APPENDIX No. 5 (continued).

REPORT OF GOVERNMENT ANALYST (MR. E. A. MANN) TO THE ENGINEER FOR GOLDFIELDS WATER SUPPLIES, DATED 17TH JUNE, 1912.

I beg to forward herewith table of analysis, showing the result of the examination of samples of soil from Esperance taken by Mr. Middleton. You will remember that Mr. Middleton from the appearance of the soils classified them into three types, but you will see from the details of the analysis that this distinction in typical character is not borne out by chemical analysis, and that the three types run into each other.

The following comments apply generally to the analysis:—

(1.) The soils are not rich is humus or decayed vegetable matter, and would probably require consideration of these points in order to reserve their moisture-retaining capacity.

(2.) Speaking generally the soils are sell supplied with lime, the result being that none of them display an acid character.

(3.) With the exception of sample No. 30, which is of poor quality throughout and worse than the remainder of the samples, all the soils are well supplied with potash. In fact this is rather a remarkable feature of the series throughout.

(4.) The greatest variation is manifested in the nitrogen content, but this variation is manifest in all three types alike. Generally speaking they may be considered as deficient in nitrogen, and this fact must be associated, to some extent, with the lack of humus.

(5.) The soils throughout are deficient in phosphoric acid, and like most of the soils of Western Australia, phosphatic manuring will be required to be a standard portion of soil treatment.

(6.) Samples Nos, 1, 2, 3, 7, 8, 9, 10, 12, 15, 18, 20, 21, 23, 24, 25, 26, 27, 28—that is 18 out of 30 samples—exhibit an amount of salt which is in excess of that generally laid down as the standard for fertile soil, namely .05 per cent., and this is a somewhat serious feature in the soils. It had to be remembered, however, that these were all virgin land which has for a long time been uncultivated. Under such conditions the salt might have become unduly concentrated on the surface of the soil, and yet with cultivation and drainage be sufficiently removed so that there would be no danger to the crops.

In order to further test the extent to which the soil is permeated with salt I therefore examined a number of subsoils, with the following results:—

TABLE II.

The results were far from reassuring, and confirm the suspicion that the country generally is salt. In view of the special importance of the matter, investigation was therefore carried further. In addition to the 30 samples of soil and 12 samples of subsoil already referred to, 128 samples of soil had been received from Mr. Middleton, but could not, in the time available, be subject to complete examination. It was determined, however, to estimate the salt in all these, and the results are shown in table III.

It will be seen that of the 128 samples there enumerated, 96 contained salt above the limit of .05 per cent. This, therefore, makes the question of settlement of these lands a very serious matter. I have throughout adopted the standard of .05 per cent. of salt as being in my opinion a reasonable one, although there is a considerable amount of variation amongst authorities on this subject, the limit of endurance for crops being stated from .03 per cent. to .5 per cent. This wide variation is probably mostly due to the varying tolerance of different crops. The standard which I have always adopted here of .5 per cent. is the same as that which is used in some of the Eastern States of Australia, and has been generally confirmed by experiences I have been able to gather in this State, and also by some experiments which were conducted in this Laboratory a few years ago. These experiments, however, were not so complete as I could wish, and it is rather surprising that in a country such as Western Australia where salt is such an important factor that definite experiments have not been undertaken by the Agricultural Department to determine this important point.

I am making some experiments during the present season in the matter, but the results will not, of course, be available for some months. I think there is very reason to believe that .05 per cent. is a reasonable standard, and it must be remembered that although this...varies very considerably from some of these to which I have referred, these were framed in many instances in countries having a very much greater rainfall than our own, and having this rainfall spread over a greater part of the year. It must be borne in mind that a comparatively low standard must be adopted here owing to the long dry summer which would lead to the concentration of the salt on the surface layers of the soil.

I can only express the opinion that in the light of the facts above disclosed and assuming the tentative standard for salinity which I have adopted is a correct one, the settlement of this land must be considered as hazardous unless its adaptability for wheat has first been fully tested by means of fairly extensive experimental crops grown on various parts of the territory.

E. A. MANN, Government Analyst.