نتایج جستجو برای: top soil
تعداد نتایج: 304166 فیلتر نتایج به سال:
Soil organic phosphorus (SOP) can greatly contribute to plantavailable P and P nutrition. The study was conducted to determine the effects of organic amendments on organic P fractions and microbiological activities in paddy soils. Samples were collected at the Changshu Agro-ecological Experiment Station in Tahu Lake Basin, China, from an experiment that has been performed from 1999 to 2004, on ...
The distribution of major and trace elements was systematically investigated by use of energy dispersive X-ray fluorescence spectrometry (EDXRF) on a former horticultural soil. The purpose of the study was to combine mapping of soil element concentration levels with multivariate statistics for characterisation of soil metal pollution in relation to previous and present land use. A 1-ha study si...
Greater urban demand for finite water resources, increased frequency of drought resulting from erratic weather, and increased pressure to reduce drainage water volumes have intensified the need to reuse drainage water. A study was initiated in 1999 on a 32.4-ha saline-sodic field (Lethent clay loam series; fine, montmorillonitic, thermic, Typic Natrargid) located on the west side of California'...
Tree uprooting creates multiple microsites that can be effective on soil heterogeneity. In order to investigate the soil features in pit and mound location, twenty hectare areas of Tarbiat Modares University Experimental Forest Station studied that is located in Mazandaran province, in the north of Iran. Numbers of thirty four uprooted trees were found in study areas. Five microsites were con...
An important component in calculating budgets of terrestrial soil carbon is an estimate of total soil organic carbon. The CENTURY model simulates organic C in the top 20 cm of soil only, so a method for projecting the depth distribution of organic C is necessary for estimates of the profile total. This document describes the implementation of the exponential depth distribution of organic C in C...
ELISA techniques were used to detect imidacloprid in guttation fluid of young cantaloupe plants in Arizona. Imidacloprid was detected at up to 4.1 microg/ml (ppm) in a coincidental guttation collection 3 d after a top label rate soil application and at 37 microg/ml one d after a separate top label rate soil application study. These imidacloprid titers exceed reported median oral toxicities for ...
Nitrate-N (NO3−) effluents from agricultural ecosystems contributing to the degradation of water quality has become a serious environmental problem. A field experiment was conducted in 1996 and 1997 at St. Emmanuel, Que., Canada, to investigate the combined effects of water table management (WTM) and N fertilization on soil NO3− level and denitrification rates in the top soil layer (0–0.15 m). ...
This study compares ERS scatterometer top soil moisture observations with simulations of a dual layer conceptual hydrologic model. The comparison is performed for 148 Austrian catchments in the period 1991–2000. On average, about 5 to 7 scatterometer images per month with a mean spatial coverage of about 37% are available. The results indicate that the agreement between the two top soil moistur...
INTRODUCTION The primary limitations of conventional weed control programs include a heavy reliance on capital intensive, toxic, and non-renewable resources (pesticides and petrochemicals) to manage weed competition. Weed emergence from the soil top layers is facilitated by the continuous disturbance created through cultivation, irrigation, pesticide applications, machinery, and other cultural ...
We characterized pit and mound (PM) topography resulting from catastrophic wind in the Coweeta Basin, and located 48 PMs a across a variety of forest types. Our measurements included pit length, width, and depth; and mound height, thickness, and width. Species of fallen trees were identified, and DBH (diameter at breast height, 1.37 m) was measured for biomass determination. We identified five ...
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