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<br />W <br />.:J1 <br />~.. <br />N <br /> <br />-- <br /> <br />moistpre, and salinity regimes on cropped and noncropped <br />conditions. Data applied to the WATEQF water equilibrium <br />model: showed that soil solutions at all profiles were super- <br />saturated with calcite. <br /> <br />Fifte~n subsurface drains on 23 acres of irrigated agri- <br />cultural land established by Nevada Agricultural Experiment <br />Stati~n scientists in salinity research at Fallon, Nevada, <br />were Sampled in 27 consecutive weeks. The time period and <br />spaci*g variabilities of electrical conductivity (EC), tem- <br />perat~re, pH, dissolved oxygen (DO), and nitrate nitrogen <br />(N03-~) were evaluated using time series and geostatistical <br />analyses. Optimum spacings for subsurface drains were com~ <br />paredJwith the resulting information. Models were <br />established that can be used for forecasting future tem- <br />poralJand spatial values and for determining the transfer <br />functton to provide a way to relate water management plans <br />with water quality control. <br /> <br />An improved experimental setup is in use at the University <br />of California-Davis to study dissolution kinetics of car- <br />bonate minerals in aqueous systems. Dissolution studies <br />were qarried out on a CaC03 mineral to determine the <br />influence of different surface areas. The same experimental <br />setup,was used to study the dissolution kinetics of gypsum <br />and pijosphogypsum. Understanding dissolution chemistry of <br />miner~ls will help develop practices to minimize contribu- <br />tionsto salinity in Basin streams. <br /> <br />Monitdrinq and Evaluation <br /> <br />Monitqring and evaluation (M&E) of the accomplishments of <br />USDA actions in salinity control has a threefold objective, <br />First land most important is to develop information about <br />actua] (rather than planned) on farm effects that have <br />occurl\ed in the area. This information will enable farmers <br />to ma~e informed choices about voluntary implementation of <br />salinuty control practices. The information includes cost <br />of pr~ctices, changes in water use, labor use, and other <br />farm ~nputs, and finally, observed changes in crop yield and <br />potentiial changes in net farm income. The second purpose is <br />to en~ble SCS to confirm or correct the data used to plan <br />salini~y control projects to do a more reliable jOb of <br />planning other projects. The final purpose is to collect <br />data tb be used to evaluate the overall effectiveness and <br />effici~ncy of USDA salinity control activities from a <br />program standpoint. <br /> <br />Althou~h continuing to be hampered by shortage of staff and <br />fundins, SCS M&E activities have moved ahead sharply during <br /> <br />39 <br /> <br />.. <br /> <br /> <br />:t <br /> <br /> <br /> .'1 <br /> ":r <br /> J <br /> :t <br /> , <br /> 1 <br /> , <br /> , <br /> '.:1 <br /> ,~': <br /> !i <br /> ~ <br /> ',~ <br /> 'iJ <br /> .;1 <br /> ~ <br /> J <br />, J <br /> & <br /> I <br /> 1 <br /> <br />'1 <br /> <br />, <br />, <br />, <br /> <br />