نتایج جستجو برای: soil depth
تعداد نتایج: 333035 فیلتر نتایج به سال:
1. The acidification effect of Ponderosa pine (Pinus ponderosa) needles on soil pH was tested by sampling and measuring pH of soil in areas with ponderosa pine needle litter and without. 2. A total of three depth classes for five samples in each category of pine needles present and absent were collected and analyzed. 3. Statistical analysis of pH data did not indicate statistically significant ...
Effects of Different Tillage and Straw Return on Soil Organic Carbon in a Rice-Wheat Rotation System
Soil management practices, such as tillage method or straw return, could alter soil organic carbon (C) contents. However, the effects of tillage method or straw return on soil organic C (SOC) have showed inconsistent results in different soil/climate/cropping systems. The Yangtze River Delta of China is the main production region of rice and wheat, and rice-wheat rotation is the most important ...
Our knowledge of the rhizosphere bacterial communities in deep soils and the role of Eucalyptus and Acacia on the structure of these communities remains very limited. In this study, we targeted the bacterial community along a depth profile (0 to 800 cm) and compared community structure in monospecific or mixed plantations of Acacia mangium and Eucalyptus grandis. We applied quantitative PCR (qP...
Data from 139 research sites throughout the Inland Northwest were analyzed for effects of ash cap on site productivity, nutrient availability and fertilization response. Stand productivity and nitrogen (N) fertilizer response were greater on sites with ash cap than on sites without. Where ash was present, depth of ash had no effect on site productivity or N fertilizer response. Site productivit...
Blowing dust from summer fallow is a major soil loss and air quality concern in winter wheat (Triricum aesrivum L.) production areas of the inland Pacific Northwest (PNW). The objective of our 3-yr onfarm study in a 286-mm precipitation zone in eastern Washington was to determine the effects of tillage mulch depth during fallow on surface soil roughness, residue retention, seed-zone water stora...
Global Positioning System (GPS) signal-to-noise ratio (SNR) measurements can be employed to retrieve environmental variables in multipath reception conditions, whereby direct or line-of-sight transmission is received simultaneously with coherent reflections thereof. Previous GPS SNR multipath studies of soil moisture and snow depth have focused on the legacy GPS L1 and L2 bands. In the present ...
Understanding the spatial and temporal variations of soil moisture is crucial for the land surface processes and their management. Accurate estimation of spatial and temporal variations of soil moisture is important for various hydrological studies also. Recently, remote sensing techniques have been used to estimate soil moisture. Estimation of soil moisture by remote sensing techniques provide...
We use prior theory and experimental results to construct a quantitative relationship between soil moisture and the penetration depth of synthetic aperture radar (SAR) microwaves at L-, C-, and X-bands. This relationship is nonlinear and indicates that a change of 5% volumetric water content (VWC) can cause between 1 and 50 mm of change in C-band penetration depth depending on initial VWC. Beca...
Tillage systems and organic manures could affect soil physical and mechanical properties. This study was conducted to investigate the impacts of two tillage systems including conventional tillage by moldboard plowing (plowing depth, 30 cm) and reduced tillage by disk plow (plowing depth, 15 cm) and three rates (0, 30 and 60 ton ha-1) of farmyard manure (FYM) on the soil penetration resistance u...
The field study was conducted in one district of Educational-Experimental forest at Tehran University (Kheirood-Kenar forest) in the North of Iran. Eighty-five soil profiles were dug in the site of study and several chemical and physical soil properties were considered. These factors included: soil pH, soil texture, bulk density, organic carbon, total nitrogen, extractable phosphorus and depth ...
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