Deep Sandy Loam Research Articles

Assessment of agricultural potential of a river command using geo-spatial techniques: a case study of Himalayan river project in Northern India

Agriculture and associated sectors are one of the primary sources of living for the global population. Sustainability in agriculture will yield long-term benefits requisite to accomplish development and mitigation of resource scarcity. Hence, realistic assessment of water requirement for agricultural use or alternatively agricultural potential from available water resources is imperative to sustainable water management keeping in view of possible scarce situation in relation to freshwater availability across the Globe. The present study focuses on assessment of the water requirement for potential agricultural use for the command area of a Himalayan river project, namely Gandak river project in Northern India using extensive geo-spatial techniques. Detailed information of extensive canal network is derived from high-resolution satellite images using GIS tools, along with other spatially distributed information for relevant parameters such as rainfall, temperature, soil type, elevation, water-holding capacity and agricultural productivity. The study reasonably identifies the spatial variability in water requirement potential in the project command with rational indication of maximum water demand in north-central section of the study area where the lowest aridity index characterized by very low slope and deep sandy loam soil is recorded. Efficient usage with growing scarcity of this essential natural resource warrants efficiency optimization of water usage with realistic assessment. This approach unlike traditional method uses high-resolution satellite data that are more scientific and accurate and will undoubtedly facilitate development of rational decision support system for efficient management of available surface water use for different purposes in the region.

Hydraulic Properties in Different Soil Architectures of a Small Agricultural Watershed: Implications for Runoff Generation

Soil architecture exerts an important control on soil hydraulic properties and hydrological responses. However, the knowledge of hydraulic properties related to soil architecture is limited. The objective of this study was to investigate the influences of soil architecture on soil physical and hydraulic properties and explore their implications for runoff generation in a small agricultural watershed in the Three Gorges Reservoir Area (TGRA) of southern China. Six types of soil architecture were selected, including shallow loam sandy soil in grassland (SLSG) and shallow loam sandy soil in cropland (SLSC) on the shoulder; shallow sandy loam in grassland (SSLG) and shallow sandy loam in cropland (SSLC) on the backslope; and deep sandy loam in grassland (DSLG) and deep sandy loam in cropland (DSLC) on the footslope. The results showed that saturated hydraulic conductivity (Ksat) was significantly higher in shallow loamy sand soil under grasslands (8.57 cm h−1) than under croplands (7.39 cm h−1) at the topsoil layer. Total porosity was highest for DSLC and lowest for SSLG, averaged across all depths. The proportion of macropores under SLSG was increased by 60% compared with under DSLC, which potentially enhanced water infiltration and decreased surface runoff. The landscape location effect showed that at the shoulder, Ksat values were 20% and 47% higher than values at the backslope and footslope, respectively. It was inferred by comparing Ksat values with 30 min maximum rainfall intensity at the watershed, that surface runoff would be generated in SSLC, DSLG, and DSLC sites by storms, but that no overland flow is generated in both sites at the shoulder and SSLG. The significantly higher Ksat under grasslands in comparison to croplands at the backslope indicated that planting grasses would increase infiltration capacity and mitigate runoff generation during storm events. The findings demonstrated that croplands in footslope positions might be hydrologically sensitive areas in this small agricultural watershed.

Evapotranspiration of Onion in Sahelian Niger

SUMMARYIrrigation responses of three locally adapted onion cultivars were studied in drainage type lysimeters and under field conditions on a deep sandy loam soil, free of salinity problems, at Maradi in Niger. Evapotranspiration (Et) was established by the water balance method, and used to establish the rate of water use. The peak rate of water use was 7.5 mm per day during the bulb formation stage. Irrigating onions when the available soil moisture to a depth of 20 cm had been depleted by 40% increased the yield more than irrigation at 60 or 80% depletion. The mean yield from plots receiving frequent irrigation was 33 t ha−1.Evapotranspiratión de la cebolla en el sahel nigeriano

Leaf responses to soil water deficits: Comparative sensitivity of leaf expansion rate and leaf conductance in field-grown sunflower (Helianthus annuus L.)

