bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Conservation Practices on Runoff, Available Soil Moisture and Cotton Yield
Authors: Burnett Earl , Fisher C. E. 
Published: July 2010

AbstractThe mechanical conservation practices of contouring and terracing have produced significant differences in runoff, available soil moisture, and cotton yield in a 26‐year experiment at Spur, Tex. The increased cotton yield may be attributed primarily to reduction or elimination of runoff with attendant deeper penetration of moisture which resulted in reduction of moisture losses by evaporation and weed growth.Available soil moisture in the second and third feet of soil on May 20 was increased from an average of 1.27 inches on plots with rows in the direction of the slope to 1.60 inches on contoured plots with closed level terraces. The average annual runoff on the former plots was 2.75 inches and was completely eliminated on the latter. The average yields of lint cotton for the two practices were 117 and 188 pounds per acre.
Field Capacity Approximation Based on the Moisture‐Transmitting Properties of the Soil
Authors: Hanks R. J. , Holmes W. E. , Tanner C. B. 
Published: July 2010

AbstractA new field capacity approximation is reported. This approximation was compared both with the field capacity and with various estimates of the field capacity of 23 soils. The field capacity approximation was found to be related to the field capacity by the equation: FC = 0.959FCA + 1.17. The data presented support the view that field capacity is the moisture content of a well drained soil when, after the soil has been thoroughly wet, drainage has decreased the moisture content to such an extent that the consequent decrease in capillary conductivity materially impedes further drainage of water. A statistical test of significance showed that the field capacity approximation is a significantly better over‐all estimate of field capacity than the moisture equivalent, buchner funnel percentage, and ⅓‐atm. percentage. The test further indicated that the field capacity approximation is not a significantly better estimate of field capacity than a modification of the Wilcox (7) method. However, the field capacity approximation is much more convenient, reproducible, and time conserving than the modified Wilcox method.
X‐Ray Diffraction of Common Silica Minerals and Possible Applications to Studies of Soil Genesis
Authors: Pollack S. S. , Whiteside E. P. , Van Varowe D. E. 
Published: July 2010

AbstractA qualitative X‐ray diffraction study indicated that quartz was present in all of 16 silica minerals. Jasper was the only sample found to contain a crystalline impurity and this was identified as hematite.A standardized sample preparation and mounting technique is described herein. Quantitative estimates of the quartz contents of three phenocrystalline varieties and two cryptocrystalline varieties of quartz were made. The cryptocrystalline varieties showed much less intense diffraction by the 3.35 A° spacing characteristic of quartz than did the phenocrystalline varieties. The available evidence indicates that these differences are probably due to fundamental differences in the nature of the quartz in these two groups. However, the possibilities of the presence of some amorphous diluents and variable particle sizes have not yet been completely eliminated.The implications of these findings for the use of X‐ray diffraction procedures for the determination of quartz in soils and the study of soil genesis are discussed.
A Chemical‐Microbiological Study of Effects of Exchangeable Cations on Soil Aggregation
Authors: Aldrich D. G. , Martin J. P. 
Published: July 2010

AbstractThis paper presents data obtained in a study of the effect of various exchangeable cations on soil aggregation and microorganisms. Twenty‐one treatments involving various combinations and ratios of exchangeable Ca, Mg, Na, K, and H were compounded by appropriate treatment of a Hanford sandy loam and a Yolo sandy loam. The soil samples of varying cation composition were incubated alone and in combination with organic matter sources of high and low carbon‐nitrogen ratio for a period of 200 days. Soil aggregation measurements and counts of kind and number of soil microorganism were made at various intervals during the incubation period. In comparison with a calcium system, the following results were noted: (1) A high percentage of Mg has no effect on aggregation. (2) Depending on the soil, a high percentage of exchangeable K may or may not reduce aggregation. (3) Increasing Na reduces aggregation. (4) An excess of free lime reduces aggregation. (5) Kinds and numbers of microorganisms are affected more by organic matter additions than by cation composition of soil. (6) Organic matter additions increase aggregation regardless of cation composition.
Unsaturated Flow of Water in Field Soils and Its Effect on Soil Moisture Investigations
Authors: Robins J. S. , Pruitt W. O. , Gardner W. H. 
Published: July 2010

