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Displaying 3769 - 3780 of 5264

Emergy evaluation and economic performance of banana cropping systems in Guadeloupe (French West Indies)

Journal Articles & Books
Décembre, 2009
Guadeloupe

Banana is the second most important agricultural commodity in Guadeloupe (French West Indies--FWI) and, to compensate the decline in international prices during the last 15 years, banana growers have intensified their production systems by increasing the use of technological inputs. Such intensification strategies, that require both material and investment increases, may impose economic as well as environmental risks, given the fragile island ecosystems.

Ascribing soil erosion types for sediment yield using composite fingerprinting technique

Journal Articles & Books
Décembre, 2014
Iran

Soil erosion and eroded sediment are serious threats to sound land management. However, less attention has been given to quantifying the importance of different soil erosion features based on appropriate control measures that could be designated. Accordingly, this research was planned to quantify the contribution of potential sediment sources, i.e. sheet, rill and gully erosion, in Idelo watershed in Zanjan Province, Iran, using composite fingerprinting. Toward this aim, 16 geochemical and organic tracers were detected in sediment sources and sediment deposited at the outlet.

Access to cryptic arthropod larvae supports the atypical winter breeding seasonality of Meyer’s Parrot (Poicephalus meyeri) throughout the African subtropics

Journal Articles & Books
Décembre, 2013
Tanzania
Zambie

Meyer’s Parrot Poicephalus meyeri has the widest distributional range of any African parrot. There are six subspecies distributed throughout the African subtropics, all of which manage to breed successfully during the winter dry season when few other cavity-nesting birds are actively nesting. In 2004, we recorded Meyer’s Parrots feeding on four cryptic arthropod larvae incubating inside fruits and pods in their seasonal diet. All of these were previously unknown in the diet of African parrots.

Long-term impact of chronosequential land use change on soil carbon stocks on a Swedish farm

Journal Articles & Books
Décembre, 2008
Europe septentrionale

Agricultural practices and land use significantly influence soil carbon storage. The processes that are affected by land use and management are generally understood, but uncertainties in projections are high. In this paper, we investigate the long-term effects of chronosequential land use change from grassland to cropland and vice versa on soil carbon stock dynamics in four fields on a Swedish farm. Between 1850 and 1920, three of the fields were converted from grassland into cropland, and one was converted back to grassland in 1971.

Weed-insect pollinator networks as bio-indicators of ecological sustainability in agriculture. A review

Journal Articles & Books
Décembre, 2016

The intensification of agricultural practices contributes to the decline of many taxa such as insects and wild plants. Weeds are serious competitors for crop production and are thus controlled. Nonetheless, weeds enhance floral diversity in agricultural landscapes. Weeds provide food for insects in exchange for pollination. The stability of mutualistic interactions in pollination networks depends on conservation of insect pollinator and weed communities. Some agricultural practices can destabilize interactions and thus modify the stability of pollination networks.

Evaluating Shuttle radar and interpolated DEMs for slope gradient and soil erosion estimation in low relief terrain

Journal Articles & Books
Décembre, 2013
Australie

The error in slope gradient estimates provided by digital elevation models propagates to spatial modelling of erosion and other environmental attributes, potentially impacting land management priorities. This study compared the slope estimates of Shuttle Radar Topographic Mission (SRTM) DEMs with those generated by interpolation of topographic contours, at two grid cell resolutions. The magnitude and spatial patterns of error in DEM slope, and derived erosion estimates using the Revised Universal Soil Loss Equation (RUSLE), were evaluated at three sites in eastern Australia.

Nitrate transport modeling to evaluate source water protection scenarios for a municipal well in an agricultural area

Journal Articles & Books
Décembre, 2011
Canada

Fertilizers that are spread on agricultural fields can leach into aquifers and contaminate groundwater sources for drinking water particularly with nitrate. Modeling this phenomenon can help in evaluating the impact of current or future agricultural practices on nitrate content within an aquifer. The three-dimensional Water flow and Nitrate transport Global Model (WNGM), that was previously developed and applied to a well-capture zone, is actually used to simulate future land management scenarios over the same zone.

Crofting and bumblebee conservation: The impact of land management practices on bumblebee populations in northwest Scotland

Journal Articles & Books
Décembre, 2010

The northwest of Scotland is a stronghold for two of the UK's rarest bumblebee species, Bombus distinguendus and Bombus muscorum. The predominant form of agricultural land management in this region is crofting, a system specific to Scotland in which small agricultural units (crofts) operate rotational cropping and grazing regimes. Crofting is considered to be beneficial to a wide range of flora and fauna. However, currently there is a lack of quantitative evidence to support this view with regard to bumblebee populations.

Effect of different agricultural management systems on chemical fertility in cultivated tepetates of the Mexican transvolcanic belt

Journal Articles & Books
Décembre, 2009
Mexique

Volcanic soils in their natural state often require some amelioration to accommodate their use for agriculture. Tepetates are defined as hardened volcanic tuffs derived from geo-pedological processes; they have been partially altered by weathering. Tepetates occupy extensive areas of Mexico's Central Highlands and some of them have been adapted for agricultural use after the mechanical breaking up of this hard material. In their native condition tepetates contain only traces of C, N and available P.

Vegetation Responses to Pinyon–Juniper Treatments in Eastern Nevada

Journal Articles & Books
Décembre, 2014

Comparisons of tree-removal treatments to reduce the cover of single-leaf pinyon (Pinus monophylla Torr. and Frém.) and Utah juniper (Juniperus osteosperma [Torr.] Little), and subsequently increase native herbaceous cover in black sagebrush (Artemisia nova A. Nelson), are needed to identify most cost-effective methods. Two adjacent vegetation management experiments were initiated in 2006 and monitored until 2010 in eastern Nevada to compare the costs and efficacy of various tree reduction methods.