检索结果-南通市图书馆

Maize （Zea mays L.） Growth and Grain Yield under Conventional and Site-Specific Nitrogen Management in a Dryland Farming System

引用

Journal of Agricultural Science and Technology(B) 2014年第8期4卷 602-611页

作者： suzan mashego.brilliant mareme petja Matshwene Edwin Moshia Shadrack Batsile Dikgwatlhe Limpopo Department of Agriculture Directorate of Research Services Polokwane 0700 South Africa Department of Plant Production Soil Science andAgricultural Engineering University ofLimpopo Sovenga 0727 South Africa Department of Crop Science Tshwane University of Technology Pretoria 0001 South Africa College of Agronomy and Biotechnology China Agricultural University Beij'ing 100094 China

Large amount of pre-plant nitrogen （N） fertilizer results in low N use efficiency due to poor synchrony between soil N supply and maize N demand, especially during N sensitive growth stages. The objectives of the study were to compare growth and yield of maize （Zea rnays L.） under conventional and site-specific N management in a dryland farming system. The study, which was designed as randomized complete block design was conducted over three site-years under continuous maize cropping system in the semi-arid regions of the Limpopo Province in South Africa. Treatments of the study consisted of three N management strategies on a maize field planted to drought resistant SNK 2147 hybrid maize cultivar. Treatments were：（i） no N application （NO）, （ii） site-specific N at variable rates ranging between 18 kg N/ha and 33 kg N/ha based on soil analysis results （N l） and （iii） conventional and uniform N application broadcasted during planting at 58 kg N/ha （N2）. Sufficiency index as indication of N deficiency was determined using CCM-200 on maize leaves based on leaf numbers during maize vegetative growth stages V6, V10 and Vl4, and thereafter N was applied only when needed. The highest maize grain yield of 5.2 Mg/ha for N 1 was significantly higher （P 〈 0.05） than 3.2 Mg/ha and 4.0 Mg/ha of N0 and N2 in site-year I, respectively. Maize grain yield of 2.2 Mg/ha （Nl） at site-year ll was significantly higher （P _〈 0.05） than 1.7 Mg/ha of the NO. The maize growth and yield under N2 and N1 was compared, N1 required between 43% and 69% lesser N fertilizer as compared to N2 over site-years, and resulted in higher maize height, number of leaves per plant, leaf length, and leaf area than that of conventional N management strategy. Therefore, site-specific N management strategy sustains and improves growth and yield of maize using minimal N fertilizer as compared to conventional approach in low fertility soils of semi-arid regions in dryland farming systems. In examining the results of

关键词： Africa maize grain yield nitrogen management precision agriculture

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

Techniques of Remote Sensing and GIS as Tools for Visualizing Impact of Climate Change-Induced Flood in the Southern African Region

引用

American Journal of Climate Change 2017年第2期6卷 306-327页

作者： Yaw A.Twumasi Edmund C.Merem Tomas Ayala-Silva Albert Osei brilliant M.petja Kia Alexander Department of Urban and Regional Planning Jackson State UniversityJacksonMSUSA USDA-ARS Tropical Agriculture Research Station MayaguezPuerto Rico Department of Mathematics and Computer Sciences Oakwood UniversityHuntsvilleALUSA Water Research Commission(WRC)Private Bag X03 GezinaSouth Africa Texas Department of Agriculture(TDA) DallasTXUSA

Flooding is a major problem facing Southern African region. The region has been experiencing flood for the past two decades. This flood event has been exacerbated in recent years by global weather pattern known as La Ni?a which cools ocean waters in the equatorial Pacific and changes rainfall patterns across the world. This change in weather pattern has resulted in increased rainfall over Southern Africa causing flash floods resulting in extensive socioeconomic loses, casualties and environmental damage. This study employs remote sensing and geographical information systems (GIS) data to visualize the impact of climate change caused by flooding in the Southern African region in order to assist decision makers’ plans for future occurrences. To achieve these objectives, the study used Digital Elevation Model (DEM), temporal Landsat Enhanced Thematic Mapper Plus (ETM+) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellites data obtained from the United States Geological Survey (USGS) and NASA’s Earth Observatory websites in order to show the spatial dimensions of the damage and the flooded area. Results of the study revealed notable damages to social and natural environments as well as flood risk zones and watercourses in the study area. The paper concludes by outlining policy recommendations in the form of the need for building drainage ditches on the flat plains identified in this study to accommodate flood flows, the design of a comprehensive Regional Emergency Information System (REIS) with support from the governments in the study area and the neighboring countries. Building such system, the paper concludes could offer decision-makers access to the appropriate spatio-temporal data for monitoring climate change induced emergencies related to seasonal floods.

