Genesis and Classification Considerations of Some Prairie-Formed Soil Profiles From Local Alluvium in Adair County, Iowa

Data are presented on three profiles formed under prairie from Late Wisconsin to Recent age local alluvium of moderately fine texture. In the upper 20 inches nitrogen and base saturation values are quite similar to those found for normative upland Brunizems. Below 20 to about 50 inches, nitrogen and base saturation values decrease and increase, respectively, more slowly in the local alluvium-formed soils. It is suggested that the classic ABC soil genesis concept does not apply to the local alluvium-formed soils of this study. Rather, through cumulative effects of new parent material at the surface, this new C was transformed to an Ac horizon (c for cumulative effect), the former A1 was transformed to a Bc horizon, and the former B became a substratum Cc horizon. Soil genesis effects in such cumulative soil genesis systems need further attention, as these soils comprise about one-fourth of the land area of Iowa, are important agriculturally, and an understanding will further knowledge of other soils of Iowa

Some Physical Characteristics of Wiesenboden and Planosol Soils Developed from Peorian loess in Southwestern Iowa.

A study by Hutton ( 1947, p. 426-31) of the gently sloping Prairie soils derived from Peorian, or Wisconsin, loess in southwestern Iowa showed that certain morphological, chemical, and physical properties are related to the thickness and distribution of the loess. Previous field studies had indicated that in a qualitative way, properties of the associated loess-derived Wiesenboden and Planosol soils also were related to thickness and distribution of the loess. The present study was undertaken to determine if quantitative information could be obtained on the functional relationship between certain soil properties, chiefly physical, and the loess distribution. The study consisted of collection of suitable profile samples, and the determination in the laboratory of certain properties by methods described elsewhere by Wilson et. al. (1946). Bulk samples were used for the determination of particle size distribution. Undisturbed core samples were used for measurement of permeability, volume weight, and porosity. Loess thickness borings were made manually with an extension auger as described by Hutton (1947, p. 424). Data are presented for a profile of each of the following soil series: Minden, Winterset, Haig, and Edina

Grainy Gray Ped Coatings in Brunizem Soils

The presence of light colored, granular material on structural units in the lower B horizon is considered to be an atypical morphological feature in the Brunizem soils of Iowa. This study indicates that there are appreciable areas of Brunizem soils, derived from Wisconsin loess and Iowan till, in eastern Iowa with such coatings in the lower B horizon. Because the grainy gray ped coatings cannot readily be accounted for by any soil-forming factor other than vegetation, and because they are similar to coatings in some associated Gray-Brown Podzolic soils, it is inferred that their presence is generally related to a prior influence of deciduous forest. Their proper classification needs further attention

Preliminary Studies of the Moody and Galva Soil Series of Northwestern Iowa

Recent studies in the midwest have confirmed a relationship between the thickness and distribution of the loess and the morphological, chemical and physical properties of soils developed from loess. In southwestern Iowa studies by Hutton (2) and Ulrich (6) showed increased differentiation of soils as the distance from the loess source increased and the thickness of the loess decreased. Hunter (1) reported similar relationships between the properties of the loess and soils developed in southeastern Iowa. This paper presents the results of a preliminary study regarding the possibility of similar relationships in northwestern Iowa. Profile sites were selected on loess of varying thickness and samples were brought into the laboratory for analyses

Profile Characteristics of Some Forest-Formed Soils Derived from Iowan Till

Three profiles were collected in Bremer and Floyd counties to represent the proposed Coggon series; detailed field and laboratory studies were conducted on these profiles. The Coggon soils have developed under forest vegetation from a two-story parent material consisting of a silty mantle-pebble band-glacial till sequence. Being formed from Iowan-age glacial till, the Coggon profiles exhibit an amount of development that is low compared to other Gray-Brown Podzolic soils of Iowa. Coarser parent material might possibly explain why Coggon is less developed than the Weller soils, which are formed from presumably younger, loessial parent material. On the other hand, the lack of development in Coggon could be explained by its youth if one considers the possibility that the present geomorphic surface of the Iowan till represents a rather young pedi-sedimented surface which is more recent than the last glaciation

Characteristics of Some Soils of the Iowan Till Area of Northeast lowa

The published county soil surveys show that Carrington loam and silt loam soils occur extensively in the CC and CKC areas of northeast Iowa outlined in Figure 1. Most of these soil surveys were made from 1914 to 1930, and as pointed out by Simonson, Riecken and Smith ( 1952), the former Carrington series in this area is now considered to consist of several series. In the present study several morphologically different profiles formerly included with the Carrington loam and silt loam soil types were sampled and certain laboratory determinations made. The data obtained and a brief discussion of their significance are presented

Characteristics of the Floyd and Some Related Soils in Floyd and Bremer Counties, Iowa

This study deals with imperfectly and poorly drained soils generally considered to have developed under prairie from a parent material consisting of a sandy-silt mantle overlying Iowan glacial loam till. Three Floyd profiles, two profiles of the proposed Tripoli series (Floyd, poorly drained variant), and one Clyde profile were studied in the field and in the laboratory. Results indicate that the Tripoli soils should be separated from the Floyd and mapped as a separate series. The present concepts of the Floyd series as a minimal Brunizem and the Tripoli as a minimal Wiesenboden are substantiated by field studies and laboratory data

Causes of Differences in Soil Series of the Missouri River Bottomlands of Monona County

The current soil survey of Monona County has revealed many differences in the alluvial deposits occurring in the Missouri River bottomlands. As a consequence the soils developed from these different deposits show numerous dissimilarities. It is the purpose of this paper to describe and explain the causes of the differences encountered. The principal factors in soil formation are climate, organisms, topography, parent material and time. In the Missouri River bottomlands of Monona County it can be assumed that climate and organisms are not important causes of soil differences. In general, differences in topography are closely related to differences in parent material. Thus parent material or time of deposition or both, must be the principal cause or causes of soil differences. The soils found on the Missouri River bottomlands are, for the most part, formed from alluvial materials. Some coarser alluvium may have been resorted by wind action subsequent to deposition but areas showing evidence of wind action are not extensive. The principal source of alluvium is the Missouri River; next, the tributary rivers and streams; and, of least importance, the steep bluffs that form the sides of the valley

Extent of the Muscatine Series in Muscatine County, Iowa

The morphology of the profiles of 35 randomly selected sites in Muscatine County, Iowa, was studied. None of these sites qualified as type locations for the Muscatine series, based on current concepts and definitions of this series. Originally established in Muscatine County in 1916, 38.2 per cent of the soils of the county were classified in this series. Now, Muscatine County seems to be no longer a suitable type location for the Muscatine series

Distribution of Soils by Natural Drainage Class and by Slope Class for Iowa Counties

Natural drainage class (namely, poor, imperfect, and well drained) and slope class are estimated for Iowa counties through a 2% ¼-section sample soil survey. Estimate of soil drainage class is given also by slope class. Counties vary widely in the amount of poorly drained soils. Kossuth County has 56.4% of poorly drained soils, while Allamakee has less than 1%. Land use management and conservation considerations are discussed briefly