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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Irrigation requirements for alfalfa in the Nicola Valley

Willcocks, Timothy John January 1970 (has links)
The Nicola Valley, in the dry interior of British Columbia, is an important cattle ranching area. Alfalfa and grass hay are grown to provide winter feed for the cattle, but due to the low annual precipitation (9.5 ins. at Merritt) and high rate of evapotranspiration, irrigation is necessary. Of the licenced water supply, 95 percent is licensed to agricultural use. In this study, which is of the reconnaissance type, current irrigation practices within the area are described, and on the basis of available data and some field measurements, a method is developed from which irrigation and drainage requirements are determined for several typical locations. Seasonal evapotranspiration was estimated from readings obtained from an Ogopogo carborundum block evaporimeter, and for Merritt, Douglas Lake, and Quilchena, seasonal requirements were found to be 26, 19, and 24 acre ins./acre respectively. The leaching or drainage requirement was found to be low in the Nicola Valley. A local maximum value of 8.3 percent was found, but drainage water not exceeding one percent of consumptive use was estimated for an average season. It was considered advisable to add gypsum to irrigation waters in certain cases to prevent sodium alkali soils from developing; the more usual tests indicating sodium hazard gave unsatisfactory results. The concept of efficiency of water use requires some careful definition: it is pointed out that present definitions of water efficiency can be misleading. Conveyance efficiencies were found to be highly variable with seepage values of 8 percent to 96 percent per mile; efficiency of distribution of irrigation water within a field was taken from comparative data. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
2

Oorsaaipraktyke en vestiging van eenjarige raaigras in lusernweiding

Badenhorst, Daniël January 2011 (has links)
Die Eden- en Overbergdistrik in die Suid-Kaap vorm die mees suidelike substreke van die winterreëngebied. Dit is geleë tussen 33° 45‟ en 34° 50‟ suiderbreedte en tussen 19° 0‟ en 23° 45‟ oosterlengte. Die westelike grens van die substreek word gevorm deur die Villiersdorp-Botrivier-gebied. Aan die noordekant word die substreek begrens deur die Sonderend-, Lange- en Outeniquabergreekse. Die oostelike grens word gevorm deur die Bloukransrivier. Die Indiese Oseaankuslyn vanaf Nature‟s Valley in die ooste tot by Kleinmond in die weste vorm die suidelike grens. In die Suidkusstreek word 54.5% van die Wes-Kaapse melkproduksie en 24% van Suid-Afrika se melkproduksie deur 1900 melkprodusente geproduseer (Dowrey 2005). Ses en dertig persent van die bruto jaarlikse veeproduk is afkomstig vanaf suiwelprodukte wat hoofsaaklik vanaf aangeplante weiding geproduseer word. Aangeplante weiding beslaan 37.7% van die totale oppervlakte van die vee- en saaigebiede van die Suidkusstreek (Botha 2003). Weens beperkte, skaars besproeiingswater in groot dele van die Suid-Kaap, word heelwat weiding slegs aanvullend besproei (Protopapas 2004). Voervloeiprogramme vir melkproduksie onder aanvullende besproeiing bestaan hoofsaaklik uit kikoejoe (Pennisetum clandestinum) en lusern (Medicago sativa) (Botha 2003). Die droëmateriaalproduksie en weikapasiteit van lusern volg, soos kikoejoe, „n baie sterk seisoenale tendens met „n piek in die somer / herfs en „n laagtepunt in die winter (Durand 1993; Botha 1998; Botha 2003). Voervloeiprogramme met lusern of kikoejoe as hoofkomponente het gewoonlik voertekorte gedurende die winter tot gevolg. Hoofsaaklik om dié rede het boere uit die lusernproduserende gebiede van Heidelberg, Riversdal, Herbertsdale en Mosselbaai, deur hul onderskeie boereverenigings, „n versoek aan Outeniqua Navorsingsplaas gerig om ondersoek in te stel na moontlike oorsaaipraktyke wat die droëmateriaalproduksie van lusernstelsels gedurende die winter kan verhoog. Kikoejoeweiding word reeds die afgelope aantal jare suksesvol met Westerworldsraaigrasse oorgesaai vir beter herfs-, winter- en lenteproduksie. Anders as by kikoejoeweidings bestaan daar huidiglik geen beproefde oorsaaipraktyke wat die produksiepotensiaal van lusern in die winter en vroeë lente kan verhoog nie (Anoniem 2002).
3

