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| 1 | Estimate of CH_4 Emissions from Year-Round Flooded Rice Fields During Rice Growing Season in China显示文摘A special kind of rice field exists in China that is flooded year-round. These rice fields have substantially large CH4emissions during the rice-growing season and emit CH4 continuously in the non-rice growing season. CH4 emission factors were used to estimate the CH4 emissions from year-round flooded rice fields during the rice-growing season in China.The CH4 emissions for the year-round flooded rice fields in China for the rice growing season over a total area of 2.66Mha were estimated to be 2.44 Tg CH4 year-1. The uncertainties of these estimations are discussed as well. However,the emissions during the non-rice growing season could not be estimated because of limited available data. Nevertheless,methane emissions from rice fields that were flooded year-round could be several times higher than those from the rice fields drained in the non-rice-growing season. Thus, the classification of 'continuously flooded rice fields' in the IPCC(International Panel on Climate Change) Guidelines for National Greenhouse Gas Inventories is suggested to be revised and divided into 'continuously flooded rice fields during the rice growing season' and 'year-round flooded rice fields'. | CAIZu-Cong KANGGuo-Ding H.TSURUTA A.MOSIER | 2005 | Pedosphere2005，15，1： | 91 |
| 2 | Litter Dynamics of Three Subalpine Forests in Western Sichuan显示文摘Litter production, components and dynamics were investigated and forest floor litter was quantified throughout awhole year in three subalpine forests, dominated by tree species of spruce (SF), fir (FF) and birch (BF), in WesternSichuan, China, in order to understand the key factors that influenced litter production and dynamics. Litterfall in thethree forests consisted mainly of leaves, woody litter, reproductive organs and moss. Contribution of leaf litter to thetotal litterfall was significantly (P < 0.05) greater than that of woody litter, reproductive organs or moss. Regardlessof the stands, litterfall exhibited a marked monthly variation with the maximum litterfall peaks occurring in October,with smaller peaks occurring in February for SF and FF, and May for BF. The analysis indicated that tree species,stand density, leaf area index (LAI), stand basal area and stand age were the key factors determining litter production.Meanwhile tree species and phenology controlled the litter dynamics, with wind and snow modifying the litter componentsand dynamics. | YANG Wan-Qin WANG Kai-Yun S. KELLOMAKI GONG He-De | 2005 | Pedosphere2005，15，5： | 81 |
| 3 | Effect of Soil Drought Stress on Leaf Water Status, Membrane Permeability and Enzymatic Antioxidant System of Maize显示文摘A simulation experiment on the responses of maize (Zea mays L.) from the third leaf stage to maturity for different soil water levels (well-watered, moderately stressed, and severely stressed) was conducted by controlling irrigation and using a mobile rain shelter in a neutral loam, meadow soil to determine the effects on leaf water status, membrane permeability and enzymatic antioxidant system for different growth stages. The results indicated that drought stress relied on drought intensity and duration, with more severe drought stress creating more serious effects on maize. Compared with well-watered conditions, during the silking and blister stages moderate stress did not significantly change the relative water content (RWC) and did change significantly the relative conductivity (RC) (P < 0.05) of the leaves; however, severe stress did significantly decrease (P < 0.01) the leaf RWC and increase (P < 0.01) membrane permeability (leaf relative conductivity). Furthermore, under severe drought stress antioxidant enzyme activities declined significantly (P < 0.01) in later stages, namely for superoxide dismutase (SOD) the tasseling and blister stages, for peroxidase (POD) the milk stage, and for catalase (CAT) during the tasseling, blister, and milk stages. Meanwhile, membrane lipid peroxidation (measured as malondialdehyde content) significantly increased (P < 0.01) in all stages. | BAI Li-Ping SUI Fang-Gong GE Ti-Da SUN Zhao-Hui LU Yin-Yan ZHOU Guang-Sheng | 2006 | Pedosphere2006，16，3： | 82 |
