scholarly journals The impact of different tillage practices on soil stability and erosion in a red soil hilly region, China

2021 ◽  
Author(s):  
Huifang Jin ◽  
Shangshu Huang ◽  
Dong Shi ◽  
Junkai Li ◽  
Jifu Li ◽  
...  
Keyword(s):  
Soil Compaction ◽  
Mechanical Stability ◽  
Aggregate Stability ◽  
Nutrient Retention ◽  
Red Soil ◽  
Soil Stability ◽  
Soil Productivity ◽  
Tillage Practices ◽  
Hilly Region ◽  
The Impact

Tillage practices can change moisture content, nutrient retention and soil properties and so affect crop growth and significantly influence soil stability. The objectives of this study were to evaluate the effects of tillage practices (conventional tillage, CT; soil compaction, CM; subsoil tillage, ST; no tillage, NT; and subsoil tillage and soil compaction, SCM) on soil stability in a hilly region of red soil in China. The parameters of soil stability were soil aggregate stability (SAS), wet aggregate stability (WAS), and soil mechanical stability (SMS). These parameters are closely related to soil erodibility (SE). The results indicated that SAS, WAS, SMS and SE varied significantly across the five tillage methods. The aggregate stability indexes (ASI) of CM (2.64) and CT (2.61) were greater than for other methods, which indicates that CM increased the compactness of soil particles and that the soil structure for NT was relatively stable and less disturbed than for other methods. NT and CM significantly increased soil shear strength (SS) and soil compactness (SC) compared to other methods. NT significantly increased soil resistance to erosion compared to other methods, with K factor = 0.26. NT (ASI = 0.43) had the greatest soil stability and resistance to erosion (SSE), followed by SCM (ASI = 0.41), for which ASI can potentially be increased. The results provide reference parameter values for selecting a suitable tillage method to reduce soil erosion and improve soil productivity in red soil sloping farmland.

Characterization of soil quality: Physical and chemical criteria

1992 ◽  
Vol 7 (1-2) ◽  
pp. 25-31 ◽  
Author(s):  
M.A. Arshad ◽  
G.M. Coen
Keyword(s):  
Soil Quality ◽  
Soil Depth ◽  
Aggregate Stability ◽  
Future Research ◽  
Soil Productivity ◽  
Retention Capacity ◽  
Human Welfare ◽  
Chemical Attributes ◽  
Physical And Chemical ◽  
The Impact

AbstractThe impact of soil degradation on human welfare and the global environment presents a major challenge. A significant decline in soil quality has occurred worldwide through adverse changes in its physical, chemical and biological attributes and contamination by inorganic and organic chemicals. There is a need to develop criteria to evaluate soil quality so that the progress of any corrective action required by the international community can be monitored.There currently are no generally accepted criteria to evaluate changes in soil quality. This lack impedes the design and evaluation of meaningful soil management programs. This paper examines the principal physical and chemical attributes that can serve as indicators of a change in soil quality under particular agroclimatic conditions. Proposed indicators include soil depth to a root restricting layer, available water-holding capacity, bulk density/penetration resistance, hydraulic conductivity, aggregate stability, organic matter, nutrient availability/retention capacity, pH, and where appropriate, electrical conductivity and exchangeable sodium. We also discuss the justification for selecting these key attributes, their measurement, critical limits for monitoring changes in soil productivity, and future research needs in soil quality.

Soil physical property changes at the North American Long-Term Soil Productivity study sites: 1 and 5 years after compaction

2006 ◽  
Vol 36 (3) ◽  
pp. 551-564 ◽  
Author(s):  
Deborah S Page-Dumroese ◽  
Martin F Jurgensen ◽  
Allan E Tiarks ◽  
Felix Ponder, Jr. ◽  
Felipe G Sanchez ◽  
...  
Keyword(s):  
Bulk Density ◽  
North American ◽  
Soil Compaction ◽  
Soil Bulk Density ◽  
Water Infiltration ◽  
Soil Productivity ◽  
Soil Monitoring ◽  
The North ◽  
The Impact

The impact of forest management operations on soil physical properties is important to understand, since management can significantly change site productivity by altering root growth potential, water infiltration and soil erosion, and water and nutrient availability. We studied soil bulk density and strength changes as indicators of soil compaction before harvesting and 1 and 5 years after harvest and site treatment on 12 of the North American Long-Term Soil Productivity sites. Severe soil compaction treatments approached root-limiting bulk densities for each soil texture, while moderate compaction levels were between severe and preharvest values. Immediately after harvesting, soil bulk density on the severely compacted plots ranged from 1% less than to 58% higher than preharvest levels across all sites. Soil compaction increases were noticeable to a depth of 30 cm. After 5 years, bulk density recovery on coarse-textured soils was evident in the surface (0–10 cm) soil, but recovery was less in the subsoil (10–30 cm depth); fine-textured soils exhibited little recovery. When measured as a percentage, initial bulk density increases were greater on fine-textured soils than on coarser-textured soils and were mainly due to higher initial bulk density values in coarse-textured soils. Development of soil monitoring methods applicable to all soil types may not be appropriate, and more site-specific techniques may be needed for soil monitoring after disturbance.

