Quantifying labile phosphorus (P) pools in biosolids is needed to manage biosolids for both agronomic and environmental purposes. Phosphorus indices originated in an effort to protect surface water quality from-non-point-agricultural P inputs. The objectives of this research were to: (1) evaluate soil test components of the western Oregon P index...
The effects of zinc and phosphorus treatments on five different
plant species were investigated in a greenhouse experiment. A
second greenhouse experiment extended these investigations in sweet
corn over a broad range of phosphorus treatments with and without
adequate zinc nutrition to study phosphorus induced zinc deficiency.
The plant responses...
The objectives of this study were to evaluate and compare the
availability of native and applied P in Central Oregon pumice soils
with that in Willamette valley soils and calcareous soils from Eastern
Oregon. The experimental work to meet these objectives included
laboratory and greenhouse studies.
The removal of P...
The relationships between zinc, iron, and phosphorus in sweet
corn were investigated under field and greenhouse conditions. The
soils used in this study (both acid and calcareous) were low in available
zinc and phosphorus.
The experiments received standard, uniform rates of nitrogen
potassium, magnesium, and sulphur. Corn was used as...
Twelve Sri Lankan Alfisols were characterized for P. Soils
were incubated for three weeks with sufficient P applied
(P2) to elevate soil solution P to 0.2 ug P/g solution as
determined by sorption curves, with 75 percent of P2 (P1),
and without P (P0). For PO treatments, (a) organic P,...
Striga, a genus of obligate parasitic weeds in the family Orobanchaceae, has been
identified as the most important biological factor limiting agricultural productivity in sub-Saharan Africa. Germination of Striga seeds is triggered by strigolactone root exudates
from host plants. Strigolactones also induce hyphal branching in arbuscular mycorrhizal
(AM) fungi, which...
Restoration of invaded aridlands is required to reduce the exorbitant ecological and monetary losses related to noxious weeds. An understanding of how reduced and increased levels of soil N and P influence interference between medusahead and squirreltail is imperative to understanding how squirreltail may be used in restoration of medusahead...
Lack of growing season precipitation and the temperate climate in north central Oregon pose challenges to growing spring wheat crops. Phosphate and sulfate fertilization can improve early growth of spring wheat in this region and soil testing aids in determining rates of fertilization. In this study, anion exchange membranes (AEM)...
Representative sites of the Dayton, Woodburn, Jory, Quillayute, Astoria, Willamette, Walla Walla, Deschutes, Laki and Owyhee soil series were investigated for seasonal changes in exchangeable potassium in air dry samples. No consistent seasonal variations were found which could be attributed to wetting and drying in the field. Cropping reduced the...
Incubation experiments with an acid poorly drained soil have
shown that the application of neutral soluble salts influenced the level
of extractable Mn. The application of a salt which lowered the soil
pH either increased the extractable Mn or retarded the oxidation
and/or fixation of extractable Mn. This effect was...
The potassium status of selected soils from central and eastern Oregon, that have shown a wide range in response from potassium was investigated. The silt and clay minerals were identified using X-ray crystallography. The potassium extracted by water, NH₄OAc, and HNO₃ was evaluated on the total soil and on the...
The effect of different soil moisture levels on the amount and
location of NO₃ -N accumulation in the soil profile were studied.
The cultivars used in this study were Mcdermid, a soft white
winter wheat, and Hudson, a medium early winter barley.
Moisture treatments simulating dry, normal and wet fallow...
Several crops grown in the Willamette valley of western Oregon
respond to applications of boron fertilizers. The acid, highly-leached
soils of this area are naturally low in plant-available B. Application
of B to the soil annually or at less frequent intervals is currently
recommended, but the fate of applied B...
The effects of different fallow moisture levels and tillage
systems on the amount of nitrate-nitrogen accumulation in the 0-30 cm
soil profile were studied.
Fallow moisture treatments simulating typical dry, normal and
wet precipitation cycles were established on trial plots.
Data were obtained for nitrate-nitrogen, soil moisture and
nitrogen mineralization...
Contamination events at Oak Creek, which runs through Oregon State University Research lands, prompted investigations into alternate transport mechanisms for moving liquid effluent from OSU Diary lands to Oak Creek. Magnetometer surveys conducted at the Diary identified magnetic signatures spatially associated with sub-surface locations of drain tiles, a 12-inch pipe,...
Lime was applied at different rates to filbert trees grown in
containers in an acid soil. As lime application rate increased, the
leaf Mn and extractable soil Mn were significantly reduced. In
control trees leaf Mn was over 1300 ppm, but no growth reduction or
Mn toxicity symptoms were found....
