A Non-Modular Cellular DEVS Model Of The Degradation Of A Cultivated Soil Surface By Rainfall

2008 ◽  
Author(s):  
G. Valette ◽  
S. Prevost ◽  
L. Lucas ◽  
J. Leonard
Keyword(s):  
Soil Surface ◽  
Cultivated Soil

Measurement and Analysis of the Vertical Stress Distribution within a Cultivated Soil Volume under Static Conditions

2019 ◽  
Vol 62 (4) ◽  
pp. 1035-1043
Author(s):  
Chunxia Jiang ◽  
Zhixiong Lu ◽  
Shrinivasa K. Upadhyaya ◽  
Muhammad Sohail Memon
Keyword(s):  
Stress Distribution ◽  
Empirical Relationship ◽  
Pressure Sensors ◽  
Quadratic Function ◽  
Soil Surface ◽  
Vertical Stress ◽  
Inflation Pressure ◽  
Cultivated Soil ◽  
Soil Volume ◽  
Static Conditions

Abstract. One of the important considerations of soil-tire interaction research is the stress distribution in the topsoil and within the cultivated soil volume due to tires. This stress distribution influences trafficability, ride performance, and tractive performance. In this study, a two-wheel-drive tractor and a group of piezoelectric pressure sensors were used at different tire loads and inflation pressures to (1) measure the vertical stress under three tire loads with three inflation pressures and determine the influence of these two parameters on the vertical stress in the topsoil, as measured by sensors with their upper surfaces at an initial depth of 50 mm within the soil volume; (2) develop an empirical relationship between the vertical stress and the depth beneath the soil surface, the tire load, the inflation pressure, and the lateral sensor distance from the tire centerline using multiple linear regression; and (3) analyze the effects of tire load and inflation pressure on vertical stress to contribute to the understanding of soil compaction processes based on the equation we developed. All vertical stress measurements were conducted when traffic was applied to the soil by the left front tire of the tractor, with forward motion of the tractor stopped before the left rear tire reached the sensors. The results indicated that (1) when the inflation pressure decreased, the soil-tire interface stress curve became smooth and the peak value of stress gradually moved to a point near the edge of the tire, whereas when the inflation pressure was higher, the peak stress value occurred in the center of the tire; (2) low inflation pressure significantly reduced the maximum vertical stress; (3) the vertical stress was influenced by all four factors investigated in this study; and (4) the stress within the soil volume varied as a quadratic function of the inflation pressure at a given tire load, and it varied as a linear function of tire load at a given inflation pressure. Keywords: Stress distribution, Tire load, Tire inflation pressure.

Modelling the mineralisation of plant residues on the soil surface

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 711-722 ◽  
Author(s):  
Axel Berkenkamp ◽  
Eckart Priesack ◽  
Jean Charles Munch
Keyword(s):  
Soil Surface ◽  
Plant Residues

Status and development prospects of standard means for reproducing units of volumetric activity of radon and thoron and radon flux density from the soil surface

2020 ◽  
pp. 69-73
Author(s):  
S.G. Birjukov ◽  
O.I. Kovalenko ◽  
A.A. Orlov
Keyword(s):  
Flux Density ◽  
Soil Surface ◽  
National Standards ◽  
Measuring Instruments ◽  
Volumetric Activity ◽  
Standard Means ◽  
Radon Flux ◽  
Technical Solutions ◽  
Development Prospects ◽  
Physical Principles

The approach to creating standard means for reproducing units of volumetric activity of radon and thoron and flux density of radon from the soil surface is described based on the physical principles of reproducing these units of quantities and using as technical means for reproducing bubblers with a radioactive solution of radium salt, reference capacities of known volume, emanation chambers for generation of a toron, a gamma spectrometer with a semiconductor detector from highly pure germanium and radon radiometers. Reproduction consists in the physical realization of units in accordance with their definition as applied to the formation of radon and thoron in the radioactive rows of radium and thorium. The proposed approach will allow to determine the structural, structural and other technical solutions of standard measuring instruments, as well as specific techniques and methods of working with them. The creation of standard tools and technologies for reproducing units of volumetric activity of radon and thoron and the density of radon flux from the soil surface will ensure the unity and reliability of measurements in the field of ionizing radiation, traceability of units and bringing the characteristics of national standards in line with world achievements.

Restoration of Ecosystem Function by Soil Surface Inoculation with Biocrust in Mesic and Xeric Alpine Ecosystems

2019 ◽  
Vol 37 (2) ◽  
pp. 101-112 ◽  
Author(s):  
Annie-Claude Letendre ◽  
Darwyn S. Coxson ◽  
Katherine J. Stewart
Keyword(s):  
Ecosystem Function ◽  
Soil Surface ◽  
Alpine Ecosystems

REHABILITATION OF THE SOIL STRUCTURE WITH THE DIRECT SOWING IN THE STAVROPOL REGION DRY ZONE

1970 ◽  
pp. 27-31
Author(s):  
V. P. Belobrov ◽  
S. А. Yudin ◽  
V. А. Kholodov ◽  
N. V. Yaroslavtseva ◽  
N. R. Ermolaev ◽  
...  
Keyword(s):  
Cover Crops ◽  
Soil Surface ◽  
Plant Residues ◽  
Agricultural Technologies ◽  
Row Crops ◽  
Dry Zone ◽  
Erosion Effect ◽  
Stavropol Region ◽  
Dry Conditions ◽  
Direct Sowing

The influence of different systems of soil cultivation is considered - traditional (recommended) technology and direct sowing, which is increasingly used under dry conditions of the region. The rehabilitation of the degraded southern chernozems and dark chestnut soils structure during 13 and 7 years of direct sowing, respectively, has not been established. It takes much longer to rehabilitation the aggregate state of soils, which is currently in a critical condition of the content of aggregates> 10 mm in size and the sum of agronomically valuable aggregates. The soils under 60-year treeline, as a control, showed a satisfactory range of aggregates, which indicates a high degree of soil degradation in the past and a long period of their recovery time. The effectiveness of direct sowing usage in the cultivation of a wider range of grain and row crops (winter wheat, sunflower, peas, chickpeas, rapeseed, buckwheat, corn) is due to the peculiarities of agricultural technologies. Abandoning of naked fallows and soil treatments with the simultaneous use of plant residues and cover crops on the soil surface between the harvest and sowing of winter crops provides an anti-erosion effect and, as a consequence, a decrease in physical evaporation, an increase in moisture and biota reserves, an increase in microbiological processes, which are noted in the form trends in improving the agrochemical and agrophysical properties of soils.

HOW CLIMATE CHANGE CAN INFLUENCE THE AGRICULTURE IN UKRAINE: A REVIEW

2020 ◽  
Author(s):  
N. Maidanovych ◽  
Keyword(s):  
Climate Change ◽  
Crop Yields ◽  
Soil Surface ◽  
Winter Period ◽  
Negative Consequences ◽  
Resource Saving ◽  
Impact Of Climate Change ◽  
Positive Effects ◽  
Average Annual Temperature ◽  
The Impact

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.

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