如何做好南方土鸡养殖与防疫

随着近年来经济的不断发展,我国的畜牧业也有了极大的进步,我国的南方土鸡养殖工作呈现逐渐扩大和发展的趋势。但近年来环境污染和自然环境的变化,土鸡出现感染的风险也在随之增大,我国出现的一系列土鸡疾病也受到了相关工作人员的重视。因此,为了更好的使我国的畜牧业得到发展,南方土鸡养殖工作人员需要对各种土鸡的传染病进行分析并做好相应的预防,这样才有助于降低土鸡感染的风险。

南方丘陵稻田土碱解氮高光谱特征及反演模型研究

以兴国县稻田土高光谱反射率为研究对象,分析南方丘陵稻田土碱解氮的光谱响应波段,运用光谱分析方法提取光谱指数,建立基于反射光谱特征的南方丘陵稻田土碱解氮高光谱反演模型。经分析可知,不同碱解氮含量的南方丘陵稻田土光谱曲线在波长小于700 nm波谱范围内呈现随着碱解氮含量的增高,光谱反射率降低,吸收深度越大的趋势;通过分析南方丘陵稻田土碱解氮含量与光谱反射率16种数学变换的相关系数,提取敏感波段为694 nm,2 058 nm和2 189 nm。基于南方丘陵稻田土光谱反射率的碱解氮含量高光谱反演模型稳定性较强(R2=0.56),具有一定的预测能力,能用于南方丘陵稻田土碱解氮含量速测。

基于机载高光谱影像的南方水稻土有机质含量估算

水稻土中有机质光谱常常受到水分、秸秆等土壤背景的影响,为了减弱或去除非有机质组分对有机质光谱的影响,构建南方水稻土有机质估算模型。利用机载高光谱(GaiaSky-Mini2-VN)作为数据源,对原始反射率进行单一和组合变换(去除包络线、倒数、对数、一阶微分、二阶微分单一变换和倒数一阶微分、对数一阶微分、倒数对数组合变换)提取一维特征光谱;通过对变化后光谱进行比值和归一化处理,提取二维特征光谱;构建基于特征光谱的线性(多元回归、偏最小二乘)和非线性(反向传播神经网络、支持向量机)有机质预测模型,监测南方水稻土有机质含量。结果表明:一维光谱变换能显著增强光谱对有机质响应的敏感度,二维光谱变换能充分挖掘光谱信息,增强有机质与光谱之间的内在联系,提高建模精度。非线性模型(BPNN、SVM)尤其是BPNN对土壤有机质拟合性好,建模精度高。基于原始反射率比值指数建立的BPNN模型建模精度达到0.952,检验精度达到0.889,建模效果最优。该结果适用于南方水稻土有机质监测,对机载高光谱在土壤有机质监测中的特征波段提取和建模方法选择具有重要借鉴意义,对现代农业发展管理提供新的思路。

雨季南方土鸡的管理

在我国南方,夏季到来之前有很长一段时间的梅雨季节。雨季影响优质鸡的主要原因是鸡舍内湿度加大、垫料潮湿、饲料霉变,部分生产单位不能获得清洁的饮用水等,很可能因此导致球虫病、大肠杆菌病暴发,氨气浓度升高,霉菌毒素中毒、呼吸道疾病感染的危险性增加。为此应做好以下雨季管理工作:

不同土壤对阿散酸和洛克沙胂添加剂的吸附研究

采用平衡振荡法,研究了不同利用类型的北方土和南方土对阿散酸和洛克沙胂2种有机胂添加剂的吸附行为.结果表明:有机质和总铁含量高的偏酸性南方土对2种有机胂的吸附强度远远大于有机质和总铁含量低的偏碱性北方土;北方土添加腐殖质后对阿散酸和洛克沙胂吸附量分别增加了3倍和10倍左右,南方土去除有机质后吸附量显著下降;南方树木园土和农场土对洛克沙胂和阿散酸的吸附更符合Langmuir吸附等温线,树木园土对阿散酸和洛克沙胂的饱和吸附量分别为1 111和1 250 mg.kg-1,农场土对阿散酸和洛克沙胂的饱和吸附量分别为66和250 mg.kg-1,初始质量浓度对洛克沙胂的吸附量影响更大.

