Inches Of Soil Research Articles

Contribution of Shrubs to the Nitrogen Economy of a Desert‐Wash Plant Community

Total nitrogen incorporated in the shrubs of a low—fertility desert plant community (principally Acacia Gregii, Cassia armata, and Larrea divaricata) was estimated from the nitrogen content of plant parts, the total weight of plants and proportional weight of roots, stems, and leaves, and the number of plants per unit area. The average nitrogen content of shrub leaves, stems, and roots was 1.31%, .87%, and .80%, respectively. Shrub cover occupied 20% of the ground surface and contained an average of 29 kg nitrogen/ha. Legume shrubs were not significantly greater in nitrogen content than nonlegume shrubs. Soil nitrogen content decreased significantly as a function of radial distance from the center of the shrub canopy. Areas between shrubs averaged 0.19% nitrogen in the surface inch of soil. Soil nitrogen content decreased significantly from the surface to 90—cm depth and was closely related to shrub species and their root—distribution patterns.

Long term effects of preplant fumigation of potato fields

The application of nematicides resulted in increased potato yields, and populations ofPratylenchus penetrans were lower for 3 years after application; but longevity of benefits of fumigating potato fields varied with the kind and amount of nematicide, application methods and with growing conditions after fumigation. Fumigation of two fields in the fall of 1965 with Vorlex, Telone, D-D, and mixtures of chloropicrin with Telone or D-D resulted in 70% to 90% control of the meadow nematode,P. penetrans, after two crops in one field, and 50% to 70% control after three crops in another. Yield increases of Kennebec potatoes averaged 42% and 16% in successive crops in the first field and yield increases of Katahdin potatoes averaged 13%, 22% and 16% in three successive crops in the other field. Fumigation resulted in 30 to 70% less vascular browning in tubers in the first two crops but there was no effect in the third crop. There was no effect on black scurf in any crop. Root injury varied proportionally with populations ofP. penetrans in roots in 1967. Populations ofP. penetrans regained injurious levels in three other fields after one crop when abundant root growth in moist 1967 followed spring fumigation with Telone and D-D. Under poor conditions for sealing of the soil following fumigation in the spring of 1968, counts ofP. penetrans collected at different soil depths after fumigation showed excellent kill below 3 inches and poorer kill in the upper 2 inches of soil.

Behavior of Pyrazon in Soil

The disappearance of 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (pyrazon) from soil was studied using Brassica species for bioassay and the spectrophotometer and chromogenic reagents for chemical determination. Loss of pyrazon from soil appeared to be an exponential function of time characteristic of the activity of soil microorganisms. On the other hand, non-biological degradation appeared negligible. Leaching of pyrazon appeared to be insignificant or minor. The greater part of the herbicide remained in the top 3 inches of soil.

Fluctuations in available mineral nitrogen in a flooded rice soil on the sub-coastal plains of the Adelaide river, N.T

Soil from the 0-3 inch and 3-12 inch layers of nitrogen fertilized and unfertilized cropped and fallow plots was sampled at two=weekly intervals throughout the growing period of flooded rice. The soil was extracted with sodium acetate-acetic acid (pH 4.8) and ammonium, nitrate, and nitrite nitrogen determined. Nitrite nitrogen levels fell from 0.4 p.p.m. before flooding to less than 0.1 p.p.m. after flooding. Ammonium nitrogen reached peak mean levels of 57 and 55 lb an acre in the surface 12 inches of the soil in fertilized and unfertilized plots respectively, eight weeks after flooding. The effect of added nitrogen was lost within four weeks of flooding. Nitrate nitrogen in the surface 12 inches of soil reached peak levels of 40 and 10 lb an acre two weeks before flooding and 28 and 25 lb an acre eight weeks after flooding in fertilized and unfertilized plots respectively. Changes in the levels of available mineral nitrogen are discussed in relation to soil pH, Eh, and temperature

Distribution, characteristics, and biotic availability of fallout, operation plumbbob. BNWL-481.