The relative importance of changes in leaf expansion rate (LER) and leaf conductance (g1) in the control of crop transpiration depends primarily on their sensitivity to soil water deficits. The aim of this paper was to quantify the responses of LER and g1 to soil water deficits in sunflower (Helianthus annuus L.) under conditions of moderate (spring) and high (summer) evaporative demand. Soil water content, g1, and LER were measured in dryland (DRY) and daily-irrigated (WET) crops established on a deep sandy-loam (Typic Xerofluvent) in a Mediterranean environment. There was no difference between g1 of DRY and WET plants (p>0.20) in contrast with a highly significant difference in LER (p<0.001). Even under the harsh conditions of the summer experiment, g1 did not respond to water deficit in a ten-day period in which LER of DRY plants was reduced to approx. 30% of that measured in WET controls. This field study indicates that g1 plays at most a minor role in the control of sunflower transpiration in the pre-anthesis period and confirms the importance of leaf expansion in the regulation of gas exchange of expanding canopies subjected to soil water deficits.

Long-term Response of Early Maturing Peach Trees to Postharvest Water Deficits

Early maturing peach trees [Prunus persica (L.) Batsch cv. Regina] growing on a deep sandy loam soil were subjected to three levels of postharvest irrigation over 4 years. The control treatment was irrigated with ≈ 10 to 15 cm of water at 2- to 3-week intervals, the medium treatment received a single irrigation (20 to 30 cm) in early August, and the dry treatment was not irrigated between early to mid-June and mid-October. All received a predormancy irrigation of 10 to 15 cm in mid- to late October. Flower and fruit density were greater in the dry treatment than the control. The occurrence of double fruit was also greatly increased in the dry treatment but not in the medium treatment, when compared with the control. After normal commercial hand thinning, yields and fruit size were no different among the three treatments over all 4 years. Vegetative growth as measured by dormant pruning weights, trunk radial growth, and canopy shaded area was reduced in the dry treatment, but there was no indication of progressively declining vigor. Soil moisture determinations indicate that water use by the control occurred mainly in the upper soil profile. In the dry treatment, as the upper profile dried, water was extracted progressively deeper, down to at least 300 cm. The main disadvantage of severe postharvest water stress was the substantial increase of double fruits.

Essai de resemis d'espèces pastorales autochtones en Tunisie centrale

Two seed mixtures of indigenous pastoral plants have been seeded in Central Tunisia (Sidi Bouzid) in natural conditions (October 1990). The first mixture was composed of Lotus creticus, Plantago albicans, Stipa lagascae and Hedysarum carnosum. It has been broadcast seeded on a deep sandy loam fallow. The second mixture was composed of Stipa parviflora, Artemisia herba-alba and Cenchrus ciliaris. It has been broadcast seeded on a shallow and gravely alluvial clay loam. At both sites, divers techniques have been applied to improve the soil moisture balance and fertility and to optimise seeding date versus rain fall. The effects of these techniques on the emergence and survival of the seedlings have been evaluated observing the evolution of plant densities. These measures have revealed interspecific differences concerning emergence and survival capacities. Stipa lagascae has shown to be the best for the installation in a sandy soil, while Artemisia herba-alba was the best performing species in the alluvial soil, which receives run-off water from the surrounding slopes. The already existant seed stock has given rise to an important density of adventice plants. Vigorous as they were because of the applied fertilisers, they competed strongly with the seeded species. The best choice of plant material, the improvement of the soil moisture balance and the reduction of its initial seed stock should add to more succès in the revegetation efforts of degraded arid pastures.

Root distribution of kiwifruit (Actinidia deliciosa) in a deep sandy loam soil of the Te Puke district, New Zealand

Abstract Quantitative data on the root distribution of mature kiwifrit vines — Actinidia deliciosa cv. Hayward (A. Chev.) C. F. Liang et A. R. Ferguson — growing in a deep sandy loam soil of the Te Puke district were obtained by coring. Root distribution followed a pattern which appeared to be influenced by the soil horizons. Root density varied from 0.01 to 1.95 cm/cm3. In a total sampling depth of 4 m, 46% of the total root length was found between 2 and 4 m. It appears likely that substantial root densities exist at even greater depths. The mean length of root/unit ground surface area (129 cm/cm2) was higher than the values recorded for many other temperate fruit crops. Comparison of cores taken at 0.5 and 1.5 m from vine stems revealed relatively little decline in root density over this distance.

