我国花生土壤黄曲霉菌分布与产后花生黄曲霉毒素污染相关性研究

为了解我国花生土壤黄曲霉分布及产毒特征与产后花生黄曲霉毒素污染相关性,本试验从我国4个典型花生产区黄河流域产区(河北保定)、西北产区(新疆吐鲁番)、长江流域产区(湖北黄冈、四川南充)和东南沿海产区(广东湛江)采集花生土壤样品124份。通过对我国不同产区花生土壤中黄曲霉菌的分布及产毒特征研究,评估我国不同产区花生黄曲霉毒素污染风险。结果表明,湖北黄冈和四川南充土壤中黄曲霉检出率、带菌量和黄曲霉毒素B1(AFB1)量均高于其他地区,产后花生受AFB1污染风险最高,其次为广东湛江和新疆吐鲁番,河北保定花生受AFB1污染风险最低。从上述4个产区收集64份花生样品开展产后花生AFB1污染调查,发现湖北黄冈花生AFB1污染情况最严重,检出率为57%,超标率为10%,其次为四川南充和广东湛江,新疆吐鲁番和河北保定花生受AFB1污染较轻。风险评估结果与实际检测结果一致,表明花生土壤中黄曲霉菌数量、产毒菌比例及产毒能力与产后花生AFB1污染呈正相关性。本研究结果为花生黄曲霉毒素污染预警及综合防控提供了理论依据和数据支撑。

红安县花生土壤的特征及改良利用

红安县花生土壤多为片麻岩发育而成的黄棕壤,耕层浅薄,质地偏砂,剖面发育不完整,水、肥、气、热资源有限,土壤养分缺乏。应充分利用坡改梯、深翻改土、发展灌溉、增施有机肥、配方施肥、合理轮作、地膜覆盖等技术措施提高地力水平,达到花生增产增效的目的。

花生植株、籽粒及田间土壤氟磺胺草醚残留分析方法研究

在前人研究基础上，确立了花生植株以甲醇、乙二胺-N-丙基硅烷（PSA）和石墨化炭黑（GCB）为基质分散萃取材料，花生籽粒和田间土壤分别以酸化甲醇和乙腈为分散萃取溶剂，以PSA为基质净化材料的3类氟磺胺草醚残留样品前处理程序，建立并优化了花生籽粒、花生植株和田间土壤氟磺胺草醚残留高效液相色谱检测方法。结果显示，氟磺胺草醚在0．05～10．0 mg／L质量浓度范围内与对应色谱峰积分面积线性响应良好，回归方程为y＝2．5628 x－0．0068（r2＝0．9998）。在0．05～0．5 mg／kg氟磺胺草醚添加范围内，花生籽粒、植株和田间土壤中的平均回收率为85．6％～113．5％，相对标准偏差为1．5％～9．7％。花生植株、籽粒和田间土壤中氟磺胺草醚的检出限分别为0．024、0．029和0．031 mg／kg。基质效应试验结果表明，该样品前处理方法获得的分析样品基质效应不明显，表明该残留样本前处理方法和样品检测方法简便、高效、经济、可靠，可满足氟磺胺草醚在花生植株、籽粒及田间土壤中残留的定量检测要求。

Relationships between Application Amount of Quicklime and Soil Nutrients,Flue-cured Tobacco Quality in Panzhihua City

[Objective] This study aimed to investigate the improving effect of quick- lime on acid soil in tobacco-growing areas in Panzhihua City. [Method] The effects of four application amounts （450, 900, 1 350 and 1 800 kg/hm2） of quicklime on soil nutrients and flue-cured tobacco quality were observed for two consecutive years. [Result] In acid soil, the application of quicklime significantly improved soil pH. In addition, it showed significant effects on soil nutrients, flue-cured tobacco quality, tobacco output and tobacco leaf chemical components. When the application amount of quicklime was increased to 1 350 kg/hm2, the improving effect of quick- lime on soil nutrients was best, the flue-cured tobacco yield and quality all reached the highest, and the chemical components of tobacco leaves were closest to the in- herent indicators of high-quality tobacco leaves. [Conclusion] This study will provide certain reference for accurate application of quicklime in tobacco-growing area in Panzhihua City.

