نتایج جستجو برای: cultivated land of region

تعداد نتایج: 21200887  

2015
Prajal Pradhan Günther Fischer Harrij van Velthuizen Dominik E. Reusser Juergen P. Kropp Jose Luis Gonzalez-Andujar

Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may...

Onwuchekwa Raphael Iheke, Ukandu Ihuoma

This study examined the effect of urbanization on agricultural production in Abia State. Specifically, it categorized the land tenancy status of the farmers, analyzed the effect of urbanization on agricultural productivity and identified the constraints to agricultural productivity. Multistage random sampling technique was used to select the respondents. Primary data collected using structured ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2009
Thomas K Rudel Laura Schneider Maria Uriarte B L Turner Ruth DeFries Deborah Lawrence Jacqueline Geoghegan Susanna Hecht Amy Ickowitz Eric F Lambin Trevor Birkenholtz Sandra Baptista Ricardo Grau

Does the intensification of agriculture reduce cultivated areas and, in so doing, spare some lands by concentrating production on other lands? Such sparing is important for many reasons, among them the enhanced abilities of released lands to sequester carbon and provide other environmental services. Difficulties measuring the extent of spared land make it impossible to investigate fully the hyp...

2012
David M. Johnson

A ca. 2010, 30 m resolution map depicting annually tilled areas across the conterminous United States was developed. Input sources included four years, spanning 2008–2011, of annual national-level coverage Cropland Data Layer (CDL) land cover classifications as produced by the National Agricultural Statistics Service. Derived total land area under tillage from the aggregate CDL product equaled ...

2016
Natali Hernández-Becerra Yunuen Tapia-Torres Ofelia Beltrán-Paz Jazmín Blaz Valeria Souza Felipe García-Oliva

BACKGROUND Global demand for food has led to increased land-use change, particularly in dry land ecosystems, which has caused several environmental problems due to the soil degradation. In the Cuatro Cienegas Basin (CCB), alfalfa production irrigated by flooding impacts strongly on the soil. METHODS In order to analyze the effect of such agricultural land-use change on soil nutrient dynamics ...

ژورنال: علوم آب و خاک 2001
محمدی, جهانگرد , گیوی, جواد ,

This study aims to evaluate land suitability for irrigated wheat in Falavarjan region (Isfahan) using the theory of fuzzy sets. This method differs from the usual land evaluation procedures in its use of weight for different land characteristics and in its method of determining land suitability index. The results were compared with those from parametric land evaluation method. The correlation b...

محمدی, جهانگرد , گیوی, جواد ,

This study aims to evaluate land suitability for irrigated wheat in Falavarjan region (Isfahan) using the theory of fuzzy sets. This method differs from the usual land evaluation procedures in its use of weight for different land characteristics and in its method of determining land suitability index. The results were compared with those from parametric land evaluation method. The correlation b...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2008
Jingzhu Zhao Qishan Luo Hongbing Deng Yan Yan

This paper introduces the concepts and aims of sustainable agriculture in China. Sustainable agricultural development comprises sustainability of agricultural production, sustainability of the rural economy, ecological and environmental sustainability within agricultural systems and sustainability of rural society. China's prime aim is to ensure current and future food security. Based on projec...

2011
R. R. Ratnayake G. Seneviratne

* Corresponding author ([email protected]) Abstract: Soil carbohydrates (SC) are important parameters in determining soil fertility in different land uses, particularly in the tropics. There are no tropical studies reported so far on the effect of heterogeneneous land uses on the concentration of SC. Therefore, SC under 13 different land uses including forests and adjacent cultivated lands in S...

2013
Gustavo Rodríguez-Alonso Raúl Arredondo-Peter

Non-symbiotic (nsHb) and truncated (tHb) hemoglobins (Hbs) have been detected in a variety of land plants. The evolution of land plant nsHbs and tHbs at the protein level is well documented; however, little is known about the evolution of genes coding for these proteins. For example, the variability of the land plant nshb and thb genes is not known. Here, we report the variability of the nshb a...

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