检索结果-南通市图书馆

Evaluation of a Wireless Solar Powered Personal Weather Station

Agricultural Sciences 2024年第1期15卷 36-53页

作者： robert j. lascano Timothy S. Goebel Dennis C. Gitz III j.hn E. Stout Cropping Systems Research Laboratory Wind Erosion and Water Conservation Research Unit USDA-ARS Lubbock TX USA

We are evaluating dryland cotton production in Martin County, Texas, measuring cotton lint yield per unit of rainfall. Our goal is to collect rainfall data per 250 - 400 ha. Upon selection of a rainfall gauge, we realized that the cost of using, for example, a tipping bucket-type rain gauge would be too expensive and thus searched for an alternative method. We selected an all-in-one commercially available weather station;hereafter, referred to as a Personal Weather Station (PWS) that is both wireless and solar powered. Our obj.ctive was to evaluate average measurements of rainfall obtained with the PWS and to compare these to measurements obtained with an automatic weather station (AWS). For this purpose, we installed four PWS deployed within 20 m of the Plant Stress and Water Conservation Meteorological Tower that was used as our AWS, located at USDA-ARS Cropping Systems Research Laboratory, Lubbock, TX. In addition, we measured and compared hourly average values of short-wave irradiance (Rg), air temperature (Tair) and relative humidity (RH), and wind speed (WS), and calculated values of dewpoint temperature (Tdew). This comparison was done over a 242-day period (1 October 2022-31 May 2023) and results indicated that there was no statistical difference in measurements of rainfall between the PWS and AWS. Hourly average values of Rg measured with the PWS and AWS agreed on clear days, but PWS measurements were higher on cloudy days. There was no statistical difference between PWS and AWS hourly average measurements of Tair, RH, and calculated Tdew. Hourly average measurements of Rg and WS were more variable. We concluded that the PWS we selected will provide adequate values of rainfall and other weather variables to meet our goal of evaluating dryland cotton lint yield per unit rainfall.

关键词： Automation Sensors Citizen Weather Station Mesonet Rainfall Weather Variables

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Review Paper: Challenges and Limitations in Studying the Shrink-Swell and Crack Dynamics of Vertisol Soils

引用

Open j.urnal of Soil Science 2012年第2期2卷 82-90页

作者： Takele M. Dinka robert j. lascano Department of Soil and Crop Sciences Texas A&M University College Station TX USA USDA-ARS1 Cropping Systems Research Laboratory Wind Erosion and Water Conservation Research Unit Lubbock TX USA.

The need to study the shrink-swell and crack properties of vertic soils has long been recognized given their dynamics in time and space, which modifies the physical properties that impact water and air movement in the soil, flow of water into the subsoil and ground water, and generally alter the hydrology of vertic soils. Measurement of crack properties has been made by numerous researchers with the purpose to understand and quantify the spatial and temporal dynamics of shrinking and swelling and the associated formation of cracks. These crack properties, which are important in modifying hydrology of soils are: width, length, depth and orientation of soil’s cracks. To better understand the hydrology of vertic soils and incorporate crack properties into hydrologic simulation models, several techniques have been developed to measure crack properties. However, little attention is given to evaluate both the advantages and the limitations associated with these techniques. Thus, the purpose of this review is to highlight challenges and limitations that have been used or might be used to measure cracking in vertic soils.

关键词： Shrink-Swell Crack Dynamics Crack Properties

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Time for cotton to uptake water of a known isotopic signature as measured in leaf petioles

引用

Agricultural Sciences 2014年第2期5卷 170-177页

作者： Timothy S. Goebel robert j. lascano Wind Erosion and Water Conservation Research Unit Cropping Systems Research Laboratory USDA-ARS Lubbock USA

While stable isotopes of water have been used to study water movement through the environment, they generally have not been used to examine shorter, more transient events, e.g., rainfall of j.ctive of this study was to measure the time required by a plant to transpire water from a source of water with a different isotopic signature than the water that the plant was irrigated. To this end, cotton (Gossypium hirsutum (L.)) plants were grown in a greenhouse and the time required for the enriched water added the soil to show up in the meristematic petioles of cotton leaves was measured. The initial divergence from the irrigation water signature occurred as quickly as 4 hours. The water from the sampled petioles then reached equilibrium with the new source water within 12 hours.