Effects of Soil Fertility on Peanut Quality

[Objective] The research aimed to discuss the key soil fertility factors affecting the peanut quality and quantify the effect degree of the key climatic factors,which will provide scientific basis for peanut quality classification,fine varieties breeding and high-yield cultivation.[Method] Based on the peanut quality data and soil data coming from the 18 main peanut producing provinces in China in 2008,the effects of soil fertility factors on peanut quality was studied by the methods of correlation analysis,path analysis and stepwise regression analysis.[Result] The results showed that the total nitrogen content in soil was the main factors affecting the peanut protein content,and the relationship between them was Y=0.000 179 4X2＋25.597.The organic matter content in soil was the main factors affecting the peanut fat content,and the relationship between them was Y=0.162X1＋43.317.The organic matter content in soil was also the main factors affecting the O/L of peanut,and the relationship between them was Y=0.162X1＋43.317.[Conclusion] Different fertility factors had the different effects on the peanut quality,so an appropriate ratio of the fertilizers should be adopted to improve the peanut quality.

Water Budget Analysis of Red Soils in Central Jiangxi Province, China

The daily soil water budgets in the red soil areas of central Jiangxi Province,southern China,were investigated with a large-scale weighing lysimeter and runoff plots. From 1998 to 2000,peanuts (Arachis hypogaea L.) and rape (Brassica napus L.) were planted in the lysimeter and in 1999,peanuts were planted in the runoff plots. The soil water budget components including rainfall,runoff,percolation and evapotranspiration were measured directly or calculated by Richards' equation and water balance equation. The results showed that most rainfall,including rainstorms,occurred from March to July,and induced the greatest soil water percolation during the year. The evapotranspiration was still large from July to September when rainfall was minimal. Thus,the lack of synchronization in soil water inputs and losses was disadvantageous to crops growing in this region. Among the soil water losses,percolation was the largest,followed by evapotranspiration,and then soil runoff. Runoff was very small on farmland with crops. It was significantly different from the uncultivated uplands where large-scale runoff was usually reported. The soil water storage fluctuated sinusoidally,with a large amplitude in the rainy season and a small amplitude in the dry season.

Diversity and Classification of Soil Fungi in Main Peanut Producing Areas of China

In the study, 1 255 fungal strains were isolated from 105 peanut soil samples collected from 15 counties in 10 provinces of China. These fungi were identified to 21 genera, using the method of microscopical observation according to morphology. And 2 genera were members of oomycetes, 3 genera of ascomycota and 16 genera of mitosporic fungi. In these soil samples, the dominant species were Penicillium, Trichoderma and Fusarium, accounting for 28.89%, 14.16% and 8.64%, respectively.

Soil Temperature Dependent Growth of Cotton Seedlings Before Emergence

Soil temperature is an important variable governing plant growth and development. Studies were conducted under laboratory conditions to determine the effect of soil temperature on root and shoot growth of cotton during emergence. Cotton seedlings were grown for 192 h at 20, 32 and 38℃ in soil packed in 300 mm long and 50 mm diameter cylinders. The data indicated that the longest roots （173 ram） as well as shoots （152 mm） were recorded at 32℃ followed by 20 （130 mm root and 82 mm shoot） and 38℃ （86 mm root and 50 mm shoot）. Roots grown at 20 and 38 ℃ were 20% and 50% shorter, respectively, than those grown at 32℃ after 192 h. Roots and shoots exhibited the lowest length and dry biomass at 38 ℃. Shoot lengths grown at 20 （74 mm） and 38℃（51 mm） were 44% and 61% shorter than those grown at 32℃（131 mm） after 180 h growth period, respectively. Growth at all three temperatures followed a similar pattern. Initially there was a linear growth phase followed by the reduction or cessation of growth. Time to cessation of growth varied with temperature and decreased faster at higher temperatures. Sowing of cotton should be accomplished before seedbed reaches a soil temperature （≥ 38 ℃） detrimental for emergence. Further, the seedbeds should be capable of providing sufficient moisture and essential nutrients for emerging seedling before its seed reserves are exhausted to enhance seedling establishment in soil.

Ecological Consequences of Elevated CO2 and Bt Cotton on Soil Collembola

Transgenic cotton was modified to express a gene derived from the bacterium Bacillus thuringiensis （Bt） to combat agriculturally important Lepidopteran pests. Elevated CO2 is expected to further alter the chemical composition of the plant, and this change may affect the role soil fauna plays in decomposition of Bt plants. A 3 months litterbag field study, consisting of four treatments using leaves from Bt cotton and near-isolines of non-Bt cotton grown under ambient and elevated CO2 levels, was conducted to investigate the abundance and community structure of soil Collembola that developed on the decaying leaf material. A total of 4,884 collembolans, including 13 genera of five families, were extracted in the present study. These results suggest that collembolan distribution was relatively uniform among the Bt cotton, elevated concentration of CO2 and control treatments, except for a significant difference in the densities of Onychiurus and Folsomides. No significant effects were detected in the decomposition rate between the two cotton varieties and two CO2 treatments. These findings indicated that transgenic Bt cotton plants and elevated CO2 do not have any adverse effect on the soil collembolans through the decomposition way in soil ecosystem.