AbstractMeasureable drainage of water within the soil profile in field plots was observed for periods of up to 8 days following irrigation under an actively transpiring alfalfa crop. Rates of movement from the 0 to 3 foot zone were of the order of 0.20 inch per day 2 days after irrigation and 0.11 inch per day 4 days after irrigation. Total drainage from the 0 to 3 foot zone for the period 2 to 8 days was 0.58 inch.This downward movement of water is shown to have material effects upon consumptive use measurements and the soil moisture extraction pattern. A computed error of 23 per cent in consumptive use for the first 8 days following irrigation is shown to have occurred in the present experiment as a result of drainage from the 0 to 3 foot zone.
Limestone, Dolomite, and Calcium Silicate Slag for White Clover Pastures on Red and Yellow Soils
Authors: Jones U. S. , Edwards W. D. 
Published: July 2010

AbstractAn experiment has been conducted on five red and yellow podzolic soils since 1949 to study the effects of three kinds and four levels of lime on white clover seed and forage yields. The exchangeable calcium in the soil and soil pH as well as percentage of protein and calcium in the clover forage were used as measures of treatment effect. Other experiments were carried on to determine the availability of phosphorus in calcium silicate slag as measured by white clover forage yields. The design of the experiment was a split plot in which the whole plots were three kinds of lime, viz. calcium silicate, calcitic and dolomitic limestone, and the sub plots were rates of lime, viz. none, 1,000, 2,500, 4,000, and 6,000 pounds per acre. Lime applied at 1,000, 2,500, and 4,000 pounds per acre progressively increased clover forage and seed yields on Prentiss f.s.l., Bowie f.s.l., and Stough v.f.s.l. over a 3‐year period. On Loring and Richland silt loams, rates of lime up to 6,000 pounds per acre produced progressive increases in forage and seed production. Lime added at 1,000 to 4,000 pounds per acre produced an annual increase of protein in the clover forage from 36 to 190 pounds per acre. The calcium in the plant material was also increased by additional increments of lime. There was a progressive increase in soil pH and exchangeable calcium at all locations as the rates of lime increased. There was little difference among the three liming materials for increasing the pH and base content of the soil. Likewise, there was little difference among the three liming materials for increasing the forage and seed yields. Mean forage yields at all experimental sites showed a similar response to phosphorus contained in 4,000 pounds calcium silicate slag as to the phosphorus in 250 pounds of superphosphate applied with 4,000 pounds of calcitic limestone. The calcium silicate contained 1.3% P2O5.
Solubility of Phosphorus in Chemical Extractants as Indexes to Available Phosphorus in Ohio Soils
Authors: Thompson L. F. , Pratt P. F. 
Published: July 2010

AbstractEighteen samples of soils were subjected to greenhouse cropping with alfalfa and corn and to various extractant solutions for measurements of soluble P. The P removed from the soils by alfalfa and the “A” values calculated from the uptake by corn of radioactivity tagged superphosphate were used as a measure of plant‐available P. The accuracy of estimation of available P by the solubility data was obtained by comparing the P solubility in the various extractant solutions against the plant‐available P. The Bray No. 1 solution (0.03 N NH4F‐0.025 N HCl) and the 0.5 M NaHCO3 solution extracted amounts of P that were accurate estimates of plant‐available P. The Bray No. 2 solution (0.03 N NH4F‐0.1 N HCl), 0.002 N H2SO4, and citric acid extracted amounts of P that when plotted against the plant data gave a distinctly different relationship for young soils formed from high‐lime late Wisconsin till than for older soils formed from more acid parent materials.
Theory of Capillary Flow: I. Practical Implications
Authors: Miller E. E. , Miller R. D. 
Published: July 2010

