scholarly journals PREDICTING DRIP IRRIGATION CONTOURS OF CHERNOZEMS OF THE STEPPE TYPE OF SOIL FORMATION

2021 ◽  
Author(s):  
V. N. Shkura ◽  
◽  
A. S. Shtanko ◽  
Keyword(s):  
Drip Irrigation ◽  
Soil Layer ◽  
Experimental Studies ◽  
Soil Formation ◽  
Moisture Distribution ◽  
Physical Clay ◽  
Functional Relationships ◽  
Irrigation Design ◽  
Qualitative Similarity ◽  
Vertical Sections

Purpose: development and testing of a method for determining the size and moisture characteristics of moisture contours formed in the southern chernozems of the steppe type of soil formation during drip irrigation. Materials and methods. Experimental studies were carried out on light, medium and heavy loamy medium thick ordinary and southern chernozems. The vertical sections of humidification zones with a system of in-contour moisture isopleths were considered. As indicators determining the contour parameters, the following are considered: the content of physical clay in the moistened soil layer, the soil density and its lowest moisture capacity. Results. In the process of studying the experimental vertical sections of soil drip moistening zones, dependences characterizing the existing functional relationships between the contour geometric parameters and the characteristics of soil, phytosoil and technological conditions of their formation were determined. On the basis of the obtained experimental dependences, a method for calculating the contours linear dimensions and graphically constructing their outlines has been developed. The proposed method for contour predicting was tested on actual data on their sizes and moisture distribution in the inner-contour space, obtained by other researchers experimentally. Comparison of the experimental and predicted contours of drip moistening testifies to their qualitative similarity both in terms of the external outline and in terms of the location of isopleths with different levels of soil moisture inside the wetted zone. The calculated value of the irrigation rate differs from the actual one by 2.2 %. Conclusions. The proposed method for predicting the sizes of moisture contours and intra-contour isopleths, formed in chernozems of the steppe type of soil formation, was developed to the level of calculations using the author's computer program. An example of approbation of the proposed method indicates its acceptability for use in the crops drip irrigation design and operational practice.

Resource-saving Technologies and Some Proposals for the Creation of Automated Reclamation Systems

2021 ◽  
Vol 25 (7) ◽  
pp. 8-12
Author(s):  
Z.G. Lamerdonov ◽  
T.Yu. Khashirova ◽  
S.A. Zhaboev ◽  
L.Zh. Nastueva ◽  
A.А. Shogenov ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Salt Content ◽  
Experimental Studies ◽  
Soil Surface ◽  
Growing Season ◽  
Resource Saving ◽  
Water Savings ◽  
Irrigation Method ◽  
High Salt Content ◽  
Reclamation System

The results of experimental studies of the local subsurface irrigation method in comparison with drip irrigation carried out in the laboratory, which showed water savings due to a decrease in evaporation from the soil surface by 10–15 percent are presented. The method of irrigation in closed greenhouse farms using water with a high salt content is described. The paper proposes new patented schematic solutions for protecting plants from frost and pests, describes a multifunctional engineering and reclamation system capable of performing various operations depending on the emerging problems during the growing season.

scholarly journals Water storage in wetted strips under irrigated coffee trees with different criteria of irrigation management

2013 ◽  
Vol 33 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Alberto Colombo ◽  
Lívia A. Alvarenga ◽  
Myriane S. Scalco ◽  
Randal C. Ribeiro ◽  
Giselle F. Abreu
Keyword(s):  
Dimensional Analysis ◽  
Drip Irrigation ◽  
Irrigation Management ◽  
Water Storage ◽  
Moisture Distribution ◽  
Water Volume ◽  
Two Dimensional ◽  
One Dimensional ◽  
Irrigation Interval ◽  
The One

The increasing demand for water resources accentuates the need to reduce water waste through a more appropriate irrigation management. In the particular case of irrigated coffee planting, which in recent years presented growth with the predominance of drip irrigation, the improvement of drip irrigation management techniques is a necessity. The proper management of drip irrigation depends on the knowledge of the spatial pattern of soil moisture distribution inside the wetted strip formed under the irrigation lines. In this study, grids of 24 tensiometers were used to determine the water storage within the wetted strip formed under drippers, with a 3.78 L h-1 discharge, evenly spaced by 0.4 m, subjected to two different management criteria (fixed irrigation interval and 60 kPa tension). Estimates of storage based on a one-dimensional analysis, that only considers depth variations, were compared with two-dimensional estimates. The results indicate that for high-frequency irrigation the one-dimensional analysis is not appropriate. However, under less frequent irrigation, the two-dimensional analysis is dispensable, being the one-dimensional sufficient for calculating the water volume stored in the wetted strip.

scholarly journals Treeline advance - driving processes and adverse factors

2007 ◽  
Vol 1 ◽  
pp. 1-33 ◽  
Author(s):  
Friedrich Karl Holtmeier ◽  
Gabriele E. Broll
Keyword(s):  
Experimental Studies ◽  
Temporal Variations ◽  
Considerable Effect ◽  
Future Climate Change ◽  
Anthropogenic Factors ◽  
Site Conditions ◽  
Mature Trees ◽  
Climatic Regions ◽  
Functional Relationships ◽  
Animal Populations

The general trend of climatically-driven treeline advance is modified by regional, local and temporal variations. Treelines will not advance in a closed front parallel to the shift of any isotherm to higher elevations and more northern latitudes. The effects of varying topography on site conditions and the after-effects of historical disturbances by natural and anthropogenic factors may override the effects of slightly higher average temperatures. Moreover, the varying treeline-forming species respond in different ways to a changing climate. Forest advance upwards and northwards primarily depends on successful regeneration and survival of young growth rather than on increasing growth rates of mature trees. Every assessment of treeline response to future climate change must consider the effects of local site conditions and feedbacks of increasing tree population in modulating the climatically-driven change. Treeline-shift will influence regional and local climates, pedogenesis, plant communities, animal populations and biodiversity as well as having a considerable effect on economic changes in primary production. A better understanding of the functional relationships between the many treeline-relevant factors and treeline dynamics can be achieved only by extensive research at different scales within different climatic regions supported by as many as possible experimental studies in the field together with laboratory and remote sensing techniques.

Drip Irrigation Design on Nonuniform Slopes

1979 ◽  
Vol 105 (3) ◽  
pp. 289-303
Author(s):  
I-Pai Wu ◽  
Harris M. Gitlin
Keyword(s):  
Drip Irrigation ◽  
Irrigation Design

Temporal changes of mobile forms of 90Sr on Pripyat River floodplain in vicinity of Chornobyl NPP: measurements and risk assessments for river water contamination

2021 ◽  
Author(s):  
Gennady Laptev ◽  
Oleg Voitsekhovych ◽  
Valentyn Protsak ◽  
Mark Zheleznyak ◽  
Kenji Nanba ◽  
...  
Keyword(s):  
Coming Out ◽  
Water Contamination ◽  
Soil Layer ◽  
Experimental Studies ◽  
Water System ◽  
Water Soluble ◽  
Computational Grids ◽  
Exclusion Zone ◽  
Drastic Increase ◽  
Fuel Particles

<p>Since the 1986 Chornobyl accident transport of radionuclides by Pripyat River shares more than 90% of the annual total flux of radioactivity coming out the Chornobyl Exclusion Zone (ChEZ).  90Sr was the main contributor to this flux. In course of time destruction of the accidentally dispersed "fuel particles" leads to increase of mobile, e.g. water-soluble, forms of 90Sr  on territories affected by, while fixation of 137Cs in soil is reflected by significant reduction in 137Cs aquatic transport outside the ChEZ.</p><p>Heavily contaminated floodplain of the Pripyat River, located in vicinity of ChNPP upstream of Yaniv Bridge up to Ukrainian - Belorussian border, was considered as a “hotspot” with highest risks to the Pripyat and Dnipro water contamination due to recurrent flooding of these territories. This was evidently elucidated after the 1991 ice jam event when drastic increase of 90Sr in water was observed. The dikes splitting leftbank floodplain from the Pripyat river channel were constructed in 1992-1993. Yet, it is still important to quantify the amount of 90Sr that can be washed off the floodplain due to potential dike breakage caused by the extreme floods. </p><p>Key parameters used to describe status of radionuclide in reaching equilibrium in soil-water system are the distribution coefficient (Kd) and kinetic rate that is reciprocal of typical time scale of desorption processes. These parameters subsequently were estimated in 1991 on the basis of batch experiment carried out with the soil monoliths sampled from the Pripyat floodplain ( Laptev and Voistekhovich, 1991). Results were used in the 2D model COASTOX for justification the construction of protecting dikes (Zheleznyak at al., 1992).</p><p>To analyze current ability of 90Sr to be washed off the floodplain, soils monoliths were collected in 2020. The experimental studies of the soil cores collected from same location as the monoliths allowed to estimate mobile speciation of 90S and calibrate mass-exchange parameters. Amount of the readily exchangeable forms of 90Sr in soils significantly increased from 10-30% in the first years after the accident up to 65-75% as to 2020. Results of field and laboratory  studies were used for simulation the scenarios of 90Sr washing off the floodplain during the dikes breaks on the basis of contemporary version of COASTOX model, that includes the parallel algorithms for numerical solution of the model equations on the unstructured computational grids for multi CPU and GPU systems. Approaches for the modelling of the secondary release of 90Sr due the rapid destruction of “fuel particles” are considered. Taking into account two concurrent processes - decrease of amount of 90Sr in uppermost soil layer due to decay and downward vertical migration (1), amid increased amount of exchangeable forms of 90Sr (2), one could project subsequent increasing of 90Sr  in Pripyat and Dnipro river waters downstream the source in case of the dike breakage scenarios. On the other hand, computer simulation suggests that the maximal values of the 90Sr concentrations expected to be not higher than the measured ones during the high floods events after the accident.</p><p> </p>