Characteristics of soil microbial community functional and structure diversity with coverage of Solidago Canadensis L

The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.

Nymphaeaceae Salisb. and Trapaceae Dumort. Families in the Collection of O.V. Fomina Botanical Garden

On basis of aquatic and riverside-aquatic plants collection of O.V. fomina botanical garden is conducted research of ontogenesis, ecology, phenology, carpogenesis, biomorphology, life forms, adaptatations, of this group＇s plants, peculiarities of their cultivation and application in conditions of temperate zone of Ukraine. Special values in research have ancient genera and species, which include representatives ofNymphaeaceae salisb, and trapaceae Dumort. families, 22 species, 6 varieties, 1 hybrid, 30 cultivars of which are presented in collection of garden in open and covered soil. For the first time in covered soil of two conservatories ecological modeling was conducted. Placement of plants is done in form of 5 models of artificial ecotopes, in 155 abatises. Four ecobiomorphological groups based on rhizome system were determined for Nymphaeaceae, among which conditionally-rhizome and conditionally-stolone are provided for the first time.

The Applicability of Soil＇s Fertilizers in Increasing of Production Effects in Lolium Perenne and Lolium Multiflorum Cultivation

The aim of the study was to determine the effect of soil fertilizers, used on the background of NPK fertilization on the productivity of Lolium perenne and Lolium multiflorum in different time of harvest. In 2012-2013 the following species and varieties of forage grasses： Lolium perenne and Lolium multiflorum were cultivated. It was the fallowing experimental subjects： K-control （without fertilization and fertilizer）, NPK （N-150 kg hal as a 34% ammonium nitrate, P-80 kg P2O5 ha-1, K-120 kg K20 ha-1）, UG-UGmax bio-preparation, EU-Eco bio-preparation （fertilizer）, HA-Humus Active as bio-preparation.

Responses of Saline Soil Properties and Cotton Growth to Different Organic Amendments

Application of organic waste to saline alkaline soils is considered to be a good practice for soil remediation. The effects of applying different organic amendments （e.g., cattle dung, vermicompost, biofertilizer） and earthworm inoculations （Eisenia fetida） on saline soils and cotton growth were investigated during i year of cotton cultivation. Compared to the control （applied with inorganic NPK fertilizer）, applying organic amendments improved soil physicochemical properties. Biofertilizer application improved available nutrient content, reduced short-term soil electrical conductivity, and produced the highest cotton yield, whereas cattle dung and vermicompost applications resulted in higher soil organic matter content. Application of organic amendments significantly increased soil microbial biomass carbon during the flowering period, which sharply declined at harvest. This was especially true for the biofertilizer treatment, which also exhibited lower nematode abundance compared with the other organic materials. Earthworm inoculation following cattle dung application failed to significantly change soil physicochemical properties when compared to the treatments without earthworm inoculation. Results suggest that biofertilizer application to saline soil would improve soil nutrient status in the short-term, whereas cattle dung application would improve soil organic matter content and increase soil organism abundance to a greater extent. However, different strategies might be required for long-term saline soil remediation.

Fate of Basal N Under Split Fertilization in Rice with ^(15)N Isotope Tracer

Split fertilization strategy is popularly adopted in rice to synchronize soil nitrogen(N) supply and crop N demand. Attention has been paid more on mid-season topdressing N, but limited on basal N. A clearer understanding of the basal N fate under split fertilization is crucial for determining rational basal N split ratio to improve the yield and reduce the loss to environment. A two-year field experiment with two N rates of 150 and 300 kg Nha^(-1), two split ratios of basal N, 40% and 25%, and two rice varieties,Wuyunjing 23(japonica) and Y-liangyou 2(super hybrid indica), was conducted. Labelled ^(15) N urea was supplied in micro-plots as basal fertilizer to determine the plant uptake, translocation, soil residual, and loss of basal N fertilizer. The results showed that basal N absorbed by rice was only 1.6%–11.5% before tillering fertilization(8–10 d after transplanting), 6.5%–21.4% from tillering fertilization to panicle fertilization, and little(0.1%–4.4%) after panicle fertilization. The recovery efficiency of basal N for the entire rice growth stage was low and ranged from 18.7% to 24.8%, not significantly affected by cultivars or N treatments. Soil residual basal N accounted for 10.3%–36.4% and decreased with increasing total N rate and basal N ratio, regardless of variety and year. 43.8%–70.4% of basal N was lost into the environment based on the N balance. Basal N loss was significantly linearly positive related with the basal N rate and obviously enhanced by the increasing basal N ratio for both varieties in both 2012 and 2013. The N use efficiency and yield was significantly improved when decreasing the basal N ratio from 40% to 25%. The results indicated that the basal N ratio should be reduced, especially with limited N inputs, to improve the yield and reduce the N loss to the environment.