| 4 | Effect of Vegetation Changes on Soil Erosion on the Loess Plateau显示文摘Vegetation is one of the key factors affecting soil erosion on the Loess Plateau. The effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from long-term field runoff plots established on the eastern slope of the Ziwuling secondary forest region, China and a field survey. The results showed that before the secondary vegetation restoration period (before about 1866-1872), soil erosion in the Ziwuling region of the Loess Plateau was similar to the current erosion conditions in neighboring regions, where the soil erosion rate now is 8000 to 10000 t km-2 year-1. After the secondary vegetation restoration, soil erosion was very low; influences of rainfall and slope gradient on soil erosion were small; the vegetation effect on soil erosion was predominant; shallow gully and gully erosion ceased; and sediment deposition occurred in shallow gully and gully channels. In modern times when human activities destroyed secondary forests, soil erosion increased markedly, and erosion rates in the deforested lands reached 10000 to 24000 t km-2 year-1, which was 797 to 1682 times greater than those in the forested land prior to deforestation. Rainfall intensity and landform greatly affected the soil erosion process after deforestation. These results showed that accelerated erosion caused by vegetation destruction played a key role in soil degradation and eco-environmental deterioration in deforested regions. | ZHENG Fen-Li | 2006 | Pedosphere2006，16，4： | 93 |
| 5 | Spatial Variability of Nutrient Properties in Black Soil of Northeast China显示文摘A total of 1400 soil samples from the plow layer (0-20 cm) at an approximate interval of 5 km were collected in the autumn of 2002 over the entire black soil arable crops region to determine the spatial variability of seven variables, such as total organic matter content (OMC), total N, total P, total K, alkali-dissolvable N (AN), available P (AP) and available K (AK), with classical statistics and geostatistical analysis across the entire black soil area in Northeast China. In nonsampled areas ordinary kriging was utilized for interpolation of estimated nutrient determinations. Classical statistics revealed highly significant (P≤0.01) correlations with all seven of the soil properties, except for OMC with AP and total K with AK. In addition, using coefficients of variation, all soil properties, except for total K, were moderately variable. A geostatistical analysis indicated that structural factors, such as parent material, terrain, and water table, were the main causes of the spatial correlations. Strong spatial correlations were noted with OMC, total N, total P, AN, and AP, while they were moderate for total K and AK. The effective spatial autocorrelation of OMC, total N, total P, and AN ranged from 1 037 to 1 353 km, whereas the ranges of total K, AP, and AK were only from 6 to 138 km. The fit of the experimental semi-variograms to the theoretical models indicated that except for AN, kriging could successfully interpolate other six variables. Thus, the geostatistical method used on a large scale could accurately evaluate the spatial variability of most black soil nutrient properties in Northeast China. | ZHANG Xing-Yi SUI Yue-Yu ZHANG Xu-Dong MENG Kai S. J. HERBERT | 2007 | Pedosphere2007，17，1： | 118 |
