Evaluation of three insitu soil nitrogen availability assays

1989 ◽  
Vol 19 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Stephen C. Hart ◽  
Mary K. Firestone
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Nitrogen Availability ◽  
Mineral Soil ◽  
N Availability ◽  
Net N Mineralization ◽  
Old Growth ◽  
The Core ◽  
Young Growth

Three indices of nitrogen (N) availability were compared in the field over a 1-year period in an old-growth and a young-growth mixed-conifer forest. The indices utilized were ion exchange resin (IER) bags, buried bags, and a core-IER method employing intact soil cores enclosed in tubes capped at both ends by IER bags. The results from all three methods indicated that in the surface mineral soil, N availability was higher in the young-growth stand than in the old-growth stand. However, seasonal patterns of N availability were generally not well correlated among the methods (correlation coefficients ranged from 0.32 to 0.62). For a given amount of net N mineralized in buried bags, more N accumulated on IER bags placed in the young-growth stand than in those placed in the old-growth stand. This was the result of greater net nitrification in the young-growth stand coupled with the greater mobility of [Formula: see text] relative to [Formula: see text] in soil. Ten-month estimates of net N mineralization measured by the core-IER and buried-bag methods were similar in the young-growth stand (about 42 mg•kg soil−1), but the core-IER estimate was almost twice that of the buried-bag estimate in the old-growth stand (31.7 and 16.8 mg•kg soil−1, respectively). The different sensitivities of the core-IER and buried-bag methods to changes in soil moisture and leaching probably account for much of the difference in their N availability estimates. Results from the core-IER method did reflect the effects of leaching; however, soil water content within the core did not follow changes in soil water content effectively. Because of the greater labor involved in using the core-IER method, its use may be most efficacious in high-precipitation environments, or when in-field soil incubations must be conducted for extended periods of time.

USE OF TEMPE CELL, MODIFIED TO RESTRAIN SWELLING, FOR DETERMINATION OF HYDRAULIC CONDUCTIVITY AND SOIL WATER CONTENT

1984 ◽  
Vol 64 (2) ◽  
pp. 265-272 ◽  
Author(s):  
T. G. SOMMERFELDT ◽  
G. B. SCHAALJE ◽  
W. HULSTEIN
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Movement ◽  
Clay Content ◽  
Core Sample ◽  
Soil Samples ◽  
The Core ◽  
Silty Loam

The Tempe cell, modified by others to determine saturated hydraulic conductivity (K), was further modified to restrain swelling of the soil and to facilitate air and water movement across the top and bottom of the sample. An apparatus was developed whereby K and water content (θ) could be determined for several soil samples concurrently and suction levels could be varied without disturbing the sample. K and θ were determined for several prepared soil samples by the constant head permeameter method and by the Tempe cell with and without swelling restrained, and for soil cores by the Tempe cell with swelling restrained. With swelling restrained, the K results from the prepared samples did not differ significantly from those of the core samples. For the sandy to silty loam soils at suction levels 0, 10, and 20 kPa, θ of the core sample was less than that from the other samples, whereas for the clay loam soils, θ of the core sample was less than that from the others at suction levels of 0 and 10 kPa. For all methods, θ was correlated to clay content of the soil. These results indicate that the Tempe cell, as finally modified with swelling restraints, can be used to determine K and θ for characterizing the drainability of a nonstructured to weakly structured soil, using either prepared samples or cores. Key words: Hydraulic conductivity, pore volume, soil water content, Tempe cell

Nitrogen availability in soil and forest floor of contrasting types of boreal mixedwood forests

2006 ◽  
Vol 36 (1) ◽  
pp. 112-122 ◽  
Author(s):  
Lucie Jerabkova ◽  
Cindy E Prescott ◽  
Barbara E Kishchuk
Keyword(s):  
Boreal Forests ◽  
Forest Floor ◽  
Nitrogen Availability ◽  
Mineral Soil ◽  
N Availability ◽  
Net N Mineralization ◽  
Deciduous Species ◽  
Mixed Stands ◽  
Mixedwood Forests ◽  
The North