AbstractThe authors describe elsewhere certain general consequences of assuming that the classical differential equations of surface tension and viscous flow govern the behavior of liquids within the microscopic pores and channels of an unsaturated porous medium. These consequences appear as macroscopic differential equations expressed in reduced variables and containing two time‐independent functionals of pressure which exhibit hysteresis and are characteristic of the medium. The present paper interprets these equations in practical terms.Because of time independence, the term ▽ K appearing in L. A. Richard's analogous equation (1931) becomes . Accordingly it is possible to solve for the conductivity and capacity functionals from experimental flow system data, provided the accuracy is sufficient for evaluation of required derivatives of pressure.The combination of reduced variables and time independence permits scale modeling of flow systems. In a small‐scale replica, the time scale is shortened, while “gravity” must be increased by means of a centrifuge. One possible application is to laboratory measurement of field capacity.The reduced variables telescope into groups macroscopic flow systems that are equivalent except for scaling factors. Reducing the microscopic geometry by comparison to a characteristic pore size may prove useful in simplifying physical description of soils.
Profile Characteristics of Some Loess‐Derived Soils and Soil Aeration
Authors: Ruhe R. V. , Prill R. C. , Riecken F. F. 
Published: July 2010

AbstractInferences are made in evaluating soil drainage conditions from morphological characteristics of soils, such as mottles and deoxidized zones. These characteristics are not infallible criteria for indicating drainage conditions, and an evaluation of local and regional relationships often is necessary for a proper interpretation. An excellent example of the need for such an evaluation is afforded by a study of weathering zones in Wisconsin loess in southwestern Iowa. A repeated occurrence in regional distribution of two deoxidized zones, the upper one surmounted by an abundantly mottled zone, was observed in the Wisconsin loess. The present positions of these deoxidized zones are moderately well or well drained, indicating that they are not related genetically to the present environment but are relict from a preexisting environment of poorer drainage. Well‐drained soils occurring on the modern landscape frequently are mottled in the B and C horizons. This mottling in the profiles is interpreted as an incidental morphological characteristic and not related genetically to the profile development, but inherited from a pre‐existing environment of poorer drainage.
The Relation of Certain Loessial Soils of Northeastern Kansas to the Texture of the Underlying Loess
Authors: Hanna Robert M. , Bidwell O. W. 
Published: July 2010

AbstractParticle size analyses were made on 10 profiles representing four soil series. The profiles were located on a traverse perpendicular to the Missouri River from the Missouri River bluffs in northwestern Doniphan County, Kansas, to a point in southwestern Brown County, 24 miles from the river. The first sampling site was located 2 miles from the Missouri River. Subsequent sites were located at approximately 2½‐mile intervals. The thickness of the loess, as measured at most sites, decreased from approximately 100 feet at the river bluffs to 6 feet at the tenth site. The textural composition and pH of each horizon were determined in the laboratory. The texture of the C, B, and A horizons was observed to become finer with increased distance from the river up to 16 miles from the bluff. Beyond that point there was little if any decrease in particle size with distance. The change in texture of the C horizon with distance from the river appears to be the dominant factor in the development of the four soil series, Monona, Marshall, Sharpsburg, Grundy, which have not been finally correlated in this area. This work further substantiates the belief that the Missouri River Valley flood plain was a source of some of the loessial deposits of northeastern Kansas.
Soil Moisture Regime in Some Forest and Non‐Forest Sites in Northern Wisconsin
Authors: Thames John L. , Stoeckeler Joseph H. , Tobiaski Robert 
Published: July 2010

AbstractThe soil moisture regime was studied in two paired sets of sites in northern Wisconsin.In comparison of a forested and non‐forested Spencer silt loam there was less available soil moisture in the surface 1 to 2 feet of the forested site because of heavy depletion of soil moisture by the tree stand, as compared with the nearby site with a timothy hay crop. Bulk density of the soil in the hay land was 25% greater for the top foot and 32% greater for the top 2 feet than the forested site.In a comparison of two paired forested sites both on sands and with permanent water table at 2.0 and 4.5 feet respectively, there was around 0.4 inch more water in the surface foot in the former, or around 4% on a weight basis in the top 2 feet during much of the growing season. Jack pine had almost the same site index on both sites, but in the case of aspen, the site index was 10 feet greater on the shallower water table area.
Theory and Measurement of Anisotropic Air Permeability in Soil
Authors: Maasland Marinus , Kirkham Don 
Published: July 2010

