Sulphur Responses In South Canterbury

Press, Volume C, Issue 29488, 14 April 1961, Page 18

Sulphur Responses In South Canterbury

gULPHUR investigations have shown that sulphur deficiencies exist in South Canterbury pastures and that the amount of sulphur relative to phosphate could be increased for pasture topdressing. Because the present 44/46 superphosphate contains only 12 lb of sulphur per hundred-weight, use of some sulphur-enriched fertiliser which increases the rate of sulphur is recommended by the Department of Agriculture. On the browntop and fescue foothill country of South Canterbury high rates of sulphur and phosphate and some molybdenum are essential for good pasture growth. On the tussock hill and high country the emphasis should be on an increased dressing of sulphur rather than phosphate. The same conclusions,

as seen from the results of several observational trials and one mowing trial, probably apply to the South Canterbury downs and alluvial soils. Some phosphate should be applied, as some trials have indicated a marginal phosphate deficiency. Crop investigations on the other hand have shown that phosphate is more essential than sulphur for rape, swedes, white-fleshed turnips, chou moellier, and kale. Sulphur may be an advantage sown with swedes, but a disadvantage when sown with white-fleshed turnips. Mixed Fanns On farms where mixed cropping is done in conjunction with fat lamb production it appears likely that more emphasis could be placed on phosphate for the crops and sulphur for the pastures. It is possible, though not yet proved, that South Canterbury soils which have been well treated with superphosphate in the past will require only sulphur for their maintenance while in grass. It is also possible that such pastures which are in grass for only four to six years may not need maintenance dressings of any kind. This is being investigated in pasture topdressing mowing trials. Where either little or no superphosphate has been used, the use of a sulphurenriched superphosphate for pasture topdressing would be advisable. Mr C. C. McLeod, farm advisory officer, Timaru offers these conclusions in an article in the March issue of “The New Zealand Journal of Agriculture,” which is the first to deal comprehensively with investigations to date into sulphur deficiency over a large part of South Canterbury.