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1. chinaXiv:201802.00449 [pdf]

Carbon storage in a wolfberry plantation chronosequence established on a secondary saline land in an arid irrigated area of Gansu Province, China

MA Quanlin; WANG Yaolin; LI Yinke; SUN Tao; Eleanor MILNE
分类: 农、林、牧、渔 >> 土壤学

Carbon (C) storage has received significant attention for its relevance to agricultural security and climate change. Afforestation can increase C storage in terrestrial ecosystems, and has been recognized as an important measure to offset CO2 emissions. In order to analyze the C benefits of planting wolfberry (Lycium barbarum L.) on the secondary saline lands in arid areas, we conducted a case study on the dynamics of biomass carbon (BC) storage and soil organic carbon (SOC) storage in different-aged wolfberry plantations (4-, 7- and 11-year-old) established on a secondary saline land as well as on the influence of wolfberry plantations on C storage in the plant-soil system in an arid irrigated area (Jingtai County) of Gansu Province, China. The C sequestration and its potential in the wolfberry plantations of Gansu Province were also evaluated. An intact secondary saline land was selected as control. Results show that wolfberry planting could decrease soil salinity, and increase BC, SOC and litter C storage of the secondary saline land significantly, especially in the first 4 years after planting. The aboveground and belowground BC storage values in the intact secondary saline land (control) accounted for only 1.0% and 1.2% of those in the wolfberry plantations, respectively. Compared to the intact secondary saline land, the SOC storage values in the 4-, 7- and 11-year-old wolfberry plantations increased by 36.4%, 37.3% and 43.3%, respectively, and the SOC storage in the wolfberry plantations occupied more than 92% of the ecosystem C storage. The average BC and SOC sequestration rates of the wolfberry plantations for the age group of 0–11 years were 0.73 and 3.30 Mg C/(hm2•a), respectively. There were no significant differences in BC and SOC storage between the 7-year-old and 11-year-old wolfberry plantations, which may be due in part to the large amounts of C offtakes in new branches and fruits. In Gansu Province, the C storage in the wolfberry plantations has reached up to 3.574 Tg in 2013, and the C sequestration potential of the existing wolfberry plantations was 0.134 Tg C/a. These results indicate that wolfberry planting is an ideal agricultural model to restore the degraded saline lands and increase the C sequestration capacity of agricultural lands in arid areas.

提交时间: 2018-02-07 来自合作期刊:《Journal of Arid Land》 点击量89下载量36 评论 0

2. chinaXiv:201801.00772 [pdf]

Potassium forms in calcareous soils as affected by clay minerals and soil development in Kohgiluyeh and Boyer-Ahmad Province, Southwest Iran

Sirous SHAKERI; Seyed A ABTAHI
分类: 农、林、牧、渔 >> 土壤学

Potassium (K) is known as one of the essential nutrients for the growth of plant species. The relationship between K and clay minerals can be used to understand the K cycling, and assess the plant uptake and potential of soil K fertility. This study was conducted to analyze the K forms (soluble, exchangeable, non-exchangeable and structural) and the relationship of K forms with clay minerals of calcareous soils in Kohgiluyeh and Boyer-Ahmad Province, Southwest Iran. The climate is hotter and drier in the west and south of the province than in the east and north of the province. A total of 54 pedons were dug in the study area and 32 representative pedons were selected. The studied pedons were mostly located on calcareous deposits. The soils in the study area can be classified into 5 orders including Entisols, Inceptisols, Mollisols, Alfisols and Vertisols. The main soil clay minerals in the west and south of the study area were illite, chlorite and palygorskite, whereas they were smectite, vermiculite and illite in the north and east of the province. Due to large amount of smectite and high content of organic carbon in soil surface, the exchangeable K in surface soils was higher than that in subsurface soils. It seems that organic matter plays a more important role than smectite mineral in retaining exchangeable K in the studied soils. Non-exchangeable K exhibited close relationships with clay content, illite, vermiculite and smectite. Although the amount of illite was the same in almost all pedons, amounts of structural and non-exchangeable K were higher in humid regions than in arid and semi-arid regions. This difference may be related to the poor reservoir of K+ minerals like palygorskite and chlorite together with illite in arid and semi-arid regions. In humid areas, illite was accompanied by vermiculite and smectite as the K+ reservoir. Moreover, the mean cumulative non-exchangeable K released by CaCl2 was higher than that released by oxalic acid, which may be due to the high buffering capacity resulting from high carbonates in soils.

