bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil Moisture under a Young Loblolly Pine Plantation
Authors: Hoover Marvin D. , Olson David F. , Greene Geoffrey E.
Published: July 2010

The study reported was made near Union, S.C., to determine the moisture available for tree growth and the effectiveness of young pines as a protective cover on watershed lands. Fibreglas electrodes were used to obtain daily estimates of soil moisture. Rain falling through the tree crowns or flowing down the stems was collected by catchment devices. The amount of rainfall reaching the soil and available soil moisture to a depth of 66‐ inches for the period October 1950 through September 1952 is reported for a loblolly pine plantation established in 1941. An average of 86% of rainfall as measured in the open reached the ground under the pines. About one‐fifth of the rain received under the trees reached the ground by flowing down the tree trunks. During the dry winter of 1950–51, rainfall was insufficient to replenish soil moisture at depths below 30 inches, and trees were almost completely dependent upon rainfall of the 1951 growing season. Rainfall during the winter of 1951–52 brought the upper 66‐ inches of soil to field capacity providing almost 10 inches of available water for tree growth. Early in the growing season, moisture was lost throughout the entire soil depth studied. Water was withdrawn most rapidly from the zone where it was most readily available regardless of depth, despite the greater concentration of roots in the surface layer. Because of the large draft upon soil moisture throughout the zone the upper 5½ feet of soil under trees has a large capacity to store water from fall and winter rainfall.
Chemical Factors in Cation Exchange Between Root Surfaces and Nutrient Media
Authors: Marshall C. E. , Upchurch W. J.
Published: July 2010

Experiments were designed to throw light on two main factors in cation uptake; the cationic activity of the nutrient medium and the mean free energy change of the reaction in which nutrient ions are exchanged for hydrogen ions. The third factor—the activity of the hydrogen ions, was not fully investigated, but has been reported on by other workers.

The theoretical basis for the determination of free energy changes is first examined. For roots growing in colloidal substrates, three possible procedures follow. (1) By adding algebraically the individual free bonding energies of the two cations to the two colloidal surfaces, the free energy change for the reaction can be calculated. This involves individual activity determinations by potentiometric methods. (2) By small exchanges, ratios of activities can be obtained which can be used directly in the equations. (3) By applying Donnan conditions to the equations, simplified equations involving ratios of concentrations are obtained. From these, the free energy changes can be calculated from determinations of total cationic composition of the two exchangers.

The composition of soybeans (roots and tops) grown in different true solutions—chlorides and bicarbonates of K and Ca, and in K and Ca Amberlite, K and Ca Putnam clay, and K and Ca bentonite— was examined. Corresponding to the 2,500–3,000 calorie advantage of bicarbonates over chlorides, greater uptake of K and of Ca from the former was observed. Where the three dominant factors were the same for two media (acidic KCl and acidic K‐Amberlite) growth and uptake were closely similar. Differences of 1,500–2,000 calories in the free energy change for different substrates markedly affected uptake.
Nitrogen Status of Marshall Silt Loam as Influenced by Different Crop Rotations
Authors: Andharia R. M. , Stanford G. , Schaller F. W.
Published: July 2010

A study to compare the effects of several different crop rotations on crop yields and on certain physical and chemical properties of the Marshall silt loam soil has been underway since 1942. The objective in the present study was to evaluate the relative nitrogen status of the plots planted to corn in 1951 as revealed by content of soil organic matter and total nitrogen, nitrification studies, and nitrogen content of the corn leaf.

Corn plots, in rotations which included one or more years of meadow, contained significantly higher amounts of organic matter and nitrogen than did plots in the corn‐oats rotation, although the differences were only 0.2 to 0.3% organic matter. Considering all rotations, the correlation between corn yields and organic matter content of the soil was not significant (r = .47); the relation between yields and total nitrogen, however, was significant (r = .64).

Marked differences in yield between first‐ and second‐year corn occurred in various rotations, although the organic matter content of these plots were the same, as might be expected. On the other hand, nitrate release on incubation of soils and content of leaf nitrogen clearly reflected the relative nitrogen availability under first‐ and second‐year corn.

Considering all rotations, a highly significant relation was found between corn yields and nitrogen content of the sixth corn leaf (correlation coefficient (r) = 0.97). A less striking, although highly significant, relationship occurred between nitrate released during a 2‐week incubation period and corn yield (r = 0.78). The value of studying leaf nitrogen as well as nitrification rate as a means of periodically evaluating the soil nitrogen status in rotation experiments is discussed and illustrated in this paper.
Residual Effect of Phosphorus on Cotton Grown on Cecil Soil as Determined with Radioactive Phosphorus
Authors: Stelly Matthias , Morris H. D.
Published: July 2010

A field experiment was conducted on Cecil sandy clay loam in 1951 to determine the residual effect on cotton of superphosphate applied in 1949 at different rates and by different methods on limed and unlimed soil. Crop yield, phosphorus content of the plants, and percentage of phosphorus in the plants derived from the fertilizer were criteria by which these variables were evaluated.

Increases in seed cotton yield and phosphorus content of the plants in 1951 resulted from the phosphorus applied in 1949. The response was directly related to the amount of phosphorus applied and to the dilute‐acid soluble phosphorus in the soil at time of planting.