| 6 | Nitrogen Balance and Loss in a Greenhouse Vegetable System in Southeastern China显示文摘High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however,the N budgets of such intensive vegetable production remain to be explored.The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato,cucumber,and celery at five N (urea) application rates (0,348,522,696,and 870 kg N ha-1 year-1).Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha-1,and N fertilizer was the main N source,accounting for 66%-83% of the total annual N input.In comparison,irrigation water,wet deposition,and seeds in total accounted for less than 1% of the total N input.The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha-1 and decreased as the application rate increased from 522 to 870 kg N ha-1.Apparent N losses were 196-201 kg N ha-1,of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha-1.Thus,leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season.Moreover,dissolved organic N accounted for 10% of the leached N,whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system. | MIN Ju ZHAO Xu SHI Wei-Ming XING Guang-Xi ZHU Zhao-Liang | 2011 | Pedosphere2011，21，4： | 91 |
| 7 | Heavy Metals, Phosphorus and Some Other Elements in Urban Soils of Hangzhou City, China显示文摘Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urban soils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals,phosphorus (P) and 8 other elements from topsoil samples collected at 82 locations in Hangzhou City were measured to:a) assess their distribution in urban environments; and b) understand their differentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionation procedure. About 8.5%,1.2%,3.6%,11.0% and 30.3% of the soil samples had Cd,Cr,Cu,Pb,and Zn concentrations,respectively,above their allowable limits for public and private green areas and residential use. However,in commercial and industrial areas,most samples had metal concentrations below their allowable limits. Statistical analyses revealed that the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sources using a hierarchical cluster analysis. Additionally,Cu,Pb,and P showed similar spatial distributions with significant pollution in commercial zones,suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also,Cd,Co,Cr,Ni,Zn,Mn and Fe had the highest concentrations in industrial locations,signifying that industrial activities were the main sources of these seven metals. Moreover,the data highlighted land-use as a major influence on heavy metal concentrations and forms found in topsoils with large proportions of soil Cd,Co,Cr,and Ni found in residual fractions and soil Cu,Pb and Zn mainly as extractable fractions. | ZHANGMing-Kui KEZi-Xia | 2004 | Pedosphere2004，14，2： | 93 |
| 8 | A Review of Methods for Studying Microbial Diversity in Soils显示文摘Soil microorganisms play a central role in decomposing organic matter, in determining the release of mineral nutrients, and in nutrient cycling. Recently, extensive studies have focused on soil microbial diversity. However, understanding the diversity of this complex microbial community in the soil environment is a challenging task. Thus, it is important to master and comprehend appropriate methods for studying soil microbial diversity. Concepts of soil microbial diversity and major methods of study are briefly introduced in this paper. Then, the application of biochemical-based and molecular-based techniques in this area, and their advantages and disadvantages are evaluated. Based on recent related research, perspectives for studying microbial diversity in soils are presented. | LIU Bing-Ru JIA Guo-Mei CHEN Jian WANG Gang | 2006 | Pedosphere2006，16，1： | 73 |