AbstractThree fundamental theorems on the movement of air through anisotropic soil are stated. New and simple proofs for two of the theorems are given; proof for one is referred to in the literature. On the basis of these theorems, formulas are derived for converting, to horizontal and vertical permeabilities, air flow measurements, previously reported in the literature, on soil clods. It is shown that the reported values of anisotropic permeabilities are apparent values, and that these apparent values depart considerably, in certain cases, from the correct values. As an extreme example, the reported ratio of the apparent horizontal to apparent vertical permeability for clod samples of Clarion soil, is 2.09, whereas the corrected ratio is 13.0. One particularly interesting general result of the theory is that an apparent value of the vertical permeability is, in fact, the geometric mean of the vertical and horizontal permeabilities of the sample. It is finally shown that the arithmetric mean of the apparent vertical and apparent horizontal permeability does not deviate greatly from the arithmetic mean of the true horizontal and true vertical permeability, the deviation being, for the Clarion sample, only 24%.
Current Status of Research in Soil Compaction
Authors: Raney W. A. , Edminster T. W. , Allaway W. H. 
Published: July 2010

AbstractDiscussion of this problem requires separation and careful definition of the kinds of soil conditions ordinarily considered under the general term soil compaction. Implement traffic, tillage operations, and livestock trampling may cause the formation of soil horizons of high bulk density and low porosity in soils which ordinarily have good physical properties. In planning research and extending research results, it is very important to distinguish these compacted layers from the conditions found in soils with genetically developed pan horizons. Examples of different kinds of both genetically‐developed and traffic‐induced pans are offered.Literature concerning the cause and nature of traffic‐induced pans and their effects on crop production is reviewed and analyzed. The extent of such pans in the Eastern and Southern states is considered. Current research dealing with prevention of compaction and the amelioration of compacted soils is reviewed and aspects of the problem requiring additional research are pointed out.
Mineral Content of a Latosolic Brown Forest Soil and a Humic Ferruginous Latosol of Hawaii
Authors: Tamura T. , Jackson M. L. , Sherman G. D. 
Published: July 2010

AbstractMineralogical analysis for two soils representing the Latosolic Brown Forest and Humic Ferruginous Latosol groups were made using X‐ray, thermal, and chemical techniques. In the A horizon of the Latosolic Brown Forest soil goethite (28%) was the predominant mineral; in the B horizon gibbsite (42%) predominated. Other minerals included hematite (15–25%), magnetite (0–10%), quartz (5–10%), and layer silicates (15–20%) in the A and B horizons, respectively. In the A2 horizon of the Humic Ferruginous Latosol from the island of Maui hematite (48%) was dominant; in the B horizon gibbsite (31%), hematite (25%) and amorphous alumino silicate (22%) were present in nearly equal quantities. In the C horizon of Humic Ferruginous Latosol the gibbsite content (48%) was substantially higher than the iron oxides (14%). The A22, B and C horizons of another Humic Ferruginous Latosol from the island of Kauai were also examined. The A22 horizon was predominately hematite (45%) with appreciable anatase (15%) and ilmenite (15%). The B horizon contained both hematite (30%) and goethite (30%) as the dominant minerals; the C horizon contained kaolinite (35%) as the major mineral constituent.
A Survey of the Nutrient Composition of Leaf Samples from North Carolina Peach Orchards
Authors: McClung A. C. , Lott W. L. 
Published: July 2010

AbstractA group of 153 leaf samples was collected from North Carolina peach orchards over the period 1950–52 using sampling techniques which were standardized in respect to date of sampling and leaf age and position. The samples were analyzed spectrographically for phosphorus, potassium, calcium, magnesium, boron, copper, manganese, iron, and aluminum. Zinc and nitrogen were determined by chemical methods. The data are discussed from the standpoint of discerning broad general trends in the nutrient status of trees in a particular area and of using this information as a basis on which to establish or expand soil fertility investigations.Levels of phosphorus, potassium, and manganese were found to be well above the deficiency ranges for peaches as reported from this and other areas. Clear‐cut foliar symptoms of deficiencies of magnesium and zinc were noted in some orchards, and leaf analyses indicate near deficiency in other orchards. Leaf levels of iron, boron, and copper were low as compared with results from surveys in other areas. Foliar symptoms of iron deficiency and symptoms possibly due to boron deficiency were noted in some orchards. Symptoms of copper deficiency were not observed here, nor have they been described for peaches elsewhere. Leaf levels of copper were in many orchards lower than the levels of adequacy reported for other crops. The results of this survey suggest that further study is warranted concerning deficiencies of magnesium, zinc, iron, boron, and copper in North Carolina peach orchards.
Fertilizer Placement for Small Grains in Relation to Crop Stand and Nutrient Efficiency in Nebraska
Authors: Olson R. A. , Dreier A. F. 
Published: July 2010