Boreal mixedwood forests with varying proportions of coniferous and deciduous species are found throughout the North American continent. Maintenance of a deciduous component within boreal forests is currently favoured, as deciduous species are believed to promote faster nutrient turnover and higher nutrient availability. Results of comparisons of deciduous and coniferous forests are, however, inconsistent in supporting this generalization. We compared indices of soil nitrogen (N) availability in the forest floor and mineral soil of deciduous, mixed, and coniferous stands of boreal mixedwood forest in northwestern Alberta. Deciduous stands had higher N availability, reflected by higher pools of NH4-N and inorganic N in the forest floor. Forest floors of deciduous stands also tended to have higher concentrations of microbial N but did not have higher levels of NO3-N or higher rates of net nitrification. Mixed stands showed the highest rates of net N mineralization. Soil N availability was more closely related to litter N content than to litter decomposition rate. The variation among the forest types is likely attributable to vegetation, as topography is fairly uniform, stands do not differ in soil texture, and N-availability indices correlated directly with the proportion of deciduous trees.

Response of Decagon 10HS soil water content sensor to different porous media

2020 ◽  
Author(s):  
Giuseppe Provenzano ◽  
Giovanni Gugliuzza ◽  
Ceres Duarte Guedes Cabral de Almeida
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Mineral Soil ◽  
The Other ◽  
Organic Substrates ◽  
Soil C ◽  
Other Hand

<p>Optimizing irrigation management requires increasing the accuracy of moisture monitoring in soils or substrates, especially when it depends on electronic sensor readings. Substrates are widely used in horticulture, for growing urban ornamental plants, as well as on green roofs. Due to the lack of information about the accuracy of soil water content sensors on substrates, this research was carried out to evaluate the accuracy of the 10HS sensor (Decagon Devices Inc., Pullman, WA) to estimate soil water content (SWC) in organic substrates and mineral soil. The study was carried out at the Hydrology Laboratory of the University of Palermo. The sensors were inserted into substrates or soil in conical vessels (4 dm<sup>3</sup> volume), drilled at the base to measure the drained volume and covered with a transparent film to limit surface evaporation. For both the substrates (A and B) and the mineral soil (C), a known amount was placed in the vessel and compacted to a value of bulk density equal to 0.177 g cm<sup>-3</sup>, 0.471 g cm<sup>-3</sup>, 1.480 g cm<sup>-3</sup>, respectively. The sensors were connected to a CR1000 datalogger (Campbell Scientific Inc., Logan, UT), which allowed the data acquisition and storage. The tests were conducted by wetting the samples with the progressive addition of known volumes of water (about 40 cm<sup>3</sup>) that were evenly distributed over the sample surface. After the end of the redistribution process of water applied to the container, the sensor readings were acquired. SWC monitoring was performed until reaching the value corresponding to the field capacity. The calibration equation recommended by the sensor manufacturer systematically underestimated the values of SWC of about 5% or more when the substrate A and B were used. On the other hand, when evaluating the sensor performance in the mineral soil (C), it was observed that the errors associated with the manufacturer's equation resulted in ±5%. Therefore, for both substrates specific calibration is necessary to improve the sensor’s accuracy, even accounting for the bulk density; on the other hand, for the mineral soil, the manufacturer's equation can be considered suitable.</p>

Patterns of water movement on a logged Gray Luvisolic hillslope during the snowmelt period

2004 ◽  
Vol 84 (1) ◽  
pp. 71-82 ◽  
Author(s):  
I. R. Whitson ◽  
D. S. Chanasyk ◽  
E. E. Prepas
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Snow Water Equivalent ◽  
Mineral Soil ◽  
Time Domain Reflectometry ◽  
Frozen Soil ◽  
Infiltration Capacity ◽  
Snowmelt Period