Published December 1923. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published June 1966. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Marine microorganisms play a significant role in the cycling of nutrients in the open ocean through production, consumption, and degradation of organic matter (OM). Carbon (C), nitrogen (N), and phosphorus (P) are essential ingredients in every known recipe for life. However, the cycling of each of these elements proceeds at...
Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
Molybdenum is an essential component of biogeochemical cycling, most notably as a component of the nitrogenase enzyme used in biological nitrogen (N) fixation. While the important role of phosphorus (P) in limiting N fixation in ecosystems has been well documented, occurrence and prevalence of molybdenum (Mo) limitation is largely unknown....
High intensity sampling was undertaken to characterize the temporal and spatial
variability of oxidized nitrogen (NO3-N + NO2-N), ammonia-nitrogen (NH3-N), total
dissolved phosphorus, total unfiltered phosphorus and orthophosphorus (PO4-P) from two
adjacent small streams in Western Oregon's Coast Range, Deer Creek (303 ha) and Flynn
Creek (203 ha). Deer Creek...
Subterranean clover was grown in nutrient solution and S
deficient Steiwer soil in the greenhouse. Plants were harvested at
15, 30, 45 and 60 days after emergence.
When subterranean clover was grown in nutrient solution significant
yield response to each increment of added sulfate (SO₄-S)
occurred in 15, 30, 45...
During the Spring of 1969, 47 surface soil samples (0 to 15 cm)
as well as foliage samples of subterranean clover were collected from
32 selected western Oregon pastures, in an effort to determine their
molybdenum status and to evaluate the use of anion exchange resin
method as a means...
A 2-year field study was conducted on the effects of two sulfur
fertilizers (calcium sulfate or elemental S, 0 or 50 kg S ha⁻¹ yr⁻¹)
on the distribution of sulfur fractions (inorganic sulfate, C-bonded,
ester sulfate, and residual S), arylsulfatase enzyme activity, and
microbial biomass carbon (C) and sulfur (S)...
Previous studies have shown loss of ethofumesate activity when
the herbicide was applied to dry soil (2% w/w moisture content) in
both field and greenhouse studies, even when rainfall or irrigation
was received within a few days. Laboratory studies were conducted to
determine the mechanism for this activity loss. Dry...
Effects of different tillage systems on nitrate-nitrogen
accumulation in a 120 cm profile and on soil structure in the top 30 cm
of the profile were studied under a fallow-wheat rotation.
Treatment effects on nitrate-nitrogen, soil moisture and soil
aggregation were measured.
Fallow tillage treatments consisting of bare fallow, stubble-mulch...
Biometric and gas exchange techniques were used to measure soil respiration (soil surface CO₂ efflux) and NEP (Net Ecosystem Production) across three climatically-distinct forest chronosequences in Oregon. Results indicate significant forest type, age, and forest type x age interaction effects on annual soil respiration. A regional age class distribution skewed...
A study of phosphorus loading and water quality implications was conducted for
the Oregon coastal lakes. The study was based on existing data for lake total phosphorus
concentrations and for watershed land uses. A phosphorus mass-balance model was
developed to predict lake total phosphorus concentrations from estimated phosphorus
loading from...
Globally, the forestry sector is the second largest contributor of greenhouse gases, and sustainable forest management is a major target of international environmental policy. However, there is the assumption underlying many policy recommendations that an increase in above-ground carbon stocks correspond to long term increases in ecosystem carbon stocks, the...
Soil solution samplers have certain inadequacies that limit their range of
possible applications. Passive Capillary Samplers (PCAPS), which apply suction to the
soil pore-water via a fiber glass wick, have shown promising results in preliminary
experiments in regard to collection efficiency of water and of bromide tracers. The
objectives of...
This study was conducted to investigate the differences of the
profile distribution of free iron and free manganese and the reduction-oxidation changes in soils of the Willamette drainage sequence.
Based on the results of the chemical analyses, free iron and
free manganese distributions in these soils were governed to a...
The optimum goal of forest management is to foster long-term productivity and ecological integrity while maintaining or increasing short-term growth and yield through sustainable practices. Understory vegetation plays a definite role in forest functions through nutrient cycling and habitat provisions. The objective of this study was to determine how salal,...
The assessment of optimum nitrogen (N) fertilizer need for winter wheat (Triticum
aestivum L.) is important for economic and environmental sustainability. A comprehensive understanding of fertilizer N requirement depends on estimation of the quantity of N needed by the crop versus that supplied by soil.