Abstract : This report includes the significant findings of CETO (Civil Effects Test Operation) Program 37, related to the distribution, characteristics, and biological availability of fallout debris originating from the Plumbbob Test Series (1957) at the Nevada Test Site. The use of aerial radiometric survey was adapted to routine radiation surveys and greatly increased the detail, accuracy and distance of fallout pattern delineation. Isodose rate and time-of-arrival contour maps are presented for seven tower mounted and four balloon mounted shots along with the predominant particle size fraction on several arcs along each fallout pattern. Particles less than 44 microns in diameter contained about 30 percent of the fallout radioactivity from tower mounted detonations as compared to about 70 percent from balloon mounted detonations within distances at which fallout arrived by H + 12 hours. Balloon mounted detonations produced fallout debris of higher water and acid solubility than did tower mounted detonations. In the environment, fallout radioactivity was apparently confined to the upper 2 inches of soil unless the soil was mechanically distributed. The majority of the fallout debris which was redistributed by environmental factors on the soil surface after original deposition consisted of less than 44 micron diameter particles; this size particle also represented the predominant contamination on forage plants. Studies clearly indicated that accumulation of radionuclides by mammals cannot be assessed only on the basis of dose rate measurements of the gamma radiation field.

Loss of Phorate from a Granular Formulation Applied in the Soil

In experiments conducted out of doors, most of the toxic residue from granular phorate in the soil had disappeared in the summer after 2 months. During the fall the residue persisted longer, and in the winter when the soil was frozen there was almost no loss of the residue. As indicated, phorate degradation or loss in the soil was dependent on the temperature. As the temperature of the soil was increased, the rate of disappearance of the phorate increased. Moisture does not affect the loss of granular phorate as much as the temperature. Regardless of the soil type, very little phorate translocated through more than 3 inches of soil. By increasing the amount of water added to the soil, an increasing amount of residue was lost by translocation. However, it represented only a small fraction of the total residue. Likewise, barley plants absorbed only a very small percentage of the phorate which was present in either sandy loam or muck.

Effects of Winter Cultural Practices on the Pink Bollworm in Arizona

Eight soil-tillage practices were evaluated during the winter and spring of 196H7 for control of Pectinophora gossypiella (Saunders). Best results were obtained where the top 6 inches of soil were thoroughly pulverized with a Howard Rotavator. Plowing with a moldboard plow to a depth of 6 inches (medium plowing) was more effective in reducing moth emergence than plowing to a depth of 12 inches (deep plowing) or chisel listing. Cultipacking medium-plowed soil resulted in no decrease in moth emergence, However, moth emergence was reduced considerably in the deep-plowed treatment when it was followed with cultipacking. A greater proportion of moth emergence was, i.e., the moths emerged after cotton began to square, in the treatments where the soil was plowed deeply.