Hillslope flow processes during the snowmelt period were studied at a logged site in the Boreal Plain Ecozone of western Canada. Fine-textured subsoils of Gray Luvisolic soils and soil frost were hypothesized to reduce infiltration capacity and promote interflow. Liquid soil water content, saturated flow through upper horizons, and soil temperature were monitored by Time Domain Reflectometry probes, zero-tension flow collectors, and thermocouples, respectively, on a 0.5-ha site with a 13% slope. Soil water content increased abruptly during snowmelt while soil temperature in the upper 65 cm was near 0°C, indicating that infiltration capacity was high despite frost. Mineral soil thawed 2 wk after snowmelt. Less than 0.1 mm of the 87 mm snow water equivalent became interflow. Size and timing of interflow events were variable and related to increased soil water content. The largest event occurred during soil thaw, and contributed 84% of total interflow. The lower Ae horizon was the preferred route for this flow, suggesting that the flowpath was not influenced by frost. Low pre-melt soil moisture probably reduced interflow volume. Interflow in Gray Luvisols is likely an infrequent happening due to high profile moisture storage capacity and rare development of the necessary saturated conditions. Key words: Snowmelt, infiltration, frozen soil, boreal, hydrologic flowpath, Luvisol

One-time application of biosolids to ungrazed semiarid rangelands: 14 yr soil responses

2018 ◽  
Vol 98 (4) ◽  
pp. 696-708 ◽  
Author(s):  
E. Avery ◽  
M. Krzic ◽  
B. Wallace ◽  
R.F. Newman ◽  
S.M. Smukler ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Biomass ◽  
Soil Aggregates ◽  
Mineral Soil ◽  
Total Carbon ◽  
Forage Production ◽  
Soil C ◽  
Biosolids Application

Biosolids have been shown to improve forage production and soil quality on semiarid rangelands in the short term, but less is known about longer-term impacts of one-time biosolids applications. The objective of this study was to determine the effects of a single, surface biosolids application (at 20 dry Mg ha−1) on stability of soil aggregates, bulk density, total carbon (C) and nitrogen (N), permanganate-oxidizable carbon (POXC), polysaccharides, pH, nutrient availability, and soil water content (all at 0–7.5 cm depth) 14 yr following application to ungrazed rangelands in the Central interior of British Columbia. Fourteen years following the biosolids application, aboveground plant biomass was almost two times greater with biosolids application than on control, while exposed mineral soil and microbiotic crust significantly decreased in biosolids plots. Despite differences in aboveground biomass, there was no difference in total soil C and N, POXC, and polysaccharides between biosolids and control plots. Biosolids-amended soil did exhibit significantly greater mean weight diameter of water-stable aggregates, lower pH, increased spring soil water content, and increased availability of Fe3+, Zn2+, Cu2+, and phosphate ions. These findings indicate that the long-term improvements to soil on ungrazed rangeland are possible even from a single biosolids application.

Evaluation of planting sites common to a southeast Alaska clear-cut. I. Nutrient status

1983 ◽  
Vol 13 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Roy C. Sidle ◽  
Charles G. Shaw III
Keyword(s):  
Nitrogen Availability ◽  
C:N Ratio ◽  
Mineral Soil ◽  
Nutrient Status ◽  
Western Hemlock ◽  
N Availability ◽  
Old Growth ◽  
Southeast Alaska ◽  
Clear Cut ◽  
Rotten Wood

Nutrient status was evaluated in the upper 15 cm of three microsite types (rotten wood, exposed mineral soil, and undisturbed duff) common in old-growth western hemlock – Sitka spruce (Tsugaheterophylla (Raf.) Sarg.) – (Piceasitchensis (Bong.) Carr.) clear-cuts. Rotten wood had significantly wider C:N ratio (>100:1) than either undisturbed duff (36:1) or exposed mineral soil (31:1), indicating lower nitrogen availability in rotten wood. Higher levels of inorganic [Formula: see text] in <2 mm fraction of rotten wood compared with the 2- to 9.4-mm fraction indicate that N availability increases as decay advances. Available P was low and could be a major factor limiting growth in all microsites. Exchangeable Mg was relatively low (0.0025 mg/cm3) in exposed mineral soil. Microsite nutrient expression on a volumetric rather than a gravimetric basis better represents availability of nutrients to planted seedlings.

SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

1985 ◽  
pp. 185-189
Author(s):  
M.C.H.Mouat Pieter Nes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Solution ◽  
Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Carbon Dioxide Emission ◽  
Nutrient Content ◽  
Soil Disturbance ◽  
Biological Properties ◽  
Soil Tillage ◽  
Favourable Effect ◽  
Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

Evaluation of a Multi-Rod Probe Performance for Accurate Measurements of Soil Water Content

2020 ◽  
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szyplowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content
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