| 9 | Nitrogen Runoff and Leaching Losses During Rice-Wheat Rotations in Taihu Lake Region,China显示文摘尽管通过流量的氮(N) 损失并且从农田沥滤被怀疑贡献包围水系统的恶化,没有最后的证据让水稻土证明这个假设。在这研究,地小区试验被进行通过流量调查 N 损失并且在大米(Oryza sativa L.) 与 3 N 受精率沥滤二连续的年小麦(Triticum aestivum L.) 在泰胡·莱克区域的旋转,中国。一个水收集系统被设计收集流量并且沥滤为米饭和小麦季节的 ates。结果出现了那溶解 N (DN ) ,而非微粒 N (PN ) ,是由流量的 N 损失的主要表格。NO3 ? 在流量的 -N 集中在 0.1 和 43.7 mg L 之间 ? ,而 NH4+-N 集中从在察觉限制下面到 8.5 mg L ? 。由流量的全部的 N (TN ) 负担是 1.0 17.9 和 5.2 38.6 kg 哈?在米饭和小麦季节期间,分别地并且主要损失在庄稼的早成长的阶段发生了。氮集中在沥滤 ates 在米饭季节期间在 1.0 mg L 下面?并且独立于 N 申请率,而那些在小麦季节期间增加了到 8.2 mg L?并且被化肥率影响。通过流量的 TN 的年度损失并且沥滤从大米小麦的 13.7 48.1 kg ha-1 正在收割系统,财务为 5.6%8.3% 总数使用了 N。它被结束在 N 受精率的那减小,特别当庄稼在生物资源是小的时,能为水系统降低 N 污染潜力。 | TIAN Yu-Hua YIN Bin YANG Lin-Zhang YIN Shi-Xue ZHU Zhao-Liang | 2007 | Pedosphere2007，17，4： | 68 |
| 10 | Soil Heavy Metal Pollution Around the Dabaoshan Mine,Guangdong Province,China显示文摘在 Dabaoshan 矿的附近的土壤污染,广东省,中国,通过全部的集中的决心和有毒的金属, Cu, Zn, Cd,和 Pb 的化学种形成被学习,用诱导地联合的血浆质谱法。结果证明在过去的十年,公害被 Cu, Zn, Cd,和 Pb 的联合引起,与跟踪和是的酸矿排水影响土壤的主要污染来源。显著地高级(P ≤ 0.05 ) 作为与稻,花园,和控制土壤相比在跟踪 Cu, Zn, Cd,和 Pb 被发现,与一般水准 1 486, 2 516, 6.42,和 429 mg kg ? 1 分别地。这些金属连续地从跟踪和废水下游地被驱散,并且因此他们在水稻土的集中象 567 一样高, 1 140 , 2.48 ,和 191 mg kg ? 1 ,分别地显著地更高( P ≤ 0.05 )作为与那些相比在花园土壤。从所有土壤类形的上述金属的顺序的抽取的结果证明剩余部分是主导的形式。然而, Fe-Mn 氧化物和有机物一定的金属的数量比那些跳到在可交换的形式存在的碳酸盐或那些相对高。当金属能从一个惰性的状态被转变到一个活跃状态,潜在的环境风险将与时间由于这些金属增加。 | ZHOU Jian-Min DANG Zhi CAI Mei-Fang LIU Cong-Qiang | 2007 | Pedosphere2007，17，5： | 66 |
| 11 | Ammonia Volatilization and Nitrogen Utilization Efficiency in Response to Urea Application in Rice Fields of the Taihu Lake Region,China显示文摘响应到稻田的脲申请的氨挥发损失,氮利用效率,和米饭收益在 Wangzhuang 镇上被调查, Changshu 城市,江苏省,中国。N 化肥处理,适用在三倍,是 0 (控制) , 100, 200, 300,或 350 kg N 哈 ? 1。在脲被用于地面水以后,一个连续气流包围方法被用来在稻田测量氨挥发。通过氨挥发的全部的 N 损失通常与 N 申请率,和申请评估的二更高的 N 增加了(300 和 350 kg N 哈 ? 1 ) 证明 N 的更高的比率通过氨挥发输了到应用 N。由在全部米饭期间,生长上演的氨挥发的全部的氨损失从 9.0% ~ 16.7% 应用 N 。增加申请率通常减少了在到在植物的 N 的种子的 N 的比率。为所有 N 处理,氮肥利用效率从 30.9% ~ 45.9%。有最高的 N 率的剩余 N 导致了米饭植物,氮肥利用的减少的率,和减少的米饭收益的住宿。从这个实验计算,最节俭的 N 化肥申请率是 227 kg 哈 ? 1 为在泰胡·莱克区域的水稻土的类型。然而,推荐适当 N 化肥申请率以便植物生长被提高,氨损失被减少能改进大米的 N 利用效率。 | LIN De-Xi FAN Xiao-Hui HU Feng ZHAO Hong-Tao LUO Jia-Fa | 2007 | Pedosphere2007，17，5： | 63 |
| 12 | Crop Yield and Soil Responses to Long-Term Fertilization on a Red Soil in Southern China显示文摘A 15-year fertilization experiment with different applications of inorganic N,P and K fertilizers and farmyard manure (M)was conducted to study the yield and soil responses to long-term fertilization at Qiyang,Hunan Province,China. Average grain yields of wheat and corn(1 672 and 5 111 kg ha-1,respectively)for the treatment NPKM were significantly higher than those(405 and 310 kg ha-1)of the unfertilized control and single inorganic fertilizer treatments.Compared with the corresponding initial values of the experiment,all treatments showed a yield decline of 9 to 111 kg ha-1 year-1 in wheat and 35 to 260 kg ha-1 year-1 in corn,respectively,and a significant pH decline of 0.07 to 0.12 pH year?1,except for the treatments PK and NPKM.After long-term fertilization,the soil organic C,soil available P,exchangeable Ca2+ and Mg2+and available Cu2+and Zn2+contents were higher in the treatment NPKM than in the treatments applied with inorganic fertilizer only.Compared to the treatment NPK,the treatment NPKM,where manure partially replaced inorganic N,had a positive impact on arresting the decline of soil pH.This improved grain yields of wheat and corn, suggesting that application of NPK fertilizer in combination with farmyard manure is important to maintain soil fertility and buffering capacity in red soil. | ZHANG Hui-Min WANG Bo-Ren XU Ming-Gang FAN Ting-Lu | 2009 | Pedosphere2009，19，2： | 76 |