提交时间: 2018-01-29 来自合作期刊:《Journal of Arid Land》 点击量32下载量29 评论 0

3. chinaXiv:201801.00773 [pdf]

Vertical distribution and storage of soil organic and inorganic carbon in a typical inland river basin, Northwest China

YANG Fan; HUANG Laiming; YANG Renmin; YANG Fei; LI Decheng; ZHAO Yuguo; YANG Jinling; LIU Feng; ZHANG Ganlin
分类: 农、林、牧、渔 >> 土壤学

Knowledge of soil carbon (C) distribution and its relationship with the environment can improve our understanding of its biogeochemical cycling and help to establish sound regional models of C cycling. However, such knowledge is limited in environments with complex landscape configurations. In this study, we investigated the vertical distribution and storage of soil organic carbon (SOC) and soil inorganic carbon (SIC) in the 10 representative landscapes (alpine meadow, subalpine shrub and meadow, mountain grassland, mountain forest, typical steppe, desert steppe, Hexi Corridor oases cropland, Ruoshui River delta desert, Alxa Gobi desert, and sandy desert) with contrasting bioclimatic regimes in the Heihe River Basin, Northwest China. We also measured the 87Sr/86Sr ratio in soil carbonate to understand the sources of SIC because the ratio can be used as a proxy in calculating the contribution of pedogenic inorganic carbon (PIC) to total SIC. Our results showed that SOC contents generally decreased with increasing soil depth in all landscapes, while SIC contents exhibited more complicated variations along soil profiles in relation to pedogenic processes and parent materials at the various landscapes. There were significant differences of C stocks in the top meter among different landscapes, with SOC storage ranging from 0.82 kg C/m2 in sandy desert to 50.48 kg C/m2 in mountain forest and SIC storage ranging from 0.19 kg C/m2 in alpine meadow to 21.91 kg C/m2 in desert steppe. SIC contributed more than 75% of total C pool when SOC storage was lower than 10 kg C/m2, and the proportion of PIC to SIC was greater than 70% as calculated from Sr isotopic ratio, suggesting the critical role of PIC in the C budget of this region. The considerable variations of SOC and SIC in different landscapes were attributed to different pedogenic environments resulted from contrasting climatic regimes, parent materials and vegetation types. This study provides an evidence for a general trade-off pattern between SOC and SIC, showing the compensatory effects of environmental conditions (especially climate) on SOC and SIC formation in these landscapes. This is largely attributed to the fact that the overall decrease in temperature and increase in precipitation from arid deserts to alpine mountains simultaneously facilitate the accumulation of SOC and depletion of SIC.

提交时间: 2018-01-29 来自合作期刊:《Journal of Arid Land》 点击量25下载量22 评论 0

4. chinaXiv:201801.00510 [pdf]

Effects of mulches on water use in a winter wheat/ summer maize rotation system in Loess Plateau, China

YIN, Minhua; LI, Yuannong; XU, Yuanbo; ZHOU, Changming
分类: 农、林、牧、渔 >> 农艺学

Limited water resources often result in reduced crop yield and low water productivity (WP). In northwestern China, crop production is generally dependent on precipitation. Therefore, a variety of agricultural rainwater harvesting (ARH) techniques have been used for conserving soil moisture, ameliorating soil environment, increasing crop yield, and improving water use efficiency. A two-year (2013–2015) field experiment was conducted under a typical sub-humid drought-prone climate in Yangling (108°24′E, 34°20′N; 521 m a.s.l.), Shaanxi Province, China, to explore the effects of mulching (same for summer maize and winter wheat) on soil moisture, soil temperature, crop water consumption, and crop yield with a winter wheat/summer maize rotation. Crops were planted in a ridge-furrow pattern and the treatments consisted of a transparent film mulch over the ridges (M1), a crop straw mulch in the furrows (M2), a transparent film mulch over the ridges and a crop straw mulch in the furrows (M3), a black film mulch over the ridges and a crop straw mulch in the furrows (M4), and a control with no mulch (CK). Results showed that M4 was the best treatment for improving soil water storage and content, and decreasing crop water consumption during the summer maize and winter wheat rotation. In both maize and wheat seasons, M1 had a higher soil temperature than M2 and CK, and M3 had a higher soil temperature than M4. In the maize seasons, M4 had the highest yield, WP, and precipitation productivity (PP), with the average values for these parameters increasing by 30.9%, 39.0%, and 31.0%, respectively, compared to those in CK. In the wheat seasons, however, M3 had the highest yield, WP, and PP, with the average values for these parameters being 23.7%, 26.7%, and 23.8% higher, respectively, than those in CK. Annual yield (maize and wheat yields combined) and WP did not differ significantly between M3 and M4. These results suggested that M3 and M4 may thus be the optimal ARH practices for the production of winter wheat and summer maize, respectively, in arid and semi-arid areas.

