Deep Sandy Soils Research Articles

Studies on some deep sandy soils in Cape York Peninsula, North Queensland. 3. Losses of applied phosphorus and sulphur

Losses of applied phosphorus and sulphur from a 100 cm profile of a deep siliceous sandy soil in Cape York Peninsula have been studied in the field over a period of three wet seasons. The P and S was applied in two treatments: superphosphate (880 kg ha-1) and 'biosuper' (1072 kg ha-1). About 50 per cent of the applied P was lost from the top 30 cm of the profile but all remained in the 100 cm depth. Only 10-30 per cent of the applied S was recovered in the 100 cm profile. Zones of P accumulation were generally related to Fe and Al content of the soil horizons. Legume growth and composition over the three seasons was adequate, and reasons for this are discussed.

The seasonal growth of lovegrass (Eragrostis curvula) on deep sandy soils in a semi-arid environment

The potential of lovegrass (Eragrostis curvula) as a perennial pasture grass on deep sandy soils in the Western Australian wheatbelt was studied at 20 deep sand sites near Meckering. The seasonal growth pattern of lovegrass resulted in over 80 per cent of annual dry matter yield being produced outside the period of most effective rainfall (April-August). Yields were considerably higher than that of annual pastures on similar soils. Highest grass yields were obtained at sites with a water table within 150 cm of the ground surface. Lovegrass is unlikely to succeed at sites without a water table because of inadequate moisture availability in summer. Two features at present detract from its value as a pasture grass in the region. Slow growth rates in winter reduce its ability to compete with winter growing annual pasture species. Low nutrient concentrations during the warmer months, especially at the highest yielding sites are likely to limit its forage value to stock. The reasons for the low nutrient concentrations are discussed.

Studies on some deep sandy soils in Cape York Peninsula, North Queensland. 1. Morphological and chemical characteristics

Deep sandy soils overlying granitic rocks are widespread in Cape York Peninsula. Rainfall is summer dominant and the annual mean is 1140 mm. Evidence is presented that some of the soils are weakly podzolised and some soil properties are influenced by an underlying clay horizon at depth. The method of soil sampling adopted permits a statistical estimate of the variability of soil chemical properties. Most data for the surface soils of this group have a sufficiently low variability both within and between sites to allow an assessment of plant nutrient status derived from associated experiments in field and glasshouse to be generally applicable throughout the region. All soils are very low in organic carbon, nitrogen, potassium, sulphur, phosphorus, copper, zinc, and exchangeable cations.

Studies on some deep sandy soils in Cape York Peninsula, North Queensland. 2. Plant nutrient status

The nutrient status of the deep siliceous sands which cover an extensive area in Cape York Peninsula has been studied in glasshouse and field experiments. Using Townsville stylo (Stylosanthes humilis) as a test legume, the soils were found to be extremely deficient in P and S, and moderately so in Zn, Cu, and K. Responses to Mo were found on most of the eight soils tested in the glasshouse but these were not confirmed at the field site in either of the two growing seasons. There was little response to Ca (lime) in spite of the very low levels of total and exchangeable Ca in these soils. Suggested reasons for this are the known tolerance of tropical legumes to low Ca supply and the fact that exchangeable Ca, although low, represented a fairly high percentage of the total exchange capacity. Levels of total N in these soils were also very low and the native grasses were able to absorb only 15 kg N ha-1 in an entire growing season. Two samples of rock phosphate (from north-western Queensland and Christmas Island) were found to be very poor alternatives to superphosphate, at least in the first season. In spite of the extreme infertility of these soils, very high levels of pasture production (> 10,000 kg of Townsville sty10 ha-1) could be achieved in well-fertilized pastures.