关键词： Cotton Stable Isotopes Water Use

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Test of the Rosetta Pedotransfer Function for Saturated Hydraulic Conductivity

引用

Open j.urnal of Soil Science 2012年第3期2卷 203-212页

作者： Carlos Alvarez-Acosta robert j. lascano Leo Stroosnij.er Cropping System Research Laboratory Wind Erosion and Water Conservation Research Unit 3810 4th St Lubbock TX 79415 USA Wageningen University Land Degradation and Development Group Soil Science Centre P. O. Box 47 6700 AA Wageningen The Netherlands

Simulation models are tools that can be used to explore, for example, effects of cultural practices on soil erosion and irrigation on crop yield. However, often these models require many soil related input data of which the saturated hydraulic conductivity (Ks) is one of the most important ones. These data are usually not available and experimental determination is both expensive and time consuming. Therefore, pedotransfer functions are often used, which make use of simple and often readily available soil information to calculate required input values for models, such as soil hydraulic values. Our obj.ctive was to test the Rosetta pedotransfer function to calculate Ks. Research was conducted in a 64-ha field near Lamesa, Texas, USA. Field measurements of soil texture and bulk density, and laboratory measurements of soil water retention at field capacity (–33 kPa) and permanent wilting point (–1500 kPa), were taken to implement Rosetta. Calculated values of Ks were then compared to measured Ks on undisturbed soil samples. Results showed that Rosetta could be used to obtain values of Ks for a field with different textures. The Root Mean Square Difference (RMSD) of Ks at 0.15 m soil depth was 7.81 × 10–7 m·s–1. Further, for a given soil texture the variability, from 2.30 × 10–7 to 2.66 × 10–6 m·s-1, of measured Ks was larger than the corresponding RMSD. We conclude that Rosetta is a tool that can be used to calculate Ks in the absence of measured values, for this particular soil. Level H5 of Rosetta yielded the best results when using the measured input data and thus calculated values of Ks can be used as input in simulation models.

关键词： Rosetta Saturated Hydraulic Conductivity Ks Pedotransfer Function

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

System for High Throughput Water Extraction from Soil Material for Stable Isotope Analysis of Water

引用

j.urnal of Analytical Sciences, Methods and Instrumentation 2012年第4期2卷 203-207页

作者： Timothy S. Goebel robert j. lascano Wind Erosion and Water Conservation Research Unit Cropping Systems Research Laboratory USDA-ARS# Lubbock USA.

A maj.r limitation in the use of stable isotope of water in ecological studies is the time that is required to extract water from soil and plant samples. Using vacuum distillation the extraction time can be less than one hour per sample. Therefore, assembling a distillation system that can process multiple samples simultaneously is advantageous and necessary for ecological or hydrological investigations. Presented here is a vacuum distillation apparatus, having six ports, that can process up to 30 samples per day. The distillation system coupled with the Los Gatos Research DLT-100 Liquid Water Isotope Analyzer is capable of analyzing all of the samples that are generated by vacuum distillation. These two systems allow larger sampling rates making investigations into water movement through an ecological system possible at higher temporal and spatial resolution.

关键词： Isotope Vacuum Distillation Soil

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Technical Note: Orientation of Cracks and Hydrology in a Shrink-Swell Soil

引用

Open j.urnal of Soil Science 2012年第2期2卷 91-94页

Crack orientations are an important soil physical property that affects water flow, particularly in vertic soils. However, the spatial and temporal variability of crack orientations across different land uses and gilgai features is not well-documented and addressed in hydrology models. Thus;there is a need to quantify crack orientations for different land uses and to incorporate their spatial and temporal dynamics into hydrological models. Our obj.ctives were to document the spatial variability of cracks orientations across two land uses and to demonstrate the potential importance of crack orientation related to the hydrology of Vertisols. The exploratory field measurements of the spatial distribution of crack orientations across two Vertisol catenae of two land uses and gilgai features are presented. The field survey showed the complexity of crack geometry in a field, the potential impact of crack orientation on Vertisol hydrology and the challenges associated with measurement of crack orientations.

关键词： Crack Orientation Hydrology

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Evaluation of Stable Isotopes of Water to Determine Rainwater Infiltration in Soils under Conservation Reserve Program

引用

j.urnal of Agricultural Chemistry and Environment 2016年第4期5卷 179-190页

作者： Timothy S. Goebel robert j. lascano Veronica Acosta-Martinez USDA-ARS Wind Erosion and Water Conservation Unit Lubbock TX USA

The Conservation Reserve Program (CRP) is a USDA program introduced in 1985 to reduce soil erosion by increasing vegetative cover of highly erodible land. Participation in the CRP is done via contracts (10 - 15 years in length) and currently the total area of land under contract is set to decline as per the 2014 Farm Bill. The Texas High Plains (THP) leads the US with >900,000 ha enrolled in CRP. A potential long- term benefit of CRP is to increase soil organic matter and to improve soil structure leading to increased water infiltration. Our obj.ctive was to evaluate the feasibility of using stable isotopes of water to measure and compare infiltration of rain in land under CRP management to land under continuous dryland cotton in the THP. For this purpose we selected two sites, with soils in the Amarillo series, enrolled in CRP, one for 25 years and the second site for 22 years. Results from several rain events showed that stable isotopes of water are a method that can be used to evaluate the depth of rainwater infiltration for soils under CRP and dryland management.

