Chapter 6 Tillage Effects on Soil Aeration A.E. Erickson, A.E. Erickson Crop and Soil Sciences Dep., Michigan State UniversitySearch for more papers by this author A.E. Erickson, A.E. Erickson Crop and Soil Sciences Dep., Michigan State UniversitySearch for more papers by this author Book Editor(s):P. W. Unger, P. W. UngerSearch for more papers by this authorD. M. Van Doren Jr., D. M. Van Doren Jr.Search for more papers by this authorF. D. Whisler, F. D. WhislerSearch for more papers by this authorE. L. Skidmore, E. L. SkidmoreSearch for more papers by this author First published: 01 January 1982 https://doi.org/10.2134/asaspecpub44.c6Book Series:ASA Special Publications AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat Summary Tillage can have a profound effect on the aeration conditions of soil depending on the initial condition of the soil and the subsequent rainfall. Of the aeration measurements available, oxygen diffusion rates best describe the soil-plant interactions. Because the aeration effects are transient, the measurements must be performed punctually during the period of aeration stress. Data from aeration studies can be very useful in describing the beneficial effects of tillage on plant growth and yield. Predicting Tillage Effects on Soil Physical Properties and Processes, Volume 44 RelatedInformation

Fabrication methods are discussed for the separate components comprising the INEEL designed Solid Oxide Fuel Cell. Primarily using plasma spray techniques, the ceramic electrode, electrolyte, and interconnect layers are deposited on a planar intermetallic bipolar plate. Combinations of dry powder, slurry suspension, and liquid injection plasma deposition techniques are used to deposit graded porosity electrode layers. A brief discussion about creating the necessary air channels, dense edge seals surrounding the electrode layers, and braze joints between completed cells is presented. All process parameters and methodologies used to deposit the graded porosity electrode layers, removable filler materials in the air channels, and fully dense seal coats on the bipolar plate are discussed.

A low CTE bipolar plate is fabricated from a NiAl intermetallic and a ceramic filler material. By using inert, ceramic filler materials the intermetallic reaction of the NiAl system is controlled resulting in net-shape formed plates with CTE comparable to the electrolyte and electrode ceramic layers. In addition, the combustion synthesis reaction moderated by the ceramic filler material creates significant porosity in the NiAl microstructure yielding a highly thermal shock resistant substrate material for the subsequent plasma deposited electrode and electrolyte layers. This paper outlines the powder metallurgy process parameters necessary to form these low CTE intermetallic plates.

Most turfgrass soil cultivation research has emphasized water infiltration and thatch responses, but has provided limited information regarding detailed soil and rooting responses to different cultivation methods. This study evaluated cultivation effects on soil physical properties and turf growth of a 'Penneagle' creeping bentgrass (Agrostis palustris Huds.) putting green. Cultivation, utilizing vertically operating hollow (HTC) or solid (STC) tines, was applied over a 3-yr period on a loamy sand soil (modified fine-loamy, mixed, mesic, Typic Hapludalfs). Cultivation treatments were applied on noncompacted and compacted plots, and at soil moisture potential ranges of -40 to -60 kPa (moist) or -2 to -4 kPa (wet). Saturated water conductivity and air porosity was 49 and 21% greater, respectively, with HTC than STC. After three seasons, wet soil cultivation reduced saturated hydraulic conductivity 31% compared to moist soil cultivation. Cultivation reduced penetration resistance 45% at the 5-cm depth compared to noncultivated plots in compacted soil, but the benefit was transient particularly on STC plots. Hollow tine cultivation under wet soil conditions yielded the best turf quality. Surface root weight density was lowered 20% with cultivation on compacted soil by the end of the study. Hollow tine cultivation lowered the organic matter fraction of the thatch/mat layer 0.24 kg kg-1, but increased total organic matter content 150 g m-2 compared to solid tine cultivation. Solid tine cultivation provided short term benefits, required repeated application to be effective in management of soil compaction, and exhibited the potential for development of a cultivation pan.

