This paper demonstrates the findings of Electrical Submersible Pump (ESPs) failure investigations of sand erosion occurring in sandy wells. The study comprises a review of reasons for sand production through well streams penetrating through the ESP internals. Remedial measures to minimize or eliminate the sand attack to the ESPs are discussed.
Prunus angustifolia, or Sand Hill plum or Chickasaw plum, is native in much of Kansas. It is the most common wild plum in western Kansas. It is found naturally on sandy prairies where it is very effective in stopping blowing sand. Sand hill plum is similar to American plum, both form thickets from roots suckers. They differ in site characteristics and plant and leaf size. Sand hill plum grows to a height of 3 to 4 feet with a spread of 4 to 6 feet. It grows at about 12 to 18 inches per year.Leaves, Stems and FruitLeaves are elliptical with small teeth on the edges. The 1 to 2 1/2 inches long leaves are slightly folded lengthwise with the tip curled down and are located on alternate sides of the twig. Flowers are white and form in early April before leaves appear. Fruits are bright red or orange with a whitish film and three-quarters to one inch long. They mature in late June or July and persist to mid-August. Twigs are rigid and often spine-tipped.UseWildlife Habitat - Sand hill plum is a popular plant for use in developing wildlife habitat on sandy soils. The thorny thicket is valuable for songbird and game bird nesting, loafing and roosting. Various other animals also use it for loafing, bedding and escape cover. The fruit is consumed by numerous birds and other animals.Windbreaks - This plant may be used as the outside row of a windbreak for ground level wind protection. White flowers are attractive and fragrant in the spring. Some people find its thicket forming habit objectionable in windbreaks.Water Erosion Control - Sand hill plum is very effective in stabilizing blowing soil. It is also used to stabilize stream banks and gullies.Human Food - The fruit is used for making wine, jam and jelly.Adaptation and SoilSand hill plum has adapted statewide and grows naturally on sandy soils, but will perform well when planted on heavier clay-loam soils. SpacingSand hill plums are spaced 3 to 4 feet apart.CultureOne-year-old, bare-root seedlings, 18 to 24 inches tall, are used in plantings. Sand hill plum seedlings are not as vigorous as American plum seedlings. Control of weed and grass competition during the first and second years is important in survival and early growth. PestsInsects and diseases may occasionally attack this species, but usually are not a serious problem. Rabbits may chew on the bark, but new sprouts will form to replace injured stems.
The trunks on Sand Pine are rarely straight. The tree usually grows with a portion of the crown missing or with a lean to one side. This may contribute to the unpopularity of the tree in the landscape trade. However, this attribute can make it well suited for planting as an accent in any large scale landscape. It is especially useful and attractive when planted in a lawn area as a single specimen. It certainly has its place in reclamation sites as a colonizer of poor soils. The tolerance to dry, sandy soils should make this tree adaptable to conditions created near asphalt and other hot areas in urban landscapes.
The ammonium sulphate deposited in forest ecosystems in the Netherlands as a result of air pollution currently exceeds 80 kg N ha -1yr -1locally. To study the influence of this air pollution on fine root density and its dynamics, fine root growth was monitored for three years in two young mature stands of Douglas-fir on sandy soils in the central part of the Netherlands in the ACIFORN project (ACIdification of FORests in the Netherlands). In the drier site the fine root density in early summer was higher and more strongly reduced after a dry spring than at the more favourable site. The fine root density appeared to depend on the proximity of the tree stems in the stand. In normal years, the main peak of fine root growth occurred in spring, with less growth during summer. After a dry spring, fine root growth on the drier site reacted strongly to periods with rain in summer. In a greenhouse trial with one-year-old seedlings of Douglas-fir in sand, ammonium sulphate was added to simulate the present acidic deposition. Part of the ammonium was nitrified into nitrate. This resulted in different ammonium, nitrate, aluminium levels and pH in the different treatments. In the treatments with the highest applications, fine root length was reduced by 50 % compared to the control, and the specific root length was reduced by 40 %.
A critical review of the results reported in the literature, to ascertain the total effect of the soil chemical changes since the start of the industrial revolution on the fine root density, revealed that aluminium is the main factor reducing fine root growth, even at sub-lethal concentrations in the soil solution. The fine root length is probably reduced by 50 % in the topsoil, and by 75 % in the subsoil. Excessive nitrogen availability reduces the total fine root biomass by 30 %. The net result is that the fine root system is less dense and more shallow than it would be without acidic deposition. This reduces the potential for water uptake on coarse sandy soils, and increases fine root mortality in long dry periods, especially on poor sites. An elementary model to describe fluctuations in the fine root density during and after a drought is used to illustrate the effects of soil acidification and nitrogen enrichment on drought susceptibility. Accumulated deposition has enhanced the risks of tree mortality or forest dieback induced by severe drought. 041b061a72