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Effective monitoring of chemical transport through the soil profile requires accurate and appropriate instrumentation to measure drainage water fluxes below the root zone of cropping systems. The objectives of this study were to methodically describe in detail the construction and installation of a novel automated PCAP (passive capillary) lysimeter...
Contexts in source publication
Context 1
... aid in the installation of the PCAP lysimeter, a tool was created that both served to keep debris out and allow the pipe assembly to be inserted into the soil with a minimum of disturbance ( fig. 2). The cylindrical shape lent itself to using a modified post-hole digger with an auger bit just slightly larger than the PCAP. Some means to maintain control of the pipe assembly when lowering it into the hole was required, as well as hold it while it was leveled and soil was backfilled around it. Usually the assembly would make several ...
Context 2
... diameter to which a wooden ring with an inside diameter slightly larger than the outside diameter of the pipe is attached. This assembly serves as a lid with a lip on it. The tool obtains its holding power from a wedge of HDPE spreading two half circles of 3.8 cm (1½ in.) thick wood until they bind forcefully against the inner wall of the pipe ( fig. 2). One of these half circles is bolted to the OSB, the other is free to move radially outward 1 cm. Two long screws hold the movable piece aligned with the stationary one and only allow it to move radially but not laterally. The long screws are inserted through holes in the stationary piece that are slightly larger than the screws so ...
Citations
... Therefore, researchers have been diligently developing better management practices that reduce agrochemical leaching into groundwater; hence, identification and quantifying of agrochemicals in drained water assists in evaluating the effectiveness of farming management practices. One device researchers often use to estimate amounts of drainage and nitrate leaching losses is the lysimeter that is used to collect and measure excess drainage amounts percolated through the soil profile, below the rootzone and eventually to the groundwater (Jabro et al., 2016;2017). ...
... Sixteen automated passive capillary lysimeters (PCAPs) with outside dimensions of 35.68 cm in diameter and 75 cm in height (1000 cm 2 surface area) were constructed and placed 90 cm below the soil surface in a Lihen sandy loam. This wireless assembly for the lysimeter incorporated radio sensing technology to enable an automated datalogger to transmit drainage water amounts simultaneously every 15 min to a remote host (Jabro et al., 2017). Each lysimeter consists of a piece of underground irrigation pipe that has a cap glued on the bottom end and a top plate with an 0.1 m 2 area made of thick high density polyethylene. ...
... Distribution of 16 installed lysimeters in the field, including contour elevation (m) and cropping pattern is illustrated in figure 1. More details regarding construction, operation, installation and efficacy of PCAP lysimeters and wireless data monitoring design are provided in Jabro et al. (2017). Two watermark soil moisture and two temperature sensors (Irrometer Company, Riverside, Calif., www.irrometer.com) ...
High levels of nitrate-nitrogen (NO 3 -N) in the nation’s groundwater are a significant environmental concern. To date no studies have yet evaluated the effects of various tillage practices on percolated drainage and NO 3 -N fluxes below the rootzone of cropping systems in the northern Great Plains. A field study was conducted to examine and compare the effect of no-tillage (NT) and conventional tillage (CT) practices on seasonal drainage fluxes and NO 3 -N leaching losses below the rootzone in irrigated corn ( L.) and soybean ( L.) on a Lihen sandy loam soil. Sixteen passive capillary lysimeters, PCAPs (75 cm long polyvinyl chloride pipe with a collecting surface area of 0.1 m ² ) were placed 90 cm below the soil surface to quantify percolated drainage water below the rootzone of corn-soybean rotation under NT and CT practices. The study was designed as a randomized complete block with four replications. Drainage and NO 3 -N fluxes were not significantly affected by the tillage in 2014, 2015, 2016, and 2017 due to substantial spatial variations among lysimeters within each treatment. Average cumulative seasonal drainage depths across 4 years were 22.26 and 34.46 mm for corn and 24.95 and 28.16 mm for soybean under NT and CT, respectively. Averaged 4-yr cumulative NO 3 -N losses were 17.61 and 26.74 kg ha ⁻¹ for corn and 25.47 and 23.56 kg ha ⁻¹ for soybean under NT and CT, respectively. Flow-weighted NO 3 -N concentrations over 4 years were 57.9 and 65.7 mg L ⁻¹ for corn while those for soybean were 74.8 and 67.0 mg L ⁻¹ under NT and CT, respectively. Nitrate-nitrogen concentrations generally exceed the safe drinking water standard of 10 mg L ⁻¹ . Reducing N inputs in well-drained soils and using site specific N and irrigation management practices are required to lower input expenses, reduce N leaching losses and sustain environmental quality. Keywords: Drainage, Fluxes, Leaching, Lysimeter, Nitrate-nitrogen, Rootzone, Tillage.
... Skaggs (2017) proposed three key coefficients to quantify and compare hydraulics of drainage systems across sites, soils, and geographic locations: steady subsurface drainage rate, drainage intensity, and drainage coefficient. Jabro et al. (2017) demonstrated that a new automated passive capillary lysimeter accurately monitored real-time drainage water fluxes in the vadose zone over the four-year study period. ...
This article highlights current research into land and water resources, agroecosystems, and agricultural production systems published by the Natural Resources and Environmental Systems (NRES) community of ASABE journals (Transactions of the ASABE and Applied Engineering in Agriculture) in 2017. Context, scope, and key results of the published articles are reviewed and perhaps more importantly areas for increased research attention are recommended. This article describes experimental and modeling advances in hydrology, agroecosystems, climate change effects, soil erosion, agricultural irrigation, agricultural drainage, forest resource management, livestock systems, natural treatment systems, international water issues, and water quality topic areas. Three special collections were published (International Watershed Technology, Crop Modeling and Decision Support for Optimizing Use of Limited Water, and Advances in Drainage). Other focal areas included 14 articles relating to livestock waste management, 13 concerning irrigated agricultural systems, 8 addressing climate change effects on land, water, and agroecosystems, and 16 on various aspects of soil erosion measurement and modeling. Building on the articles reviewed from 2017 and toward a vision of future agroecosystems research, the NRES community of ASABE journals strives to expand its role in making new knowledge accessible to sustain agricultural and natural systems in a changing world. With this goal in mind, recommendations for future research needs are proposed with an emphasis on increased application of remote sensing data to agroecosystems research, improved assessment of agroecosystem resiliency and vulnerability to land and climate change, development of integrated models of agroecosystem services, meeting stubborn water management challenges in agricultural production systems, and focusing on publishing fully reproducible model results. © 2018 American Society of Agricultural and Biological Engineers.