AbstractNormal fall and spring tillage practices create poor physical conditions for crop growth on lake plain soils in Michigan. Charity clay [fine, illitic (calcareous), mesic Aeric Haplaquept] (Mahjoory and Whiteside, 1976) is an example of such a soil. It has poor internal drainage due to its naturally dense subsoil and is susceptible to physical degradation because of its unstable surface. Tillage studies were conducted from 1983 to 1985 to evaluate the potential for reducing the physical limitations of Charity clay. Treatments consisted of four combinations of a primary and secondary tillage variable. The primary tillage variable involved the application or omission of deep tillage using a triple‐shanked subsoiler prior to moldboard plowing. The secondary tillage variable involved the presence or absence of tractor wheel traffic prior to planting. Subsoiling improved the physical conditions of Charity clay below the Ap horizon. Soil bulk density (ρb) was reduced by 0.05 Mg m−3, and pore size distribution (PSD) was altered such that the volume of pores with radii larger than 150 µm was doubled. Preplant wheel traffic caused subsoil compaction, increasing ρb by about 0.06 Mg m−3, and altered all indicators of soil compaction in the Ap horizon, especially PSD and saturated hydraulic conductivity. The need to minimize wheel traffic regardless of the primary tillage practices employed was evidenced by the results of this study.

The relationships between root exudation, root disease and anaerobic root stresses were investigated. Sand culture and mist chamber studies demonstrated that low O2 and high CO2 reduced plant growth and increased the exudation of ethanol, amino acids, and sugars by pea roots. The relative loss of ethanol by roots was much greater in treatments with atmospheres of N2 containing 30% CO2 than in treatments of air containing 30% CO2 or N2. Ethanol was not detected in the nutrient solution of aerated plant roots. Atmospheres of N2 plus 30% CO2 caused 500% greater mycelial growth ofFusarium solani f. sp.pisi and 400% more disease of inoculated pea roots. Relative losses of four amino acids and four sugars were much greater in atmospheres of N2 plus 30% CO2 than in N2 or air.

AbstractA study was conducted to determine losses and distributions of nitrogen (N) and phosphorus (P) in runoff waters and sediments from heavily fertilized agricultural watesheds during both the growing and nongrowing seasons. The study was done on two small watersheds having well‐drained, fine, sandy loam soils. Runoff was measured continuously and sampled proportionately during 50–60 events over a 2‐year period.Ninety nine percent of the sediment loss over the period occurred during 11 months; 64–86% occurred during a single storm in April when no crop canopy was present. This event was associated with rainfall probabilities rising rapidly toward a primary annual peak for East Lansing, Mich. A second storm of equal magnitude in August was associated with a secondary annual peak in normal rainfall for this location. Both storms exceeded the 20‐year expectancy in erosion potential (erosion index = 68). Seventy to 95% of the N in runoff, and 90–98% of the P, were carried in sediments, except during winter months when up to 80% of the N and 33% of the P were in solution. Sediments were enriched, relative to soils, in total N, but not in extractable P.

The 1977 Clean Water Amendments to Public Law 92-500 were enacted to ~strengthen the ori@nalpolicy of encouraging the utilization ofinnovative, alternative management techniques far the treatment and disposal of municipal wastewater. These alternative techniquesinclude spmy krigation and overland flow land treatment systems which can be used individual& cr combined with lagoons. The lagoons serve as pre-treatment systems for settling, microbial degradation of BOD, and/or for storage during periods of cold or wet weather. The proper selection and management -of vegetation k ckritical.for the efIlcient renovation of municipal wktewater by slow rate, overland flow, or spray irrigation systems.

AbstractAlthough plants have been grown with their roots in mist chambers and sterile nutrient solutions, these methods have not been combined to provide a system which permits rapid changes in the gaseous composition of an aseptic rhizosphere. The objectives of this study were to design a mist chamber system which would withstand heat sterilization, maintain an aseptic rhizosphere, permit rapid gaseous exchange without altering rootwater relationships, and permit the measurement of morphological and physiological root responses without disrupting the system.A pyrex glass mist chamber system is described which permitted a complete exchange of the root atmosphere in 5 min. Pea (Pisum sativum L.) seedlings were treated from 6 to 17 days in the aseptic mist chamber. Root respiration, root exudation, and rhizosphere volatiles were monitored. Detection limits were 1.0 ppm of ethanol, 1.0 and 0.25 μg for the TMSi amino acids and sugars.This system provides for concise control of the rhizosphere and precise measurements of root responses to environmental stresses.