Root Development of Intensively Cultivated Slash Pine

AbstractRoot development of 12‐year‐old airlayers and seedlings of Pinus elliottii Engelm. was investigated after 10 years of cultural management on a moderately deep sandy soil. Cultural treatment included a factorial arrangement of irrigation vs. no irrigation, fertilization vs. no fertilization, and disking vs. a legume cover crop. Root surface area and root distribution were estimated from soil core samples, soil pits, and root excavations. Intensive culture significantly altered root surface area and root distribution. Airlayers and trees grown from seed did not differ significantly in total root surface area or in shoot growth. However, all seedlings had well‐defined taproots, while most airlayers had one to three heavy sinkers arching from the root collar to the maximum depth of rooting. Overall, 50% of the total root surface area was in the surface 0.3 m of the soil, while 6% was below 1.35 m. However, within a horizontal distance of 1 m from the bole of a tree, 42% of the roots were in the surface 0.3 m and 24% were below 1.35 m. Roots less than 2 mm in diameter made up 50% of the total root surface area. Results indicate that vegetative propagules develop equally as well as seedling stock and that both root profusely to a depth of 2.5 m.

Factors Affecting Interaction and Distribution of Haplopappus Divaricatus and Conyza Canadensis in North Carolina Old Fields

Haplopappus divaricatus and Conyza canadensis commonly appear in first—year old fields of North Carolina. Haplopappus is very rare in fields of the North Carolina Piedmont, but occurs in varying densities on the coastal plain (0—83.8% relative density in 26 coastal plain old fields). Within the coastal plain, there is no east—west or north—south trend in the distribution of Haplopappus, and no correlation with the most recent grown crop is found. Fields disturbed in fall or winter, and fields with deep sandy soils and soils with low clay content, low moisture retention, and low available nutrients had high densities of Haplopappus and correspondingly low densities of Conyza. Haplopappus plants transplanted from the coastal plain to the Piedmont survived and produced large numbers of viable seeds, but no seedlings grew the following year around these transplants. Transplants from greenhouse to coastal plain and Piedmont fields survived and grew, but those in the coastal plain had greater dry weights. Haplopappus seeds planted in three plots in the Piedmont produced only one plant which set viable seeds. In greenhouse experiments both species were more affected by competition in sandy soil than in heavy soil. Haplopappus was more sensitive to interspecific competition, but decreased nutrients reduced the competitive ability to Conyza plants more than that of Haplopappus. Drought stress, which did not affect old or young Conyza plants, reduced the growth of young Haplopappus plants. Haplopappus showed less sensitivity to specific nutrient deficiencies than did Conyza. In the field and in greenhouse flats Haplopappus seeds did not germinate in heavy soil. The presence of added organic matter in sand reduced the germination percentage of Haplopappus, as did decay products of Conyza shoots. Haplopappus seeds in petri dishes on a temperature—gradient bar germinated at lower temperatures than did Conyza seeds. Germination percentages of Haplopappus were also greater when less water was available in the substrate. It is concluded that fall and winter disturbance of old fields kills many Conyza seedlings and opens bare soil. Because Haplopappus seeds germinate at low temperatures and in bare soil, this species is able to invade these areas. If no such disturbance occurs, few Haplopappus plants will mature, because Conyza plants are better competitors. Haplopappus apparently is prevented from becoming established in the Piedmont by the inability of its seeds to germinate in heavy soil and by the superior competitive ability to Conyza plants in the richer Piedmont soils.

Properties of deep sandy soils and the growth of Lovegrass, Eragrostis curvula (Schrad.) Nees

The relationships between soil properties and the annual yield of lovegrass were studied on deep sandy soils near Meckering, Western Australia. Mean annual rainfall of the area is 378 mm, most of which falls between May and September. At sites with a water table a close relationship was established between annual yield and two properties-the depth to a water table, and the silt and clay content in the 30-60 cm layer. The relationship accounted for at least 87% of the between-site variation in yield, and was maintained between years, and over a range of nutrition levels. At sites without a water table, yield was closely related to soil mechanical composition. Where the coarse sand content in the profile exceeded 70%, survival of the grass was poor. The importance of soil moisture supply to growth of the grass in these soils is discussed, and the success of the 'edaphic' trial technique is briefly assessed.