Influence of Different Levels of Irrigation and Nitrogen on Yield and Nutrient Uptake by Wheat1

AbstractIrrigation and fertilizers are two vital but costly inputs in irrigated agriculture. Their economic use demands that maximum yield should be obtained per unit application of these inputs. A constraint on irrigation water supply must accompany a corresponding cut on fertilizer application and vice versa. A study was, therefore, conducted to find out the response of wheat (Triticum aestivum L.) to different levels of irrigation and N for 3 years in a deep sandy loam soil underlain by a clay loam, belonging to the family fine loamy, hyperthermic, mixed, calcareous, Typic Ustocherpt. The irrigation treatments were check, 1, 2, and 3 irrigations applied according to irrigation water applied per pan evaporation ratio of 0.90 and N levels were 60, 80, 100, and 120 kg N/ha. In the normal rainfall years of 1974–75 and 1976–77, wheat yield increased with number of irrigations. In the unusually wet year of 1975–76, however, response to irrigation was non‐significant. No response was observed beyond a N application of 80 kg/ha without irrigation, whereas, the response was linear up to 120 kg N/ha in the three irrigation treatment. The uptake of N was a linear relationship with crop yield. Apparent water use by the crop increased in the high rainfall year and with increasing number of irrigations.

Growth and yield of sugar beet on contrasting soils in relation to nitrogen supply: I. Soil nitrogen analyses and yield

SUMMARYNine field experiments with sugar beet in 1968–70 tested eight amounts of nitrogen fertilizer (0–290 kg N/ha) on a shallow calcareous loam (Icknield Series), on a deep sandy loam (Newport Series) and on a heavy clay loam (Evesham Series). Top soils and subsoils, sampled during autumn, winter and spring before the experiments, were analysed by several methods for available and potentially-available nitrogen. The largest increases in potentially-available mineral-nitrogen shown by incubation occurred in the calcareous loams every year in both top soil and sub-soil, and the sandy loam, particularly the sub-soil, generally produced least. Attempts to forecast the optimum nitrogen fertilizer dressing from the soil analyses were moderately successful, the best technique being anaerobic incubation of air-dry soil; the date of sampling had little effect. The optimum dressings were always between 0 and 125 kgN/ha, the calcareous loams generally needing least nitrogen fertilizer and the loamy sands most.

Growth and yield of sugar beet on contrasting soils in relation to nitrogen supply: II. Growth, uptake and leaching of nitrogen

SUMMARYNine field experiments with sugar beet in 1968–70 tested eight amounts of nitrogen fertilizer (0–290 kg N/ha) on a shallow calcareous loam (Icknield Series), on a deep sandy loam (Newport Series) and on a heavy clay loam (Evesham Series). The amount of mineral nitrogen in the top and sub-soils was determined before applying fertilizer and at monthly intervals from May to October in plots given 0, 125 and 250 kg N/ha. The crop on these plots was also sampled at monthly intervals throughout the growing season and the yield and nitrogen uptake determined. The soil analyses indicated that in springs with average rainfall, the leaching losses of nitrogen fertilizer are negligibly small, although there was some evidence that losses may be greatest on sandy loams. In very wet springs such as 1969, with almost double the normal rainfall, losses through leaching are considerable – on average, 40 kg N/ha. Dry-matter yields and response to nitrogen fertilizer differed between the three soils consistently from year to year. On the calcareous loam, neither amount of fertilizer changed the dry-matter yield of roots in any year. The crop on the clay loam needed a small dressing and on the sandy loam a larger dressing of fertilizer for maximum root dry-matter yield. Uptake of nitrogen by the crops usually paralleled the decreases in soil mineral nitrogen although on the clay loam nearly a third of the nitrogen applied could not be accounted for in the soil or plants, suggesting that some denitrification may have taken place. When the amount of nitrogen taken up by unfertilized crops is allowed for, the percentage recovery of applied fertilizer nitrogen at final harvest ranged from 42% on the calcareous loams to 62% on the sandy loams.