No significant response in yield, phosphorus content, or percentage phosphorus in the plant derived from the fertilizer was obtained from the addition of lime. The method of applying the phosphorus in 1949, broadcast or drilled, had no significant effect on any of the criteria evaluated.

Approximately 28% of the plant phosphorus was derived from the fertilizer applied in 1951 to soil which had received no phosphorus in 1949. The percentage of the phosphorus in the plants derived from the fertilizer applied in 1951 decreased sharply and directly with increases of phosphorus additions in 1949.
Ion Exchange Equilibria in the Presence of Small Amounts of Electrolyte
Authors: Harward Moyle E. , Coleman N. T.
Published: July 2010

Studies were conducted to obtain quantitative information on cation distribution in clay‐water systems in the presence of small amounts of electrolyte and to test the ability of mass action type exchange equations to predict the distributions of metal cations in these systems.

Small amounts of HCl (0.004 to 0.10 symmetry) were added to variously base saturated bentonite and halloysite suspensions. The distributions of cations were determined from an analysis of the supernatant liquid after equilibrium was obtained.

When HCl was added to Ca‐K‐clays, the exchange constant, kK‐Ca, as calculated by the “statistical” exchange equation, was not invarient. The value of kK‐Ca increased with increasing K‐saturation and decreased with increasing Ca‐saturation. Variations in kK‐Ca were somewhat smaller when the exchange acidity was assumed to be associated with exchangeable Al.

It was shown, nevertheless, that the “statistical” exchange equation may be used to estimate fairly satisfactorily the amounts of K+ and Ca++ in solution when HCl is added to these clay systems.
Mineral Content of Low Humic, Humic and Hydrol Humic Latosols of Hawaii
Authors: Tamura T. , Jackson M. L. , Sherman G. D.
Published: July 2010

Data from X‐ray diffraction, elemental, differential and integral thermal, and infrared absorption analyses were used to characterize quantitatively the minerals in the clay fractions of representative soils of the Low Humic, Humic and Hydrol Humic Latosols of Hawaii. Allophane was identified in substantial amounts (approximately 30%) in the < 0.2u fractions of two Hydrol Humic Latosols. Other minerals present in the clay fractions of the Hydrol Humic Latosols include gibbsite (25–35%), goethite (10–35%), magnetite (5–20%), mica (1–10%) and quartz (0–3%). The Humic Latosol contained kaolin (15–20%), gibbsite (15–20%), hematite (20–25%), goethite (10–20%), montmorin (5–10%), interstratified 2:1 layer silicate (5–10%), mica (1–5%) and quartz (1–5%). The Low Humic Latosols were predominantly kaolinic (45–55%) with hematite (15–25%), allophane (5–10%) and montmorin (5–15%) in substantial amounts. The fractions < 2u constitute the major portion of the Latosols. All percentages given are of the < 2u fractions except that two whole soils are included with the Low Humic Latosol group.
The Availability of High‐Temperature Process Alkali (Rhenania‐Type) Phosphates to Crops When Applied to Calcareous Soils
Authors: Schmehl W. R. , Brenes E. J.
Published: July 2010

Four field experiments were conducted on two soil types to test the effectiveness of high‐temperature alkali (Rhenania‐type) phosphate fertilizers on calcareous soil. The results showed that Rhenania‐type phosphate and concentrated superphosphate had about the same fertilizer value for crops grown on phosphate‐deficient soils when the fertilizer was plowed under or broadcast, but there were indications that Rhenania‐type phosphate was less effective than superphosphate when the fertilizer was side‐dressed. Laboratory studies using various procedures for the determination of available soil phosphorus showed that Rhenania phosphate and concentrated superphosphate were equally effective in increasing the available phosphorus in the soil. The results indicate that the Rhenania‐type phosphates offer promise as substitutes for superphosphate under many cropping conditions.
The Influence of Wind‐Blown Material on the Soils of Massachusetts
Authors: Colby Wm. G. , Light Mitchell A. , Bertinuson T. A.
Published: July 2010

Most of the soil profiles of Massachusetts exhibit a surficial mantle of material that is genetically different from the underlying geologic formation. This surficial deposit exhibits a high content of very fine sand and silt and a very low content of the coarse fractions and clay. The deposit is relatively uniform in texture and mineralogical composition throughout its entire depth, irrespective of the underlying geologic formation. Results of field observations and mineralogical and mechanical analysis, give convincing evidence that the surficial mantle is of wind‐blown origin. Although this surficial mantle is not universal in its occurrence, most of the agricultural soils of the state are either entirely of wind‐blown origin or strongly influenced by such material.
Brown Forest, Polygenetic, and Congeliturbate Profiles of Potter County, Pennsylvania
Authors: Goodman Kenneth V.
Published: July 2010

A Brown Forest soil, soils having polygenetic profiles, and soils believed to have developed in materials formed by frost action and slope creep were mapped in Potter County, Pa., an area of normally well developed Podzol soils. Because of the complex conditions which existed at the margins of the continental glaciers, soil classification is difficult in these areas.

Field observations and the following laboratory analyses were made: mechanical analyses, pH determinations, X‐ray diffraction analyses, and exchangeable cation and base saturation determinations.

