نتایج جستجو برای: soil productivity

تعداد نتایج: 258354  

2017
G. A. Peterson D. G. Westfall L. A. Sherrod T. M. Shaver

The objective of this paper is to report the cumulative effects of cropping system intensification on the near surface soil physical properties (surface one inch of soil) within the Colorado dryland agroecoystem project, which has been in existence since 1986. Intensifying cropping systems from wheat-fallow to wheat-com-fallow to continuous cropping, increased crop residue return to the soil. R...

2006
W. W. Verstraeten P. R. Coppin J Feyen

Carbon emission and fixation fluxes are key variables to guide climate change stakeholders on the use of remediation techniques. To develop Kyoto Protocol support tools, a sound application perspective is offered by expert systems based on earth observation (EO). This allows estimates of vegetation carbon fixation using a minimum of meteorological data. The core module of this type of expert sy...

1998
Manohar Sharma Lynn Brown Aamir Qureshi

In agrarian developing countries the natural environment is a key determinant of both poverty and nutritional status. Climate, terrain, and soil characteristics drive the agricultural system, determining in large part cropping patterns, choice of crops, yield rates, and overall productivity levels. The human resources crucial to agricultural productivity are also influenced by the natural envir...

2009
Tarendra Lakhankar Nir Krakauer Reza Khanbilvardi

Agricultural irrigation is the largest (80%) user of freshwater resources. With increasing freshwater demand, it is important to make optimal use of water resources with improved agricultural productivity through objective and accurate information provided by remote sensing. This paper reviews the potential of applications of microwave remote sensing of soil moisture and vegetation for agricult...

2017
Roland C. Wilhelm Erick Cardenas Hilary Leung Kendra Maas Martin Hartmann Aria Hahn Steven Hallam William W. Mohn

The scarcity of long-term data on soil microbial communities in the decades following timber harvesting limits current understanding of the ecological problems associated with maintaining the productivity of managed forests. The high complexity of soil communities and the heterogeneity of forest and soil necessitates a comprehensive approach to understand the role of microbial processes in mana...

2015
Heinz Rennenberg Michael Dannenmann Eric J. Jokela

Nitrogen (N) is an essential nutrient that is highly abundant as N2 in the atmosphere and also as various mineral and organic forms in soils. However, soil N bioavailability often limits the net primary productivity of unperturbed temperate forests with low atmospheric N input. This is because most soil N is part of polymeric organic matter, which requires microbial depolymerization and mineral...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2017
Ying Fan Gonzalo Miguez-Macho Esteban G Jobbágy Robert B Jackson Carlos Otero-Casal

Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observ...

2017
Nicola Imperiali Xavier Chiriboga Klaus Schlaeppi Marie Fesselet Daniela Villacrés Geoffrey Jaffuel S. Franz Bender Francesca Dennert Ruben Blanco-Pérez Marcel G. A. van der Heijden Monika Maurhofer Fabio Mascher Ted C. J. Turlings Christoph J. Keel Raquel Campos-Herrera

In agricultural ecosystems, pest insects, pathogens, and reduced soil fertility pose major challenges to crop productivity and are responsible for significant yield losses worldwide. Management of belowground pests and diseases remains particularly challenging due to the complex nature of the soil and the limited reach of conventional agrochemicals. Boosting the presence of beneficial rhizosphe...

An attempt was made to identify the productivity level of different zones of Nanak Sagar reservoir through the application of Geographical Information System (GIS). Based on biological, hydrological and soil parameters, thematic layers were created by interpolating point wise annual average value of given parameters and three models were developed using the weighted overlay method in ArcGIS v.1...

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