نتایج جستجو برای: soil depth
تعداد نتایج: 333035 فیلتر نتایج به سال:
This paper describes a new method to monitor continuously soil CO2 profiles using small solid-state CO2 sensors buried at different depths of the soil. Based on the measurement of soil CO2 profile and a gaseous diffusivity model, we estimated soil CO2 efflux, which was mainly from heterotrophic respiration, and its temporal variation in a dry season in a Mediterranean savanna ecosystem in Calif...
BACKGROUND Termiticides are applied at concentrations much higher than those used in agricultural settings. The longevity of fipronil has not yet been examined at the rates used for termite control, nor has the compound's movement in the soil been addressed. RESULTS Fipronil was detected in the eluates of treated soil cones, increasing initially and then decreasing to a steady concentration o...
Overgrazing and climate change strongly affect alpine meadows by decreasing the plant community biomass and deteriorating the soil environment. To understand how the plant community and soil microbial community structure respond to grazing and N deposition, we conducted an experiment to remove or maintain the plant litter under the chronic addition of N in the Haibei Alpine Meadow in 2005. The ...
The effects of three levels of soil moisture content (8-10, 10-12 and 12-14% d.b.) and three levels of plowing depth (15, 20 and 25 cm) on draft, specific draft and drawbar power requirement of a 7-shank chisel plow in a clay loam soil were investigated. The experimental design was a randomized complete block design with a 3×4 factorial. The effect of plowing depth on all of the parameters ment...
This paper explores the potential to retrieve surface soil moisture and optical depth simultaneously for several different patches of land cover in a single pixel from dual polarization, multiangle microwave brightness temperature observations such as will be provided by, for instance, the Soil Moisture and Ocean Salinity (SMOS) mission. MICRO-SWEAT, a coupled land-surface and microwave emissio...
plant litter is an important factor for soil conservation and sustainability that could modify soil chemical properties and increase the plant biomass production. the aim of this research was to compare plant litter chemical composition and its effects on soil properties in three species including hordeum bulbosum, poa bulbosa, bromus tectorum. first, soil samples were taken in the depth of 0-3...
the aim of this research is to classification of soil seed bank in populus caspica protected area. the study of above ground vegetation and soil seed bank were carried out with braun-blanquet and seedling emergence method respectively. results showed that size of soil seed bank in upper layer (713 seeds per m2) were significantly lower than depth layer (1163 per m2) but species richness from 42...
For an appropriate drip irrigation system design, a prediction of soil wetting pattern is needed for a given soil texture. The wetting pattern geometry is a key factor for emitter distance determination as well as crop type. The geometry of the wetting bulb is dependent on the parameters such as soil hydraulic properties, emitter discharge and the irrigation time. This study has been conducted ...
The Gonghe Basin region of the Tibet Plateau is severely affected by desertification. Compared with other desertified land, the main features of this region is windy, cold and short growing season, resulting in relatively difficult for vegetation restoration. In this harsh environment, identification the spatial distribution of soil nutrients and analysis its impact factors after vegetation est...
the split-block experimental design with three replications was used to study the effect of subsoiling in different distances from drain axison soil salinity,and wheat yield. the measurements included soil cone index, soil bulkdensity, infiltration rate and electrical conductivity of saturated extract. each treatment was composed of two factors. the main factors consisted of 3 different distanc...
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