Standard English and American texts teach that liming effects a liberation of soil potash through ionic interchange. As examples we have the statement of Hall(8): “The action of lime upon potash compounds in the soil is equally marked: as the soil water carries down the dissolved calcium bicarbonate it attacks the zeolitic double silicates in the clay and some of their soluble bases, potash among them, change place with the lime and come into solution.” Similar statements, “One of the most important effects of calcium compounds is the conversion of insoluble into soluble forms of potassium…” by Van Slyke(25) and “but it also has some power to increase the solubility of phosphorus and potassium…” by Hopkins(9), have been accepted as authoritative.

1. A volumetric method for the determination of sodium which can be separated as a triple salt (uranium zinc sodium acetate) from mixed solutions is described. The reduction of the uranium with titanous chloride, upon which it depends is shown to be quantitative.

2. Calcium, magnesium, and relatively large proportions of potash do not interfere. The procedure for the removal of iron, aluminium and phosphates by gentle ignition is simple and obviates the risk of error by the introduction of sodium as an impurity in the chemical reagents necessary for precipitation methods.

3. 0.1 mg. of sodium can be determined accurately.

The fluctuation in the nitrate content of arable soils in southern Australia is of special significance in connection with the practice of bare fallowing as a preparation for wheat growing. In the wheat areas of Western Australia, South Australia, Victoria and the southern districts of New South Wales, fallowing is the recognised cultural basis for successful wheat production, and from a purely mechanical point of view the practice in the hands of the more skilful farmers has probably reached a degree of perfection which it would be difficult to surpass.

1. The colorimetric determination of phosphoric acid in hydrochloric and citric acid extracts of soils by a method involving the evaporation of the extract, ignition and acid extraction of the residuewith either the Denigès and Fiske-Subbarow methods of colour development was satisfactory only with light soils. Clay soils gave low results owing to the presence of larger amounts of iron.

2. A method is given in which the organic matter and iron are removed by treatment with sodium permanganate and potassium ferrocyanide. The results are in good agreement with the gravimetric method.

1. It is shown that results for the loss in weight of a soil on oven heating can be obtained to a very satisfactory degree of accuracy when a Hearson electrically controlled oven is used.

2. Results obtained by heating soils to temperatures ranging from 5° to 250° give smooth curves connecting loss in weight with rise in temperature; from which it is concluded that there is no sudden alteration in the structure of a soil when it is heated to 100°, and that the airdry moisture of a soil, as determined with sufficient accuracy by the usual methods, is a convenient empirical factor, but not a representation of any fundamental soil property.

3. An examination is made of the factors contributing to the observed total loss in weight when the soil is heated, and an explanation offered of the contributions made by the different types of soil water and by the soil colloids. It is found that the conclusions drawn from this discussion confirm views developed earlier with regard to the behaviour of the water in the soil, and the absence of any sharp dividing line between the different classes into which the soil water is usually divided.

The decomposition of urea has been investigated in 59 soil samples of extremely varied character. Urea was decomposed readily in all and very rapidly in most of the samples.

In mountain and heath soils the decomposition was generally active, especially in soil tests. Strongly acid peat samples (pH. 3·1 to 3·3) decomposed from 0·44 to 0·86 per cent, of their own dry weights of urea in 24 hours at 22° to 23° C.

In solution and soil tests samples from permanent pastures produced a more rapid decomposition than those from cultivated land. In soil tests with pasture samples quantities of urea as large as 1 per cent, of the dry weight of soil were converted to ammonia in 24 hours at 22° to 23° C. Fertile arable soils produced a relatively slow decomposition in soil tests.

The growth of barley and the phosphate concentration of the soil solution, of the soil cropped and uncropped, were examined simultaneously in pot cultures, after treatment of an acid soil deficient in phosphate, with lime with and without slag or superphosphate.

Liming at the rate of half the lime requirement increased the concentration from about 0·7 p.p.m. P2O5 to about 1 p.p.m. and at the rate of twice the lime requirement to over 2 p.p.m. P205. Phosphates depressed the concentration on the lightly limed soils, and on the heavily limed had variable effects. The superphosphate-treated soils showed rather lower concentrations than the slag-treated. Cropping raised the concentration on the lightly limed treatments, but on the heavily limed reduced it on the control and had a variable effect on the phosphate treatments.

1. Herbage from pastures managed under the Intensive System of Grassland Management, and representing three to five weeks’ growth, from three centres in three seasons, was closely comparable with that obtained by other workers from “pasture cuts” at one- to three-weekly intervals from unmanured pastures, in respect of the chemical composition of its dry matter, which is, in fact, a concentrated feeding stuff of narrow nutritive ratio and low in fibre content.

2. The nutritive ratio is somewhat wider in a dry than in a wet season, but the average fibre content is not markedly different.

3. During the grazing season, drought or the early summer flush period produce some reduction in protein content and an increase in fibre content, with a recovery following the cessation of the drought or after the flush period respectively.

A Notable contribution to our knowledge of the factors which influence the nutritive value of grass has been made by Dr J. B. Orr in a recent publication dealing with minerals in pastures and their relation to animal nutrition (l). The treatise was primarily the outcome of the deliberations of a sub-committee appointed in 1926 by the Civil Research Committee of the Cabinet to consider and report on the relationship between the mineral content of pastures and their nutritive value. From the initial enquiries instituted by this sub-committee, it was evident that malnutrition in cattle and sheep arising from deficiency of minerals in grass was widespread in the pastoral areas of the Empire, and that the subject, which was of great economic significance, warranted close and systematic investigation. A report to this effect was duly forwarded to the Civil Research Committee, on whose further recommendation grants were made by the Empire Marketing Board in aid of a comprehensive scheme of investigations into the mineral aspects of pastures within the Empire. A two-fold scheme of work was adopted, actual investigations in selected grassland areas being supplemented by a detailed search of the literature dealing with every phase of the subject.

1. The changes in composition of the clay fraction in different horizons of some typical North Welsh profiles have been studied.

2. The changes in the molecular ratio of silica to sesquioxides (SiO2/Al2O3 + Fe2O3) throughout a soil profile afford an indication of the nature of the eluviation which has affected the mineral portion of the soil.

3. The data for North Welsh soils indicate a general tendency to enrichment of the lower layers in sesquioxides, particularly ferric oxide, at the expense of the surface layers.

4. The silica-sesquioxide ratio of the clay fraction is an important aid to series definition.

5. The soils of North Wales, particularly in the uplands, have probably been subjected to considerable erosion in the past. The profiles are therefore considered to be more or less truncated.