نتایج جستجو برای: soil moisture contents at three different levels air
تعداد نتایج: 6066260 فیلتر نتایج به سال:
Laboratory studies were conducted to evaluate effect of microwave irradiation of sandy loam soil on thermal energy absorption and control of plant-parasitic nematodes when air dry soil layers were placed on top of less moist, moist, and wet soil layers. The soil was packed in 12 cm high and 10 cm dia columns to a bulk density of 1.4 g/cm3. Moisture contents of air dry, less moist, moist, and we...
Nitrous oxide is an important greenhouse gas and contributes to stratospheric ozone destruction, but still little is known about emissions of this trace gas from soils in semiarid environments and how emissions are affected by irrigation. Therefore, nitrous oxide emissions from a runoff-irrigated and rainfed endosodi-calcaric Fluvisol in the semiarid northwest of Kenya were measured using the c...
Root zone soil moisture is a key variable in many land surface hydrology models. Often, however, there is a mismatch in the spatial scales at which models simulate soil moisture and at which soil moisture is observed. This complicates model validation. The increased availability of detailed datasets on space-time variability of root-zone soil moisture allows for a posteriori analysis of the unc...
Seed enhancement methods are applied to eliminate or decrease adverse environmental stresses effects and increase seed germination rate and vigor of rangeland plants. The aim of this study was to assess different methods of seed coating effects on germination speed of Onobrychis sativa at different sowing depths and soil moisture levels. The experiment was conducted at growth chamber to apply a...
-Compaction is one of the efficient ways to improve the strength and stiffness properties of soils, such as elasticity modulus and shear modulus. Moreover, compaction decreases soil settlement, improves bearing capacity and the stability of sloped embankments. An optimum water content is required to provide the best path to enter energy into soil and compact it. A constant value of energy appli...
PCBs are persistent organic pollutants which, due to high environmental hazards, must be traced, determined, and decomposed to reduce their risks. . To detect this material in the soil, the method of extraction and appropriate measuring conditions should be investigated. Two soil samples with two kg weight were selected with two different soil textures and the solutions of soil were made with t...
A mathematical model for the transport and fate of organic chemicals in unsaturated/saturated soils.
A mathematical model, simulating the transport and fate of nonionizable organic compounds in unsaturated/saturated porous media (soils) in a terrestrial microcosm has been developed. Using the principles of water mass, momentum, heat energy and chemical mass balance, the three fields: moisture, temperature, and liquid phase chemical concentration are solved for simultaneously by coupling the so...
A number of radioisotopes have recently become commercially available as alternatives to radium-225 in moisture gauging devices using alpha-neutron sources for determining soil moisture, for well logging, and for other industrial applications in which hydrogenous materials are measured. To date, little work has been reported on 21 the comparability of data obtained with different sources when u...
Skidding operations can cause considerable and wide spread soil disturbance. The objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. Four levels of traffic intensity (3, 8, 13, and >13 passes of a Crawler Tractor Onezhets ? 110) and three levels of slope ( ...
Soil moisture is a key state variable of the hydrologic cycle. It plays a significant role in many hydrological, meteorological and other natural processes in the land-atmosphere continuum. In the past two decades we have conducted several field campaigns to better understand the underlying processes controlling the spatio-temporal variations of soil moisture using multiple ground, air, and spa...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید