scholarly journals MODELING OF SUBSURFACE HORIZONTAL POROUS PIPE IRRIGATION UNDER DIFFERENT CONDITIONS

2021 ◽  
Vol 52 (4) ◽  
pp. 949-959
Author(s):  
Z. K. Rasheed

Horizontal porous pipe method is one of the most efficient systems of irrigation in arid and semi-arid areas.  The main aim of this study is to simulate the subsurface horizontal porous pipe irrigation under different conditions.  By this method of irrigation, an optimum amount of water is reached to the crop.  Moreover, it saves more water than the other irrigation systems.  Simulation models by HYDRUS/2D  are described the distribution of wetting shapes in two different soil textures through the system of United States Department of Agriculture, USDA, namely as loam and silt soils.  The system is designed for three diameters of 6, 7, and 8 cm installed at 15, 20, and 25 cm below the soil surface under three application heads of 25, 50, and 75 cm.  Horizontal and vertical advance of the wetting front shapes in loam are greater than silt soil.  The numerical values of horizontal and vertical advance are compared with those of predicted by the formulas, showing that average relative error values not more than 2 %.  This indicated that the formulas may be used as a tool for designing and investigating the subsurface horizontal porous pipe irrigation system.  

2004 ◽  
Vol 50 (2) ◽  
pp. 61-68 ◽  
Author(s):  
C. Choi ◽  
I. Song ◽  
S. Stine ◽  
J. Pimentel ◽  
C. Gerba

Two different irrigation systems, subsurface drip irrigation and furrow irrigation, are tested to investigate the level of viral contamination and survival when tertiary effluent is used in arid and semi-arid regions. The effluent was injected with bacteriophages of PRD1 and MS2. A greater number of PRD1 and MS2 were recovered from the lettuce in the subsurface drip-irrigated plots as compared to those in the furrow-irrigated plots. Shallow drip tape installation and preferential water paths through cracks on the soil surface appeared to be the main causes of high viral contamination in subsurface drip irrigation plots, which led to the direct contact of the lettuce stems with the irrigation water which penetrated the soil surface. The water use efficiency of the subsurface drip irrigation system was higher than that of the furrow irrigation system. Thus, subsurface drip irrigation is an efficient irrigation method for vegetable crops in arid and semi-arid regions if viral contamination can be reduced. Deeper installation of drip tapes, frequent irrigations, and timely harvests based on cumulative heat units may further reduce health risks by ensuring viral die-off under various field conditions.


2020 ◽  
Vol 31 (3) ◽  
pp. 113-114
Author(s):  
Nelson Laville ◽  
Kenrick Witty ◽  
Ulises Garcia

The Beyond Compliance Global team held an interview by video link with Dr Eric Jang, United States Department of Agriculture, Agricultural Research Service (USDA/ARS), now retired. His lab was based in Hawaii, where he continues to reside. Eric was an early advocate and one of the originators of the concepts for Systems Approach.


1971 ◽  
Vol 2 (2) ◽  
pp. 79-92 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
H. C. ASLYNG

The lysimeter installation described comprises 36 concrete tanks each with a soil surface of 4 m2. The installation is useful for plant growth experiments under natural conditions involving different treatment combined with various controlled water supplies. The ground installation is at least 20 cm below the soil surface and tillage can be done with field implements. The lysimeter tanks are provided with a drainage system which can drain the soil at the bottom (100 cm depth) to a tension of up to 100 cm. A constant ground-water table at less than 100 cm soil depth can also be maintained. The soil moisture content at different depths is determined from an underground tunnel by use of gamma radiation equipment in metal tubes horizontally installed in the soil. Rainfall is prevented by a movable glass roof automatically operated and controlled by a special rain sensor. Water is applied to the soil surface with a special trickle irrigation system consisting of a set of plastic tubes for each lysimeter tank and controlled from the tunnel. Fertilizers in controlled amount can be applied with the irrigation water.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 65-68
Author(s):  
Michelle Miller

The following case study addresses the difficulties and promise of developing a statewide interagency public information campaign to raise general awareness of water quality issues and governmental programs to address them. Due to only moderate success of voluntary programs to curb nonpoint source pollution, agencies are looking toward information and education programs to motivate the public toward conservation behavior. One of the biggest obstacles in developing an effective information/education program is institutional barriers to interagency cooperation, mirroring difficulties local conservationists encounter in their work to restore and maintain water quality at the watershed level. Cooperation between federal agencies, and resource commitment to public information is necessary at the federal level, as well as state and local levels. Agencies involved to date include the United States Department of Agriculture-Soil Conservation Service; Wisconsin State Departments of Natural Resources, and Agriculture, Trade and Consumer Protection and Administration; University of Wisconsin-Extension; Wisconsin Land Conservation Association.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Brittany L Schappach ◽  
Rayda K Krell ◽  
Victoria L Hornbostel ◽  
Neeta P Connally

Abstract The Asian longhorned tick (ALT), Haemaphysalis longicornis Neumann (Acari: Ixodidae), is a three-host tick that was first detected outside of United States Department of Agriculture (USDA) quarantine in Hunterdon County, New Jersey, in 2017 and subsequently found in another 14 states. In its native Asia, and where it has become established in Australia and New Zealand, ALTs feed on a variety of hosts and are economically important livestock pests and competent vectors of multiple pathogens to humans and other animals. The degree to which ALT will become a persistent livestock pest or competent vector for introduced or existing pathogens in the United States is yet unclear. Because of its vast host availability, ability to reproduce asexually, known vector competence, and the presence of multiple life stages on hosts, the expansion of ALT establishment in the United States is expected, and is a significant public health and veterinary concern. In this paper, we discuss the biology, geographical distribution, life cycle and seasonal activity, reproduction, identification, medical and veterinary implications, management options, and future concerns in the United States.


1958 ◽  
Vol 90 (7) ◽  
pp. 439-440 ◽  
Author(s):  
A. M. Harper

Normally the sugar-beet root aphid, Pemphigus betae Doane, lives and feeds on sugar-beet roots below ground during the summer and fall. However, in many beet fields between Lethbridge and Monarch, Alberta, in September, 1956, a large number of these aphids were found on the soil surface and on the crowns and leaves of the plants. Many of the aphids had crawled up the plants and, even after death, remained clinging to the leaves (Fig. 1). This clinging reaction seemed similar to that of grasshoppers infected with Entomophthora grylli Fresen. Mr. R. B. Baird, Entomology Laboratory, Canada Department of Agriculture, Belleville, Ontario, identified the organism causing the disease destroying these aphids as Entomophthora aphidis Hoffm. This is the first record of this disease killing subterranean aphids in Canada. The only other reports of E. aphidis on root aphids are those of Maxson (1916) in Colorado and Charles (1941) in California. In Canada, it has been previously reported as a factor in control of the pea aphid, Acyrthosiphon pisum (Harr.), in the Annapolis Valley, Nova Scotia (MacLeod, 1953).


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