The results show that the outstanding characteristics of the Brown Forest great soil group can be identified in units as small as a single soil type. The Brown Forest profile has a characteristic granular structure, brown color, and a variation in pH from nearly neutral to acid to alkaline from the surface downward. The presence of gibbsite, usually associated with tropical weathering, in the lower part of the Sweden (tentative) series suggests that it is of polygenetic nature and that the lower part of the profile formed prior to Wisconsin glaciation. The physical and chemical analyses of the congeliturbate profiles, as well as a lack of erratics and rounded sands and gravels, suggest that although till‐like in nature, such profiles may have developed in materials formed as a result of frost action rather than glacial action. Further study is needed to substantiate this hypothesis.
The Dissolution and Migration of Phosphorus from Granular Superphosphate in Some Michigan Soils
Authors: Lawton Kirk , Vomocil J. A.
Published: July 2010

The purpose of this study was to determine the rate of dissolution and migration of phosphorus from granular superphosphate under different soil conditions. The effect of variation in soil type, soil moisture, compaction, and soluble phosphorus level in soils was considered.

Laboratory studies were conducted in which fertilizer granules and tablets were placed in soils for varying time periods, after which the remaining phosphorus in the recovered granule and in the soil was measured by chemical or radioactive isotope techniques.

Rapid dissolution of phosphorus from fertilizer granules in contact with moist soil was experimentally verified. At field capacity moisture contents, 50 to 80% of water soluble phosphorus moved out of the granules in 24 hours. Even in soils as low as 2 to 4% moisture, approximately 20 to 50% of the phosphorus moved from the granule into the soil in a one day period. It was found that both commercial and experimental superphosphate 4–8 mesh granules had a strong tendency to absorb moisture when placed in a saturated atmosphere. In relatively dry soils, moisture is drawn from the soil mass toward the granule, thereby forming a moist shell.

The degree of soil compaction around the granule affects the rate of fertilizer dissolution. However, differences in compaction were found to have less effect than variations in soil moisture.

Placing radioactive fertilizer granules in soils with extremely high available phosphorus contents or in contact with non‐radioactive superphosphate did not markedly reduce the rate of dissolution of granular phosphorus.

Migration studies showed that phosphorus moved very little under the conditions studied. Maximum movement of about one inch occurred at soil moistures approximating field capacity on three soils. Most of this movement took place in the first week of a 4‐week period. Compacting soil tended to increase both dissolution and migration of fertilizer phosphorus. The larger the superphosphate granule, the more extensive was phosphorus migration.
Availability of Phosphorus in Granulated Fertilizers
Authors: Starostka Raymond W. , Caro Joseph H. , Hill William L.
Published: July 2010

A greenhouse test to measure the effect of placement, granule size, and the relative phosphate fixing capacity of the soil upon the efficiency of superphosphate and dicalcium phosphate was performed. The materials, labeled with P32, granulated, and sized to 4–6, 8–10, 14–20, 28–35, and −35 mesh were used in band and mixed placements on Evesboro and Davidson soils. A major difficulty encountered in greenhouse experimentation with granulated fertilizers stems from the problem of securing small samples for pot application that truly represent the test materials. Even with close‐sized materials the minimum representative sample of coarse granules is several‐fold larger than the quantity required for pot application. The test crop was wheat. Using increased yields, total phosphorus uptake, and percentage of the plant phosphorus derived from the fertilizer as criteria of agronomic value, the 14–20 mesh granules of superphosphate were the best size tested with this material while the 28–35 and −35 were the best sizes tested with dicalcium phosphate.
Changes in Drainage Properties of a Muck Soil as a Result of Drainage Practices
Authors: Jongedyk H. A. , Hickok R. B. , Mayer I. D.
Published: July 2010

Investigations of physical properties of muck soils using core samples, field observations of structure, and draw‐down studies, showed that the drainage characteristics of organic soils may be changed as a result of drainage practices. Studies were conducted on tiled drainage plots at the Northern Indiana Muck Experiment Farm at Walkerton, Ind. Average water table depths of 1.3 feet, 2.1 feet, and 3.3 feet were maintained from 1944 through 1950.

Significant changes have occurred in depth of soil, horizontal and vertical permeability rates, pore space distribution, and soil structural characteristics in the soil of the deeper drained plots (2.1 feet to 3.3 feet deep water tables) compared with shallow drained plots which may be considered as checks. Soils with very high permeability rates and desirable structural characteristics, favorable to crop growth and easy water control, exist on plot areas which had the deeper water tables. High water table plots have had more peaty muck soil with blocky, spongy structure and low effective permeability rates. Increased decomposition of soil, root growth, and earthworm activity occurred with lower water tables.