| 13 | Remediation of Heavy Metal-Polluted Agricultural Soils Using Clay Minerals: A Review显示文摘Heavy metal contamination of agricultural soils poses risks and hazards to humans. The remediation of heavy metal-polluted soils has become a hot topic in environmental science and engineering. In this review, the application of clay minerals for the remediation of heavy metal-polluted agricultural soils is summarized, in terms of their remediation effects and mechanisms, influencing factors,and future focus. Typical clay minerals, natural sepiolite, palygorskite, and bentonite, have been widely utilized for the in-situ immobilization of heavy metals in soils, especially Cd-polluted paddy soils and wastewater-irrigated farmland soils. Clay minerals are able to increase soil p H, decrease the chemical-extractable fractions and bioavailability of heavy metals in soils, and reduce the heavy metal contents in edible parts of plants. The immobilization effects have been confirmed in field-scale demonstrations and pot trials. Clay minerals can improve the environmental quality of soils and alleviate the hazards of heavy metals to plants. As main factors affecting the immobilization effects, the p H and water condition of soils have drawn academic attention. The remediation mechanisms mainly include liming, precipitation, and sorption effects. However, the molecular mechanisms of microscopic immobilization are unclear. Future studies should focus on the long-term stability and improvement of clay minerals in order to obtain a better remediation effect. | XU Yi LIANG Xuefeng XU Yingming QIN Xu HUANG Qingqing WANG Lin SUN Yuebing | 2017 | Pedosphere2017，27，2： | 66 |
| 14 | Salt Contents in Soils Under Plastic Greenhouse Gardening in China显示文摘Field experiments were conducted on three main soils, brown soil, meadow soil and cinnamon soil, of Shandong Province to study the effect of plastic greenhouse gardening on soil salt contents. As compared to the open fields, the soil nutrient contents in the fields under plastic greenhouse gardening all increased significantly. The organic matter, quickly available N and P increases were extremely significant and the quickly available K increase was also significant. Along with the nutrient increases the soil salt contents increased clearly in all the soils investigated not only in the top layer but also in the deeper layers, being extremely significant in the 0~10 cm layer and significant in the 10~40 cm layers. The salt contents in the plastic greenhouses had significant correlations with the soil available nitrogen and phosphorous. Soils with longer plastic greenhouse gardening time tended to have more salt. The plastic greenhouse soils contained less CO-3~(2-) and much more NO-3 than the open soils, which indicated a higher influence of human intervention in plastic greenhouses. Among the constituent ions, Cl~(-), NO-3~(-) , Ca~(2+) and Mg~(2+) had positive while HCO-3~(-) had negative significant or extremely significant correlations with total salt, with correlation coefficients being 0.66*, 0.80**, 0.92**, 0.80** and -0.64* , respectively. Nitrate decreased from the top to deeper layers both in the plastic greenhouses and in the open fields. The plastic greenhouse soils contained much more nitrate than the open fields in every layer and even the nitrate contents of the 80~l00 cm layer were still several times those of the top layer in the open fields. The main reason for the salt increases was considered to be the inappropriate fertilization and selective absorption of nutrients by plants in the plastic greenhouses. The methods recommended to avoid soil salt increase in the plastic greenhouses were to apply fertilizers rationally according to the soils, vegetables and fertilizer properties and to adopt a good intercropping or rotation system. | LIWENQING S.VANDERZEE 等 | 2001 | Pedosphere2001，11，4： | 67 |