AbstractFood processing waste waters at two irrigated land disposal sites and subsurface waters (perched and ground waters) were monitored at daily to monthly intervals over one annual cycle of production. Soil profiles were sampled to depths up to 6.6 m in the early fall.Yearly inputs were calculated at 487 kg/ha total N (Kjeldahl plus NO3‐N) and 101 kg/ha soluble PO4‐P (orthophosphate) from cannery wastes at site 1. Estimates for milk wastes at site 2 were 562 kg/ha total N and 522 kg/ha PO4‐P.The range for NO3‐N in subsurface waters was 7 to 16 ppm at site 1 (perched water at 1.5 m) and 2 to 41 ppm at site 2 (ground water at 0.9 m). Maximum concentrations, found in summer, were essentially the same as the average for total N in the input wastes (16 ppm at site 1 and 38 ppm at site 2). Nitrate was stable in the percolation stream below the root zone. Annual additions to subsurface waters were estimated at 76% of input N at site 1 and 65% at site 2.The range of PO4‐P in subsurface waters was 0.5 to 1.5 ppm at site 1 and 0.04 to 1.8 ppm at site 2; average waste water concentrations were 3 and 35 ppm. The highest concentrations in subsurface water were found in spring. Annual subsurface discharge was estimated at 27% of input P at site 1 and 2% at site 2. The extensive removals of PO4 and the similar concentrations encountered in subsurface waters are of theoretical and practical interest since PO4‐P had already accumulated in soil profiles at both sites in quantities which exceed the Langmuir maxima for nonirrigated control soils.During seasons of major irrigation input, NO3 appeared in subsurface waters in concentrations exceeding public health standards; PO4 concentrations exceeded environmental guidelines at all times except where irrigation was discontinued during the winter at site 2.Soil systems appeared poised to discharge at the observed rates because of the large quantities of organic N and fixed P which had accumulated in the profiles over 20 years operation at site 1, and 10 years at site 2. The rate of residual accumulation in soil could have been reduced by harvest, to extend system life materially. The harvest potential of three grass clippings per season removed for silage, was estimated experimentally at 31% of input N at both sites and 80% of input PO4 at site 1; 27% at site 2.

AbstractTomato plants were studied to assess the potential value of ethanol accumulation in plant tissue as a measure of O2 stress resulting from short periods of soil flooding. Ethanol concentration in xylem exudate was markedly associated with air temperature, and to a lesser extent with light intensity and soil temperature under conditions of flooding. Field flooding results agreed closely with simulated environments.A small amount of ethanol was eliminated by transpiration from flooded tomato plants under environmental conditions that favored accumulation. A slightly higher amount of ethanol was excreted from the roots.Ethanol in tomato plant samples appeared to indicate the intensity of O2 deficiency during flooding by reflecting both soil O2 supply and environmental effects, and could serve as a useful indicator in relating tomato plant injury to flooded conditions.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of Asphalt to Increase Water-Holding Capacity of Droughty Sand SoilsC. M. Hansen and A. E. EricksonCite this: Ind. Eng. Chem. Prod. Res. Dev. 1969, 8, 3, 256–259Publication Date (Print):September 1, 1969Publication History Published online1 May 2002Published inissue 1 September 1969https://pubs.acs.org/doi/10.1021/i360031a008https://doi.org/10.1021/i360031a008research-articleACS PublicationsRequest reuse permissionsArticle Views71Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