The Yellow-Faced Pocket Gopher, Pappogeomys castanops, in Kansas

The yellow-faced pocket gopher, Pappogeomys (Cratogeomys) castanops was described by Baird in 1852 from Bent County, Colorado, and later reported from Monon, Baca County, Colorado (Cary, 1911), a locality only two miles west of the Kansas state line. Rinker (1941) reported the discovery of a fragmentary skull with lower jaws of this gopher in Meade County, Kansas, in a Pleistocene deposit approximately nine feet below the present soil zone. Later, Hibbard (1944) recorded a second skull from Meade County, which was found in a mound of dirt excavated by a plains pocket gopher, Geomys bursarius. On the strength of these two reports and the known occurence of the species in adjacent Colorado, both Cockrum (1952) and Hall (1955) included P. castanops in their lists of mammals possibly occuring in Kansas. Although extant populations of Pappogeomys castanops were sought for many years in the state, the unqualified occurrence of this pocket gopher in Kansas was not documented until May of 1968, when Robert R. Patterson of the Museum of Natural History at The University of Kansas collected eight specimens at localities in Hamilton, Finney, and Hodgeman counties. Subsequently, an additional 51 specimens of P. castanops have been obtained in Kansas by field parties from the Museum of Natural History. These specimens, which better document the distribution (Fig. 1) and add Ford, Gray, and Lane counties to the area of known occurrence (see list of specimens examined for exact localities), were collected in the periods from 19-25 May 1968, 5-8 September 1968, 15-17 November 1968, and 2-5 October 1969. Pappogeomys castanops is said to prefer deep sandy soils or open plains mantled by sandy soils (Miller, 1964; Russell, 1968). However, in Kansas we took this gopher almost exclusively in deep upland soils of the High Plains. Miller (1964) found the habitat preferences of Geomys bursarius and P. castanops to be much the same in Colorado and that G. bursarius was competitively superior. It seems plausible, therefore, that in pliable soils Geomys excludes Pappogeomys in Kansas, thus limiting the latter to those areas not inhabited by, or only peripherally suitable to, the former. To date, P. castanops has been taken in association with G.

Use of a numerical method in determining affinities between some deep sandy soils

The application of computer-based numerical methods and Adansonian concepts shows considerable promise in the grouping of certain soil units into groups or sets. In this paper relationships between 43 sites with deep sandy soils sampled from southern Australia have been determined using all variant field and laboratory data available for the surface layer. Information on 28 variant characters was available for the soil surface layer (0–8 cm) at these sites. The qualitative and semi-quantitative date was ranked and, with the quantitative data, was then standardized (zero mean, unit variance). Product-moment correlation coefficients were determined between each pair of soils and a similarity matrix formed. Grouping was carried out using a flexible sorting procedure. Additional statistical analyses of subsurrface characters and an inverse analysis showing relationships between characters were also carried out. Four main groups were delineated and these show a geographical pattern indicating that the character patterns on which the affinities are based are associated largely with geographical location. Two main character clusters were found, the first comprising chroma (wet and dry), iron, exchangeable potassium, manganese, pH and phosphorus; and the second phosphorus, nitrogen, cation exchange capacity, exchangeable calcium, exchangeable magnesium and value (wet and dry). the first cluster appears to be associated with either parent material or climate, the second with soil organic matter. The fact that phosphorus is included in both clusters emphasizes the important role of this element in these soils. Only a very broad relationship existed between vegetation and groups of sites delineated on the basis of soil characters.

Response of Slash Pine to Nitrogen and Phosphorus Fertilization

AbstractA slash pine plantation in the lower Coastal Plain of Georgia was fertilized at age 9 with 200 pounds per acre of N, 44 pounds per acre of P, and with both elements. Diameter and basal area growth response to N was obtained for each of the first 3 years following treatment, but maximum stimulation occurred the year after fertilization. Diameter growth of the largest 400 trees per acre was also significantly increased by N treatment. P supplements gave no response in the deep sandy soil. Height growth responses were not apparent.Concentration of N in needles was increased 1 year after treatment, but by the end of the third growing season, no differences were apparent for N, P, K, and Ca content in foliage. Chemical analyses are also given for L and F layers, the latter being high in N. Neither needle lengths nor soil analyses differed between treatments after 3 years.

