82 
Field Experiments on Clover-Seeds 
with salt and sulphate of potash, was somewhat less than that of 
the unmanured plots. I attach no value to the apparent diminution 
of the produce on plots 4 and 7, for the decrease is not sufficiently 
large to entitle us to infer from the result that the saline matters 
used on these two plots had an injurious effect upon the crop. 
3. On plot 8 sulphate of lime was used at the rate of 1 ton 
per acre. This is a very large dose. Although sulphate of lime 
or gypsum is but sparingly soluble in water, and for that reason may 
be used with perfect safety in much larger quantities than in this 
experiment, provided it is well mixed Avith the soil, a large dose 
of finely-powdered gypsum, when applied as a top-dressing to 
young clover-seeds, appears to injure the plants and to retard their 
growth. 
4. It is worthy of notice that whilst common salt had no effect 
upon the produce, muriate of potash materially increased it. We 
have here another direct proof that soda is incapable of taking 
the place of potash in the nutrition of plants. 
5. On plot 3 mineral superphosphate alone had no effect what- 
ever on the crop. This is an interesting result, for it seems to 
indicate that the great deficiency of potash, which is characteristic 
of the soil of the experimental-field, entirely prevented the display 
of the useful functions which we know perfectly well that super- 
phosphate of lime does discharge on land of a better character. 
On poor light sandy soils we may learn from this that a purely 
mineral superphosphate cannot be used with advantage for clo- 
ver-seeds. I may observe in passing that on such soils mineral 
superphosphate has even little effect upon root-crops, for which 
phosphatic manures are so largely used with the best effect. 
6. It is remarkable that whilst plot 3, manured with mineral 
superphosphate, gave no increase whatever, and plot 6, manured 
with muriate of potash, gave an increase of 1 ton 4 cwts. and 
42 lbs. over the average produce of the two unmanured plots 
(average produce 8 tons 11 cwts. and 98 lbs.), the mixture of both 
manures on plot 10 gave the largest weight of clover-seed and 
rye-grass per acre of apy of the eleven experimental plots. 
In the first cutting, plot 10 produced 9 tons, and in the second 
nearly 5 tons of green clover-seeds, or both cuttings yielded in 
exact weight 13 tons 15 cwts. and 40 lbs., which is an increase of 
5 tons 3 cwts. and 64 lbs. per acre over the average yield of the 
two unmanured plots. 
Plot 10 gave not only the largest increase per acre, but the quality 
of both the clover and rye-grass was much superior to that of the 
produce of any other of the various experimental plots. 
7. There is another circumstance connected with the result 
obtained on Plot 10, which deserves the best attention of the 
practical agriculturist. It will be seen that, although the first 
cutting produced a heavy crop of clover-seeds of by far the best 
