@article {JRN55306,
	title = {Comparative analysis of water budgets across the U.S. long-term agroecosystem research network},
	journal = {Journal of Hydrology},
	volume = {588},
	year = {2020},
	month = {05/04/2020},
	abstract = {Understanding the movement and storage of water within agricultural landscapes as functions of management and climate is essential for more efficient and sustainable water use. However, knowledge of water storage and fluxes on U.S. agricultural lands is largely incomplete. The Long-Term Agroecosystem Research (LTAR) network provides a unique and geographically diverse set of agricultural study sites in the United States. The objectives of this study were to: 1) characterize the hydrologic variability across the LTAR network; 2) identify data gaps in the water budgets across the LTAR network; and 3) identify opportunities to leverage the LTAR network to improve understanding of water budgets across agricultural landscapes. For each of the 18 LTAR sites, we developed water budgets on an average annual basis. Uncertainties for each component were based on the quantification method and the length of the data sets. Uncertainty propagation methods combined these uncertainties and the unquantified components to calculate an overall water budget uncertainty. Datasets length ranged from three to 50 years, depending on the component and the site. The network covers a range of precipitation from 240 to 1400 mm yr-1, evapotranspiration from 228 to 1080 mm yr-1, and surface runoff and subsurface flow from negligible to 1500 mm yr-1. However, uncertainties of where all the water is going remained high, in part because soil water storage and downward movement of water were often neglected or measured for very short periods, resulting in average water budget uncertainty of 25\% of the water inputs. More accurate measurement of the major inputs and outputs, and direct measurement of water content and percolation are keys to understanding how agricultural lands affect terrestrial water budgets.},
	keywords = {evapotranspiration, hydrologic characterization, irrigation, percolation, precipitaiton, soil water storage, subsurface outflows, surface outflows, water budget},
	doi = {10.1016/j.jhydrol.2020.125021},
	url = {files/bibliography/20-040.pdf},
	author = {Claire Baffaut and J. M. Baker and Joel A. Biederman and David D. Bosch and Erin S. Brooks and Anthony R. Buda and Eleonora M. Demariac and Emile H. Elias and Gerald N. Flerchinger and David C. Goodrich and Stephen K. Hamilton and Stuart P. Hardegree and R. Daren Harmel and David L. Hoover and K.W. King and Peter J. A. Kleinman}
}
@article {JRN54576,
	title = {Few multiyear precipitation{\textendash}reduction experiments find a shift in the productivity{\textendash}precipitation relationship},
	journal = {Global Change Biology},
	volume = {22},
	year = {2016},
	pages = {2570-2581},
	abstract = {<p class="rtejustify">Well-defined productivity{\textendash}precipitation relationships of ecosystems are needed as benchmarks for the validation of land models used for future projections. The productivity{\textendash}precipitation relationship may be studied in two ways: the spatial approach relates differences in productivity to those in precipitation among sites along a precipitation gradient (the spatial fit, with a steeper slope); the temporal approach relates interannual productivity changes to variation in precipitation within sites (the temporal fits, with flatter slopes). Precipitation{\textendash}reduction experiments in natural ecosystems represent a complement to the fits, because they can reduce precipitation below the natural range and are thus well suited to study potential effects of climate drying. Here, we analyse the effects of dry treatments in eleven multiyear precipitation{\textendash}manipulation experiments, focusing on changes in the temporal fit. We expected that structural changes in the dry treatments would occur in some experiments, thereby reducing the intercept of the temporal fit and displacing the productivity{\textendash}precipitation relationship downward the spatial fit. The majority of experiments (72\%) showed that dry treatments did not alter the temporal fit. This implies that current temporal fits are to be preferred over the spatial fit to benchmark land-model projections of productivity under future climate within the precipitation ranges covered by the experiments. Moreover, in two experiments, the intercept of the temporal fit unexpectedly increased due to mechanisms that reduced either water loss or nutrient loss. The expected decrease of the intercept was observed in only one experiment, and only when distinguishing between the late and the early phases of the experiment. This implies that we currently do not know at which precipitation{\textendash}reduction level or at which experimental duration structural changes will start to alter ecosystem productivity. Our study highlights the need for experiments with multiple, including more extreme, dry treatments, to identify the precipitation boundaries within which the current temporal fits remain valid.</p>
},
	keywords = {aboveground productivity, ANPP, drought, precipitaiton, precipitation-reduction experiments, spatial fit, temporal fit},
	doi = {10.1111/gcb.13269},
	url = {files/bibliography/JRN54576.pdf},
	author = {Marc Estiarte and Sara Vicca and Josep Pe{\~n}uelas and Michael Bahn and Claus Beier and Bridget A. Emmett and Philip A. Fay and Paul J . Hanson and Roland Hasibeder and Jaime Kigel and G. Kroel-Dulay and Klaus Steenberg Larsen and Lellei -Kov{\'a}cs, Eszter and Jean-Marc Limousin and Ogaya, Rom{\`a} and Jean-Marc Ourcival and Sabine Reinsch and O. E. Sala and Inger Kappel Schmidt and Marcelo Sternberg and Tielb{\"o}rger, Katja and Albert Tietema and Ivan A. Janssens}
}
@proceedings {51882,
	title = {Field water regimes of sandy loam soils on arid rangelands of southern New Mexico},
	year = {1985},
	month = {1985},
	pages = {514-516},
	address = {Kyoto, Japan},
	abstract = {<p class="rtejustify">There is little information on field measurement of soil water on arid rangelands. Forage production is largely dependent upon adequate water. The soil water potential is characterized for three sandy loam soils during 1957-76 on arid rangelands of southwestern United States. Gypsum-impregnated resistance blocks were placed at soil depths of 10, 25, 41, 61, and 91 cm. The average annual precipitation during the study periods was 244, 265, and 233 mm. At the 10-cm soil depth, the probability of soil water >= -1.5 megapascals during December March was 66, 70, and 68\% at the three sites; during July-September, it was 40, 50, and 49\%, respectively. Factors affecting soil water were: 1) precipitation amount, 2) surface soil characteristics, 3) topography, 4) soil texture, and 5) vegetation type. This information is useful for modeling the range ecosystem.</p>
},
	keywords = {precipitaiton, probabilities, soil structure, soil water potential, vegetation},
	url = {/files/bibliography/280.pdf},
	author = {C.H. Herbel and Gibbens, Robert P.}
}