Some practical aspects of the changes in soil properties are presented.
Forest Soils‐Site Index Studies in Maine
Authors: Young Harold E.
Published: July 2010

The field, laboratory and analysis technique employed by Coile and his students in forest soils‐site index studies in the South have been tried on a modest scale in Maine. A White Pine study based on 16 plots located in 16 different White Pine stands in the vicinity of Orono, Maine, yielded a regression equation which correlated site index with the depth of the A horizon and the percentage of stones in the B horizon. As both of these factors increase, the site index decreases. This was field checked in a series of white pine stands within a 50 mile radius of Orono and in the southern part of the state along the Maine Turnpike. Data were also collected on 16 plots in spruce‐fir stands on the Penobscot Experimental Forest and this yielded a regression equation correlating the site index of spruce with the depth of the A horizon and the inhibitional water value of the A horizon. As both of these increase, the site index for spruce decreases. It is apparent that Coile's methods apply in Maine. Further study based on many more plots and covering a wider range of conditions are essential to obtain equations that can be used in practical forest management.
Response of Beans (Phaseolus vulgaris L.) to Inoculation with Mixtures of Effective and Ineffective Rhizobia
Authors: Burton J. C. , Allen O. N. , Berger K. C.
Published: July 2010

Ineffective rhizobia have often accounted for poor growth and low yields of certain leguminous plants despite the presence of effective rhizobia in the rhizosphere. The purpose of this study was to determine the plant growth response of beans to effective and ineffective rhizobia applied at different time intervals. Precedence in the addition of the different inocula and time of harvest were also employed as major variables.

Beans receiving both effective and ineffective rhizobia simultaneously made as good growth and fixed as much nitrogen as did those which received only effective strains at planting or 21 days later. Plant response to the inoculation treatments was not different at the 35, 45, and 68‐day harvests.

Plants bearing ineffective nodules and nodule‐free plants of the same age were equally susceptible to nodulation by effective rhizobia added at the 21‐day period. Ineffective rhizobia added to 21‐day old plants bearing effective nodules had no adverse effect on growth or on nitrogen content of these plants.

The amount of nitrogen in the bean nodules examined was related to the kind of inoculum applied. Effective nodules contained 6–8% nitrogen, ineffective ones averaged 3–4% nitrogen and those from plants treated with mixed inocula showed a range of 5–8% nitrogen.
The Effect of Anhydrous Ammonia on Nitrification and the Microbiological Population in Sandy Soils
Authors: Eno Charles F. , Blue William G.
Published: July 2010

Anhydrous ammonia was applied to Arredondo loamy fine sand and Lakeland fine sand at rates of 100 and 250 pounds of nitrogen per acre. In all soils the numbers of fungi were decreased. The numbers of bacteria and actinomycetes were increased except for a period not longer than 3 days after application, on the neutral soil, during which time they were decreased. A more detailed study of the zone of retention showed that both the numbers of fungi and bacteria were decreased on the first day. This decrease occurred in both acid and neutral soil. On the tenth day the numbers of fungi were still markedly reduced, whereas the numbers of bacteria had increased to 6 to 25 times those in the check soil. The changes in the microbiological population were noticeable while high concentrations of ammonia were present and were restricted to a 3‐inch zone centered on the injector row; this corresponded to the zone in which most of the ammonia was retained. From a total population standpoint, none of the changes noted are likely to permanently disturb the ecological balance in the soil.

The drastic reduction in numbers of fungi in the anhydrous ammonia‐treated soil indicated that there may be a possibility of it being used as a fungicidal agent in soil.

Compared to ammonium sulfate, anhydrous ammonia nitrified more rapidly in the slightly acid soils and less rapidly in the neutral soil. This may be of practical significance in choosing between these two fertilizer materials.
Wheat Yields and Soil Fertility on the Canadian Prairies after a Half Century of Farming
Authors: Hill K. W.
Published: July 2010

At three Experimental Stations in Western Canada the yields of spring wheat on summerfallow in grain rotations have been maintained for 40 years without the addition of fertilizer or manure. Yields of wheat following wheat in these rotations at two Stations may have declined slightly but this was not due entirely to reduced fertility since weed infestations have adversely affected yields.

At the Lethbridge Station in Alberta, average losses of 25% nitrogen and 19% organic matter have occurred in the grain rotations since 1910.

It appears that a cropping practice which includes wheat and summerfallow can be continued profitably for some time to come in Western Canada if soil erosion and weeds can be controlled.
Identification of Lime‐Deficient Peat Soils
Authors: Nygard Iver J.
Published: July 2010

Field and laboratory studies were made of 37 Minnesota peat bogs to fix the upper limit of lime content in the surface of lime‐deficient bogs, and to determine criteria of lime‐deficient peats3 other than the lime content. Field trials to determine whether the peats were lime‐deficient, using common farm crops, were conducted on peats from 35 uncultivated bogs and two cultivated bogs. All lime‐deficient peats and most of the lime‐sufficient peats were extremely acid as indicated by pH measurements. A close correlation existed between the lime (calcium oxide) content and lime‐deficiency. No native plant species were found to indicate lime‐deficiency reliably.
Phosphorus Diffusion in Soils
Authors: Bouldin D. R. , Black C. A.
Published: July 2010