关键词： Remote Sensing Geographic Information Systems Climate Change Flooding La Nina

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

Land Resource Areas and Spatial Analysis of Potential Location of Bioenergy Crops Production in Mississippi

引用

Journal of Sustainable Bioenergy Systems 2021年第4期11卷 187-214页

作者： Yaw Adu Twumasi Edmund Chukwudi Merem John Bosco Namwamba Jacob Banafo Annan Tomas Ayala-Silva Abena Boatemaa Asare-Ansah Zhu Hua Ning Judith Oppong Priscilla Mawuena Loh Diana Botchway Frimpong Faustina Owusu Janeth Ernest Mjema Ronald Okwemba Olipa Simon Mwakimi brilliant mareme petja Caroline Olufunke Akinrinwoye Joyce McClendon-Peralta Hermeshia Jonee Mosby Department of Urban Forestry and Natural Resources Southern University and A&M College Baton Rouge Louisiana USA Department of Urban and Regional Planning Jackson State University Jackson Mississippi USA USDA-ARS Tropical Agriculture Research Station 2200 P.A. Mayaguez Puerto Rico USA Institute of Resource Assessment University of Dares Salam Dares Salam Tanzania Water Research Commission (WRC) Private Bag X03 Gezina South Africa

Mississippi State is renowned for its land resource areas (LRA) and production of bioenergy crops which generate both agricultural and economic benefits. Agricultural commodities play a key role in economic growth, therefore the ability to produce more would enhance development. This paper offers an analysis of the production of bioenergy crops in Mississippi. Relative measures, time series graphs and descriptive statistics coupled with geographic information systems (GIS) mapping using ArcMap were employed to generate the outcome of this research. The outcome of the statistical analysis indicated that corn and soybeans were the most produced crops in Agricultural Districts 10 and 40. These districts produced more bioenergy crops than the other districts. GIS mapping results also showed that the potential area for bioenergy crops is in zone 131 of the Mississippi Land Resource Area (MLRA). This zone has an absolute advantage in the production of these crops which includes the diversity of biomass production such as corn, cotton, soybeans, wheat, rice, barley, grain sorghum, canola, camelina, algae, hardwoods, and softwood. The paper recommends a constant GIS mapping and land management systems for each agricultural district in Mississippi to enable researchers and farmers to determine the factors which contribute towards the increasing and decreasing trends in the production of the bioenergy crops.

关键词： Land Resource Areas GIS Bioenergy Crops Descriptive Statistics Mississippi

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 Series Analysis on Selected Rainfall Stations Data in Louisiana Using ARIMA Approach

引用

Open Journal of Statistics 2021年第5期11卷 655-672页

作者： Yaw A. Twumasi Jacob B. Annan Edmund C. Merem John B. Namwamba Tomas Ayala-Silva Zhu H. Ning Abena B. Asare-Ansah Judith Oppong Diana B. Frimpong Priscilla M. Loh Faustina Owusu Lucinda A. Kangwana Olipa S. Mwakimi brilliant M. petja Ronald Okwemba Caroline O. Akinrinwoye Hermeshia J. Mosby Joyce McClendon-Peralta Department of Urban Forestry and Natural Resources Southern University and A&M College Baton Rouge Louisiana USA Department of Urban and Regional Planning Jackson State University Jackson Mississippi USA USDA-ARS Tropical Agriculture Research Station Mayaguez Puerto Rico USA Institute of Resource Assessment University of Dares Salam Dares Salam Tanzania Water Research Commission (WRC) Private Bag X03 Gezina South Africa

Precipitation is very important for both the environment and its inhabitants. Agricultural activities mostly depend on precipitation and its availability. Therefore, the ability to predict future precipitation values at specific stations is key for environmental and agricultural decision making. This research developed Autoregressive Integrated Moving Average (ARIMA) models for selected stations with Integrated component and Autoregressive Moving Average (ARMA) for selected stations without Integrated component at Louisiana State. The ARIMA module is represented as ARIMA(p, d, q)(P,D,Q). The selected lag order for the Autoregressive (AR) component is represented with p and P for seasonal AR component, while the integrated form (number of times data were differenced) is d and D for seasonal differencing, and the Moving Average (MA) lag order is q and Q for seasonal MA component. Data from 1950 to 2020 were employed in this research. Results of the analysis indicated that Baton Rouge (ARIMA (0,1,1) (0,0,2)12), Abbeville (ARMA (0,0,1) (0,0,2)12), Monroe Regional (ARMA (0,0,1) (0,0,0)12), New Orleans Airport (ARMA (1,0,0) (0,0,2)12), Alexandria (ARMA (1,0,1) (0,0,0)12), Logansport (ARIMA (0,1,2) (0,0,0)12), New Orleans Audubon (ARMA (1,0,0) (0,0,0)12), Lake Charles Airport (ARMA (2,0,2) (0,0,0)

关键词： Precipitation ARIMA Models Time Series Lowess Louisiana

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

Estimation of Land Surface Temperature from Landsat-8 OLI Thermal Infrared Satellite Data. A Comparative Analysis of Two Cities in Ghana