The economic feasibility of pipeline water conveyance for alfalfa production in the state of Nevada /

Swainston, Rolf K. January 2006 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 86-87). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.
4

Growth, canopy temperature, and spectral reflectance of alfalfa under different irrigation treatments

Johnson, David Ernest, Jr January 2011 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
5

Water use, yield, and water use efficiency of differentially irrigated alfalfa

Matulka, Matthew Neil. January 1985 (has links)
Call number: LD2668 .T4 1985 M378 / Master of Science
6

Alfalfa water-production functions under conditions of deficit irrigation with saline water

Pennington, Karrie Sellers,1949- January 1986 (has links)
This experiment was designed to determine the shape of the yield response function relating crop yield to total amount of saline irrigation water applied. Such a function contains a built-in leaching fraction that is the inevitable consequence of the inability of the plant to extract 100 % of the water from a saline soil. In order to define the production function and to determine the leaching fractions, alfalfa (Medicago sativa L. cv. 'Mesa Sirsa') was planted in soil columns in a greenhouse. Two experiments were run sequentially. These were irrigated with water of differing salinities. The first with an EC of 4 dS/m (1.4 bars) and the second with an EC of 8 dS/m (2.9 bars). Both solutions were prepared by adding equivalent amounts of sodium chloride and calcium chloride to distilled water. The treatment variables were amounts of irrigation water applied. The amounts in both experiments were 110%, 100%, 75%, 50% and 25% of the measured evapotranspiration (ET). Four crop harvests were made in each experiment. At the end of experiment 1, (approximately 120 days), one column from each treatment was destructively sampled for soil salinity and water content measurements. The remaining columns were similarly sampled at the end of experiment 2 (approximately 120 days). The crop-saline water production functions for both experiments were linear. Leaching fractions in experiment 1 were 9, 9, 6, 5 and 5% for treatments 1-5 respectively. Experiment 2 leaching fractions for treatments 1-5 respectively were 23, 25, 18, 15 and 17%. The lowest rootzone soil water osmotic potentials achieved by the end of experiment 1 for treatments 1-5 were -19, -20, -18, -26 and -24 bars. Corresponding treatment values achieved by the end of experiment 2 were -18, -22, -28, -31 and -45 bars.
7

Suboptimal Irrigation Strategies for Alfalfa in the Lower Colorado Region, 2009

Ottman, Michael J. 09 1900 (has links)
Alfalfa has the highest water requirement of any crop grown in Arizona, and any strategies that conserve water growing this crop could have a large impact on water availability in the state. The purpose of this study is to determine yield and profitability of sub-optimal irrigation strategies in alfalfa. An irrigation study was conducted at the University of Arizona Maricopa Agricultural Center on a sandy clay loam soil. The following irrigation treatments are included in this study: 1) One irrigation per cutting, 2) Two irrigations per cutting, 3) Summer (August) irrigation termination, 4) Winter (December, January, February) irrigation termination, and 5) Summer and Winter irrigation termination. The Winter irrigation termination treatments were initiated in December 2009 and data is not available yet for these treatments. The amount of water applied from January through November 2009 was 69.7 inches (one irrigation per cut), 80.5 inches (two irrigations per cut), and 78.6 (Summer irrigation termination). The annual hay yields were 12.5 tons/acre (one irrigation per cut), 13.7 tons/acre (two irrigations per cut), and 12.9 tons/acre (Summer irrigation termination). Sub-optimal irrigation increased the forage quality by decreasing fiber (ADF and NDF) and increasing protein content. Sub-optimal irrigation did not reduce stand density. The water use efficiency of applied water (plus rainfall) was not affected by irrigation treatment.
8

The Use and Duty of Water in the Salt River Valley

Marr, James C., Smith, G. E. P. 01 July 1927 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project. / Preface by G. E. P. Smith

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