The validity of activity measurements as estimates of phosphorus diffusion from P32‐tagged phosphate sources was investigated. Significant changes in the apparent specific activity of diffusing phosphorus were found; these could be accounted for by assuming exchange between diffusing P32 and native soil P31. Despite such changes in apparent specific activity, the overall picture of phosphorus diffusion obtained from activity measurements was not substantially different from that obtained by total phosphorus analysis. One‐dimensional diffusion of tagged phosphates from Ca(H2PO4)2 and KH2PO4 sources was studied in 10 water‐saturated soils using x‐ray film and Geiger tubes to estimate the resulting distribution of diffused phosphorus. The x‐ray film revealed many local areas of P32 concentrations 0.5 to 2 millimeters in diameter. Large‐scale irregularities in the curves relating phosphorus concentration in the soil column to distance from the source were found in three cases. In both Miami silt loam and Muscatine silt loam with Ca(H2PO4)2 as source, peaks of phosphorus concentration were found at 4‐cm. intervals. With Miami silt loam and KH2PO4 as source, one peak of phosphorus concentration was found about 1 cm. from the source. Distribution of diffused calcium, as measured by extraction with 0.5 N acetic acid, was similar to distribution of diffused phosphorus in Muscatine and Miami silt loam columns treated with Ca(H2PO4)2.
Further Studies Involving Cationic Activities in Systems of Plant Roots
Authors: McLean E. O. , Adams D.
Published: July 2010

Cationic activities were determined by means of clay membrane electrodes, and mean free bonding energies were computed for Ca and K in systems of plant roots representing five different plant species. The study involved measurements in both homoionic and biionic systems of roots from Reed canary grass, red top, oats, alfalfa, and buckwheat.

When all cation saturations of the roots studied are considered, results indicate that on a molar basis Ca is usually bonded to plant roots more strongly than is K. Using the homoionic systems at 100% saturation as a basis for comparison, buckwheat roots were found to have bonded Ca 3.3 times as strongly as K. Reed canary grass roots under the same conditions, however, held K equally as strongly as Ca. Roots from the other plant species were intermediate between these extremes in relative bonding energies for these two cations. Varietal differences in the relative bonding energies were also noted.

The ratio of the mean free bonding energies of the cations in the homoionic systems at 100% saturation was found not to be closely related to the cation exchange capacity of the roots. This suggests that the root exchange capacity alone will not be a reliable guide in predicting relative uptake of Ca and K by different crops.

It is suggested that buckwheat's well known ability to utilize phosphates of low solubility may be related to the relatively high mean free bonding energy for Ca by its roots. Such a high relative bonding energy might well be the weathering force necessary to release the phosphate from the otherwise unavailable form.
How Accurate is a Summary of Soil Test Information?
Authors: McCollum R. E. , Nelson W. L.
Published: July 2010

Chemical analyses of soils from 1184 systematically sampled fields in Duplin County, N. C., were compared with results from 538 voluntary farmer samples sent into the Soil Testing Division. Cropping history for fields included in both samples was obtained by personal contact and by correspondence, respectively. Results were compared on the basis of the previous crop as well as on the basis of the general mean of the two samples.

The pH and content of organic matter and potassium were significantly higher in the farmer samples but the differences were small in magnitude. The calcium and magnesium were distinctly higher in the farmer samples. On the other hand, the phosphorus was significantly lower in the farmer sample but again the difference was small. The tendency for higher levels of pH, potassium, calcium and magnesium may serve to substantiate the idea that the better farmers are sending in the majority of the samples. However, the difference in results for pH, organic matter, phosphorus and potassium is not considered sufficiently great to invalidate a summary of results from farmer samples. Seasonal effects on values obtained for pH, phosphorus and potassium present a problem. However, assuming the same type of seasonal distribution from year to year and the same type of farmers sending in samples, relative differences among areas, among crops, or in trends can be established.
Influences of Varying Plant Population, Soil Fertility and Hybrid on Corn Yields
Authors: Duncan E. R.
Published: July 2010

Four experiments on widely different soil types were carried out in 1952 to study the influences of varying plant population, fertility level, and hybrid on yield of corn grain and on plant characteristics. Selected hybrids of three maturity ratings were used at each location.

Corn yields were increased by an application of fertilizer, assumed to be adequate, at all locations. The degree of response to applied fertilizer was influenced by plant population level, the initial fertility level of the soil, and to a lesser extent by the hybrids grown. Yield increases attributable to fertilizer ranged from 7.5 to 101.9 bushels per acre.

Grain yields of all hybrids were increased on the high fertility level plots by increasing plant populations above 8,000 plants per acre. Lowest yields at this fertility level occurred at the lowest population and best yields were obtained at the highest population (approximately 24,000 plants per acre). Yield responses to different populations were not consistent at the low fertility level. Responses varied with higher populations from slight increases to slight, but consistent decreases. Yield differences attributable to increasing plant populations from 8,000 to 24,000 plants, ranged from a decrease of 22.7 on the lowest fertility level to an increase of 64.8 bushels on the high fertility level. Intermediate populations at both fertility levels resulted in intermediate yield differences.

The “late” hybrid on the high fertility level generally produced higher yields than the “adapted” and “early” hybrids up to 16,000 plants per acre. Above this population the adapted hybrid was generally equal or higher in yield.

There were small and inconsistent differences between hybrids at the low fertility level. Any general yield advantages favored the adapted and early hybrids over the late hybrid.
The Absorption of Phosphorus from Radioactive Phosphate Fertilizers Applied to Established Meadows I. Effect of Source, Rate, and Time of Application
Authors: Caldwell A. C. , Hustrulid A. , Hammers F. L. , MacGregor J. M.
Published: July 2010

In the spring of 1950 radioactive superphosphate and fused tricalcium phosphate at rates of 40 and 120 pounds of P2O5 per acre were applied as a topdressing to alfalfa on two fields of Waukegan silt loam. Superphosphate was more effective than fused tricalcium phosphate in supplying phosphorus to the plant but differences became less with time. The yield and phosphorus content of alfalfa were increased by both sources of phosphorus.

