Agricultural Research at the Central Substation, Highmore, South Dakota: A Progress Report

Central Substation has been serving central South Dakota for over 50 years. It was established in 1901 on land deeded to the state by Mr. and Mrs. Frank Drew in 1899. There are 117.15 acres, and the location is immediately northwest of Highmore on Highway 14. For many years the research was conducted under the watchful eye of the late Steve Sussex. He served as superintendent from 1908 to 1948. After Mr. Sussex retired, he and Mrs. Sussex continued to live at the substation. I became superintendent in 1950 and found his counsel very helpful in carrying on the research activities. Gerald Keehn had served as superintendent from 1948 to 1950. Much has been accomplished at the station since the original one-tenth-acre plots were laid out permanently in 1908. In July 1932, crop yields over a 19-year period were summarized in Experiment Station bulletin 272. Four types of crop rotations were started in 1912 and have been continued ever since. The fruits of these trials are perhaps just being realized. That is the great value of your experiment stations. They formulate recommendations from results obtained over 5 or 10 or even 40 years or more of research-not just a year or two. Extreme care must be taken to avoid errors in our results. That is why we use long-time research results and repeat each trial a number of times and at various locations. Highly trained scientists of the State Experiment Station staff help us conduct the research. We find that people of this area have a friendly feeling toward the substation and its activities. Results of the research have been brought to their attention through field days and reports in newspapers and publications. When Mr. Drew donated the Janel for the substation he said that knowledge secured from this land would serve as a basis for farming. We should keep his foresight in mind

Soils of Clay County South Dakota

The Clay County soil survey is an inventory of the soil resources found in that area. It is designed to help answer questions such as: What soil types do I have on my farm? Do different soil types need different management practices? If so, what are the suggested practices? Are certain crops better adapted to different soil types? Do soil types have different yield potentials? Published soil surveys are made up of two parts: a map and a report. The Clay County soil map, bound in the middle of the report, shows the location and extent of the various soils in the county. Descriptions of each of the soils shown on the map and the suggested management practices for each are given in the report. Tables are included which list estimated yields of principal crops for each soil, the general agricultural rating for each soil, specific management recommendations, and suitability for irrigation

Evaluation of HCMM data for assessing soil moisture and water table depth

Soil moisture in the 0-cm to 4-cm layer could be estimated with 1-mm soil temperatures throughout the growing season of a rainfed barley crop in eastern South Dakota. Empirical equations were developed to reduce the effect of canopy cover when radiometrically estimating the soil temperature. Corrective equations were applied to an aircraft simulation of HCMM data for a diversity of crop types and land cover conditions to estimate the soil moisture. The average difference between observed and measured soil moisture was 1.6% of field capacity. Shallow alluvial aquifers were located with HCMM predawn data. After correcting the data for vegetation differences, equations were developed for predicting water table depths within the aquifer. A finite difference code simulating soil moisture and soil temperature shows that soils with different moisture profiles differed in soil temperatures in a well defined functional manner. A significant surface thermal anomaly was found to be associated with shallow water tables

Evaluation of HCMM data for assessing soil moisture and water table depth

Data were analyzed for variations in eastern South Dakota. Soil moisture in the 0-4 cm layer could be estimated with 1-mm soil temperatures throughout the growing season of a rainfed barley crop (% cover ranging from 30% to 90%) with an r squared = 0.81. Empirical equations were developed to reduce the effect of canopy cover when radiometrically estimating the 1-mm soil temperature, r squared = 0.88. The corrective equations were applied to an aircraft simulation of HCMM data for a diversity of crop types and land cover conditions to estimate the 0-4 cm soil moisture. The average difference between observed and measured soil moisture was 1.6% of field capacity. HCMM data were used to estimate the soil moisture for four dates with an r squared = 0.55 after correction for crop conditions. Location of shallow alluvial aquifers could be accomplished with HCMM predawn data. After correction of HCMM day data for vegetation differences, equations were developed for predicting water table depths within the aquifer (r=0.8)

