Impact of controlled drainage on subsurface drain flow and nitrate load: A synthesis of studies across the U.S. Midwest and Southeast

Abstract. Controlled drainage combined with winter crops was investigated for the first time as a mitigation measure for reducing nitrate loss through drainage systems during a three-year period (2012–15) on a loamy soil in Denmark. The impact of controlled drainage on groundwater levels, drain flow, total nitrogen, nitrate, ammonium, nitrous oxide, total phosphorous, and phosphate when applying regulation levels of 50 and 70 cm above drain pipes were determined by using a before-after control-impact (BACI) study design. The regulation level had to be 70 cm to significantly elevate groundwater levels and reduce drain outflow and nitrate loss, which were reduced by 38–52 % (97–127 mm) and 36–48 % (6–8 kg nitrate-N ha−1) relative to conventional drainage levels, respectively. Controlled drainage did not appear to influence harvest yield or cause pollution swapping as the loss of total phosphorous, phosphate, and nitrous oxide was reduced by 44–45 %, 44–54 %, and 36–38 %, respectively. Stable isotope analysis of δ15N and δ18O in nitrate from drain water supported by measurements of nitrate, sulphate, and ammonium concentrations in drain water revealed that denitrification was not enhanced markedly at the impacted plots, except during one event where a pronounced decline in nitrate concentrations and ceased drain flow was observed.

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EFFECTS OF CONTROLLED DRAINAGE ON SOIL WATER REGIME AND QUALITY IN LITHUANIA

AGROFOR ◽

10.7251/agreng1901119r ◽

2019 ◽

Vol 4 (1) ◽

Author(s):

Aurelija RUDZIANSKAITĖ ◽

Stefanija MISEVIČIENĖ

Keyword(s):

Sandy Loam ◽

Moisture Regime ◽

Controlled Drainage ◽

Nitrogen And Phosphorus ◽

Soil Water Regime ◽

Tile Drains ◽

Drain Flow ◽

Nitrogen Concentrations ◽

The Baltic ◽

Water Drain

Lithuania remains one of the most extensively drained of the Baltic and Nordiccountries. The overall drained area (ditches plus tile drains) totalled 87% of theagricultural land area. Many nutrients from soil are leached through drainageresulting in polluting streams (drain flow receivers) water. Drain flow is treated asa major determinant of water quality. Therefore, the reduction of nutrients enteringthe drains is very important. Controlled drainage conception, when the outflowheight is increased at the mouth, helps reduce drainage runoff and partially purifywater. The aim of the research was to establish controlled drainage influence on thesoil moisture regime, nitrogen and phosphorus leaching. Investigations werecarried out in sandy loam and loam soils in the Middle Lithuanian Lowland. Basedon studies, several tendencies were observed: when drainage outflow began, theamount of soil moisture in subsoil (50-80 cm layer of the soil) of controlleddrainage plot was higher than in the conventional drainage plot, and highermoisture supplies stayed for a longer period of time. Controlled drainage had nodirect impact on phosphorus and nitrogen concentrations but they were influencedby the leaching quantities of plant usable nutrients. The reason that in many caseslower nitrate nitrogen (54% of all measurements) and phosphorus concentrations(77% of all measurements) were found in the conventional system rather than inthe controlled drainage might be connected to the fact that the latter area containedpredominantly lighter textured soils (sandy loam) making it easier to wash awaythe nutrients unused by plant.

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Making and Selling Cars: Innovation and Change in the U.S. Automotive Industry. By James M. Rubinstein. Baltimore and London: The Johns Hopkins University Press, 2001. Pp. ix, 401. $45.00.

The Journal of Economic History ◽

10.1017/s0022050703542358 ◽

2003 ◽

Vol 63 (3) ◽

pp. 910-913

Author(s):

ANTHONY PATRICK OBRIEN

Keyword(s):

Automotive Industry ◽

Johns Hopkins University ◽

Innovation And Change ◽

The U.S

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Historical Introduction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077670 ◽

1977 ◽

Vol 35 ◽

pp. 2-5

Author(s):

R. D. Heidenreich

Keyword(s):