| 15 | Ammonia Volatilization from Winter Wheat Field Top Dressed with Urea显示文摘Ammonia volatilization was measured with a continuous air flow enclosure method from a winter wheat field in the Experimental Farm of Jurong Agricultural School to investigate its main influencing factors. The experiment with five treatments in triplicate, no N (control), 100, 200 and 300 kg N ha-1 with rice straw cover at a rate of 1500 kg ha-1 and 200 kg N ha-1 without rice straw, started when the winter wheat was sown in 1994. Sixty percent of the total amount of N applied was hasal and 40% was top-dressed. The measurement of ammonia volatilization was immediately conducted after urea was top-dressed on soil surface at wheat elongation stage in spring of 1996 and 1997. The results showed that there was a diurnal variation of ammonia volatilization rate from the winter wheat field, which synchronized with air temperature. N losses through ammonia volatilization increased with increasing N application rate, but the ratio of N lost through ammonia volatilization to applied N was not significantly affected by N application rate. The coverage of rice straw had no significant effect on ammonia volatilization. Soil moisture and rain events after urea was top-dressed affected ammonia volatilization significantly. | TIANGUANGMING CAOJINLIU 等 | 1998 | Pedosphere1998，8，4： | 75 |
| 16 | Recent Trends and Recommendations for Nitrogen Fertilization in Intensive Agriculture in Eastern China显示文摘The Taihu Region in eastern China is one of China's most intensive agricultural regions and also one of the economically most developed areas. High nitrogen balance surpluses in the summer rice-winter wheat double-cropping systems are leading to large-scale non-point source pollution of aquifers. In an interdisciplinary approach, four-year (1995-1998) field trials were carried out in two representative areas (Jurong County and Wuxi City) of the Taihu Region. Five farmers' field sites were chosen in each of the 2 locations, with each site divided into 'standard' (farmers' practice) and 'reduced' (by 30%-40%) N fertilization. For both fertilization intensities, N balance surpluses and monetary returns from grain sales minus fertilizer expenditures were calculated in an economic assessment. Based on the field trials, the mineral N fertilizer application rates reduced by about 10% for rice and 20%-30% for wheat were recommended in 1999. Since 1999, the research focused on the trends in N fertilizer application rates and changes in grain and agricultural commodities prices.Summer rice N fertilizer use, in Wuxi City as of 2001, dropped by roughly 25%, while for winter wheat it decreased by 10%-20%, compared to the 1995-1998 period. This has been achieved not only by grain policy and price changes, but also by an increased environmental awareness from government officials. Nitrogen balance surpluses in Anzhen Town (of Wuxi City) have consequently diminished by 50%-75% in rice and by up to 40% in wheat, with reductions being achieved without concomitant decreases in physical grain yields or returns from sales minus fertilizer costs. | M.ROELCKE HANYong K.H.SCHLEEF ZHUJian-Guo LIUGang CAIZu-Cong J.RICHTER | 2004 | Pedosphere2004，14，4： | 54 |
| 17 | Spatial and Temporal Variability of N, P and K Balances for Agroecosystems in China显示文摘Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems. | SHENRun-Ping SUNBo ZHAOQi-Guo | 2005 | Pedosphere2005，15，3： | 52 |
| 18 | Leaching and Transformation of Nitrogen Fertilizers in Soil After Application of N with Irrigation: A Soil Column Method显示文摘A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surface fertilization combined with flood irrigation (SFI), and to study the leaching loss and transformation of three kinds of nitrogen fertilizers (nitrate fertilizer, ammonium fertilizer, and urea fertilizer) in two contrasting soils after the fertigation. In comparison to SFI, DFI decreased leaching loss of urea-N from the soil and increased the mineral N (NH4+-N + NO3- -N) in the soil. The N leached from a clay loam soil ranged from 5.7% to 