Estimating Plant-Available Water in the Ap Horizon Using Geospatial Analysis of Field and SSURGO Data

Soil provides many of the requirements needed for terrestrial plant growth, including an adequate supply of water. Because the proportion of plant roots is usually greatest in the top 10 to 15 cm of soil, the soil moisture content in the Ap horizon is particularly important for plant growth and crop yields. Uncertainties in estimates of plant available water in the Ap horizon (AW_Ap) often arise from variabilities in field, laboratory and geospatial data at a farm scale. The objectives of this study were to quantify and compare AW_Ap estimates across the 147-ha Cornell University Willsboro research farm using four different approaches: a) AW_Ap calculated from values reported in the SSURGO database for available water capacity (AWC) and Ap thickness for the soil map units (SMUs) present on the farm, b) AW_Ap estimated from soil texture data reported for the SSURGO SMUs, c) AW_Ap estimated from soil texture data determined from soil cores taken across the farm that were then averaged within each SMU, and d) spatially interpolating the AW_Ap values predicted from soil cores across the entire farm irrespective of SMU boundaries. Available water in the Ap horizon varied with soil order in the general trend of Alfisols > Inceptisols > Entisols regardless of the estimation approach used. Field measurement-based estimates of AW_Ap were lower, in general than the reported SSURGO values and estimates based on reported texture in the SSURGO database. The higher abundance of coarse fragments in the Ap horizon of the soil cores collected on the farm partially explains the lower field measurement-based AW_Ap estimates. In the SSURGO database, values reported for AWC are frequently obtained from a selected pedon from a “type location” and not from the actual study location. These “type locations” can be located far from study sites and even in different states. Although collecting detailed field data may not always be possible due to the high costs of field and laboratory measurements, it is important to understand the potential benefits and limitations of making field-scale and regional AW estimates using the SSURGO database.     

土壤含水量的Kriging和Cokriging估值研究

分析了田间同深度土壤含水量的半方差和不同深度土壤含水量的交互半方差特征 ,探讨了土壤含水量的Kriging和Cokriging估值方法。研究表明 ,同深度土壤含水量与不同深度的土壤含水量之间均具有显著的空间相关性 ,用Kriging方法进行土壤含水量的估值精度较传统方法高。加入浅层土壤含水量用Cokriging方法来估测深层土壤含水量 ,可进一步提高估值精度     

Batch Sorber Design Using Equilibrium and Contact Time Data for the Removal of Lead

The two-stage batch sorption design ofthe sorption of lead ions onto peat has been studiedbased on a Langmuir isotherm type equation obtainedfrom different contact time studies. A model has beendeveloped to predict the optimised minimum operatingtime to determine a specified amount of lead removal.The sorption capacity at any contact time has beenevaluated with an equation also based on themathematical form of the Langmuir equation.     

泥沙搬运能力方程的比较分析

泥沙搬运是小流域土壤侵蚀、搬运和沉积过程中一个很重要子过程,搬运能力的定量研究是刻画土壤侵蚀过程和建立物理过程侵蚀模型的理论基础。对于目前被广泛采用的坡面漫流输移方程和沟道挟沙水流方程的试验条件进行了比较分析,探讨了其在黄土高原地区侵蚀模拟过程中的应用可能性和局限性。同时,表述了在黄土高原地区选择搬运能力方程需要考虑修正条件的必要性。     

Chemical Reduction of Hexavalent Chromium and Its Immobilisation Under Batch Conditions Using a Slurry Reactor

Water, Air, & Soil Pollution - Risks posed by antifouling agents (irgarol 1051, diuron and dichlofluanid) to the aquatic environment of the Gulf of Napoli have been estimated. Seawater samples...     

Estimating Deoxynivalenol Content of Ground Oats Using VIS‐NIR Spectroscopy

The potential of VIS‐NIR spectroscopy as a rapid screening method for resistance of Fusarium‐inoculated oats to replace the costly chemical measurements of deoxynivalenol (DON) was investigated. Partial least squares (PLS) regression was conducted on second‐derivative spectra (400–2,350 nm) of 166 DON‐contaminated samples (0.05–28.1 ppm, mean = 13.06 ppm) with separate calibration and test set samples. The calibration set had 111 samples, and the test set had 55 samples. The best model developed had three PLS components and a root mean square error of prediction (RMSEP) of 3.16 ppm. The residual predictive deviation (RPD) value of the prediction model was 2.63, an acceptable value for the purpose of rough screening. Visual inspection and the VIS spectra of the samples revealed that high‐DON samples tended to be darker in color and coarser in texture compared with low‐DON samples. The second‐derivative spectra showed that low‐DON samples tended to have more water and fat content than high‐DON samples. With an RMSEP value of 3.16 and RPD of value of 2.63, it seems possible to use VIS‐NIR spectroscopy to semiquantitatively estimate DON content of oats and discard the worst genotypes during the early stages of screening.     