Electron Emission ◽

Secondary Electron ◽

Secondary Electron Emission ◽

50Th Anniversary ◽

Secondary Emission ◽

Wave Nature ◽

Nobel Prize In Physics ◽

Primary Electrons ◽

The U.S ◽

Mutual Agreement

This program has been organized by the EMSA to commensurate the 50th anniversary of the experimental verification of the wave nature of the electron. Davisson and Germer in the U.S. and Thomson and Reid in Britian accomplished this at about the same time. Their findings were published in Nature in 1927 by mutual agreement since their independent efforts had led to the same conclusion at about the same time. In 1937 Davisson and Thomson shared the Nobel Prize in physics for demonstrating the wave nature of the electron deduced in 1924 by Louis de Broglie.The Davisson experiments (1921-1927) were concerned with the angular distribution of secondary electron emission from nickel surfaces produced by 150 volt primary electrons. The motivation was the effect of secondary emission on the characteristics of vacuum tubes but significant deviations from the results expected for a corpuscular electron led to a diffraction interpretation suggested by Elasser in 1925.

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Variations in Surface Textures of Quartz Sand using Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069466 ◽

1970 ◽

Vol 28 ◽

pp. 494-495

Author(s):

Eugene J. Amaral

Keyword(s):

Electron Microscopy ◽

Glass Industry ◽

Glass Slide ◽

Distilled Water ◽

Early Paleozoic ◽

Secondary Effects ◽

Surface Textures ◽

High Silica ◽

Sand Deposit ◽

The U.S

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.

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The Effects of Estradiol on Chronically Damaged Human Fallopian Tubes: A SEM Study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119934 ◽

1985 ◽

Vol 43 ◽

pp. 648-649

Author(s):

A. Toledo ◽

G. Stoelk ◽

M. Yussman ◽

R.P. Apkarian

Keyword(s):

Menstrual Cycle ◽

Epithelial Cell ◽

Secretory Cell ◽

Estrogen Therapy ◽

Fallopian Tubes ◽

Cell Surfaces ◽

Proliferative Phase ◽

Cyclic Patterns ◽

Sem Study ◽

The U.S

Today it is estimated that one of every three women in the U.S. will have problems achieving pregnancy. 20-30% of these women will have some form of oviductal problems as the etiology of their infertility. Chronically damaged oviducts present problems with loss of both ciliary and microvillar epithelial cell surfaces. Estradiol is known to influence cyclic patterns in secretory cell microvilli and tubal ciliogenesis, The purpose of this study was to assess whether estrogen therapy could stimulate ciliogenesis in chronically damaged human fallopian tubes.Tissues from large hydrosalpinges were obtained from six women undergoing tuboplastic repair while in the early proliferative phase of fheir menstrual cycle. In each case the damaged tissue was rinsed in heparinized Ringers-lactate and quartered.

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Antitrust: U.S. Supreme Court Affirms FTC Jurisdiction but Vacates Scope of Analysis on CDA Policy

The Journal of Law Medicine & Ethics ◽

10.1017/s1073110500012912 ◽

1999 ◽

Vol 27 (2) ◽

pp. 197-198

Author(s):

Joseph R. Zakhary

Keyword(s):

Public Relations ◽

Supreme Court ◽

Federal Trade Commission ◽

Ninth Circuit ◽

Court Of Appeals ◽

For Profit ◽

Rule Of Reason ◽

Antitrust Analysis ◽

Business Financing ◽

The U.S

In California Dental Association v. FTC, 119 S. Ct. 1604 (1999), the U.S. Supreme Court reviewed a decision by the U.S. Court of Appeals for the Ninth Circuit that a nonprofit affiliation of dentists violated section 5 of the Federal Trade Commission Act (FTCA), 15 U.S.C.A. § 45 (1998), which prohibits unfair competition. The Court examined two issues: (1) the Federal Trade Commission's (FTC) jurisdiction over the California Dental Association (CDA); and (2) the proper scope of antitrust analysis. The Court unanimously held that CDA was subject to FTC's jurisdiction, but split 5-4 in its finding that the district court's use of abbreviated rule-of-reason analysis was inappropriate.CDA is a voluntary, nonprofit association of local dental societies. It boasts approximately 19,000 members, who constitute roughly threequarters of the dentists practicing in California. Although a nonprofit, CDA includes for-profit subsidiaries that financially benefit CDA members. CDA gives its members access to insurance and business financing, and lobbies and litigates on their behalf. Members also benefit from CDA marketing and public relations campaigns.

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