Mallee - Part 2

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Mr Mann's results are somewhat higher than the average, but from the details of Table 4 (Appendix A) it may be seen that except for one soil out of twelve (No. 14), the deviations from the average are comparatively unimportant. In these circumstances it becomes possible to use the returns of the Government Laboratory for common salt in those cases where the soils were submitted only to one analyst, and to this we may now proceed.

                                                                                    Study of Salt Action upon Crops.

In order to examine the effects of common salt upon crops, the following summary statement is given. Figures marked (a) are based upon Mr Mann's analyses alone, and the remaining data are founded upon the average results obtained by the three analysts. The data include the soils at all depths down to three feet.

                                                                      TABLE 7.

                             Common salt on cropped lands, and on Bush lands adjoining crops.

_________________________________________________________________________________ Sample. Per cent. of Salt. Remarks. _________________________________________________________________________________

                                                                              Esperance—cropped land.

2 .. .. .. •108 (a) Crop very fair ; Wheat and Oats. 3 .. .. .. •113 Crop very fair ; Wheat. 5 .. .. .. •034 Crop good ; Wheat. 22 .. .. .. •115 (a) Crop apparently affected ; Wheat. _________________________________________________________________________________

                                                                                  Outside Esperance—cropped land.

13 .. .. .. •328 Crop affected ; Wheat. 18 .. .. .. •108 (a) Crop affected ; Wheat. 23 .. .. .. •495 (a) Crop affected ; Oats. 24 .. .. .. •978 (a) Crop killed ; Oats. _________________________________________________________________________________

                                                                                            Esperance—bush near crop.

7 .. .. .. •035 Adjoining wheat—poor. 8 .. .. .. •368 Adjoining wheat—good. 9 .. .. .. •410 Adjoining wheat—good.* 14 .. .. .. •216 Adjoining wheat—very fair.* 20 .. .. .. •301 Adjoining wheat—fair.* _________________________________________________________________________________

                                                              *Photographs of these crops in Appendix A.

of the three crops in the upper division of the table, those on soils 2, 3, and 5 were very fair to good. Crop 2 was mixed wheat and outs. Crop 3 was wheat which I estimated at 10 to 12 bushels; others estimated several bushels more. Crop 5 was good. Crop 22 was beside a salt lake and was probably subjected to more salt earlier in the season. It was obviously affected by salt and was somewhat spindly; all other crop on higher ground in this same paddock was good. So far as the crops looked (except on No. 22) there was nothing to suggest that the quantities of salt mentioned and spoiled the land for cropping.

The soils in the second division of the table were taken outside the Esperance district with the object of ascertaining the tolerance of cereals for salt. The crops growing on the actual spots where samples 13, 18, and 23 were taken were all more or less affected by salt, and sample 13 was badly damaged. The samples were taken in affected crop round the fringe of salt patches where the crops were completely killed; further back from the salt patches on the high land the crops were all good. It is not to be expected that profitable crops can be grown where the soil contains •328 or •495 per cent. of common salt, but it is useful to know that these amounts did not kill the crops out. At Meckering where separate crops of wheat and oats ran side by side down to a salt patch, the wheat crop appeared to be sooner affected as the salt was approached than did the oats. Sample 23, at York, was taken in oats—samples 18 and 13 in wheat. The oat crop on No. 24 had been entirely killed out by salt.

Interesting information is found also in the lower division of the table where the samples were taken in bush lands just over the fence from growing crops. The crop adjoining 7 was poor, but it was badly put in, part of it being self-sown. The crop adjoining 8 (Machen's) was good, as was also the crop (Shepherd's) adjoining sample 9. A high percentage of salt is indicated by all the analysts for these samples of bush land. Crop adjoining 14 was variously estimated to yield from 10 to 12 bushels. Crop adjoining 20 was fair, and would yield about 8 to 10 bushels. With the exception of Simpson's, all the crops in this section of the table were fair to good.

In the circumstances of their close proximity to the crops growing, and the number of instances in which the same facts repeat themselves, it is safe to say that bush land is not—as has been suggested—to be rejected for •05 per cent. of salt. Fair crops have been grown on lands here adjoining bush lands containing from •3 to •4 per cent. of salt. The recurrence of these facts cannot be accidental. In my opinion •2 per cent. of salt in bush lands should not cause anxiety if the district gets sufficient rainfall for agricultural settlement, but •25 per cent. would give rise to doubt. With higher than •25 per cent. paying crops could certainly be expected only in a wet season.

                                                                                      Salt found in miscellaneous bush.

In addition to the samples taken from cropped lands and bush lands adjoining crops, a number were also taken from typical bush lands remote from cropping. These include sample 4 at Grass Patch, Sample 6 at 60-Mile Post, sample 10 about six miles N.E. from Scaddan, sample 12 at North Patch, sample 15 about seven miles N.E. of Grass Patch, sample 16 near Salmon Gums Hotel, sample 17 about three miles West of Grass Patch, sample 19 near 82-Mile Post, and sample 21 from near 120-Mile Post.

Table 8 gives the common salt contents of those soils including all depths—the figures being the average of three analysts except those marked (a) which are the result of the Government Laboratory alone.