胡枝子栽培香菇试验

利用豆科多年生落叶灌木胡枝子的木屑做培养基主料栽培香菇,所产香菇味美可口,营养丰富,符合卫生标准。一亩水土流失山地栽植胡枝子800株,第二年便可产干枝条500公斤。用以栽培香菇,可产鲜菇约500公斤,获纯收入约650元。这不仅大大提高群众种植胡枝子的积极性,促进治理水土流失,而且也为水土流失地区找到了一条脱贫致富的新门路。     

Design of an Organic Farming Crop-Rotation Experiment

A field experiment is being conducted which focuses on crop rotations for cereal production in organic farming. The objective of the experiment is to explore the possibilities for both short-term and long-term increases in organic cereal production through manipulation of crop-rotation design on different soil types. This paper describes the design of a rather complex experiment, and later papers will describe and discuss the results. Three factors are included in the experiment in a factorial design with two replicates: (1) fraction of grass-clover and pulses in the rotation (crop rotation); (2) catch crop (with or without catch crop or bi-cropped clover); and (3) manure (with or without animal manure applied as slurry). All fields in all rotations are represented in each year. The experimental factors are defined to allow management to be adjusted for optimization of the individual treatment combinations. This makes the systems more realistic and the results more applicable in practical farming. The experiment is being conducted at four locations representing major soil types and climate regions in Denmark. The main design criteria are related to requirements for a long-term experiment and the need for performing studies and experiments within the experiment itself.     

Improvement of a Gravity Oil Separator Using a Designed Experiment

Several authors have pointed out the need to improve the design procedure of conventional oil-water separator. In this work, a batch test and various continuous runs based on a Plackett-Burman statistical plan were performed, in order to optimize a small (10 L/min) gravity oil-water separator technology intended to pre-treat wastewaters from vehicle service facilities. The results from the tracer tests realized did not show a coherent relationship between the performance of the separator (E) and the mixing regime qualified by means of the variable ε (ratio between the actual and nominal mean residence times). The statistical analysis showed that the oil removal efficiency variations (69-82%) were mainly dictated by the way the separator is configured. A two-step design procedure alternative of small gravity separators was suggested.     

Experiment on Cryopreservation of Porcine Oocytes by Using Glass Micropipette

用自制的玻璃微管（glass micropipette，GMP）冷冻猪卵母细胞。以FDA染色鉴定冷冻-解冻后卵母细胞存活力，结果表明，用常规细管程序化冷冻和GMP管玻璃化冷冻猪成熟（MⅡ期）卵母细胞时，冻后存活率分别为34.5%和63.3%（P <0.05）；以玻璃化冷冻比较细管和GMP管对猪MⅡ期卵母细胞冷冻效果的影响，两组冻后存活率分别为45.0%和65.9%（P < 0.05）；用常规细管程序化和GMP管玻璃化冷冻猪GV期卵母细胞时，冻后存活率为30.0%对59.7%，有显著性差异（P < 0.05）。研究表明，GMP法为一种有效的猪卵母细胞冷冻保存方法。     

利用ArcGIS实现CAD图斑批量录入水土保持信息系统的方法

国家水土保持重点工程项目管理信息系统是水利部针对水土保持项目点多、面广的特点,为创新管理模式而研发的集数据录入、存储、查询、统计、报表等功能于一体的决策管理工具,是水土保持信息化建设的重要组成部分,特别是图斑的精细化入库,使项目管理、检查验收等都更为直观、更为精准。但基层单位受专业技术能力的限制,图斑入库工作效率低,甚至出现了信息录入不及时、不完整、不规范等问题。基于此,为提高工作效率,并考虑到小流域设计资料大部分是CAD图纸的实际,重点介绍了利用Arc GIS实现CAD图斑批量录入的方法。     

Reduction of Hexavalent Chromium in Soil and Ground Water Using Zero-Valent Iron Under Batch and Semi-Batch Conditions

Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe⁰ _G (granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456?±?35 mg kg^?1. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ～280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.     