Similar trials were conducted in 1951 on the same soil type with the added teatment of potassium to the heavier phosphate application. Again superphosphate was superior to fused tricalcium phosphate as a source of phosphorus for alfalfa. The uptake of phosphorus was increased by the addition of potassium to the soil.

Phosphate broadcast after removal of first‐crop alfalfa was effective in supplying phosphorus to the plant (1951). In 1952, in a similar type of experiment, superphosphate at 40, 80, and 120 pounds of P2O5 per acre was broadcast after the removal of first crop alfalfa. Approximately one‐half of the phosphorus in mature alfalfa came from the fertilizer. The addition of potassium increased the uptake of phosphorus. The phosphorus content of alfalfa increased progressively with increased rates of phosphate application.

The recovery of applied phosphorus was low regardless of kind, rate, or time of application. The best recovery was only 11.6% of the phosphorus from superphosphate applied at 120 pounds of P2O5 per acre.
Evaluation of Residual Soil Phosphorus in Permanent Fertility Plots
Authors: Webb J. R. , Pesek J. T.
Published: July 2010

Areas of four long‐time fertility experiments that were planted to oats in 1952 were used to study the effect of different past treatments upon the level of available soil phosphorus.

Phosphorus A values, as derived by Fried and Dean, were compared with the Bray soil phosphorus test, and with crop yields as a means of evaluating the soil phosphorus level. The A values appeared to be very satisfactory for this purpose, and correlated significantly with soil test phosphorus values and with oat yields. At three of the four locations, a higher degree of correlation existed between A values and yields than between soil test phosphorus and yields. Phosphorus A values, determined from plant samples harvested at maturity were higher than those determined from an earlier sampling, but did not correlate any better with yields or soil test phosphorus.

The 1952 results from the long‐time experimental treatments indicated that ordinary superphosphate, concentrated superphosphate, and calcium metaphosphate applied at equal rates of P2O5 over a period of years appear to have an equal effect upon the residual level of available soil phosphorus and upon the yield of oats. Fused tricalcium phosphate compared favorably with these materials on an acid soil but was less effective as a phosphate source on a calcareous soil. Rock phosphate applied at equal or higher rates of P2O5 was a less effective source at all locations and by all three standards of comparison.
An Instrument for the Determination of Soil Compactibility
Authors: Bruce R. R.
Published: July 2010

Methods commonly used for the determination of soil compactibility require a large quantity of soil as well as much time and effort. A method is described which requires only 600–800 gm. of soil and 1 hour of time for each bulk density‐moisture curve. The compacter described is of the impact type and easily adjusted for application of a wide range of compaction energies. The procedure adopted applies three to four times as much compaction energy as the standard Proctor method.

Experience has shown that a sample weight of 100 ± 5 gm. is satisfactory. It has been shown that as compaction energy increases, the maximum bulk density increases and the moisture content at which it occurs decreases. Compaction data and aggregate stability data from two different experiments show similar differences in soil physical properties due to soil treatment. In general, this instrument has proved to be very satisfactory for the measurement of soil compactibility.
The Effect of Soil Reaction on the Availability of Phosphorus for Alfalfa in Some Eastern Ontario Soils
Authors: MacLean A. J. , Cook R. L.
Published: July 2010

The yields and phosphorus contents of alfalfa grown with and without phosphorus fertilizer in six soils previously limed to different pH levels in pots, and the amounts of phosphorus extracted with four chemical methods from soil samples taken prior to seeding and after harvest of the crop, were used to evaluate the effect of soil reaction on the availability of native and applied phosphorus for alfalfa.

The greatest uptake of phosphorus by alfalfa occurred at a pH of about 7.5, the highest level employed in the experiment. In most instances, the phosphorus contents of the plants were highest at a pH of about 7.5, at which level the yields were either similar to or higher than those obtained at any lower pH.

The results for phosphorus in most of the soils as measured with the Truog and sodium bicarbonate methods and for Bray adsorbed phosphorus in three of the soils showed that liming to or slightly above the neutral point increased the amounts of available soil phosphorus.
Chemical and Clay Mineral Properties of a Red‐Yellow Podzolic Soil Derived from Muscovite Schist
Authors: Rich C. I. , Obenshain S. S.
Published: July 2010