提交时间: 2018-01-23 来自合作期刊:《Journal of Arid Land》 点击量240下载量43 评论 0

5. chinaXiv:201801.00129 [pdf]

Utilizing a new soil effective temperature scheme and archived satellite microwave brightness temperature data to estimate surface soil moisture in the Nagqu region, Tibetan Plateau of China

TIAN Hui; Mudassar IQBAL
分类: 农、林、牧、渔 >> 土壤学

Since the early 2000s, many satellite passive microwave brightness temperature (BT) archives, such as the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) BTs, have become the useful resources for assessing the changes in the surface and deep soil moistures over both arid and semi-arid regions. In this study, we used a new soil effective temperature (Teff) scheme and the archived AMSR-E BTs to estimate surface soil moisture (SM) over the Nagqu region in the central Tibetan Plateau, China. The surface and deep soil temperatures required for the calculation of regional-scale Teff were obtained from outputs of the Community Land Model version 4.5 (CLM4.5). In situ SM measurements at the CEOP-CAMP/Tibet (Coordinated Enhanced Observing Period Asia-Australia Monsoon Project on the Tibetan Plateau) experimental sites were used to validate the AMSR-E-based SM estimations at regional and single-site scales. Furthermore, the spatial distribution of monthly mean surface SM over the Nagqu region was obtained from 16 daytime AMSR-E BT observations in July 2004 over the Nagqu region. Results revealed that the AMSR-E-based surface SM estimations agreed well with the in situ-based surface SM measurements, with the root mean square error (RMSE) ranging from 0.042 to 0.066 m3/m3 and the coefficient of determination (R2) ranging from 0.71 to 0.92 during the nighttime and daytime. The regional surface soil water state map showed a clear spatial pattern related to the terrain. It indicated that the lower surface SM values occurred in the mountainous areas of the northern, mid-western and southeastern parts of Nagqu region, while the higher surface SM values appeared in the low elevation areas such as the Tongtian River Basin, Namco Lake and bog meadows in the central part of Nagqu region. Our analysis also showed that the new Teff scheme does not require special fitting parameters or additional assumptions, which simplifies the data requirements for regional-scale applications. This scheme combined with the archived satellite passive microwave BT observations can be used to estimate the historical surface SM for hydrological process studies over the Tibetan Plateau regions.

提交时间: 2018-01-10 来自合作期刊:《Journal of Arid Land》 点击量46下载量40 评论 0

6. chinaXiv:201712.00399 [pdf]

Spatio-temporal variations of soil water content and salinity around individual Tamarix ramosissima in a semi-arid saline region of the upper Yellow River, Northwest China

YANG Benman; WANG Ruoshui; XIAO Huijie; CAO Qiqi; LIU Tao
分类: 农、林、牧、渔 >> 土壤学

Ecological restoration by Tamarix plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations of soil water content and salinity around natural individual Tamarix ramosissima Ledeb. were investigated in a semi-arid saline region of the upper Yellow River, Northwest China. Specifically, soil water content, electrical conductivity (ECe), sodium adsorption ratio (SARe), and salt ions (including Na+, K+, Ca2+, Mg2+ and SO42–) were measured at different soil depths and at different distances from the trunk of T. ramosissima in May, July, and September 2016. The soil water content at the 20–80 cm depth was significantly lower in July and September than in May, indicating that T. ramosissima plants absorb a large amount of water through the roots during the growing period, leading to the decreasing of soil water content in the deep soil layer. At the 0–20 cm depth, there was a salt island effect around individual T. ramosissima, and the ECe differed significantly inside and outside the canopy of T. ramosissima in May and July. Salt bioaccumulation and stemflow were two major contributing factors to this difference. The SARe at the 0–20 cm depth was significantly different inside and outside the canopy of T. ramosissima in the three sampling months. The values of SARe at the 60–80 cm depth in May and July were significantly higher than those at the 0–60 cm depth and higher than that at the corresponding depth in September. The distribution of Na+ in the soil was similar to that of the SARe, while the concentrations of K+, Ca2+, and Mg2+ showed significant differences among the sampling months and soil depths. Both season and soil depth had highly significant effects on soil water content, ECe and SARe, whereas distance from the trunk of T. ramosissima only significantly affected ECe. Based on these results, we recommend co-planting of shallow-rooted salt-tolerant species near the Tamarix plants and avoiding planting herbaceous plants inside the canopy of T. ramosissima for afforestation in this semi-arid saline region. The results of this study may provide a reference for appropriate restoration in the semi-arid saline regions of the upper Yellow River.

