N. However, the total aquatic N was only 4.4 % of the total N input to the watershed, and thus most of the surplus N in the watershed was likely to be either denitrified or stored in soil.Conclusions
High doses of N in a rice-paddy-dominated watershed did not lead to high stream N concentrations due to limited input of N into waterways and the high efficiency of waterways in removing N through denitrification. 相似文献15.
中国华北地区近40年物候春季变化 总被引:17,自引:4,他引:17
根据华北地区7个观测站物候资料,分析了华北地区1963-1996年及北京1963-2005年物候春季的变化特征及其与气温的关系。结果表明:华北地区的物候春季有明显提早来临的趋势,而造成这一变化的主要因素是本地区近40 a来冬春季气温的明显上升。其中1963-1996年间华北地区1-3月及4月的平均气温分别上升了2.3℃与1.7℃,物候春季起止日期分别提前了9d和4d,因而使得春季长度也延长了5d;北京1963-2003年间1-3月及4月的平均气温分别上升了3.5℃与2.6℃,物候春季的起止日期分别提前了11d和10d,但春季长度没有明显变化。 相似文献
16.
Water, Air, & Soil Pollution - Epiphytic lichens were sampled in a Dutch national monitoring survey, which was carried out twice within 5 yr. The samples were analyzed by neutron activation... 相似文献
17.
Howard B. Ross 《Water, air, and soil pollution》1987,36(3-4):349-363
Trace metals (Cd, Cu, Fe, Mn, Pb, and Zn) concentrations in atmospheric precipitation have been routinely monitored in Sweden since the autumn of 1983. Concentrations are highest in southern Sweden and decrease northward. It is postulated that the long range transport of anthropogenic pollutants from the rest of Europe is the major source of Cd, Pb, and Zn in precipitation. Evidence for this hypothesis is that enrichment factors indicate anthropogenic origin, and Swedish atmospheric emissions of Zn and Cd are 2 to 3 times smaller than deposition fluxes. Also, Cd, Pb, and Zn concentrations are correlated in both space and time and are also well correlated with exSO4 +, a substance known to be of anthropogenic origin transported long distances. 相似文献
18.
Phytoremediation is an emerging technology based on the use of green plants to remove, contain, inactivate or destroy harmful
environmental pollutants. Recent developments in Europe and the USA show that the approach is somewhat different on both sides
of the Atlantic. In Europe, phytoremediation has more basically been research driven and, based on the outcomes, applications
have been envisaged. By contrast, the approach in the USA is more application and experience driven. In spite of a growing
track record of commercial success, more demonstration projects are needed to prove that phytoremediation is effective in
order to rigorously measure its underlying economics, and to expand its applications. More fundamental research is also required
to better understand the complex interactions between pollutants, soil, plant roots and micro-organisms at the rhizosphere
level, to increase the bioavailability of pollutants, to fully exploit the metabolic diversity of plants and, thus, to successfully
implement this new green technology. 相似文献
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Shu Wang 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(7):583-589
Proteolytic bacterial communities, which mineralize organic nitrogen, play a key role in agricultural systems. In this study, alkaline metalloprotease (apr) gene fragments from proteolytic bacteria were investigated in bulk and rhizosphere paddy soil from four fields under organic management (for 2, 3, 5, and 9 years), and from one field under conventional management (for 2 years). We analyzed the abundance and structure of the proteolytic bacterial communities using real-time quantitative PCR and denaturing gradient gel electrophoresis. Our results showed that the abundance of proteolytic bacteria ranged from 1.57?×?108 to 8.02?×?108?copies/g of soil. In addition, the abundance of the proteolytic bacteria in the paddy soils under organic management was significantly higher than those in the paddy soil under conventional management. Moreover, the gene copy numbers in the rhizosphere soils were significantly higher than those in the bulk soils. The abundance of proteolytic bacteria tended to increase with the duration of organic management, with the highest abundance being found in the soil that had been under organic management for 5 years. However, the proteolytic bacteria communities in the paddy soils were not significantly affected by management practices. Phylogeny analysis showed that all gel bands obtained represented genes from Pseudomonas. Additionally, correlation analysis and canonical correspondence analysis showed that C/N, C, and N were important factors that influenced the abundance and community structure of the proteolytic bacteria. These results suggest that proteolytic bacteria are indicators in organic management systems, depolymerize organic N and hence maintain soil sustainability.Abbreviations: CM: conventional management; OM: organic management; DGGE: denaturing gradient gel electrophoresis; qPCR: real-time quantitative PCR detecting system; COFCC: China organic food certification center; CCA: canonical correspondence analysis 相似文献