Lead Shot Ingestion by Mourning Doves and Incidence in Soil

Biologists in Tennessee collected 1,949 gizzards from doves harvested on fields managed for public hunting. One percent of the doves had ingested between 1 and 24 lead shot. Preand posthunt soil samples were collected from a field with a history of 8 years of managed public dove shooting. In the top % inch of soil there were 10,890 shot per acre before the September 1 and 2 hunt. The posthunt sample indicated 43,560 shot per acre in the top 3/% inch. For four decades wildlife managers have known that lead poisoning is an important cause of annual mortality to waterfowl. These losses continue to be a management problem (Bellrose 1959, Mississippi Flyway Council 1965, Bagley et al. 1967). Recent cases of lead poisoning in game birds have stimulated interest in spent lead shot as a cause of wildlife mortalities. Locke and Bagley (1967:515) reviewed literature reporting lead poisoning in bobwhite (Colinus virginianus), pheasant (Phasianus colchicus), mourning doves (Zenaidura macroura), and scaled quail (Callipepla squamata). Ingested lead shot was found in bobwhite gizzards being examined for food habits studies in Alabama (C. A. McConnell, personal communication) and Texas (C. J. Barstow, personal communication). Locke and Bagley (1967) also reported the capture of an emaciated immature mourning dove whose gizzard contained two lead shot. The tibia and liver of this bird showed concentrations of lead of 187 ppm and 72 ppm respectively. These authors examined 62 gizzards from hunter-killed doves and in four found 1-3 ingested lead shot. They also found the lead content of 40 dove livers to range from 0.4-14.0 ppm (wet weight). Bagley and Locke (1967), 1 Present address: Oklahoma Cooperative Wildlife Research Unit, Stillwater. 476 studying the concentrations of lead in normal liver tissue of birds, reported a range of 0.4-7.0 ppm for mourning doves. McConnell (1967) studied experimental lead poisoning of quail and mourning doves. Ten percent of the quail and 32 percent of the doves died after being fed lead shot. Some doves died after ingesting between 5 and 35 shot. Others survived when fed as many as 20 lead shot. The increasing popularity of dove hunting and increased public and private dove field management are resulting in concentrations of spent shot which might cause substantial lead poisoning losses of upland game birds. McCartney (1964:185) surveyed the 31 states having an open season on mourning doves. Of these, 18 reported they had dove field management programs of some kind. As Crider (1965:57) pointed out, Since the inclusion, in 1960, of 'normal agricultural plantings' in the hunting methods permitted for migratory birds, public dove hunting programs have rapidly expanded. In 1962, a single large field near Miami, Florida, provided 11,289 doves for approximately 2,400 hunters. Most fields managed by the Florida Game and Fish Commission contain between 125-500 acres. Tennessee has been managing fields for public dove hunting since 1959. These fields are located on wildlife management This content downloaded from 207.46.13.120 on Wed, 14 Sep 2016 05:11:32 UTC All use subject to http://about.jstor.org/terms LEAD SHOT IN MOURNING DOVES * Lewis and Legler 477 areas, often waterfowl areas, adjacent to reservoirs where equipment and personnel are already available to carry out the agricultural operations. The same fields are often hunted year after year, resulting in a buildup in deposits of spent shot, defined as shotgun-fired pellets which fall to the ground after losing their momentum. Brakhage (1966) found up to 122,839 shot per acre in the top 2 inches of soil around shooting blinds at the Duck Creek Wildlife Area in Missouri. Bellrose (1959) reported on a series of nationwide studies of lead shot accumulation on waterfowl hunting areas. The square-foot samples taken in the various studies ranged from 1/2 to 10 inches deep. Accurate comparisons cannot be made but shot accumulations on 24 areas ranged from 0 to 118,048 per

Initial Soil Penetration by Insecticide Emulsions Used for Subterranean Termite Control1

Among 7 soils from various parts of the United States, chlorinated hydrocarbon insecticide emulsions penetrated least in arid soils from Arizona and Oregon and most in soil from Missouri. Soil moisture at application time appeared to enhance penetration. After 24 hours in most tests, more than half of the insecticide applied was found in the upper ¾ inch of soil. The parts per million of insecticide measured in 6 layers of soils did not differ appreciably in samples taken 1,4, and 24 hours after application. Chlordane, dieldrin, and heptachlor were the insecticides tested.

Título en español.