scholarly journals Estimating Soil Moisture Distributions across Small Farm Fields with ALOS/PALSAR

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yuki Kojima ◽  
Kazuo Oki ◽  
Kosuke Noborio ◽  
Masaru Mizoguchi
Keyword(s):  
Soil Moisture ◽  
Soil Layer ◽  
Ground Surface ◽  
Time Domain Reflectometry ◽  
Moisture Distribution ◽  
Small Scale ◽  
Alos Palsar ◽  
Coverage Ratio ◽  
Fine Resolution ◽  
Soil Moisture Distribution

The ALOS (advanced land observing satellite) has an active microwave sensor, PALSAR (phased array L-band synthetic aperture radar), which has a fine resolution of 6.5 m. Because of the fine resolution, PALSAR provides the possibility of estimating soil moisture distributions in small farmlands. Making such small-scale estimates has not been available with traditional satellite remote sensing techniques. In this study, the relationship between microwave backscattering coefficient (σ) measured with PALSAR and ground-based soil moisture was determined to investigate the performance of PALSAR for estimating soil moisture distribution in a small-scale farmland. On the ground at a cabbage field in Japan in 2008, the soil moisture distribution of multiple soil layers was measured using time domain reflectometry when the ALOS flew over the field. Soil moisture in the 0–20 cm soil layer showed the largest correlation coefficient with σ (r=0.403). The σ values also showed a strong correlation with the ground surface coverage ratio by cabbage plants. Our results suggested that PALSAR could estimate soil moisture distribution of the 0–20 cm soil layer across a bare field and a crop coverage ratio when crops were planted.

Subsurface drip irrigation in raised bed tomato production. II. Soil acidification under current commercial practice

Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1305 ◽  
Author(s):  
P. R. Stork ◽  
P. H. Jerie ◽  
A. P. L. Callinan
Keyword(s):  
Soil Ph ◽  
Drip Irrigation ◽  
Management Practices ◽  
Soil Layer ◽  
Subsurface Drip Irrigation ◽  
Tomato Production ◽  
Commercial Practice ◽  
Murray Darling Basin ◽  
Subsurface Drip ◽  
Basin Region

The effects of ammonium-based fertilisers on the soil pH of vegetable beds that utilised subsurface drip irrigation (SDI) for commercial tomato production were investigated at field sites in the southern Murray–Darling Basin region (SMDB). The soils at these sites were Vertosols (sites 1, 3, 4, and 5) and a Chromosol (site 2). At site 1, rapid transport and hydrolysis of urea occurred within the 0–90 cm soil layer of vegetable beds after a 6-mm fertigation of 30 kg urea-N/ha during cropping. Soil pH decreased by 0.2–0.4 units in individual 15-cm soil layers up to 90 cm within 12 days after the fertigation. A longer study at site 1 showed that there was severe acidification in topsoil and subsoil by the second consecutive year of SDI cropping. The rate of acidification was highest, at 52 kmol H+/ha.year, immediately beneath the dripline, in the 15–30 cm soil layer. Topsoil and subsoil acidification was also evident in vegetable beds at sites 2, 3, 4, and 5 after 2 consecutive years of tomato cropping using SDI. The results from the 5 sites indicated that acidification under SDI production may be widespread. A survey of 21 other sites in the SMDB under similar production showed that one-third of the sites had soil pH ≤6.0 in their 0–30 cm soil layer. Several soil types were individually represented at acid and alkaline pH levels, by 2 or more sites. This indicated that management practices influenced the change in soil pH for a given soil type. Altogether, the combined results of these studies strongly indicated that surface and subsoil acidification can occur in soils used for intensive SDI production. This may diminish their productivity in the long term.

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