9.6% of the total N added as fertilizer, whereas for a sandy loam soil they ranged between 16.2% and 30.4%. Leaching losses of mineral N were higher when nitrate fertilizer was used compared to urea or ammonium fertilizer. Compared to the control (without urea addition), on the first day when soils were fertigated with urea, there were increases in NH4+-N in the soils. This confirmed the rapid hydrolysis of urea in soil during fertigation. NH4+-N in soils reached a peak about 5 days after fertigation, and due to nitrification it began to decrease at day 10. After applying NH4+-N fertilizer and urea and during the incubation period, the mineral nitrogen in the soil decreased. This may be related to the occurrence of NH4+-N fixation or volatilization in the soil during the fertigation process. | ZHOU Jian-Bin XI Jin-Gen CHEN Zhu-Jun LI Sheng-Xiu | 2006 | Pedosphere2006，16，2： | 58 |
| 19 | Soil Microbial Community Structure in Diverse Land Use Systems:A Comparative Study Using Biolog,DGGE,and PLFA Analyses显示文摘Biolog,16S rRNA gene denaturing gradient gel electrophoresis(DGGE) ,and phospholipid fatty acid(PLFA) analyses were used to assess soil microbial community characteristics in a chronosequence of tea garden systems(8-,50-,and 90-year-old tea gardens) ,an adjacent wasteland,and a 90-year-old forest. Biolog analysis showed that the average well color development(AWCD) of all carbon sources and the functional diversity based on the Shannon index decreased(P < 0.05) in the following order:wasteland > forest > tea garden. For the DGGE analysis,the genetic diversity based on the Shannon index was significantly lower in the tea garden soils than in the wasteland. However,compared to the 90-year-old forest,the tea garden soils showed significantly higher genetic diversity. PLFA analysis showed that the ratio of Gram positive bacteria to Gram negative bacteria was significantly higher in the tea garden soils than in the wasteland,and the highest value was found in the 90-year-old forest. Both the fungal PLFA and the ratio of fungi to bacteria were significantly higher in the three tea garden soils than in the wasteland and forest,indicating that fungal PLFA was significantly affected by land-use change. Based on cluster analysis of the soil microbial community structure,all three analytical methods showed that land-use change had a greater effect on soil microbial community structure than tea garden age. | XUE Dong YAO Huai-Ying GE De-Yong HUANG Chang-Yong | 2008 | Pedosphere2008，18，5： | 56 |
| 20 | Immobilization of Lead and Cadmium in Contaminated Soil Using Amendments: A Review显示文摘Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large number of soils are nowadays contaminated over widespread areas, posing a great threat to public health worldwide. Unlike organic pollutants, Pb and Cd do not undergo chemical or microbial breakdown and stay likely in site for longer duration after their release. Immobilization is an in-situ remediation technique that uses cost-effective soil amendments to reduce Pb and Cd availability in the contaminated soils. The Pb and Cd contamination in the soil environment is reviewed with focus on source enrichment, speciation and associated health risks, and immobilization options using various soil amendments. Commonly applied and emerging cost-effective soil amendments for Pb and Cd immobilization include phosphate compounds, liming, animal manure, biosolids, metal oxides, and biochar. These immobilizing agents could reduce the transfer of metal pollutants or residues to food web(plant uptake and leaching to subsurface water) and their long-term sustainability in heavy metal fixation needs further assessment. | Amanullah MAHAR WANG Ping LI Ronghua ZHANG Zengqiang | 2015 | Pedosphere2015，25，4： | 56 |
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