The objectives of this study...
In order to properly utilize organic amendments as nitrogen sources, reliable methods
to estimate plant-available nitrogen (PAN) are needed. The objectives of this study
were to (1) evaluate the use of crop and soil responses in fertilizer N equivalence
(FNE) calculations, (2) examine the relationships between the C/N ratio, total...
Cover crop selection and management depend on many factors, among them the cover crop’s ability to accumulate dry matter (i.e., residues) and nitrogen (N). Dry matter provides energy for soil organisms, contributes to soil organic matter, improves tilth, and acts as a sink for nutrients.
Humus is one of the important factors controlling the soil
formation process. The nutrients released from it during the decomposition
process also affect the growth and reproduction of the
forest. The type of humus formed is influenced by the nature of the
forest litter and the environment in which it...
The effect of moisture stress and nutrients on the rate of growth
of wheat (Triticum aestivum L. Var. Gaines) seedlings was studied.
A special apparatus in which the moisture stress of several perlite
cells could be maintained constant by osmotic solutions was used.
Predetermined amounts of nitrogen were added to...
This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
Volatile hydrophobic compounds (HOCs) brought into soil and sediment
systems represent a serious threat to the environment. Dissolved
organic carbon (DOC) may exert an important influence over the total
aqueous solubility and mobility of organic pollutants through their
incorporation into micelles or the formation of soluble complexes.
To date, however,...
Microorganisms can be a valuable tool in assessing the toxicity of heavy metals. The soil respiration rate is a commonly explored endpoint. I utilized a fully automated respirometer incorporating an infrared gas analyzer (IRGA) and developed a method for measuring the effect of Zn on soil microbial populations. Zinc, in...
Nitrogen availability in agricultural soils from fertilizer, plant residue inputs, and soil organic matter has important implications beyond crop yield. Legume winter cover crops and one fourth the recommended N rate on sweet corn resulted in yields equivalent to those at the recommended rate in the Willamette Valley of western...
Published December 1938. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Most soil organic C is in a stable form, associated with clay minerals in the upper soil profile. Upon environmental and land-use changes, stable soil C is subject to losses, which influence the global C cycle and the productivity of terrestrial ecosystems. However, mechanisms controlling soil C destabilization are not...
Application of N fertilizer is a common forest management practice in the Pacific
Northwest, yet the long-term influence of fertilization on forest soil properties is not well known. Although elevated N often increases mineralization of C and N from labile organic matter, negative effects have been documented in recalcitrant organic...
This publication describes the use of post harvest soil nitrate testing as a tool for assessment of nitrogen (N) management in manured cropping systems west of the Cascade Mountains in Oregon, Washington, and south coastal British Columbia. The first section of this publication gives general information on the test and...
Soil respiration, or the combined CO₂ emissions from roots and soil microorganisms, constitutes one of the largest losses of carbon (C) from terrestrial ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate quality, have been known for some time. Nevertheless,
correlations between these drivers and...
The mechanisms governing short- and long-term belowground carbon dynamics need to be understood. As part of a larger project developed to assess the effect of quantity and quality of litter inputs on the rate of soil organic matter (SOM) formation, I examined SOM in the H. J. Andrews Detritus Input...
Soil organic carbon (SOC, kg C m-2) is an important component in evaluating global C stores. The nitrogen (TN, kg N m"2) cycle is closely linked to C and understanding its role is also important. Contents and distributions of SOC and TN in soil profiles, to 1-meter depth, were estimated...
Protection of the quality and integrity of food supplies is of global concern. Crops can accumulate non-nutritive and sometimes toxic metals and metalloids. Accumulated metals/metalloids can come in part, from fertilizers, which may contain variable levels of non-nutritive metals or metalloids such as arsenic (As), cadmium (Cd), lead (Pb), nickel...
The anthropogenic introduction of nutrients to water bodies has been shown to alter the structure and function of natural aquatic ecosystems, yet national EPA lake and reservoir nutrient criteria remain too broad for effective regional water quality management. This study uses a reference site approach to propose numeric nutrient criteria...
There is a growing consensus that anthropogenic warming will impact soil organic matter (SOM). Globally, soil contains 2-3 times more carbon (C) than plants, and like plants, temperature induced change of SOM could have significant climate repercussions. Although, the majority of warming experiments have increased day and night temperatures equally,...
