Restricting the grazing time of cattle to decrease phosphorus, sediment and E. coli losses in overland flow from cropland

Soil Research ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 61 ◽  
Author(s):  
R. W. McDowell ◽  
J. J. Drewry ◽  
R. W. Muirhead ◽  
R. J. Paton
Keyword(s):  
Bulk Density ◽  
Overland Flow ◽  
Soil Bulk Density ◽  
Forage Crops ◽  
E Coli ◽  
P Loss ◽  
Quality Guidelines ◽  
Particulate Form ◽  
The Mean ◽  
Total P

This study investigated the effects of grazing management of brassica crops during winter on soil physical properties and sediment, phosphorus (P), and E. coli loss via overland flow. Dairy cows were allowed either unrestricted grazing, grazing restricted to 3 h, or no grazing. Treading in the unrestricted treatment decreased soil bulk density and saturated hydraulic conductivity (Ksat), and increased surface roughness, loads and concentrations of suspended sediment, and E. coli and P loss in overland flow relative to the ungrazed treatment. Only bulk density was different in the restricted compared with the ungrazed treatment. For total P, the mean load in overland flow from the unrestricted grazing treatment after grazing was 3.31 mg/plot compared with restricted grazing (0.74 mg/plot) and ungrazed (0.76 mg/plot) treatments, with most of the increase in particulate form. E. coli concentrations only exceeded water quality guidelines in the first event after grazing, and only in the unrestricted grazing treatment. We found that restricting grazing on forage crops during winter was beneficial for minimising contaminant loss.

Cattle treading and phosphorus and sediment loss in overland flow from grazed cropland

Soil Research ◽  
2003 ◽  
Vol 41 (8) ◽  
pp. 1521 ◽  
Author(s):  
R. W. McDowell ◽  
J. J. Drewry ◽  
R. W. Muirhead ◽  
R. J. Paton
Keyword(s):  
Overland Flow ◽  
Sediment Concentration ◽  
Soil Disturbance ◽  
Cattle Dung ◽  
Forage Crops ◽  
P Loss ◽  
Sediment Loss ◽  
Particulate Form ◽  
Before And After ◽  
Total P

This 1-year study investigated the effect of dairy cow treading on soil physical properties and sediment and phosphorus (P) loss via overland flow from pasture and cultivated soil used for wintering dairy cows in southern New Zealand. Treading decreased soil macroporosity and Ksat, and increased overland flow volumes. Treading increased mean suspended sediment concentration in overland flow in the cultivated + trodden treatment (2.6 g/L) compared with ungrazed pasture (0.44 g/L) and ungrazed cultivated (0.98 g/L) treatments over 2 slope positions. Following grazing in the cultivated + trodden treatment, only 25% more sediment was lost in subsequent overland flow events (2.09 and 2.63 g before and after grazing, respectively), and mean total P (TP) losses increased by >250% (from 0.7 to 2.5 mg P). Meanwhile in the cultivated but ungrazed treatment, sediment and TP loss decreased. The increased loss of sediment and P following grazing in the cultivated + trodden treatment was attributed to P from cattle dung, and soil disturbance. Consequently, wintering of animals on cultivated paddocks with forage crops increases the risk of losing much P, especially in particulate form.

Effect of Wind Power Station on Underlying Surface Soil Bulk Density in Northern China

2013 ◽  
Vol 864-867 ◽  
pp. 2587-2594
Author(s):  
Yun Hu Xie ◽  
Rui Ping Zhou ◽  
Cong Cong Cheng ◽  
Hong Tao Jiang ◽  
Xiao Jia Li ◽  
...  
Keyword(s):  
Bulk Density ◽  
Wind Power ◽  
Surface Soil ◽  
Control Sample ◽  
Soil Bulk Density ◽  
Power Station ◽  
Production Time ◽  
Space And Time ◽  
Wind Power Station ◽  
The Mean

This study sampled and tested the soil samples in wind power station of Huitengxile. Analyze soil bulk density in the different space and time and study the effect of wind power station on soil bulk density in different space and time. Results show that the mean soil bulk density of each year has the tendency of increase with the increase of depth in the range of 0 to 50 centimeters, but the increase extent is not much. The increase of soil bulk density in deep soil layer is the biggest in 1996 and the smallest in 2009 comparing that in the surface soil. The soil bulk density in the range of 0 to 40 centimeters is without obvious change regularity contrasting the control samples. The soil bulk density of control sample is greater than other experiment samples in the range of 40 to 50 centimeters. The change of topsoil soil bulk density is not significant with the increase of wind power station production time in the 10 to 30 centimeters. The change of soil bulk density is significant with the increase of wind power station production time at the depth of 40 to 50 centimeters. The mean soil bulk density takes the trend of decrease with the distance increasing from the wind power station base in different production time. The trend of mean soil bulk density is decreasing more significant in range of 0-60 meters. The change of mean soil bulk density is not big in the range of 80 to 100 meters from the base, and the value of soil bulk density trend to stability. It has not significant change contrasting the mean soil bulk density of different direction. The electricity generated by wind power has not effect on the direction of soil bulk density.

