نتایج جستجو برای: soil profile

تعداد نتایج: 398248  

2017
Huimei Wang Wenjie Wang Scott X. Chang

We currently have a poor understanding of how different soil sampling methods (pedogenetic horizon versus fixed-depth) influence the evaluation of soil properties. Here, 159 soil profiles were sampled from larch (Larix gmelinii) plantations in northeast China using both the pedogenetic horizon and fixed-depth sampling methods. Analysis of variance was used to determine how sampling method influ...

2016
Jay D. Jabro William B. Stevens William M. Iversen Brett L. Allen Upendra M. Sainju

Efforts have increased to measure nitrate losses from farmland under different management practices due to environmental and public concerns over levels of nitratenitrogen (NO3-N) in surface and ground waters. This study evaluated the effect of conventional tillage (CT) and strip tillage (ST) practices and three N application rates on NO3-N concentrations in soil water at a 76 cm depth under ir...

2015
Chong Chen Kelin Hu Hong Li Anping Yun Baoguo Li Wenju Liang

Understanding spatial variation of soil organic carbon (SOC) in three-dimensional direction is helpful for land use management. Due to the effect of profile depths and soil texture on vertical distribution of SOC, the stationary assumption for SOC cannot be met in the vertical direction. Therefore the three-dimensional (3D) ordinary kriging technique cannot be directly used to map the distribut...

1997
Binayak P. Mohanty Rameshwar S. Kanwar

Soil nitrate-nitrogen (NO3-N) data arranged on a three-dimensional grid were analyzed to compare tillage effect on the spatial distribution of residual NO3-N in the soil profile of agricultural plots drained by subsurface tiles. A three-dimensional median-based resistant (to outlier(s)) approach was developed to polish the spatially located data on soil NO3-N affected by directional trends (non...

A. Fatemi F. Kananro Foomani F. Khormali, Sh. Ayoubi

Soil genesis, physico-chemical properties and tea yield were investigated along different hillslope positions in the major tea cultivation area of Iran, i.e. Lahijan, Gilan Province. Land suitability was also determined for the tea production in this hilly region. Four different slope positions i.e., summit, shoulder, backslope and toeslope were sampled on three slope aspects following the prof...

2017
Daegeun Ko Gayoung Yoo Seong-Taek Yun Seong-Chun Jun Haegeun Chung

Background: Soil microorganisms play key roles in nutrient cycling and are distributed throughout the soil profile. Currently, there is little information about the characteristics of the microbial communities along the soil depth because most studies focus on microorganisms inhabiting the soil surface. To better understand the functions and composition of microbial communities and the biogeoch...

شریف‌بیان‌الحق, محمدحسین, مصطفی زاده, بهروز, موسوی, ‌ سیدفرهاد,

To determine the effects of field slope, emitter discharge, irrigation water volume and soil texture on soil moisture profile and soil surface wetted shape from a point source, field data were collected on three different soil types, three emitter discharges (4, 8, and 12 lph), four slopes (0, 2, 5, and 10%), and five irrigation water volumes (10, 20, 30, 40, and 50 liters) with three replicati...

Journal: :Ecology 2010
Douglas A Frank Alyssa W Pontes Eleanor M Maine Julie Caruana Ramesh Raina Surabhi Raina Jason D Fridley

There is little comprehensive information on the distribution of root systems among coexisting species, despite the expected importance of those distributions in determining the composition and diversity of plant communities. This gap in knowledge is particularly acute for grasslands, which possess large numbers of species with morphologically indistinguishable roots. In this study we adapted a...

M. Noshadi P. Torkaman

ABSTRACT- Despite the benefits of herbicides, their persistence in soil can harm other plants in next rotations and contaminate ground water. The main purpose of this research is to simulate 2,4-dichlorophenoxyaceticacid(2,4-D) movement in silty clay loam soil using HYDRUS-1D model in a corn root zone. The maximum contaminant level goal, MCLG, of 2,4-D in water resources is 10 ppb. The 3.5 kg a...

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