Accumulation Of Soluble Salts Research Articles

LONG-TERM EFFECTS OF IRRIGATION-SALINITY MANAGEMENT ON A VALENCIA ORANGE ORCHARD

Fruit production and tree growth characteristics of a Valencia orange orchard are related to equilibrium distribution of salts throughout the root profile in response to uniform applications of irrigation waters varying in salinity and sodicity hazards. Eight years of differential irrigation treatments consisting of basin irrigation with four waters representing low to moderately high salinity, and also with Cl and SO4 waters, resulted in soil salinity profiles specific for each water. Both the quantity and quality of oranges have declined under irrigation treatments producing accumulation of soluble salts within the rootzone. Specific ion, osmotic, and soil suction effects are discussed in relation to salinity stress.

Factors affecting growth and response of white clover in pots to applied phosphorus

Abstract The effect of three levels of soil moisture on growth and response of white clover in pots to applied phosphorus was studied with soils of low and high phosphorus status. On both soils highest yields were obtained at the highest level of moisture, maintained by daily watering until leaching occurred. Maintenance of the pots at a soil moisture level of estimated ‘field capacity’ resulted in lower yields at all rates of applied phosphorus. The differences between yields due to watering treatments were greatest at the nil and low rates of applied phosphorus on the soil of high phosphorus status, and at the high rates of applied phosphorus on the soil of low phosphorus status. The leaching method of watering resulted in responses to phosphorus in the pots similar to those expected in the field on both soils. It also produced the highest phosphorus content in the plants on both soils and prevented the accumulation of soluble salts on the surface of the pots, although not completely on one of the soils.

Damage by Accumulation of Soluble Salts in Stonework

(1971). Damage by Accumulation of Soluble Salts in Stonework. Studies in Conservation: Vol. 16, Preprints of the Contributions to the New York Conference on Conservation of Stone and Wooden Objects. 7–13 June 1970. Second Edition 1971, Volume 1: Conservation of Stone, pp. 35-45.

The Natural Accumulation of Soluble Salts in the Casing Layer of Mushroom Beds

(1961). The Natural Accumulation of Soluble Salts in the Casing Layer of Mushroom Beds. Journal of Horticultural Science: Vol. 36, No. 2, pp. 139-144.

Movement of Soluble Salts in Development of Chernozems and Associated Soils

In the formation of Chernozem, Chestnut, and associated soils in northwestern North Dakota, translocation of carbonates and other soluble salts takes place. Salts are removed completely from the uppermost 15 to 36 in. of the Chernozem and Chestnut profiles formed from medium-textured till with initial contents of 0.13 to 0.41%. Maximum accumulations of soluble salts may be at depths between 48 and 108 in., but may also occur at greater depths such as between 78 and 132 in. Accumulations of calcium carbonate are nearer the surface than are the accumulations of other soluble salts. Important local factors affecting the amount and distribution of soluble salts and carbonates in soils are topography, permeability of the soils and parent materials, salinity of the parent materials, and the presence of a relatively high water table. The influence of topography is evident in that soluble salts are removed to greater depths in the nearly level Hamlet loam than the somewhat more strongly sloping Renville loam. The effects of both permeability and salinity are apparent in the lack of accumulation of soluble salts in well-drained and moderately well-drained soils formed from rapidly permeable, sandy, water-laid drift originally containing less than 0.15% soluble salt. Upward capillarity results in the accumulation of soluble salts in the surface layers of soils with a high water table whether the underlying sediments are saline or not. The large quantities of soluble salts in the upper part of the profile of solodized-Solonetz soils are considered to be a result of upward capillary movement from a high water table which may no longer be present.

The Formation, Evolution, Reclamation, and the Absorbed Bases of Alkali Soils

Summary1. The formation of alkali soils is primarily a question of soluble salt accumulation. Those processes which bring about the accumulation of soluble salts in soils also tend to cause the accumulation of CaCO3. Under certain conditions simple calcium silicates may also be precipitated in alkali soils. Hilgard's researches were concerned chiefly with the soluble salts. On the other hand, more recent investigators have emphasised the base-exchange aspects of the subject. Sodium salts tend to react with the clay and humus constituents of the soil, converting them into Na-absorption compounds. These components produce extremely adverse conditions in the soil.2. Under certain conditions alkali soils tend to pass through four evolutionary stages, namely, salinisation, alkalinisation, desalinisation, and degradation. As to whether or not an alkali soil will pass beyond the salinisation stage, depends on the composition of the soluble salts that accumulate in it. Where sodium salts predominate, more or less alkalinisation of the exchange complex has taken place. However, this is not true where soluble calcium is relatively abundant.3. Desalinisation (by leaching, whether natural or artificial) of alkalinised soil is usually accompanied by the formation of Na2CO3and by pronounced deflocculation. If CaCO3be present, the formation of Na2CO3is accompanied by the replacement of absorbed sodium by calcium. Under these conditions the degradation stage will not be attained. If CaCO3be absent, base-unsaturated constituents arise under leaching conditions, and more or less of the inorganic-exchange complex becomes decomposed into simple oxides.

Irrigation and Crops1

THE deleterious effect of irrigation on the soil, and therefore on the crops grown when it is not duly balanoa by drainage, are described simply and clearly in an important memorandum drawn up by Dr. B. A. Keen, of Rothamsted, for the Empire Marketing Board. The memorandum is the work of an experienced soil physicist, and deals in summary form with the chemical and physical reasons for the accumulation of soluble salts on the surface of the ground, usually but somewhat erroneously described as ‘alkali.’ Such concentration can, obviously, only take place where there is great evaporation of soil moisture, but little or no rain to wash the salts away, and the parts of the world where these conditions prevail are somewhat clearly defined. Taking the rainfall map as our guide, it can be seen at a glance that the amount of rain falling in the temperate and tropical regions is generally what may be called ample for crop production. But, round about and just outside the tropics of Cancer and Capricorn, belts of little rain or deserts are met with in the Old World, while in the New such tracts are confined more or less to the western sides of the continents. These conditions are due, in the main, to the distribution of the ocean winds and currents. Clear skies are met with in these tracts, which in the local summer are connoted with intense heat and great evaporation of the soil moisture; whereas within the tropics the amount of cloud is much greater, the retarding force of the sun on vegetation is less, and a greater amount of rain falls.