提交时间: 2017-12-08 来自合作期刊:《Journal of Arid Land》 点击量89下载量81 评论 0

7. chinaXiv:201711.02327 [pdf]

县域农业生态文明评价指标体系及实证研究——以石家庄市为例

刘若莎; 赵儒丹; 李振勤; 赵好战
分类: 农、林、牧、渔 >> 农业基础学科

农业生态文明在我国生态文明建设中占重要部分, 建设县域农业生态文明评价指标体系, 可判断县域农业生态文明水平, 并因县施策, 对构建科学合理的农业发展格局具有重要意义。本文从农业生态文明建设的角度出发, 以区间层次分析法和聚类分析法为基础, 选取生态、经济、社会和协调发展4 个领域22 个指标构建县域农业生态文明评价指标体系, 并以河北省石家庄市17 个县域为例, 应用2012 年统计数据, 对县域农业生态文明进行了单领域分析及生态文明综合评价, 并提出相应对策及建议, 为农业生态文明建设提供更为完善的理论基础。结果显示, 石家庄新乐市、平山县、藁城市、栾城县、灵寿县、鹿泉市、晋州市在生态领域的整体优势显著, 藁城市、辛集市、鹿泉市、正定县在经济领域的整体评价较好, 平山县与栾城县的社会领域优势最为明显,赞皇县、藁城市、晋州市、无极县的社会领域整体最差; 在协调发展领域, 藁城市、鹿泉市、栾城县协调发展领域整体较好。对县域农业生态文明进行综合分析得出: 指标水平的高低是由4 个领域共同决定, 且经济领域影响较大, 大部分经济领域较强的区县, 综合水平较高。以上说明经济建设、社会发展和协调因素等有力地支持了农业生态文明建设和发展。因此, 在石家庄市农业生态文明建设过程中要充分认识各县域之间的生态、社会、经济发展水平, 坚持因地制宜, 分区施策的原则, 提高各县域农业发展水平, 优化生态农业发展格局。

提交时间: 2017-11-10 来自合作期刊:《中国生态农业学报》 点击量197下载量138 评论 0

8. chinaXiv:201711.02328 [pdf]

辽河干流坝间耕地土壤重金属污染特征研究

刘 强; 张婉秋; 周贵宇; 梁 雷; 白晓亮; 陈 杨
分类: 农、林、牧、渔 >> 农业基础学科

通过对辽河干流坝间10 个断面耕地土壤0~5 cm、5~15 cm、15~30 cm 沉积层重金属铜、镉、锌、铅含量测定, 评价了该区土壤重金属污染程度, 并采用地质累积指数法评价单一重金属污染状况与潜在生态危害指数, 综合评价重金属生态危害程度。研究结果表明, 该区土壤铜、铅、锌与镉含量均值分别为32.42 mgkg1、38.23 mgkg1、47.35 mgkg1 和1.625 mgkg1; 铅、锌含量均值在达牛渡口最大, 分别为55.54 mgkg1 和80.51 mgkg1; 铜、镉含量均值在通江口处最大, 分别为50.24 mgkg1 和3.103 mgkg1。除镉外, 铅、铜、锌含量各断面不同深度浓度均低于全国土壤环境质量Ⅱ级标准, 镉含量均值是全国土壤环境质量Ⅱ级标准的1.70 倍, 最大值为3.402 mgkg1;辽河大桥上游干流镉含量是下游镉含量的6.47 倍。镉的地质累积指数值在坝间均显污染, 其中, 辽河大桥以上各断面显强污染。通江口至毓宝台特大桥重金属潜在生态风险指数值最强。各断面镉对多种金属潜在生态风险指数值的贡献达78.77%~98.23%, 贡献率与潜在生态危害指数(RI)呈正相关。多种重金属潜在生态风险指 数值变化趋势与镉地质积累指数分布趋势相同, 最大值出现于通江口断面。