引用

Advances in Remote Sensing 2021年第4期10卷 131-149页

作者： Yaw A. Twumasi Edmund C. Merem John B. Namwamba Olipa S. Mwakimi Tomas Ayala-Silva Diana B. Frimpong Zhu H. Ning Abena B. Asare-Ansah Jacob B. Annan Judith Oppong Priscilla M. Loh Faustina Owusu Valentine Jeruto brilliant M. petja Ronald Okwemba Joyce McClendon-Peralta Caroline O. Akinrinwoye Hermeshia J. Mosby Department of Urban Forestry and Natural Resources Southern University and A&M College Baton Rouge Louisiana USA Department of Urban and Regional Planning Jackson State University Jackson Mississippi USA Institute of Resource Assessment University of Dares Salam Dares Salam Tanzania USDA-ARS Tropical Agriculture Research Station Mayaguez Puerto Rico USA Water Research Commission (WRC) Private Bag X03 Gezina South Africa

This study employs Landsat-8 Operational Land Imager (OLI) thermal infrared satellite data to compare land surface temperature of two cities in Ghana: Accra and Kumasi. These cities have human populations above 2 million and the corresponding anthropogenic impact on their environments significantly. Images were acquired with minimum cloud cover (ere used. The shapefiles of Accra and Kumasi were used to extract from the full scenes to subset the study area. Thermal band data numbers were converted to Top of Atmospheric Spectral Radiance using radiance rescaling factors. To determine the density of green on a patch of land, normalized difference vegetation index (NDVI) was calculated by using red and near-infrared bands i.e. Band 4 and Band 5. Land surface emissivity (LSE) was also calculated to determine the efficiency of transmitting thermal energy across the surface into the atmosphere. Results of the study show variation of temperatures between different locations in two urban areas. The study found Accra to have experienced higher and lower dry season and wet season temperatures, respectively. The temperature ranges corresponding to the dry and wet seasons were found to be 21.0985

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

Flood Mapping in Mozambique Using Copernicus Sentinel-2 Satellite Data

引用

Advances in Remote Sensing 2022年第3期12卷 80-105页

作者： Yaw A. Twumasi Edmund C. Merem John B. Namwamba Abena B. Asare-Ansah Jacob B. Annan Zhu H. Ning Rechael N. D. Armah Caroline Y. Apraku Harriet B. Yeboah Julia Atayi Matilda Anokye Diana B. Frimpong Ronald Okwemba Olipa S. Mwakimi Judith Oppong brilliant M. petja Janeth Mjema Priscilla M. Loh Lucinda A. Kangwana Valentine Jeruto Leah Wangari Njeri Joyce McClendon-Peralta Department of Urban Forestry and Natural Resources Southern University and A & M College 102 Fisher Hall Baton Rouge Louisiana USA Department of Urban and Regional Planning Jackson State University 101 Capitol Center Jackson Mississippi USA Department of Geography and Tourism Studies Brock University St. Catharines Ontario Canada Institute of Resource Assessment University of Dares Salam Dares Salam Tanzania Water Research Commission (WRC) Private Bag X03 Gezina South Africa

Over the last two decades, Mozambique has experienced tremendous tropical cyclonic activities causing many flooding activities accompanied by disastrous human casualties. Studies that integrate remote sensing, elevation data and coupled with demographic analysis in Mozambique are very limited. This study seeks to fill the void by employing satellite data to map inundation caused by Tropical Cyclones in Mozambique. In pursuit of this objective, Sentinel-2 satellite data was obtained from the United States Geological Survey (USGS)’s Earth Explorer free Online Data Services imagery website covering the months of March 20, 2019, March 25, 2019, and April 16, 2019 for two cities, Maputo and Beira in Mozambique. The images were geometrically corrected to remove, haze, scan lines and speckles, and then referenced to Mozambique ground-based Geographic: Lat/Lon coordinate system and WGS 84 Datum. Data from twelve spectral bands of Sentinel-2 satellite, covering the visible and near infrared sections of the electromagnetic spectrum, were further used in the analysis. In addition, Normalized Difference Water Index (NDWI) within the study area was computed using the green and near infrared bands to highlight water bodies of Sentinel-2 detectors. To project and model the population of Mozambique and see the impact of cyclones on the country, demographic data covering 1980 to 2017 was obtained from the World Bank website. The Exponential Smoothing (ETS) method was adopted to forecast the population of Mozambique. Results from NDWI analysis showed that the NDWI is higher for flood areas and lower for non-flooded ones. The ETS algorithm results indicate that the population of Mozambique would nearly double by 2047. Human population along the coastal zone in the country is also on the rise exponentially. The paper concludes by outlining policy recommendations in the form of uniform distribution of economic activities across the country and prohibition of inland migration to the coas

关键词： Tropical Cyclones Floods Remote Sensing NDWI Exponential Smoothing (ETS) Digital Elevation Model (DEM) Sentinel-2 Satellite Mozambique

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

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

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：