Prevention of groundwater contamination by agricultural
chemicals requires an understanding of the complex
processes that control pesticide movement below the soil
surface. Through this understanding it is possible to try
to predict which areas may be most vulnerable to
contamination. The many models that have been developed to
characterize pesticide...
A study was made to evaluate the effect of different rates of N
fertilization on Nugaines wheat. The variable N treatments provided
different N regimes as a basis for evaluating potential diagnostic
tests for assessing the N status of the wheat plant. The crop was
grown in Lane county during...
Although legumes have been widely studied for their nitrogen-fixing ability, it is uncertain to what extent legume cover crops achieve their nitrogen-fixing potential under the climatic conditions encountered in western Oregon. Furthermore, it is unknown what factors control the proportions of legume cover crop N that are either sequestered into...
Published January 1994. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Many studies suggest that weedy plant species are most successful when
soil nitrogen in abundant. Consequently, I used soil nitrogen manipulations to
determine if altering nitrogen would affect the establishment of both weedy and
native plant species in a western Oregon wetland prairie. In two studies, we
added carbon amendments...
As large-scale restorations of degraded rangelands are initiated, land managers need to
understand how decades of dominance by the invasive annual grass, cheatgrass (Bromus tectorum
L.), have altered ecosystem processes. One way to assess such alterations is by observing
differences in decay rates, since decomposition is determined by factors such...
Published April 1996. Reprinted August 1997. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published December 1937. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
A better understanding of grass seed crop and soil fertility is necessary to
improve fertilizer practices and preserving water quality in Willamette Valley,
Oregon, where 55% of land-use is in grass seed production that directly impacts
adjacent waterways containing native protected fish species. I determined tillage
effects on soil N...
The procedure described in this publication helps
you assess the potential for any specific pesticide
to travel through any specific soil to reach
groundwater.
Published June 1972. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Soils are a globally significant carbon (C) pool and have the potential to respond to elevated CO2 and environmental changes through positive feedback cycles that enhance the turnover of soil organic matter (SOM). Understanding the mechanisms governing the turnover of SOM is particularly important for modeling the fate of C...
The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
Understanding how N availability influences base cation stores is critical for long-term ecosystem sustainability. Indices of nitrogen (N) availability and the distribution of nutrients in plant biomass, soil, and soil water were examined across ten young, unpolluted Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Coast Range spanning a three-fold soil...
Landscape positions have been used to determine soil properties. My soil study in Monteverde on the Pacific slope of Costa Rica was designed to examine soil-landscape relationships for sites with various land use histories and management. Soil pits were dug at Nacimiento y Vida, Crandell, Curi-cancha, La Calandria, and Finca...
Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants produced mainly from the incomplete combustion and pyrolysis of organic matter. PAHs are among the major contaminants at over 800 Superfund sites, nationwide. Thermal remediation is used as a method to remediate soils contaminated with PAHs through the use of heat to mobilize...
Dry land agriculture using summer fallow is a common crop production
practice in the Columbia Plateau region of eastern Oregon. Farmed-over level
terraces are used to control surface water runoff and soil erosion. More than
70 percent of the average annual precipitation around Pendleton, Oregon (350 -
400 mm) falls...
Soil carbonate is used to interpret paleoenvironmental conditions in the Eastern Korinthia, Greece, with the use of stable carbon and oxygen isotopes. The Eastern Korinthia consists of a series of marine terraces ranging in age from ~600 to 70.2 ka. The lateral stratigraphic context of the marine terraces allows the...
Published August 1940. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Four factors govern the potential for groundwater
contamination by pesticides passing through the soil:
• Properties of the soil
• Properties of the pesticide
• Hydraulic loading on the soil
• Crop management practices
Population dynamics, plant communities, and abiotic environments of three narrowly endemic, allopatric mariposa lilies (Calochortus Pursh) are described and compared. All were restricted to ultramafic soils in southwestern Oregon with high concentrations of nickel, zinc, and chromium, and low calcium to magnesium ratios. Soils inhabited by the three species differed...
The objective of this study was to examine the variation among ammonia-oxidizing and denitrifying communities in soils of a natural Fennoscandian boreal forest and of a forest with a long history of fertilization with different levels of nitrogen (N), and to examine whether there are any changes in the microbial...
Ecosystem nitrogen (N) supply strongly influences the availability and cycling of other essential nutrients in temperate forests, especially calcium (Ca). Short-term additions of N that exceed ecosystem demands often increase dissolved nitrate fluxes and decrease soil pH, which can stimulate soil Ca loss. However, the long-term effects of high N...