提交时间: 2017-11-10 来自合作期刊:《中国生态农业学报》 点击量313下载量128 评论 0

9. chinaXiv:201711.02329 [pdf]

河北板蓝根产地土壤-植物中镉铅汞砷含量特征及其污染评价

耿丽平; 高宁大; 赵全利; 薛培英; 刘文菊
分类: 农、林、牧、渔 >> 农业基础学科

采用野外调查和室内分析相结合的方法, 研究了河北省安国市和蔚县板蓝根产地土壤-植物中Cd、Pb、Hg、As 含量特征及其在菘蓝中的累积特性, 并对板蓝根产地土壤和草药中Cd、Pb、Hg、As 污染状况进 行了评价, 为该地区安全、合理地发展中草药生产提供数据支撑和科学依据。结果表明, 安国市和蔚县板蓝根产地土壤中重金属Cd、Pb、Hg、As 含量差异不大, 土壤重金属含量的变异系数11.70%~97.65%。以《土壤环境质量标准》(GB 15618—1995)一级标准值进行评价, 综合污染指数评价结果显示45%板蓝根种植区土壤Cd、Pb、Hg、As 污染等级为警戒限, 其他处于清洁水平; 而以《土壤环境质量标准》二级标准值进行评价, 种植区单项污染指数及综合污染指数结果均<0.7, 土壤环境清洁。此外, 菘蓝地上部(大青叶)Cd、Pb、Hg、As平均含量分别为0.22 mg·kg1、0.89 mg·kg1、0.04 mg·kg1、0.25 mg·kg1, 对重金属的富集能力表现为Cd>Hg>Pb>As; 菘蓝地下部(板蓝根)Cd、Pb、Hg、As 含量均值分别为0.14 mg·kg1、0.57 mg·kg1、0.04 mg·kg1、0.26 mg·kg1, 对重金属的富集能力表现为Cd>Hg>As>Pb。所有菘蓝样品中Pb、Hg、As 含量均未超出《药用植物及制剂进口绿色行业标准》(WM2—2001), 大青叶9.09%样品中Cd 超标, 且Cd 平均污染指数>0.7, 属警戒限污染等级。因此, 在中药材GAP(良好的农业规范)产地环境质量评价时, 除板蓝根产地土壤完全符合土壤环境质量二级标准外, 也不应忽视板蓝根和大青叶吸收和累积重金属的自身特性。

提交时间: 2017-11-10 来自合作期刊:《中国生态农业学报》 点击量270下载量136 评论 0

10. chinaXiv:201711.02330 [pdf]

有机和常规苹果生产环境影响的生命周期评价

蔡宇杰; 乔玉辉; 徐 敬; 孟凡乔; 吴文良
分类: 农、林、牧、渔 >> 农业基础学科

本文以我国园艺产业中的重要果品——苹果的生产为研究对象, 通过实地调研, 采用生命周期评价方法, 对山西浮山、陕西白水和甘肃天水等3 个代表性地区的有机及常规苹果生产的环境影响进行了研究, 以期为我国农业可持续发展和生态文明建设提供科学依据。结果表明, 山西浮山的有机苹果生产养分利用效率高于常规苹果, 陕西白水和甘肃天水相反。3 个地区单位苹果有机生产方式的能源消耗均占常规方式的26%以下,有机生产的能量利用效率高于常规生产。在能源消耗、全球变暖、环境酸化以及富营养化等4 类环境影响中, 富营养化对环境影响的贡献最大, 均占80%以上。有机和常规苹果生产的环境影响按照大小均表现为陕西白水>甘肃天水>山西浮山。由于山西浮山有机苹果的肥料等投入远低于常规苹果生产, 产量相差不大, 因而表现为有机苹果的综合环境影响仅为常规苹果的22%; 陕西白水和甘肃天水呈现相反的情形, 其有机苹果的综合环境影响分别是常规苹果的356%和138%。在高量有机养分投入的前提下, 有机农业可以达到和常规农业相当的作物产量, 但其代价是较高的负面环境影响和较低的养分和能源利用效率。

提交时间: 2017-11-10 来自合作期刊:《中国生态农业学报》 点击量286下载量131 评论 0

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