化肥配施土壤调理剂对酸化红壤性水稻土改良效果研究

【目的】针对我国南方酸化红壤性稻田,研究化肥配施土壤调理剂对水稻产量及土壤化学性质的影响,以期为土壤调理剂在酸性稻田土壤的改良提供理论依据和技术支撑。【方法】以南方酸性稻田土壤为研究对象,以杂交水稻品种H优518为供试材料,通过大田试验,分析化肥(常量、减10%、20%、30%)配施不同用量土壤调理剂(750,1500,2250 kg/hm^2)对水稻产量及其构成因素、成熟期干物质积累量、土壤pH及土壤养分的影响。【结果】增施土壤调理剂能显著提升土壤pH,相较于常量施肥,处理70%F+150 pH上升0.48个单位,而且增施2250 kg/hm^2土壤调理剂对提高土壤有机质和有效磷含量具有显著效果,但是对土壤氮素养分和速效钾含量影响不明显。水稻产量处理100%F+100和100%F+150最高,且显著高于处理80%F+100和70%F+150,增幅分别为8.79%和9.39%。常量施肥条件下,处理100%F+50、100%F+100和100%F+150产量均高于处理100%F,但未达到显著水平。减施化肥条件下,水稻产量处理90%F+50略高于处理100%F,但差异不显著。各处理的成熟期总干物质积累量差异不显著,水稻产量与成熟期总干物质积累量呈显著直线正相关。【结论】常量施肥添加2250 kg/hm^2土壤调理剂能改良酸性土壤、提高土壤有效养分含量和实现水稻高产。

云南先锋露天煤矿排土场防排水工程设计

南方露天煤矿降雨量丰富,地下水水量大,煤矿的防排水工程是安全生产的重要工程,露天矿排土场全部是松散剥离物,排土场防排水措施的合理、完善是保证排土场边坡稳定的前提。介绍了云南先锋露天煤矿排水工程中存在的难题,分析了排土场水文地质特征,结合目前防排水工程现状提出2种排水方案,并经技术经济比较确定采用方案2,即利用现有防洪沟,将其改造为暗涵工程。不但减轻了征地工作压力,而且具有广泛的实用价值,对露天煤矿排土场防排水工程具有很大的现实意义和指导作用。

地铁基坑临近建(构)筑物咬合桩方案的优化

针对南方地铁临近建(构)筑物的软土基坑咬合桩方案,对比并定量、定性简析软土基坑未设与设咬合桩支撑格构柱的变形特征、机理及基坑周围软土滞后蠕变的时间间隔,并建议优化措施,设咬合桩支撑格构柱是防止建(构)筑物受损的关键,否则钢支撑水平轴力较难持续增大,以供岩土同行在今后的南方软土基坑设计和施工参考。

Soil Erosion Changes over the Past Five Decades in the Red Soil Region of Southern China

This paper reports the dynamic changes of soil and water loss in the red soil region of Southern China since the 1950s. The red soil region covers eight provinces: Jiangxi, Zhejiang, Fujian, Anhui, Hubei, Hunan, Guangdong and Hainan. From the 1950s to 1986, the annual rate of soil erosion increased by 3.4%. From 1986 to 1996 and from 1996 to 2000, the annual rates of soil erosion decreased by 2.0% and 0.32%, respectively. Field surveys showed that from 2000 to 2005, the area of soil and water loss decreased annually by 1.2%. This decrease was a result of large-scale erosion control activities across China. Although the eroded soil has been restored, the restoration process is very slow and full restoration will take a long time. Our report suggests that controlling soil and water loss is a challenging task, and additional measures must be taken to effectively control the soil erosion in the red soil region.

Function of Soils in Regulating Rainwater in Southern China: Impacts of Land Uses and Soils

One of the most important functions of soils is to regulate rainwater and mitigate flooding and associated damages; this function can be estimated by the rainwater regulation ratio （η）, i.e., percent of regulated rainwater. Fifteen experimental plots were set up on the hills in Yingtan of Jiangxi Province, southern China. These plots were under three land use patterns, cultivated cropland, noncultivated land, and orchard interplanted with cash crops. With aid of an artificial rainfall simulator and Guelph method, rainfall, runoff, soil infiltration, and so on were measured in situ. Results showed that the orchard interplanted with cash crops was more effective in regulating rainwater than the other two land use patterns. When the maximum infiltration intensity was three times higher than the observed mean,η was higher than 70% for all plots. 77 was related to land use, slope gradient, and soil properties such as soil infiltration, organic carbon, bulk density, and texture. There is still more room to improve capacity of rainwater drainage （underground percolation） than that of rainwater storage in soils. Therefore, enhancing soil permeability is vital to improve the rainwater regulation efficiency in soils.