关键词： Conservation Reserve Program Rain Infiltration Stable Isotopes Dryland Cotton

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phosphate Sorption in Water by Several Cationic Polymer Flocculants

引用

j.urnal of Agricultural Chemistry and Environment 2016年第1期5卷 45-51页

作者： Timothy S. Goebel robert j. lascano Todd A. Davis Cropping Systems Research Laboratory USDA-ARS Lubbock TX USA Department of Chemistry United States Air Force Academy Colorado Springs CO USA

Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters lead to adverse effects in the environment. These effects are attributed to runoff from rain or irrigation events that may cause the sorbed phosphate to be transported from the application sites and to move into neighboring watersheds. Increased phosphate concentration in watersheds may lead to a variety of environmental problems including increased algal blooms, bacterial contamination, and in some cases eutrophication. To overcome these effects, polymer flocculants have been shown to reduce the phosphate concentration in water by removing suspended solids and thereby removing the phosphate sorbed to the solids. The purpose of this study is to determine the amount, if any, of phosphate removed by several commercial polymers. The polymers chosen include the polyacrylamides Magnifloc 494C, Magnifloc 985N and Poly (diallyldimethyl ammonium chloride) (Poly (DADMAC)). Using these polymers, it is discovered that the positive charge density of the polymers affects the amount of phosphate removed from solution with Poly (DADMAC) (having 100% positive charge density) removing 40% of the phosphate from a solution containing 10 ppm phosphate.

关键词： Polymer Flocculants Phosphate Sorption Polyacrylamides Poly (DADMAC) Smectite

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stable Carbon Isotope Discrimination (δ¹³C) of Cotton Burrs and Seeds as a Season-Long Integrator of Crop Water Stress

引用

American j.urnal of Plant Sciences 2022年第12期13卷 1448-1459页

作者： Dennis C. Gitz III j.ffrey T. Baker robert j. lascano Cropping Systems Research Laboratory ARS-USDA1 Lubbock USA

Plant-based irrigation management schemes typically use surrogates such as canopy temperature, alone, or in conj.nction with environmental variables, to infer the degree of “crop stress” (biological strain) induced by drought. Few systematic studies of the relationship between “crop stress”, as defined by such surrogates, and physiological estimates of water use efficiency (WUE) exist over both daily and seasonal time scales relevant to agronomic irrigation control. The systematic application of stable carbon isotope discrimination (δ13C) might allow post hoc evaluation of irrigation scheduling schemes and might also be a useful germplasm screening tool if the source(s) of variability can be uncovered and/or controlled. Results from preliminary efforts comparing leaf and cotton seed δ13C to season-long water deficits showed that seeds are more useful indicators of season-long water stress and water use efficiency during crop development.

关键词： Irrigation-Scheduling Germplasm Screen Water Management

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Scaling Leaf Measurements to Estimate Whole Canopy Gas Exchanges of Cotton

引用

American j.urnal of Plant Sciences 2016年第14期7卷 1952-1963页

作者： Dennis C. Gitz III j.ffrey T. Baker robert j. lascano Wind Erosion and Water Conservation Unit Cropping Systems Research Laboratory USDA-ARS1 Lubbock TX USA

Diurnal leaf and canopy gas exchanges of well-watered field grown cotton were measured. Our obj.ctive was to scale leaf-level values of transpiration and net assimilation to the whole canopy level using estimates of canopy leaf area. Single leaf gas exchange measurements were made with two portable photosynthesis systems and canopy measurements with four open Canopy Evapo-Transpiration and Assimilation (CETA) chamber systems. Canopy leaf area was measured at the end of the experiment and estimated during gas exchange by fitting values to a growth curve. Leaf level measurements were arithmetically scaled to estimate canopy level gas exchange based on canopy leaf area and then compared to the measured values. Scaled values of single leaf transpiration were very similar to canopy transpiration measurements, although both whole canopy transpiration and assimilation were overestimated around mid-day. We conclude that canopy cotton transpiration of well-watered field grown plants could be estimated within 5% throughout the day by scaling leaf level measurements to the whole canopy using measured canopy leaf area. Estimating canopy assimilation from leaf level measurements remains problematic.

关键词： Cotton Gossypium hirsutum Scaling Assimilation Transpiration Drought Stress

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：