Replacement of Turkey Oak Vegetation with Low-Growing Soil Cover

Among 15 different herbicides tested for eradication of Turkey oak (Quercus laevis Walt.) over a period of four years on Lakeland fine sand in Florida, only monuron, diuron, and fenuron at minimal rates of 10 lb/A were effective. One full growing season after application was required for complete kill. Phenoxy compounds gave variable top-kill but not satisfactory control. AMS, dalapon, and four formulations of benzoic acid were ineffective in these tests. Out of 13 different grasses, Pensacola bahiagrass (Paspalum notatum Flugge) and weeping lovegrass (Eragrostis curvula Schrad.) were best adapted to these deep sandy soils. Seedbed preparation was essential to obtain a good stand of either. After establishment, the lovegrass vigorously persisted throughout the experiment; the bahia also persisted but the lack of fertilization was extremely evident. Both grasses could be established satisfactorily on soil treated two years earlier with monuron or diuron at 10 lb/A.

Water balance and the water-table in deep sandy soils of the upper south-east, South Australia

A water-table occurs at an average depth of 11.3 m below the surface in deep sand country of the upper south-east of South Australia (County Cardwell). By observing the depth to which water penetrated into the soil profile during the wet season, and the static level of the water in bore-holes, it was proved that the watertable was not replenished by local rainfall. In three years of records, the wetting front penetrated 6.0, 2.1, and 3.6 m on the average, and the soil water thus stored was all used by the prevailing vegetation, either natural mallee heath or lucerne. The performance of the vegetation growing on the deep sand in ability to resist drought was characterized quantitatively by the supply rate of soil moisture as a function of the soil water storage. It was estimated that the yearly potential evaporation for 1957 was 113 cm. The mean annual rainfall is about 50 cm. The ground-water comes, it is suggested, from intake areas about 40 km east of the area under study, where surface floodwaters accumulate in wet seasons. The quantity of water flowing through the aquifer at present is calculated to be about 37 m3/(metre width of strip)/year.

THE NECESSITY OF ZINC FOR PINUS RADIATA

In Western Australia a number of softwood plantations have been established on poor soils. Of the many species of Pinus planted, only P. radiata and P. pinaster are practicable on many of the areas. Even in these hardy species numerous disorders arise, fundamentally owing to soil poverty. Soil analyses (5) show that phosphate is extraordinarily low in the majority of cases. At the request of the Forests Department of Western Australia, the nutrition of Pinus radiata in culture solution was studied. Field experiments (4, 5) had shown that zinc deficiency, and probably phosphate deficiency, were the most common causes of disease. Zinc spraying, and fertilizing with superphosphate, have been resorted to on a large scale. A number of puzzling features related to ''rosetting'' (as the zinc deficiency disease is called) require an explanation, such as the very slow response to even large applications of a zinc salt to the soil, and the favorable results often obtained with superphosphate. There is reason to believe that the soil contains sufficient zinc for the needs of the plant, but that it is in some way rendered unavailable. The unavailability seems to be accentuated by clearing and burning of the native forest or scrub. It is conceivable that burning, followed by heavy rains, will result in almost complete loss of zinc from the surface layers (3) of a deep sandy soil such as the one in question. The problem is further complicated by the mycorrhizal habit of the pine. One would expect the associated fungal mycelium to be a more capable assimilator of zinc than the roots of non-mycorrhizal pines. And in fact analyses of fructifications of the mycorrhizal fungus indicate a much higher concentration of zinc than in healthy leaves of Pinus radiata. This suggests the possibility that in a zinc deficient soil, the fungus exerts a priority over the limited amount of zinc absorbed by the mycorrhizae. Field trials (5) with diseased trees, using a large number of metals (including zinc, copper, manganese, boron, molybdenum, cobalt, iron, and magnesium) applied by injection, or by spraying the foliage with dilute solutions, showed that zinc alone remedied the rosetting.'' This indicated that the disease is due to a deficiency of zinc, a conclusion which is supported by analyses in which the needles of resetted,'' cured, and healthy untreated plants, exhibited a fairly definite increasing gradation of zinc content. It is not yet known, however, whether rosetting ' ' will subsequently recur in trees which have been cured by spraying, and the spray-