A study was made of a Red‐Yellow Podzolic soil with particular regard to the properties of dioctahedral vermiculite, one of its major clay minerals. The soil, Nason silt loam, which is derived from a muscovite schist residuum, was found to be nearly devoid of exchangeable calcium and low in other bases. Although the cation exchange capacity of the B3 horizon was 25 me. per 100 gm. soil, this horizon contained only 0.08 me. Ca per 100 gm. Clay minerals present were kaolinite, dioctahedral vermiculite, and regularly and randomly interstratified illite‐vermiculite. The 14.7A basal spacing of vermiculite from the C1 horizon moved to 10.5A when the clay was K saturated, but the effectiveness of K saturation decreased from the C1 horizon through the A horizon where there was only slight collapse. Boiling the clay from the B1 horizon for 102 hours in 1N KCl caused a change of the 14.7A basal spacing to only 14.2A. However, treatment of the clay in 1N KCl plus 0.1N HCl or treatment with 1N NH4F altered this spacing to near 10A. The difficultly collapsed mineral had a high internal surface, high base exchange capacity, and low divalent cation content. Easily collapsed dioctahedral vermiculite was made difficultly collapsed by repeated Al saturation and drying. Heat treatment at 800°C. collapsed the 14.7A spacing of the mineral in all horizons to 10.3A. Glycerol solvation caused no increase of the 14.7A spacing. These results together with D.T.A. data support the theory that non‐exchangeable Al in the interlayer position in vermiculite restricts collapse of the mineral on K saturation.
The Effect of Certain Site and Soil Factors on the Establishment of Douglas‐Fir on the Tillamook Burn
Authors: Lowry G. L. , Youngberg C. T.
Published: July 2010

This paper presents a preliminary report of studies dealing with soil moisture‐seedling survival relationships conducted on the Tillamook Burn in northwestern Oregon during 1953. Ten one‐fifth acre plots were selected from the current years planting program. Survival was calculated on the basis of total trees planted.

Factors investigated include: Percent slope, aspect, soil texture, structure, depth, organic matter content, and range of available moisture. Weather data were obtained from nearby lookouts. Soil moisture determinations were made weekly throughout the summer period.

Although there were not sufficient plots to establish statistical significance, certain factors were found to be affecting survival. Among these were aspect, percent slope, and soil texture. Southerly aspects coupled with coarse textured soils and slopes greater than 40% showed the highest mortality. On the other hand, northerly aspects, loam and silt loam textures and slopes less than 40% had excellent survival. Between these two extremes various gradations existed. In all cases where high mortality occurred, soils had been depleted of available moisture (below 15 atm.) for periods approaching 30 days.
Soil Properties Related to Forest Cover Type and Productivity on the Lee Forest, Snohomish County, Washington
Authors: Forristall Floyd F. , Gessel S. P.
Published: July 2010

Five one‐tenth acre plots were established on Lee Forest to investigate forest site and type and soil relationships. One plot was in each of the following types and sites: western hemlock‐Douglas fir, site class III; Douglas fir, site class II; Douglas fir, site class III; western red cedar, site class III; red alder, site class I.

Soils were sampled on these plots and the following data taken: effective depth, bulk density, texture, moisture equivalent, reaction, total nitrogen, and cation exchange capacity. In addition, weight and nitrogen content of the forest floor were determined and soil moisture followed throughout the 1953 growing season.

Depth to a hardpan layer was an important criterion for productivity rating. High bulk densities impeded root growth and determined effective soil depth. The critical density differed for the different tree species. Total soil nitrogen and total cation exchange capacity were much greater in the more productive forest soils. The western red cedar and the red alder plots had shallow soils with excess soil moisture during a considerable portion of the year. Low soil moisture did not appear to be a factor in tree growth on any of the plots in the 1953 growing season although the soil on the red alder plot did become quite dry in late August and early September. The dominating influence in determining forest type seemed to be poor soil drainage.
Cation‐Exchange Properties of a Number of Clay‐Conditioner Systems
Authors: Archibald J. A. , Erickson A. E.
Published: July 2010

The cation‐exchange properties of bentonite and kaolinite, treated with a wide range of concentrations of a vinyl acetatemaleic acid copolymer, and an isobutylene‐maleic acid co‐polymer were studied. Results obtained by two different methods indicate that there is a definite clay‐conditioner interaction between bentonite and these conditioner materials. Very low concentrations of conditioner caused a marked decrease in the cation‐exchange capacities of bentonite suspensions. Slightly higher concentrations increased the exchange capacity for both a monovalent and a divalent cation. A further increase in concentration resulted in a second decrease in exchange capacity which persisted for all higher conditioner concentrations used.
Phosphate Fixation by Montmorillonite
Authors: Ellis Roscoe , Truog Emil
Published: July 2010

The factors involved in fixation of phosphorus, added as Ca(H2PO4)2 · H2O, by montmorillonite clay were investigated. The influence of the free iron and aluminum oxides, which accompany this clay, on the fixation was determined by measuring fixation before and after removal of these oxides. It was found that the free iron and aluminum oxides accounted for most of the fixation against weak acid extraction. No appreciable fixation against water extraction occurred when the free iron and aluminum oxides were removed and the clay was H‐saturated.

The influence of saturation of the clay with the exchangeable cations usually found in soils on phosphorus fixation was investigated. Ca‐saturation clay, treated to remove free iron and aluminum oxides, fixed large amounts of phosphorus against water extraction. However, this phosphorus was recovered by weak acid extraction. The evidence obtained in this investigation indicates that the phosphorus fixed by Ca‐saturated clay is fixed as calcium phosphate complexes, and not by a H2PO4‐Ca‐clay bonding as has been proposed. Clays which were saturated with Na, K or Mg, fixed only small amounts of phosphorus against water extraction.
The Relative Growth and Potassium Absorption by Four Crops Under Intensive Culture in a Limited Volume of Soil
Authors: Reid P. H. , York E. T.
Published: July 2010

Two successive crops of peanuts, soybeans, corn, and cotton were grown in small volumes of Ruston fine sandy loam to study the relative efficiencies of the four crops to absorb potassium in a limited root environment. One series of treatments was fertilized and another unfertilized with respect to potassium. The roots of all four crops were found to have thoroughly permeated the soil, providing conditions for the rapid exhaustion of readily available sources of potassium.