Qanats on the Varamin Plain, Iran

THE VARAMIN PLAIN is situated in northern Iran, 40 km south-east of the capital Tehran, and lies between the barren slopes of the Elburz mountains and the desolate salt waste of the Great Kavir (Fig. i). It covers an area of approximately I300 km2, and owes its origin to alluvial deposition in the form of a large cone, at a point where the Jajerud (River Jaj) leaves the foothill zone. The highest point of the plain reaches II o m at the mouth of theJajerud, and drops to 800 m some 50 km farther south on the edge of the desert. The plain is almost completely flat, and the drainage of theJajerud consists of a maze of braided channels incised i-5 m below the general level of the plain. The climate is of the continental desert type. Rainfall is low and comes mainly in the form of light showers between December and April. Precipitation totals over the plain average about ISo mm, but yearly variations from 54 to 230 mm have been recorded. The winters are cold with a mean January temperature of 3.7°C, and a minimum recorded temperature of - I7°C. Air frosts are common in December and January, but snowfall is rare. In contrast, the summers are extremely hot and dry, with a meanJuly temperature of28.9°C, and maximum recorded temperatures up to 47°C. The prevailing winds in summer are from the south-east, and bring with them large quantities of dust from the edge of the Kavir. Geologically, the plain is a structural basin at the southern margin of the Elburz mountains, formed by the downwarping of Palaeozoic and Mesozoic sediments and Eocene volcanics. In this basin thick Miocene beds were laid down, and more recently thick alluvial deposits from the Jajerud. On the plain itself, all evidence of the older strata is deeply buried beneath recent alluvium, except for a discontinuous line of hills stretching westward from Pishva. In the Pishva ridge, Tertiary or Mesozoic limestone is exposed together with Miocene gravels, while in the extreme western part of the plain, Oligo-Miocene andesitic lavas rise from beneath alluvial deposits to form steep-sided massifs. The recent alluvial gravels, which are in places more than 250 m in thickness, consist mainly of coarse gravels at the apex of the fan, grading to clays and fine-grained loessic material at the desert margin. The soils of the plain are derived from the alluvial deposits of the Jajerud and eolian material from the Kavir. Three main soil associations can be distinguished. Near the mouth of theJajerud, the parent material is coarse gravel, and the soils are thin and lack horizon development. The absence of fme-grained material and organic matter means that these soils have little agricultural value. To the south of the alluvial cone and forming most of the area of plain are deep sandy loam or silty loam soils. These desert to semi-desert soils possess good arable and irrigable qualities, and form the basis of the agricultural productivity of the plain. Calcium carbonate accumulations are common in the profile of these soils and, where there has been no recent irrigation, salt accumulations are sometimes found. Where these soils lack protective vegetation cover they are particularly susceptible to wind erosion. On the extreme southern and western margins of the plain Solonchak soils are found. In this area a high saline