El abonamiento abundante y las aplicaciones variables de cal a un suelo Cialitos arcilloso (ultisol) durante 7 años consecutivos afectaron marcadamente las propiedades de este suelo y los rendimientos de la caña de azúcar que se sembró luego. Durante el período, las aplicaciones de abono por acre a todas las parcelas fueron 3,680 libras de nitrógeno, 480 de fósforo y 2,870 de potasa. Los rendimientos de la caña aumentaron de menos de 1 tonelada por acre cuando no se aplicó cal, a 40 toneladas cuando se aplicaron 20 toneladas de cal por acre, durante el período de 7 años. Los rendimientos aumentaron, según aumentó el contenido de bases intercambiables en el suelo, de menos de 10 toneladas por acre cuando el contenido era inferior a 3 meq./100 g. de suelo, a más de 40 toneladas cuando estas bases excedieron a 8 meq./100 g. de suelo (58 por ciento de saturación). Los rendimientos aumentaron, según fue disminuyendo el aluminio intercambiable en el suelo, de menos de 10 toneladas por acre, cuando este elemento excedió de 8 meq./100 g. de suelo, a más de 40 toneladas, cuando el contenido de aluminio fue menor de 2 meq./100 g. de suelo. Los rendimientos aumentaron según fue aumentando el pH del suelo, pero la presencia de sales solubles en este suelo, tan abundantemente abonado, hizo que el grado de pH fuera un criterio inadecuado para determinar la necesidad de aplicar cal. La aplicación de 8 toneladas de cal sobre la superficie de un suelo Cialitos arcilloso muy ácido, antes de sembrar la caña, aumentó el rendimiento de ésta de un promedio de 12.4 a 34.5 toneladas por acre y redujo el contenido de aluminio intercambiable de 7.3 a 0.5 meq./100 g. de suelo. Tanto la composición foliar de la caña de 9 meses, como su contenido de sacarosa, no fueron afectados por los factores de suelo que se estudiaron o por las aplicaciones de cal, y continuaron a niveles satisfactorios en las parcelas experimentales de las cuales se obtuvieron producciones, de aproximadamente 0 a más de 40 toneladas de caña por acre. En un reconocimiento que se hizo se encontró que muchos de los suelos que se dedican a la producción de la caña de azúcar en la Región Húmeda del País contenían una cantidad de aluminio intercambiable mayor que la que causó una reducción en el rendimiento de la caña en el experimento que aquí se describe y que se llevó a cabo en un suelo Cialitos arcilloso.

Alteration of Surface Soil Characteristics by Four Tree Species

Changes in soil proprties were studied in a 30—year—old mixed plot plantation of Norway spruce (Picea abies (L.) Karst.), red oak (Quercus rubra L.), white pine (Pinus strobus L.), and red pine (P. resinosa Ait.). The species plots were arranged in a Latin square. The surface 5 inches (12.8 cm) of soil below Norway spruce contained the highest percentage of organic matter and the greatest pore volume of the four species. However, it had a slower inflitration rate than the soil supporting the other two conifers, but not as slow as that below oak. Organic matter content in the soil below all species decreased rapidly with depth. Differences in the nitrogen, postassium and calcium content of the soil below the four species were concentrated in the surface 2 inches of soil and generally disappeared below that level. Soil below Norway spruce had the highest concentrations of the three aforementioned elements at the surface inch and that of white pine the least. The amount and quality of litter—derived organic matter in the soil was evidently the key factor in determining differences in the nutrient content of the soil in which these four tree species were growing.

Spring Soil Temperatures Related to Drainage Problems

Drainage problems persist in many irrigation districts where alfalfa, irrigated by the border method, is grown extensively. Early spring growth of alfalfa results from root activity (water removal) in only the upper inches of soil where a wide range of daily soil temperature fluctuation occurs. Attempting to replenish depleted soil moisture in this shallow root zone by irrigating with the border system results in applying excess water. In areas susceptible to high water table fluctuations, excess irrigation water causes alfalfa to become shallow-rooted. Shallow-rooted alfalfa requires frequent irrigation, but each irrigation further contributes to the water-table problem. An alternative corrective measure is presented. The principal feature involves delaying the first irrigation in the spring until the soil temperature at 18 in. reaches 12.8○ C (55○ F).

Quantitative Estimates of Mycorrhiza Populations in Radiata Pine Forests

SUMMARY A description is given of a technique for assaying the mycorrhizas found in a forest soil using a wet sieving method with two B.S.S. standard sieves of mesh size 0.066 and 0.0197 inches. Sampling is restricted to the top six inches of soil, from which the samples are collected with a corer. After extraction from the soil cores, the mycorrhizas are counted on a 10-inch square grid subdivided into numbered, one-inch squares that are further subdivided into 0.1-inch squares. A travelling stereo-zoom binocular microscope is used to examine and count the mycorrhizas on randomly-sampled 1-inch squares. It is estimated that there are about 580kg/acre of mycorrhizas in the top six inches of a good quality radiata (P. radiata D. Don) forest soil, and that approximately 55.2 per cent of them are living. A proposal is made that the results of future mycorrhiza assays include an ‘attrition ratio’, (ratio of inactive mycorrhizas to the total number seen in the sample). Examples are given of the use of this exp...