Monitoring and Evaluation of Soil Changes Under Landuse of Different Patterns at a Small Regional Level in South China

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Polycyclic Aromatic Hydrocarbons in Agricultural Soils of the Southern Subtropics,China

The contributions of persistent organic pollutants （POPs） from the subtropical regions of China to pollution of the global environment have been paid great attention; however, little is known about the state of POPs in agricultural ecosystems within these regions of China. This study primarily revealed the state of the contamination and distribution of polycyclic aromatic hydrocarbons （PAH） in agricultural soils in the subtropical regions. 115 surface soils （0-20 cm） were sampled in the breadbaskets of these regions. The concentrations and types of PAH were determined using gas chromatography linked to mass spectrometry （GC-MS）. The total PAH concentrations ranged from 22.1 to 1 256.9 ng g^-1 with a mean of 318.2 ± 148.2 ng g^-1. In general terms, the current PAH concentrations were lower than most PAH levels reported in a number of investigations from different countries and regions. PAH isomer ratios indicated that pyrolytic origins, such as fossil fuel combustion related to vehicle tail gas and industrial emissions, were the dominant sources of PAH in the southern subtropical areas of China. Although PAH concentrations decreased with decreasing pollution, population, and traffic density, to a great extent PAH compositions were similar throughout subtropical soils, with naphthalene, phenanthrene, fluoranthene, and benzo（b）fluoranthene being dominant.

The Effects of Land Use and Landscape Position on Labile Organic Carbon and Carbon Management Index in Red Soil Hilly Region,Southern China

Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of L0C and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands （pine forest （PF） on slope land, barren hill （BH） on slope land, citrus orchard （C0） on terrace land and Cinnarnornum Camphora （CC） on terrace land） at a sampling depth of 20 cm. Soil nutrients, soil organic carbon （SOC）, L0C and CMI were measured. Results showed that the L0C and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC 〉 PF 〉 CO 〉 BH at the upper- slope, while CO 〉 CC 〉 BH 〉 PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order： upper-slope 〉 down-slope 〉 mid- slope. As whole, the mean values of LOC and CMI in different lands followed the order CC 〉 CO 〉 PF 〉 BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high~ quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.

Land Use and Land Cover Change on Slope in Qiandongnan Prefecture of Southwest China

This study uses DEM （Digital Elevation Model） data and remote sensing maps of the study area in 1993, 1999, and 2009 to analyze the slope gradient change of land use patterns in Qiandongnan Prefecture, Guizhou province, China. The land use data were classified into five types, forest, farmland, grassland, water and built-up, the slope gradients were divided into four grades. Indices for analyzing land use features were defined by their proportions, transformation matrixes, land use degree and changes The results showed that all land use types can be found at every gradient. Generally, with the slope degree increased, the area of forest being augmented as well, while the area of the other land use types （farmland, grassland and build-up） declined. Moreover, a mass of farmland were shifted from other land use types from o° to 25°, while a quantity of forest were transformed from the other land use types on 〉 25° from 2993 to 2009. In terms of land use degree and changes, the area of farmland and buildup land use types decreased when slope degree increased. Finally, we calculated the five landscape pattern metrics： Patch Density （PD） value, Largest Patch Index （LPI）, Shannon＇s Diversity Index （SHDI）, Area-Weighted Mean Shape Index （AWMSI） and Contagion Index （CONTAG）. The results of metricsanalysis showed that PD values, SHDI values and CONTA values had a similar variation trend, that is, they decreased when slope degree increased. There was no obvious variation trend on LPI value.

Phosphate-solubilizing microbes in rhizosphere soils of 19 weeds in southeastern China

Low phosphorus (P) availability is one of the most important factors limiting plant growth in red soils across southeastern China. Many non\|symbiotic microorganisms in rhizosphere can enhance P solubility, but little is known about the magnitude of their phosphorus\|solubilizing ability (PSA) and the difference in phosphorus\|solubilizing microorganisms (PSM) among plant species. The number of phosphorus\|solubilizing microorganisms and their PSA in rhizosphere soils of 19 weed species in a citrus orchard on red soil at Changshan, Zhejiang, China, were investigated. Inorganic P (powdered phosphate rock, PR) and organic P (lecithin, OP) were respectively used as the sole P\|source to examine the PSA of isolated microbes. The PS actinomycetes community varied greatly among the different weed rhizospheres while the PS fungus community showed to be most stable to the weed rhizosphere. The highest number of PR\|PS and OP\|PS bacteria was found in rhizosphere soil of \%Mollugo pentaphyll\%, and the highest number of PR\|PS and OP\|PS actinomycetes was found in rhizosphere soil of \%Polygonum lapathifolium\%. The highest number of PR\|PS fungi was found in \%Erigeron annuus\% and \%Mollugo pentaphyll\% rhizosphere soil, and the highest number of OP\|PS fungi was found in rhizosphere soil of \%Mazus stachydifolius\%. \%Mazus stachydifolius\% showed the strongest PR\|PS ability (6340.75μg) while \%Eragrostis pilosa\% showed the strongest OP\|PS ability (1301.84μg). The PR\|PS ability and OP\|PS ability of \%Mollugo pentaphyll\% was 4432.87μg and 1122.05μg respectively. A significant correlation between the number of PR\|PSM and OP\|PSM was found. Significant correlation was only found between the PR\|PS fungi number and its PSA( r =0.75, P <0.05) and between the number of OP\|PS fungi and its PSA( r =0.87, P <0.01}). It indicated that plant species had significant influence on components of the non\|symbiotic PSM community and their activity in its rhizosphere soil. Fungi play a leading role in phosphorus solubilization in weed rhizopshere. It suggested that weed conservation could benefit soil microbe development in agroecosystems, especially in the initial stage of agroecosystem development because there is less organic carbon in bare soil. The results suggested that weed conservation could increase PSA of PSM.