AbstractTime and method of fertilizer nutrient application have been found to markedly influence stand and growth of small grains in Nebraska. Severe stand reductions and yield losses have been noted as a result of moderate rates of N as well as K applied with the seed. These losses do not occur every year, nor are they uniform across the state in the years when noted. On the other hand, efficiency of applied P usually has been much greater when applied with the seed than by other methods.Investigations in the field and constant temperature laboratory suggest a low moisture level at which the most serious damage of fertilizer salts to germination occurs, but full germination is not assured at any soil moisture level without a surface increment to leach fertilizer away from the seed. Emergence loss from N adjacent to the seed at low moisture level is in direct proportion to the time interval before rain or irrigation raises the level. In general, N materials are more detrimental per unit weight than K, and the latter more than P. Damage to germination under critical soil moisture is apparent at 10 lbs. N/acre, increasing to the point of stand elimination with 160 lbs. N/acre. Among N carriers, CaCN2 and NH4OH are most deleterious to germination followed by CO(NH2)2 > NaNO3 > KNO3 > (NH4)2SO4 > NH4NO3. Straight carriers of phosphate cause little damage, but ammonium phosphates of 1:1:0 ratio are harmful when placed with the seed under conditions of limited moisture; the damage is less with pelleted than finely ground material. Fertilizer and seed need not be in immediate contact for germination inhibition, as evidenced by appreciable migration of N and P to the imbibing seed.Soil microorganisms are in part responsible for fertilizer injury to germinating seed, occasioned by their greater tolerance of low moisture supply and high salt concentration. Seed treatment at the lower moisture levels alleviates but does not eliminate the fertilizer detriment.Phosphorus placement with the seed of small grains is desirable in the drier regions so long as the N concurrently added with the seed does not exceed 10 or 15 lbs./acre. Supplementary N is essential to maximum P fertilizer utilization, but much of it should be applied separate from the seed.
Efficiency of Various Nitrogen Sources for Pasture Grasses in Large Lysimeters of Lakeland Fine Sand
Authors: Volk Gaylord M. 
Published: July 2010

AbstractA 3‐year study of the efficiency of various amounts and sources of nitrogen for Pensacola Bahiagrass, Pangolagrass, coastal Bermudagrass, and carpetgrass was made in 12 lysimeters approximately 22 square feet in area and 4 feet deep filled with Lakeland fine sand. There was no consistent difference in yield or nitrogen content of forage when three 20‐pound applications of nitrogen were derived from urea, NH4NO3 or NaNO3, nor between urea and NH4NO3 when applied at 60 pounds of nitrogen per month for 6 or 8 months.Leaching loss of nitrogen generally was low even for the high nitrogen applications, except in the case of carpetgrass. Percentage recovery of nitrogen in the forage ranged from 50% to 80% depending on the amount applied and the vigor of the grass. Leaching losses were not a major factor in accounting for the lack of recovery of nitrogen in the forage.The pH of the 0 to 10 inch surface soil was lower, and that of the 10 to 18 inch subsoil higher at the end of the study than it had been at the time the lysimeters were filled. The pH of the entire 0 to 18 inch depth was consistently lower where NH4NO3 had been used as compared to urea.The use of evapotranspiration values and soil moisture reserves calculated for the conditions of the lysimeters indicated that reduced leaching due to interruption of the moisture profile by the lysimeter bottom probably would not exceed 2 to 2.5 inches of leachate per growing season, and would not introduce a major error in the estimation of the efficiency of the nitrogen materials.