Ecological Studies on the Eggs of the Northern Corn Rootworm1

The northern corn rootworm, Diabrotica longicornis (Say), adult was found to oviposit in the soil between plants within a row of maturing corn fields. Eggs were found in decreasing numbers at 4, 8, and 10 inches from the row but none were found in the middle between 40-inch rows. The depth of egg deposition is probably governed by the degree of soil cracking, but an average of 4 samples in 1963 and 1964 showed 92.8% of the eggs in the top 4 inches of soil. In a separate study, 88% of the eggs were noted in the upper 3 inches of soil, but after plowing to a depth of 9 inches, all eggs were recovered from the 3- to 9-inch layer. Sampling between plants in several fields before plowing showed 19-558 eggs per 100 cubic inches of soil 4 inches deep. Subsequent larval counts indicated 0.19 larva per egg detected by the particular egg assay employed. Hatch occurs in northern corn rootworm eggs after diapause is broken by low temperatures, but hatch was found to be reduced or prevented when the microclimate was –2°C or below for 6 or more weeks. Spring-collected eggs held in a refrigerator (around 4.4°C) for 24 months displayed a normal hatching pattern when removed to ambient laboratory temperatures. Eggs taken from the field in early spring showed first hatch in 15.3 days when held at 25°C, but when spring-collected eggs were held at 4.4°C for 8 months first hatch occurred 9.7, 14, and 18 days after being placed at temperatures of 26.7, 22.8, and 18.3°C, respectively. This fact might indicate some physiological development of diapause-free eggs retained at 4.4°C. No eggs hatched when incubated at 31.7 or 33.9°C. Contact moisture was employed for all studies on embryonic development. Laboratory-produced eggs retained at ambient laboratory temperatures displayed 13.3% hatch in the absence of a chilling period. Likewise, eggs collected from the field on October 12 showed 21.4% of the eggs free of diapause.

Seasonal Trends in Mineral Nitrogen Content of the Soil in a Long-Term Npk Trial on Dessert Apples

SummaryThe seasonal levels of ammonium and nitrate nitrogen were determined, over 3 years, within the top 24 inches of soil of a long-term NPK trial on dessert apples. The four treatments selected provided comparisons of cultivated and grassed plots receiving spring applications of Nitrochalk with those having received no nitrogen since 1930. The three seasons included a very dry one in 1959 and the unusually wet summer of 1960.Ammonium nitrogen did not persist as such for long periods, and nitrate nitrogen was the major form of mineral nitrogen.There was a marked contrast between the levels under the two management systems. Grass maintained a low level throughout most of the season, whereas a steady rise in nitrate nitrogen took place until July or later in the cultivated soil; thereafter, the level fell in response to rainfall. By mid-winter, very little nitrate nitrogen remained in the 24-inch profile.Applications of nitrogenous fertilizer did not markedly affect the mineral nitrogen status in the gras...

Coastal Bermudagrass Response to Applications of P and K as Related to P and K Levels in the Soil

AbstractThe response of Coastal bermudagrass (Cynodon dactylon L. Pers.) to applications of P and K as related to P and K levels in the loamy sand and sandy loam soils of the Lakeland‐Norfolk series was studied from 1959 to 1963. The annual rate of 240 lb N/acre was applied in four applications. Effect of treatment on yield, plant content of P, K, Ca, and Mg, and change in soil test values of the surface 24 inches were determined each year.The relationships between yield and soil test P and K were described by curves calculated with a modification of the Mitscherlich equation to the form log (A − y) = log A − bc using data for initial and final years. The curves obtained showed yield response to P at soil test values < 25 ppm P and yield response to K at soil test values < 40 ppm K. Chemical analysis of samples from the surface 2 inches of soil was representative of the P and K fertility.Plant contents above 0.16% P and 1.0% K were adequate for maximum production.A fungal disease apparently associated with K deficiency was observed on plots receiving no K at 10 of the 18 locations in 1961 and subsequent years.