Impact of Irrigation Methods on Soil Salt Content and Their Differences in Whole Cotton Growing Season in Arid Area of Northwest China

Research for changes of soil water and salt is an important content of land sciences and agriculture sciences in arid and semi arid regions. In this paper, sampling in actual agricultural fields, laboratory analysis of soil samples and statistical analysis methods are used to quantitatively analyze soil salinity changes under different ir- rigation methods throughout the cotton growing season in Shihezi reclamation area. The results show that irrigation methods play an important role in soil salt content in the surface soil （0-20 cm） and sub-deep soil （40-60 cm）, fol- lowed by deep soil layer （60-100 cm） and root soil layer （20-40 cm）. Furrow irrigation yields the maximum soil salt content in deep layer （60-100 cm） or sub-deep layer （40-60 cm） and the maximum salinity occurs in the first half of the cotton growing season （June or earlier）. In contrast, drip irrigation yields the maximum soil salinity in the root layer （20-40 cm） or sub-deep （40-60 cm）, and this usually appears in the second half growing season （July or af- ter）. The ratio of chloride ion to sulfate ion （Cl-/SO2- 4） and its change in the soil are on the rise under furrow irrigation while the value first increased and then decreased with a peak point in June under drip irrigation. This suggests that furrow irrigation may shift the type of soil salinization to chloride ion type moreso than drip irrigation. Potassium and sodium ion contents of the soil show that soil sodium＋potassium content will drop after the first rise under furrow irrigation and the value is manifested by fluctuations under drip irrigation. Potassium＋sodium content change is relatively more stable in the whole cotton growth period under irrigation methods. The maximum of sodium and potassium content of the soil usually occur in deep soil layer （60-100 cm） or sub-deep soil layer （40-60 cm） in most sample points under furrow irrigation while it is inconsistent in different sample points under drip irrigation. A non- parametric test for paired samples is used to analyze differences of soil salt content under different irrigation methods. This analysis shows that the impact of irrigation on soil salinity is most significant in July, followed by August, June, May, and April in most sample points. The most significant impact of irrigation methods occurs in the surface soil layer （0-20 cm）, followed by deep layer （60-100 cm）, root layer （20-40 cm） and sub-deep （40-60 cm）. These conclusions will be benefitial for mitigation of soil salinization, irrigation and fertilization and sustainable land use.

Effects of Earthworms and Ryegrass on the Removal of Fluoranthene from Soil

Earthworms can promote the bioremediation of contaminated soils through enhancing plant growth and microorganism development. The individual and combined effects of earthworms and ryegrass （Lolium multifloram Lain.） on the removM of fiuoranthene from a sandy-loam alluvial soil were investigated in a 70-d microcosm experiment. The experiment was set up in a complete factorial design with treatments in four replicates： without earthworms or ryegrass （control, CK）, with earthworms only （E）, with ryegrass only （P）, and with both earthworms and ryegrass （EP）. The residual fluoranthene, microbial biomass C, and polyphenol oxidase activity in the soil changed significantly （P 〈 0.01） with time. In general, the residual concentration of fluoranthene in the soil decreased sharply from 71.8-88.7 to 31.7-37.4 mg kg-1 in 14 d, and then decreased gradually to 19.7-30.5 mg kg-1 on the 70th d. The flu- oranthene concentration left in the soil was the least with both earthworms and ryegrass, compared to the other treatments at the end of the experiment. Half-life times of fluoranthene in the E, P, and EP treatments were 17.8%-36.3% smaller than that of CK. More fluoranthene was absorbed by earthworms than ryegrass. However, the total amounts of fluoranthene accumulated in both the ryegrass and earthworms were small, only accounting for 0.01%-1.20% of the lost fluoranthene. Therefore, we assumed that microbial degradation would play a dominant functional role in fluoranthene removal from soil. We found that earthworms significantly increased microbial biomass C and polyphenol oxidase activity （P 〈 0.01） in the presence of ryegrass at the end of the experiment. Furthermore, microbial biomass C and polyphenol oxidase activity were significantly （P 〈 0.05） and negatively related to the residual fluoranthene concentration. This implied that earthworms might promote the removal of fluoranthene from soil via stimulating microbial biomass C and polyphenol oxidase activity.