At the present time no exact records exist (except those given in British Breeds of Live Stock published by the Board of Agriculture and Fisheries and by McConnell in his Notebook of Agricultural Facts and Figures) which show the relative qualities of the various British breeds of cattle in respect of their ability to grow, fatten and increase in weight. Also there exists no estimate as to the actual average amount of food produced by the different breeds on slaughter and the average proportion of consumable meat and offal in the dead body.

With the development of irrigation projects in intermountain areas of the Rocky Mountain States has come an enormous increase in the amount of wheat produced annually with irrigation. The crop commands the attention and consideration of millers and grain men generally in intermountain sections and will continue to do so because there is in cultivation at present a small fraction only of the acreage that can be successfully farmed with irrigation. The general run of irrigated wheat regardless of the class to which the varieties may belong is plump and relatively heavy. It is unfortunately at the same time soft and starchy and because of its relatively low protein content is almost invariably sold on markets that do not stress strength in wheat flour.

1. Craibstone soil—a glacial drift soil which has not undergone very profound weathering and is free from calcium carbonate—has a considerable absorptive power for ammonia from a solution of sulphate of ammonia.

2. It was found possible to make a mechanical analysis of a large quantity of this soil without the use of acid and alkali, and although the separation into fractions was by no means perfect, a very fair comparison was obtained of the absorptive capacities of the different fractions.

3. The absorptive power per unit weight of the fractions, as would be naturally expected, increases with the decrease in size of the particles, reaching a maximum in the case of “clay.”

4. “Fine silt” and “silt” have also a high absorptive power. This may be partly due to the presence of organic matter, but allowing for that, these fractions have a high power of absorption.

5. It was not the object of these experiments to draw any detailed conclusions as to the relation between surface and absorptive power, but it seems probable, from the results obtained, that the absorptive power is not determined by surface alone, and that the chemical composition of the fractions has an influence on the absorptive power.

It has been shown in Part II that a glacial drift soil in a comparatively unweathered condition has a considerable power of absorption for ammonia, although it has sometimes been held that it is the weathered material in soils that is responsible for the absorptive power. Glacial drift, as exemplified in the Craibstone soil, however, though its weathering is geologically recent compared with that of many English soils, has been subjected to age-long weathering since the glacial period, and in the process of soil formation a certain amount of weathering with the resultant decomposition has necessarily taken place. Craibstone soil has also been shown (Table II, Part II) to contain a fairly large percentage of organic matter and it might be contended that the absorptive power was chiefly due to either or both of these factors.