All crops except cotton were found to have absorbed essentially the same amount of potassium under high levels of fertilization; however, cotton tended to absorb slightly more potassium than the other crops under low potassium conditions.

Potassium deficiency symptoms appeared first and were most severe on corn, followed by cotton, soybeans, and peanuts in that order.

All four crops responded in dry matter production to the application of potassium. In the second planting, the dry matter produced by the unfertilized peanuts, soybeans, cotton, and corn was 69%, 85%, 45%, and 20%, respectively, of the plants fertilized with potassium. Thus with equivalent amounts of potassium absorbed, marked differences were observed in the degree to which potassium deficiencies limited the growth of the four crops.
The Adsorption of Carbohydrates and Related Compounds on Clay Minerals
Authors: Lynch D. L. , Wright L. M. , Cotnoir L. J.
Published: July 2010

Studies were made with the adsorption of carbohydrates on clay minerals. The carbohydrates utilized were ethyl cellulose, methylcellulose 15 cps, cellulose dextrin, starch dextrin, inulin, glycogen, corn polysaccharide, hydroxyethylcellulose, carboxy‐methylcellulose, corn starch, and sucrose.

These carbohydrates were adsorbed on both a calcium and hydrogen saturated montmorillonitic type clay. A calcium saturated kaolinitic type clay was also used.

Increasing increments of carbohydrates, ranging from 26 mg. to as much as 450 mg. in certain cases, were added to 1‐g. samples of the clays. Twenty ml. of water was added, and the materials were thoroughly mixed by mechanical shaking for 48 hours. The clays were allowed to stand 96 hours to attain equilibrium and were centrifuged. The clear supernatant liquid was then tested for carbohydrate by the anthrone reaction. The difference between the amount of carbohydrate added and the amount in the supernatant liquid was taken as the amount adsorbed on the clay.

Adsorption on the calcium saturated kaolinitic clay ranged from 0.0% to 3.7%. The greatest amount of adsorption on bentonite, the montmorillonitic type clay, was with ethyl cellulose, starch, and cellulose dextrin, 20.5%, 21.6%, and 12.4% respectively. Little difference was noticed between the calcium and hydrogen saturated clays.

X‐ray diffraction analyses demonstrated that the carbohydrate materials were adsorbed between the interplanar spacings of the montmorillonitic clay. Infrared spectra analysis suggests that hydrogen bonding plays a role in the adsorptive mechanism. Extractions with bases, acids, and salts suggest that cation and anion exchange are not involved in the adsorption of these carbohydrates.
Effect of Placement and Rate of Phosphate, Potash, and Limestone on the Growth of Alfalfa and Lespedeza
Authors: Woodhouse W. W.
Published: July 2010

Placements at 2 rates each of phosphate, potash, and limestone were compared on 2 legume‐grass mixtures for a period of 3 years. The placements were surface, plow sole, and mixed with the plow layer. The mixtures were alfalfa‐orchardgrass and Kobe lespedeza‐Dallisgrass. Lime placement effects on the alfalfa‐orchardgrass mixture were very pronounced. The surface application was least effective and mixing with the plow layer was the most favorable placement. Surface placement of phosphate was inferior to the other two placements the first year while placement of potash had no effect. Placement of phosphate, potash, or lime did not measurably affect growth of the lespedeza‐Dallisgrass mixture.
Residual Availability in the Soil of Various Sources of Phosphate as Measured by Plant Absorption of P32 and by Soil Test
Authors: Caldwell A. C. , Hustrulid A. , Hammers F. L.
Published: July 2010

Ordinary superphosphate, concentrated superphosphate, calcium metaphosphate, liquid phosphoric acid, fused tricalcium phosphate, rock phosphate with colloidal clay, and rock phosphate were broadcast annually on a Kenyon silty clay loam at the rate of 40 pounds of P2O5 per acre per year for 6 years. Rock phosphate was also broadcast annually at the rate of 100 pounds of P2O5 per acre per year. Yields were secured of grain, mixed legume hay, and corn grown across these treatments. The only crop showing consistent increases in yield was mixed legume hay, and the phosphates giving responses were those in which the phosphorus was in water‐ or citrate‐soluble form or both.

The seventh year 20 pounds of radioactive superphosphate was applied across the various phosphate treatments on hay, wheat, and corn. Available phosphorus in the soil calculated from absorption data was greater—sometimes 100% or more—in the soils that had received ordinary superphosphate, concentrated superphosphate, calcium metaphosphate, fused tricalcium phosphate, and liquid phosphoric acid, than in check plots or those that had received the rock phosphates. Available phosphorus in the check and rock phosphate plots was essentially the same, as measured by absorption data. There was close correlation between Bray's adsorbed phosphorus soil test and the available phosphorus in the soil as indicated by absorption of P32, but this was not true for Bray's adsorbed and acid‐soluble phosphorus or the Thornton soil test for soil phosphorus.