SULPHUR VITAL

Press, Volume C, Issue 29500, 29 April 1961, Page 6

SULPHUR VITAL

Lake Pearson Trials

Manurial trials conducted by the soils department of Canterbury Agricultural College for the North Canterbury Catchment Board on a shingle fan near Lake Pearson have indicated that sulphur is very deficient. GypSum alone has given a big increase in production but some phosphate is needed to give best results. This information was given to a party which visited the trials in the company of Professor T. ■ W. Walker, professor of soil science at the college, last week-end ’ ,

The trials were laid down In September. 1956. when fertiliser dressings and uninoculated clovers <red. white and alsike) were broadcast. Because of a noor strike due to late sowin?, a dr- summer and possibly to the clover not being inoculated, further inoculated clovers were broadcast in August. 1957. and where necessary fertiliser dressings have since been applied each September

In the first year lewt of superphosphate doubled the yield, 2cwt trebled it and 4cwt gave five times the yield of the control plot Although the yield from an initial application of 4cwt of super and none since is the highest so far, there has been a gradual decline after the first year and this year’s rield ! s less than that from the plot receiving lewt of super each rear. ' r ields begin to decline gradually whenever the super is not applied. On this soil the recommendation of the Lincoln College scientists is that 2cwt of sulphurised super <Boolb of sulphur to the ton) would probably be suitable when oversowing initially, with lewt to 2rwt every other year thereafter. Dr. Walker said it was desirable that sulphur in the form of gypsum be used for a start with the idea of getting the clovers growing but thereafter a slower acting form of sulphur, such as flowers of sulnhur. could be used.

Where strong clover growth had resulted in a build up in nitrogen in the soil Dr Walker said it was striking how it bad benefitted the grasses. On one plot he commented that the browntop almost looked like timothy Lime and molybdenum applications have made no difference to ptoduction. he told the visitors.