Rate of Incisor Growth in the Mountain Pocket Gopher

Since pocket gophers use their incisor teeth to excavate rather extensive burrow systems in hard soil, their rate of incisor growth and attrition is unusually high (Howard and Smith, 1952). The purpose of this study was to compare the rates of incisor growth of pocket gophers from different habitats, and to determine the extent to which extrusive incisor growth is a subspecific adaptation to local habitat conditions. I am grateful to Drs. Ernst Mayr and Richard M. Hansen for suggestions during the preparation of the manuscript, and to Dr. Elmer Remmenga for advice on statistical procedures. Methodsand materials .—The pocket gophers used in this study were collected from two ecologically different localities, each within the range of a different subspecies of Thomomys talpoides . One of the localities, Black Mesa, is located on the western slope of the Rockies about 27 miles west of Gunnison in Gunnison County, Colorado. The elevation of this locality is approximately 10,000 feet, the growing season is short and, although there is a fairly heavy winter snowfall, the total annual precipitation is low. The Black Mesa sample was taken from mountain meadows in which the vegetation is predominantly grasses and mixed forbs and the soil is relatively coarse and shallow. The other locality is at Livermore, Colorado, on the eastern slope of the Rocky Mountains, about 20 miles north of Fort Collins in Larimer County, at an elevation of approximately 6,200 feet. The gophers from Livermore were trapped in irrigated alfalfa fields where the soil is a deep sandy loam. Although the gophers from Black Mesa differ from topotypes of Thomomys talpoides fossor Allen, they are at present assigned to this subspecies; those from Livermore belong to the subspecies retrorsus Hall. Pocket gophers from deep soils and low elevations tend to be larger on the …

British Society for the Promotion of Vegetable Research

A STATION for research in vegetable production in Great Britain has now been established under a governing body constituted as a company limited by guarantee and without a share capital, with the title of the Britian Society for the Promotion of Vegetable Research. For the funds for its work, the Society will at the outset depend on grants from the Ministry of Agriculture (for stations in Scotland, from the Department of Agriculture for Scotland). The Agricultural Research Council will exercise general scientific guidance and will supervise the work and staff of the Society. The members of the governing body twenty—three in number—include nominees of the Ministry of Agriculture and the Department of Agriculture funjScotland, the Department of Scientific and Industrial Research, various learned societies, universities and institutions concerned with horticulture, vegetable producers large and small (through the National Farmers’ Union and that of Scotland, and the National Allotments and Gardens Society) and trade interests. The chairman of the Society is “Prof. F. T. Brooks, of the University of Cambridge, and the director of the research station is Dr. James Philp (see Nature, 161, 715 ; 1948). The headquarters research station will be at Wellesbourne, Warwickshire (where the registered office of the Society will also be situated), and consists of 280 acres of deep sandy loam over gravel or keuper clay ; the land is being purchased by the Ministry of Agriculture and will be leased to the Society. The site is admirably suited to research on vegetables; but some time must necessarily elapse before buildings and equipment can be provided, staff engaged and the farm generally developed for research purposes. The Ministry is also leasing to the Society 150 acres of land which it owns at Paglesham, Essex, for a substation primarily to be used for the multiplication of stocks of seed of vegetables bred at the main station or elsewhere. A second sub-station is the former Horticultural Research Station at Cambridge, which has been taken over from the University of Cambridge, and the staff of which will continue to work there until they can be transferred to the head-quarters station.

Snowdrifts as a Factor in Growth and Longevity of Shelterbelts in the Great Plains

In 1934 and 1935 a survey was made of shelterbelts in the Great Plains (Hayes and Stoeckeler, '35) to determine which species had survived the recent drought years, and to study soil adaptability, longevity, and comparative effectiveness of belts of various composition and design. This survey revealed that, on lines of apparently equal effective rainfall, tree plantings in the northern plains had an average life span of about 20 years more than in the central or southern plains. This is explained partly on the basis of a longer growing season in the south and a more rapid exhaustion of the subsoil moisture. Another point of interest was the fact that tree plantings remained thrifty for a much longer time on deep sandy loam soils than on heavy soils such as clays or clay loams. This difference was much more striking in the southern than in the northern plains. Subsequent moisture samplings in the southern plains (Stoeckeler and Bates, '39) revealed a greater supply of available soil moisture in the sandy soils, and this was attributed to higher infiltration rate, relatively deep storage of water, and less evaporation loss. It was also observed that shelterbelts flanked by dense low-growing shrub rows retained their effectiveness longer than open poorly-stocked plantings, because the former more readily attain a dense crown canopy, shade out competing weeds and grass, and retain enough leaves to form a forest floor of litter and humus. It is a matter of common knowledge that dense plantings accumulate a considerable depth of snow in winter, and, since this might be a factor in the growth and longevity of tree belts, a study was made to determine to what extent snow replenished the soil moisture in and near shelterbelts.