The Homogeneity of Interstellar Oxygen in the Galactic Disk

We present an analysis of high resolution HST Space Telescope Imaging Spectrograph (STIS) observations of O I 1356 and H I Lyman-alpha absorption in 36 sight lines that probe a variety of Galactic disk environments and include paths that range over nearly 4 orders of magnitude in f(H_2), over 2 orders of magnitude in mean sight line density, and that extend up to 6.5 kpc in length. Consequently, we have undertaken the study of gas-phase O/H abundance ratio homogeneity using the current sample and previously published Goddard High-Resolution Spectrograph (GHRS) results. Two distinct trends are identified in the 56 sight line sample: an apparent decrease in gas-phase oxygen abundance with increasing mean sight line density and a gap between the mean O/H ratio for sight lines shorter and longer than about 800 pc. The first effect is a smooth transition between two depletion levels associated with large mean density intervals; it is centered near a density of 1.5 cm^-3 and is similar to trends evident in gas-phase abundances of other elements. Paths less dense than the central value exhibit a mean O/H ratio of log_10 (O/H) = -3.41+/-0.01 (or 390+/-10 ppm), which is consistent with averages determined for several long, low-density paths observed by STIS (Andre et al. 2003) and short low-density paths observed by FUSE (Moos et al. 2002). Sight lines of higher mean density exhibit an average O/H value of log_10 (O/H) = -3.55+/-0.02 (284+/-12 ppm). The datapoints for low-density paths are scattered more widely than those for denser sight lines, due to O/H ratios for paths shorter than 800 pc that are generally about 0.10 dex lower than the values for longer ones.Comment: 33 pages, including 8 figures and 4 tables; accepted for publication in ApJ, tentatively in Oct 200

OB Stars in the Solar Neighborhood I: Analysis of their Spatial Distribution

We present a newly-developed, three-dimensional spatial classification method, designed to analyze the spatial distribution of early type stars within the 1 kpc sphere around the Sun. We propose a distribution model formed by two intersecting disks -the Gould Belt (GB) and the Local Galactic Disk (LGD)- defined by their fundamental geometric parameters. Then, using a sample of about 550 stars of spectral types earlier than B6 and luminosity classes between III and V, with precise photometric distances of less than 1 kpc, we estimate for some spectral groups the parameters of our model, as well as single membership probabilities of GB and LGD stars, thus drawing a picture of the spatial distribution of young stars in the vicinity of the Sun.Comment: 28 pages including 9 Postscript figures, one of them in color. Accepted for publication in The Astronomical Journal, 30 January 200

Reconnaissance Soil Survey of Potter County

Potter County covers an area of 568,320 acres in north central South Dakota. The topography is gently sloping in the central part with a belt of hilly land along the east border and the steep, dissected bluffs of the Missouri River trench along the west border of the county. Elevations above sea level range from 1,900 to 2,000 feet on the upland to 1,600 feet on the Missouri River flood plain. Materials from which the soils have developed include glacial deposits which occur in all parts of the county except on the Missouri River bluff where shale is exposed. Soils of the county have been classified into 35 mapping units, each of which is described with regard to composition, distribution, and agricultural use. Principal problems of management are discussed and estimated yields of important crops are given for each soil, along with its potential irrigability

Soils Survey of Spink County South Dakota

This soil survey report with its accompanying map presents information about the soils, crops, and agriculture of Spink County. It also deals briefly with such related topics as topography and cultural features. This soil survey is designed to meet the needs of a wide variety of readers. The following paragraphs indicate the sections of interest to persons concerned with specific tracts of land, to those concerned with the county as a whole, and to students and teachers of soil science and related agricultural subjects

Adiabatic decaying vacuum model for the universe

We study a model that the entropy per particle in the universe is constant. The sources for the entropy are the particle creation and a lambda decaying term. We find exact solutions for the Einstein field equations and show the compatibilty of the model with respect to the age and the acceleration of the universe.Comment: 10 pages, 2 figure