FLO-2D Simulation of Mudflow Caused by Large Landslide Due to Extremely Heavy Rainfall in Southeastern Taiwan during Typhoon Morakot

Daniau Village in Daniau Creek Watershed, Taitung County, Taiwan, sustained damages from landslides and mudflows during Typhoon Morakot in 2009. The purpose of this study is to adopt the FLO-2D numerical model recognized by Federal Emergency Management Agency （FEMA） to simulate the mudflow, and the Daniau Village was used as a case study, along with rainfall and digital terrain data for this simulation. On the basis of sediment yields, the residual sediment volume in the landslide area was determined to be 33,276 ma by comparison of digital elevation models （DEMs） and by using the universal soil loss equation （USLE）. In addition, this study performed a hydrological frequency analysis of rainfall to estimate the flow discharge as conditions of the simulation. Results of disaster surveys were collected to compare with outputs of the numerical model. Results of the simulation conducted with FLO- 2D indicated that if the countermeasure was not destroyed, the drainage work would function without overflow. This study aimed to review the effectiveness of eountermeasure on the basis of simulation results obtained by using the model to provide references for future disaster prevention and resident evacuation plans.

Status of Soil Zn in Citrus-Cultivated Area of South China

INTRODUCTION In recent 10 years,citrus production has developed rapidly in China.The citrus-cul-tivated area of our country is among the largest and its yield occupies the third place inthe world(Shen,1991).However,in some of our citrus-producing areas the yield is onthe low side and the sugar content of the fruit tends to reduce.The“mosaic”-a physio-

Cadmium in agricultural soils,vegetables and rice and potential health risk in vicinity of Dabaoshan Mine in Shaoguan,China

Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China's maximum permission level(MPL)for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi(XY)Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery>lactuca sativa L>Chinese cabbage>Romaine lettuce>asparagus lettuce>mustard>cabbage mustard>cabbage.The mean hazard quotient(HQ)of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA(2009)threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents.

Micronutrient Contents of Citrus Orchard Soils in Southern China

Investigations were carried out on the micronutrient contents,of major citrus orchard soils (involving seven soil great groups in 8 provinces and an autonomous region of southern China),and an evaluation on the abundance and deficiency of available micronutrients in these soils was made in this paper.In southern China,citrus orchard soils derived from sandstone,sandy shale,Quaternary red clay,diluvial deposit,granite gneiss and neritic deposit were deficient in available Mo and B and low in Zn.Those developed on purple sandy shale,limestone and slope deposit were all in short supply of available Zn,B and Mo.Coastal solonchak was fairly abundant in B,but its available Fe,Zn and Mo contents were rather low.

Soil Organic Carbon Sequestration Potential in Nectarine Orchards under Different Reclamation Systems

The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on the global carbon cycle and the seasonal fluctuation of atmospheric CO_2. To better evaluate the effects of reclamation systems in orchards converted from grasslands on soil carbon sequestration, we investigated soil organic carbon(SOC) content and stable C isotope(δ^(13)C)composition in three nectarine orchards at Yuchi Experimental Station in South China. Compared with the sloping clean tillage orchard and terraced clean tillage orchard, SOC content in the terraced orchard with grass cover was increased by 14.90% to 38.49%, and 7.40% to 15.33%, respectively. During the 14 years after orchard establishment, the soil organic matter sources influenced both δ^(13)C distribution with depth and carbon replacement. SOC turnover of the upper soil layer in the terraced orchard with grass cover(a mean 63.05% of replacement in the 20 cm after 14 years) was 1.59 and 1.41 times larger than that of the sloping clean tillage orchard and terraced clean tillage orchard under subtropical conditions, respectively. The equilibrium value of soil organic carbon in the three treatments ranged from 16.067 to 25.608 g/kg under the experimental conditions. The equilibrium value of soil organic carbon in the surface layer under grass cover was 54.801 t/hm^2, and the carbon sequestration potential was 24.695 1 t/hm^2.