scholarly journals Reforestation and slope-position effects on nitrogen, phosphorus pools, and carbon stability of various soil aggregates in a red soil hilly land of subtropical China

2015 ◽  
Vol 45 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Li-Qun Zou ◽  
Fu-Sheng Chen ◽  
David S. Duncan ◽  
Xiang-Min Fang ◽  
Huimin Wang
Keyword(s):  
Soil Aggregates ◽  
Red Soil ◽  
Slope Position ◽  
Subtropical China ◽  
Position Effects ◽  
Masson Pine ◽  
Organic C ◽  
Hilly Region ◽  
C Stocks ◽  
The Impact

The impact of slope position on forest restoration processes may dominate the interaction among topsoil aggregates, nutrients, and organic carbon (C) stability following reforestation on degraded hilly land. Six paired plots of shrubland and Masson pine (Pinus massoniana Lamb.) plantation reforested on shrubland were selected at different positions along a 25° slope in subtropical China. Soil and ecosystem nitrogen (N), phosphorus (P), and organic C stocks were quantified using a combination of excavation, harvest, and modeling methods. Carbon stability in differently sized soil aggregates was measured using dry sieving and closed-jar alkali-absorption methods. Reforestation increased total ecosystem C, N, and P stocks, but did not alter soil C and P stocks, and decreased N stocks at 0–75 cm soil depth by 18%. The shift from shrubland to forests increased organic C stability for various soil aggregates, particularly with a mean increase of 34% and 30% at lower and middle slope positions, respectively. The slope-position effect was largely attributable to the increased mean mass diameter of soil aggregates and the reduced organic C mineralization potential in larger soil aggregates relative to smaller soil aggregates. Soil aggregates had more stable organic C in forests than in shrubland due to increase in the carbon to nitrogen (C/N) and carbon to phosphorus (C/P) ratios with reforestation. Slope position influenced restoration effectiveness in the red soil hilly region.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

scholarly journals Nutrient retention behind a tropical mega-dam: a case study of the Sardar Sarovar Dam, India

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Harish Gupta ◽  
S. Kiran Kumar Reddy ◽  
Mounika Chiluka ◽  
Vamshikrishna Gandla
Keyword(s):  
Arabian Sea ◽  
Inorganic Nitrogen ◽  
Nutrient Retention ◽  
Significant Loss ◽  
N Removal ◽  
Narmada River ◽  
Sardar Sarovar ◽  
The Impact

AbstractIn this study, we demonstrate the impact of the construction of a mega-dam on the nutrient export regime of a large tropical river into the Arabian Sea. Long-term (11 years) fortnight nutrient parameters, upstream and downstream to Sardar Sarovar (SS) Dam, were examined to determine the periodical change in nutrient fluxes from the Narmada River, India. During this 11-year period, the average discharge of the Narmada River upstream to Rajghat (35.3 km3 year−1) was higher than that of downstream at Garudeshwar (33.9 km3 year−1). However, during the same period, the suspended sediment load was reduced by 21 million tons (MT) from 37.9 MT at Rajghat to 16.7 MT at Garudeshwar. Similarly, mean concentrations of dissolved silica (DSi) reduced from 470 (upstream) to 214 µM (downstream), dissolved inorganic phosphate (DIP) from 0.84 to 0.38 µM, and dissolved inorganic nitrogen (DIN) from 43 to 1.5 µM. It means that about 54%, 55%, and 96% flux of DSi, DIP, and DIN retained behind the dam, respectively. The estimated denitrification rate (80,000 kg N km−2 year−1) for the reservoir is significantly higher than N removal by lentic systems, globally. We hypothesize that processes such as biological uptake and denitrification under anoxic conditions could be a key reason for the significant loss of nutrients, particularly of DIN. Finally, we anticipated that a decline in DIN fluxes (by 1.13 × 109 mol year−1) from the Narmada River to the Arabian Sea might reduce the atmospheric CO2 fixation by 7.46 × 109 mol year−1.

scholarly journals Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

2015 ◽  
Vol 63 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Karsten Schacht ◽  
Bernd Marschner
Keyword(s):  
Hydraulic Conductivity ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Treated Wastewater ◽  
Soil Aggregate Stability ◽  
Irrigation Effects ◽  
Physical And Chemical ◽  
The Impact

Abstract The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties.

Bone ingrowth in total knee arthroplasty: The impact of HA-coatings and the relation with mechanical stability

1998 ◽  
Vol 31 ◽  
pp. 26
Author(s):  
L. Labey ◽  
H. Van Campenhout ◽  
J. Vander Sloten ◽  
R. Van Audekercke ◽  
G. Van der Perre ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Stability ◽  
Bone Ingrowth ◽  
Total Knee ◽  
The Impact
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