نتایج جستجو برای: global hectare

تعداد نتایج: 450841  

1999
Martin Ricker Robert O. Mendelsohn Douglas C. Daly

Tropical forests continue to be deforested because forest owners believe they can earn more income through land uses involving forest conversion. A case study in a Mexican rainforest revealed that enrichment planting with the native tree species Pouteria sapota (‘mamey’) is a management approach that can increase the commercial value of the forest enough to compete with these destructive land u...

Journal: :Bioresource technology 2014
Giorgio Ragaglini Federico Dragoni Marco Simone Enrico Bonari

This study aimed to investigate the potential of giant reed for biomethane production by examining the influence of harvest time and frequency on the Biochemical Methane Potential (BMP), the kinetics of biomethane accumulation in batch reactors and the expected methane yield per hectare. The crop was cut at five different times, regrowths from early cuts were harvested in autumn and BMP of each...

2012
Matthew Magruder Sophan Chhin Andrew Monks Joseph O’Brien

Changes in climate are predicted to significantly affect the productivity of trees in the Great Lakes region over the next century. Forest management decisions, such as initial stand density, can promote climatic resiliency and moderate decreased productivity through the reduction of tree competition. The influences of climate (temperature and precipitation) and forest management (initial stand...

2015
Dennis Collentine Holger Johnsson Peter Larsson Hampus Markensten Kristian Persson

Riparian buffer zones are the only measure which has been used extensively in Sweden to reduce phosphorus losses from agricultural land. This paper describes how the FyrisSKZ web tool can be used to evaluate allocation scenarios using data from the Svärta River, an agricultural catchment located in central Sweden. Three scenarios are evaluated: a baseline, a uniform 6-m-wide buffer zone in each...

Journal: :Animal : an international journal of animal bioscience 2013
J L Peyraud R Delagarde

Grazed pasture, which is the cheapest source of nutrients for dairy cows, should form the basis of profitable and low-input animal production systems. Management of high-producing dairy cows at pasture is thus a major challenge in most countries. The objective of the present paper is to review the factors that can affect nutrient supply for grazing dairy cows in order to point out areas with sc...

2013
Valerie Mueller

T he average smallholder farmer in Malawi is tasked to feed a family of five on a farm of less than one hectare in size (NSO, 2008). The intensification of land through, for example, fertilizer use plays a prominent role in Malawi’s policy to increase the productivity potential of smallholder farmers. With the population almost doubling in the last twenty years (NSO, 2008), additional measures ...

Journal: :Science 1967
G M Woodwell C F Wurster P A Isaacson

DDT residues in the soil of an extensive salt marsh on the south shore of Long Island averaged more than 13 pounds per acre (15 kilograms per hectare); the maximum was 32 pounds per acre (36 kilograms per hectare). A systematic sampling of various organisms from the vicinity showed concentrations of DDT increasing with trophic level through more than three orders of magnitude from 0.04 part per...

2005
H. Vatandoost

1School of Public Health and Institute of Health Research, Tehran University of Medical Science, Tehran, Islamic Republic of Iran. Received: 22/10/02; accepted: 18/08/03 ABSTRACT An insecticide containing azadirachtin, a neem tree (Azadirachta indica) extract, was tested against mosquito larvae in the Islamic Republic of Iran under laboratory and field conditions. LC50 and LC90 values for Neema...

2015
Emine Kucuker Kenan Yildiz Yakup Ozkan

This study was carried out on Topaz, Cooper 39 and Muscat apple cultivars grafted on M27 rootstocks under Tokat ecological conditions during 2008 2010. The trees planted in 2.0 m x 0.5 m row spacing (10,000 trees ha-1) and trained to super spindle (SS) training system. The vegetative development, yield and fruit quality performances of the trees supported by wire – pole combination were observe...

Journal: :PLoS Biology 2006
Tristram G Seidler Joshua B Plotkin

Theories of tropical tree diversity emphasize dispersal limitation as a potential mechanism for separating species in space and reducing competitive exclusion. We compared the dispersal morphologies, fruit sizes, and spatial distributions of 561 tree species within a fully mapped, 50-hectare plot of primary tropical forest in peninsular Malaysia. We demonstrate here that the extent and scale of...

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