Production of surface casts by the earthworm Eisenia rosea

1974 ◽  
Vol 52 (5) ◽  
pp. 659-659 ◽  
Author(s):  
A. J. Thomson ◽  
D. M. Davies
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Bulk Density ◽  
Fine Silt ◽  
First Time

Eisenia rosea was shown to produce surface casts for the first time. The number increased with soil bulk density, organic matter, and fine silt particles. Soil moisture had little effect.

Study on Correlation between Vegetation Restoration and Physics and Chemistry Characters of Soil in Embankment Slope

2013 ◽  
Vol 361-363 ◽  
pp. 1024-1027
Author(s):  
Yang Liu ◽  
Zhong Ping Qiu ◽  
Jun Ru Shen ◽  
Yue Hu ◽  
Yin Yin Liu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Moisture ◽  
Bulk Density ◽  
Organic Matter Content ◽  
Soil Bulk Density ◽  
Matter Content ◽  
Vegetation Changes ◽  
Content Increase ◽  
Embankment Slope

By study features of recovering vegetation and physics and chemistry characters of soil in embankment slopes of 3 years and10 years respectively, the correlation among those factors were investigated . The results show: the physics and chemistry characters of soil vary observably with recovering process; Soil bulk density decreases while soil moisture,TP,TNand organic matter content increase evidently; Although the coverage of vegetation changes little, the structure of vegetation community becomes more complex and spatial distribution is more even; The correlation between spatial distribution of vegetation and characters of soil is most remarkable. With process of restoration, the vegetation is affected more effectively by water and nutrients in site.

scholarly journals Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge

2021 ◽  
Vol 42 (2) ◽  
Author(s):  
Eric R. Labelle ◽  
Dirk Jaeger
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Forest Soils ◽  
Mineral Soil ◽  
Soil Bulk Density ◽  
Organic Layer ◽  
Correction Factors ◽  
Non Destructive

The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications.

A generally applicable pedotransfer function that estimates field capacity and permanent wilting point from soil texture and bulk density

2008 ◽  
Vol 88 (5) ◽  
pp. 761-774 ◽  
Author(s):  
J. A. P. Pollacco
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Texture ◽  
The United States ◽  
Pedotransfer Functions ◽  
Pedotransfer Function ◽  
Data Set ◽  
Wide Range ◽  
Fitting Parameters

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping

scholarly journals Effects of winter wheat season tillage on soil properties and yield of summer maize  

2017 ◽  
Vol 63 (No. 1) ◽  
pp. 22-28 ◽  
Author(s):  
Wang Yunqi ◽  
Zhang Yinghua ◽  
Wang Zhimin ◽  
Tao Hongbin ◽  
Zhou Shunli ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Bulk Density ◽  
Grain Filling ◽  
Soil Bulk Density ◽  
Grain Weight ◽  
Filling Rate ◽  
Summer Maize ◽  
Maize Production ◽  
Grain Filling Rate

The North China Plain (NCP) serves as China’s second most important maize production region. Rotary tillage, a popular method used in winter wheat/summer maize systems in the region, has adverse effects on maize production. The current study was conducted to determine whether rotary tillage after subsoiling in the winter wheat season (RS) improves the grain-filling rate and yield of summer maize by decreasing soil bulk density, when compared with rotary tillage (R), in the NCP. The RS treatment decreased soil bulk density and increased soil moisture in the summer maize season when compared with the R treatment. Root number under the RS treatment at 8 collar and silking stages was 22.4−35.3% and 8.0−11.7% greater than under the R treatment, respectively. The RS treatment significantly enhanced the grain-filling rate and grain weight as compared to the R treatment. Yield, thousand grain weight, biomass, and harvest index under the RS treatment were 7.7, 7.2, 2.3 and 5.3% higher than under the R treatment. Thousands grain weight was correlated with soil bulk density and soil moisture after silking. Consequently, the increase in grain weight and yield of summer maize resulted from the decrease in soil bulk density and a consequent increase in soil moisture, root number and grain-filling rate.  

scholarly journals Modeling and correction of soil penetration resistance for variations in soil moisture and soil bulk density

2016 ◽  
Vol 36 (3) ◽  
pp. 449-459 ◽  
Author(s):  
Wininton M. da Silva ◽  
Aloísio Bianchini ◽  
Cesar A. da Cunha
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
Linear Models ◽  
Clay Soil ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Good Representation ◽  
Soil Resistance ◽  
Soil Penetration Resistance ◽  
Resistance Value

ABSTRACT This study aimed to describe the behavior of models for adjusting data of soil penetration resistance for variations in soil moisture and soil bulk density. The study was carried out in Lucas do Rio Verde, MT, Brazil in a typic dystrophic red-yellow Latosol (Oxisol) containing 0.366 kg kg−1 of clay. Soil penetration resistance measurements were conducted in the soil moistures of 0.33 kg kg−1, 0.28 kg kg−1, 0.25 kg kg−1 and 0.22 kg kg−1. Soil penetration resistance behavior due to variations in soil moisture and soil bulk density was assessed by estimating the soil resistance values by non-linear models. There was an increase of the soil penetration resistance values as soil was losing moisture. For the same edaphic condition studied, small differences in the data of soil bulk density affect differently the response of soil resistance as a function of moisture. Both soil bulk density and soil moisture are essential attributes to explain the variations in soil penetration resistance in the field. The good representation of the critical soil bulk density curve as a limiting compression indicator requires the proper choice of the restrictive soil resistance value for each crop.

scholarly journals Aspen and white spruce productivity is reduced by organic matter removal and soil compaction

2012 ◽  
Vol 88 (03) ◽  
pp. 306-316 ◽  
Author(s):  
Richard Kabzems
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Bulk Density ◽  
Soil Compaction ◽  
Forest Floor ◽  
Mineral Soil ◽  
White Spruce ◽  
Soil Bulk Density ◽  
Post Treatment ◽  
Organic Matter Removal

Declines in forest productivity have been linked to losses of organic matter and soil porosity. To assess how removal of organic matter and soil compaction affect short-term ecosystem dynamics, pre-treatment and year 1, 5 and 10 post-treatment soil properties and post-treatment plant community responses were examined in a boreal trembling aspen (Populus tremuloidesMichx.)-dominated ecosystem in northeastern British Columbia. The experiment used a completely randomized design with three levels of organic matter removal (tree stems only; stems and slash; stems, slash and forest floor) and three levels of soil compaction (none, intermediate [2-cm impression], heavy [5-cm impression]). Removal of the forest floor initially stimulated aspen regeneration and significantly reduced height growth of aspen (198 cm compared to 472–480 cm) as well as white spruce (Picea glauca [Moench] Voss) height (82 cm compared to 154–156 cm). The compaction treatments had no effect on aspen regeneration density. At Year 10, heights of both aspen and white spruce were negatively correlated with upper mineral soil bulk density and were lowest on forest floor + whole tree removal treatments. Recovery of soil properties was occurring in the 0 cm to 2 cm layer of mineral soil. Bulk density values for the 0 cm to 10 cm depth remained above 86% of the maximum bulk density for the site, a soil condition where reduced tree growth can be expected.

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