MEASUREMENT AND PALEOCLIMATIC SIGNIFICANCE OF SOIL BULK DENSITY FOR LOESS IN EXTREME ARID REGION

2010 ◽  
Vol 30 (2) ◽  
pp. 127-132
Author(s):  
Jinbo ZAN ◽  
Shengli YANG ◽  
Xiaomin FANG ◽  
Xiangyu LI ◽  
Yibo YANG ◽  
...  
Keyword(s):  
Bulk Density ◽  
Arid Region ◽  
Soil Bulk Density ◽  
Paleoclimatic Significance

scholarly journals Machine-Learning Classification of Soil Bulk Density in Salt Marsh Environments

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4408
Author(s):  
Iman Salehi Hikouei ◽  
S. Sonny Kim ◽  
Deepak R. Mishra
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
Salt Marsh ◽  
Bulk Density ◽  
Remote Sensing Data ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Marsh Soil ◽  
Landsat 7 ◽  
Salt Marsh Soil

Remotely sensed data from both in situ and satellite platforms in visible, near-infrared, and shortwave infrared (VNIR–SWIR, 400–2500 nm) regions have been widely used to characterize and model soil properties in a direct, cost-effective, and rapid manner at different scales. In this study, we assess the performance of machine-learning algorithms including random forest (RF), extreme gradient boosting machines (XGBoost), and support vector machines (SVM) to model salt marsh soil bulk density using multispectral remote-sensing data from the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) platform. To our knowledge, use of remote-sensing data for estimating salt marsh soil bulk density at the vegetation rooting zone has not been investigated before. Our study reveals that blue (band 1; 450–520 nm) and NIR (band 4; 770–900 nm) bands of Landsat-7 ETM+ ranked as the most important spectral features for bulk density prediction by XGBoost and RF, respectively. According to XGBoost, band 1 and band 4 had relative importance of around 41% and 39%, respectively. We tested two soil bulk density classes in order to differentiate salt marshes in terms of their capability to support vegetation that grows in either low (0.032 to 0.752 g/cm3) or high (0.752 g/cm3 to 1.893 g/cm3) bulk density areas. XGBoost produced a higher classification accuracy (88%) compared to RF (87%) and SVM (86%), although discrepancies in accuracy between these models were small (<2%). XGBoost correctly classified 178 out of 186 soil samples labeled as low bulk density and 37 out of 62 soil samples labeled as high bulk density. We conclude that remote-sensing-based machine-learning models can be a valuable tool for ecologists and engineers to map the soil bulk density in wetlands to select suitable sites for effective restoration and successful re-establishment practices.

scholarly journals THE DNA OF CAENORHABDITIS ELEGANS

Genetics ◽  
1974 ◽  
Vol 77 (1) ◽  
pp. 95-104
Author(s):  
J E Sulston ◽  
S Brenner
Keyword(s):  
Caenorhabditis Elegans ◽  
Chemical Analysis ◽  
Dna Sequences ◽  
Base Composition ◽  
Nematode Caenorhabditis Elegans ◽  
5S Rna ◽  
Base Pairs ◽  
Small Component ◽  
E Coli ◽  
The Mean

ABSTRACT Chemical analysis and a study of renaturation kinetics show that the nematode, Caenorhabditis elegans, has a haploid DNA content of 8 x IO7 base pairs (20 times the genome of E. coli). Eighty-three percent of the DNA sequences are unique. The mean base composition is 36% GC; a small component, containing the rRNA cistrons, has a base composition of 51% GC. The haploid genome contains about 300 genes for 4s RNA, 110 for 5s RNA, and 55 for (18 + 28)S RNA.

Measurement of Soil Bulk Density and Water Content with Time Domain Reflectometry: Algorithm Implementation and Method Analysis

2021 ◽  
pp. 126389
Author(s):  
Marco Bittelli ◽  
Fausto Tomei ◽  
Anbazhagan P. ◽  
Raghuveer Rao Pallapati ◽  
Puskar Mahajan ◽  
...  
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Time Domain ◽  
Soil Bulk Density ◽  
Time Domain Reflectometry ◽  
Algorithm Implementation ◽  
Method Analysis
Sign in / Sign up

Export Citation Format

Share Document