Lateral Root Development in Progenies of Creeping and Noncreeping‐Rooted Medicago sativa L.1

Progenies between 2 creeping‐rooted and 2 noncreepingrooted clones crossed in all combinations were evaluated for differences in root development. Plant heights and dry weights of tops and roots were measured.Lateral root development began within the first 3 months of growth and a cross involving 2 creeping clones produced the highest proportion of progeny with lateral roots. The first vigorous lateral roots produced on plants from creeping ✕ creeping clones were closer to the crown (nearer the soil surface) and formed a larger angle with the main root than laterals on plants from noncreeping ✕ noncreeping clones. Crosses of the 2 creeping‐rooted clones produced more plants with adventitious shoot sites on roots and more sites per plant than other crosses. Adventitious shoots were observed as early as 5 months after planting.Forage yields between progenies of creeping ✕ creeping and noncreeping ✕ noncreeping crosses were not significant. Negative but nonsignificant correlations were found between the distance from the base of the crown to the first vigorous lateral and the angle formed between this lateral and the main root. Dry weight of the roots in the top 18 inches of soil was positively and significantly correlated with height and yield. The lateral roots on the creeping‐rooted plants developed early and suggested that such types less than one year old may resist heaving better than noncreeping types.

Frequency and Rate of Irrigation as Factors in Forage Growth and Water Absorption1

SynopsisAlfalfa irrigated with 3 inches of water whenever available soil moisture to an 18‐inch depth was 60, 40, 20, or 0% produced relative yields of 100, 81, 63, and 37%. Moisture absorption was greatest in upper 6 inches of soil and decreased when available soil moisture dropped to 25 to 30%. Below 15% available soil moisture, plants showed moisture stress and rate of stem elongation dropped almost to nil. Similar water efficiency in production of top growth, decreased production, and rate of stem elongation as soil approached the permanent wilting point indicates that water is not equally available between field capacity and permanent wilting point.

Soil Conservation Measures Benefit the Nilgirı Farmers

Soils are the natural bodies on which plants grow. The top few inches of soil which is called "Top Soil" is the most fertile portion containing the needed plant nutrients, organic matter and favourable physical properties. It is this layer that has to be preserved and properly managed for obtaining sustained and successful agriculture. If through man's folly of land neglect and faulty agricultural practices, this productive layer of soil is lost, the land not only loses the capacity to sustain crops but also its productivity until cultivation is rendered unprofitable, if not unsuccessful.

The Influence of Vegetation on Soil Thermal Regime at the San Dimas Lysimeters

AbstractSoil temperatures for four lysimeters (bare, grass, scrub oak, and pine) during a 7‐year period (1952–1959) were studied. Observed temperature data of each lysimeter was subjected to harmonic analysis reducing the temperature time curves to a series of Fourier coefficients and the following empirical equations: Tz = 62.70 + 18.53 exp (−0.1273z) sin (30t − 8.15 [3] −7.98z) °F. for the bare lysimeter Tz = 58.20 + 16.02 exp (−0.1240z) sin (30t − 16.17 [4] −7.22z) °F. for the scrub oak lysimeter Tz = 60.44 + 18.32 exp (−0.1167z) sin (30t − 15.48 [5] − 7.05z) °F. for the Coulter pine lysimeter Tz = 60.96 + 17.43 exp (−0.1179z) sin (30t − 16.15 [6] −7.19z) °F. for the grass lysimeter Presence of vegetation has altered the soil temperature regime by reducing mean annual soil temperature and temperature amplitudes. Vegetation has introduced patterns of time delay in the soil temperature profile characteristic of the vegetation cover and directly related to the soil moisture regime. When the lysimeters with vegetation cover are compared, the influence of vegetation is of varying magnitude as shown by marked differences in soil temperature regime and soil thermal properties.With exception of the top 6 inches of soil, observed data for the average annual cycle of temperature agrees well with calculated values using the theory of heat flow. The slight difference in average monthly temperatures are much smaller than the natural differences from year to year.