ABSTRACT Following the publication of Lillie’s (1917) observations and theories on the endocrine basis of the development of the bovine freemartin, experiments were initiated to determine if heterosexual gonad grafts to the chorio-alantoic membrane of chicks could stimulate formation of intersexes (Willier, 1927). Hormone extracts of testes and urine were used by Dantchakoff (1935) and Kozelka & Gallagher (1934), and synthetic hormones were tested in the chick by Wolff & Ginglinger (1935). Estrogens feminized the left gonad of male embryos and resulted in retention of Mullerian ducts in males and occasional cystic develop-ment of Mullerian ducts in females. Less extensive feminization of the left testis, dilation of Wolffian ducts, and partial deletion of Mullerian ducts occurred in androsterone-treated embryos (Wolff, 1935). Sensitivity of the genital papilla to exogenous steroids was described by Reinbold (1951). Riddle & Dunham (1942) demonstrated that a single injection of estradiol benzoate into laying birds resulted in feminization of genetic males which developed from ova released shortly thereafter. Lutz & Lutz-Ostertag (1959) described spontaneous chick freemartins developing in double-yolked eggs. Studies of individual male embryos which had access to the resources of two yolks in double-yolked eggs (Ruch, 1961) revealed the occurrence of gonadal modifications similar to those resulting from administration of estrogens or from implantation of female gonads adjacent to the genital ridge of young male embryos (Wolff, 1946–47). When heterosexual implants of gonads of sufficient size were placed on the chorioallantoic membrane, male left testes developed into ovotestes and Mullerian ducts were reduced in the female (Groenedijk-Huijbers, 1960). The immunological consequences of vascular anastomoses between bovine twins discussed by Owen (1945), and more recently by Fecheimer, Herschler & Gilmore (1963) and Goodfellow, Strong & Stewart (1965) afford an additional point of departure in studying the freemartin.

Summary. A single subcutaneous dose of cadmium chloride (1 mg/100 g body-weight) was administered over the breast muscle of male chicks ranging in age from 4 to 180 days. Necrosis of seminiferous tubules had not occurred by the time of autopsy 21 days after treatment. The only consistent finding was a post-injection lethargy and, frequently, tissue damage at the site of injection. Organ/body-weight ratios of comb-wattles and combined testes did not differ significantly between experimental and control animals.

SynopsisThe distribution of photosynthetically fixed C14O2 among 14 metabolites of tomato plants (watered normally) was compared with th t from plants which were flooded. The flooding treatments produced marked changes in the percent of C14 label found as glucose, fructose, sucrose, malic acid, citric acid, gamma amino butyric acid, and the lipid fraction.

AbstractThe aeration status of a Brookston clay loam was varied by varying aggregate size, moisture content, and moisture tension. Moisture tensions ranged from saturation to about field capacity. Determinations for pH, NH4+, NO3‐ and oxygen diffusion rate were made periodically during 2 months' incubation at 35°C. Oxygen diffusion rate was determined amperometrically, using platinum electrodes 4 mm. long by 0.8 mm. in diameter. Average rates associated with aggregate size and moisture content ranged from 3 to 43 g. O2 × 10‐8 cm.‐2 minute‐1.Fluctuations in oxygen diffusion rate with time paralleled changes in concentrations of NH4+ and NO3‐ and appeared to reflect changes in metabolic demand for oxygen by components of the microbial population other than the nitrifiers.Large discrepancies between NH4+ disappearance and NO3‐ accumulation made it necessary to distinguish between nitrification as the biological oxidation of reduced forms of nitrogen and net nitrification as the observed accumulation of nitrate.Net nitrification varied with apparent delay period and rate of NH4+ oxidation, and with losses of nitrified N. Rates of ammonium oxidation were related directly to the general level of oxygen supply as measured grossly with the platinum electrode. Apparent delay periods were influenced primarily by anaerobic metabolism in microenvironments too small to be differentiated by the electrodes which were used. Mineral N deficits appeared to be due primarily to enzymatic denitrification at oxygen diffusion rates less than 20; at higher levels of oxygen supply, chemical instability of NO2‐ appeared to become increasingly important because of an accompanying decrease in pH.

AbstractExperiments were designed to measure the influence of soil oxygen stress and other environmental variables on the accumulation of ethanol in tomato plants. Oxygen stress was imposed by varying the soil moisture tension over a narrow range of low values. Ethanol was observed in the exudate samples when the rate of oxygen diffusion through the soil solution fell below 38 × 10‐8 g.cm.‐2min.‐1. A small reduction in oxygen supply below this value was associated with a large increase in ethanol. In cases of severe oxygen stress the physiological concentration of ethanol was sufficient to be toxic. Plants bearing flowers accumulated more ethanol than younger ones and those subjected to oxygen stress in bright light accumulated more ethanol than those in the dark.