Enhanced Microalgal Growth and Effluent Quality in Tertiary Treatment of Livestock Wastewater Using a Sequencing Batch Reactor

Water, Air, & Soil Pollution - The Pantanal is an extensive flooded plain, rich in biodiversity and considered a Biosphere Reserve and World Heritage Site. It has great complexity and can be...     

骆驼行走步态的实验与分析

为合理设计沙漠地区步行车辆行走机构及合理确定整车参数,采用高速摄影记录方法,对骆驼行走时的步法、形态及特点进行了一系列试验,经数据处理、绘制曲线、建立数学模型,研究了骆驼腿关节行走运动过程和步态规律。所获成果为步行运输车辆设计提供了理论依据。     

紫色土和黄壤含水率的室内光谱反演

[目的] 选择西南地区代表性土类紫色土和地带性黄壤,分析其光谱信息,构建土壤水分反演模型,估测土壤含水率,为西南地区土壤水分快速监测提供方法依据。[方法] 通过室内配置紫色土和黄壤不同土壤含水率水平,运用地物光谱仪测量其光谱反射率,比较不同含水率条件下两类土壤的高光谱特征;采用多种数学变换和相关分析法提取特征波段,运用多元逐步回归（SMLR）和BP神经网络（BPNN）分别构建土壤含水率的高光谱估测模型。[结果] ①随土壤含水率的增加,紫色土和黄壤的光谱反射率均逐渐降低;在相同含水率条件下,紫色土的光谱反射率低于黄壤。②土壤含水率对可见光波段（380～760 nm）反射率的影响显著低于红外波段（760～2 500 nm）;均在1 400,1 900,2 200 nm附近存在明显水分吸收谷。③经数学变换的紫色土和黄壤光谱反射率均与土壤含水率存在极强的相关性。④基于BPNN建立的土壤水分反演模型整体优于SMLR模型。[结论] BPNN模型为西南地区紫色土和黄壤土壤含水率光谱反演的最优模型,能够快速准确估测紫色土和黄壤土壤水分状况。     

使用积分法估算原状土van Genuchten模型参数

The van Genuchten model is the most widely used soil water retention curve (SWRC) model. Two undisturbed soils (clay and loam) were used to evaluate the accuracy of the integral method to estimate van Genuchten model parameters and to determine SWRCs of undisturbed soils. SWRCs calculated by the integral method were compared with those measured by a high speed centrifuge technique. The accuracy of the calculated results was evaluated graphically, as well as by root mean square error (RMSE), normalized root mean square error (NRMSE) and Willmott’s index of agreement (l). The results obtained from the integral method were quite similar to those by the centrifuge technique. The RMSEs (4.61 × 10-5 for Eum-Orthic Anthrosol and 2.74 × 10-4 for Los-Orthic Entisol) and NRMSEs (1.56 × 10-4 for Eum-Orthic Anthrosol and 1.45 × 10-3 for Los-Orthic Entisol) were relatively small. The l values were 0.973 and 0.943 for Eum-Orthic Anthrosol and Los-Orthic Entisol, respectively, indicating a good agreement between the integral method values and the centrifuge values. Therefore, the integral method could be used to estimate SWRCs of undisturbed clay and loam soils.     

USLE用于估算工程建设项目水土流失量的讨论

USLE是适用于估算缓坡农耕地多年平均土壤侵蚀量的模型 ,由于工程建设项目水土流失预测的时段及范围与USLE的适用条件有较大差别 ,经工程建设施工扰动的土体结构与农耕地的土壤结构有较大差异 ,因此工程项目施工引起的水土流失不能直接用USLE进行估算。     

无损检测桃子电特性的试验研究

利用智能ＬＣＲ测量仪和平板电极系统，用无损检测方法测定了桃子在储藏过程中电特性的变化。结果表明：在１２Ｈｚ～１００ｋＨｚ的频段内，桃子的最佳测试频段为１５ｋＨｚ以下，此时桃子随着储藏时间的增加，等效阻抗增大而相对介电常数和介质损耗因数减小；当桃子开始腐烂时，电特性数值出现了一个大的反复