330 



THE GENESEE FARMER. 



were poor, shrivelled, spindling things, rang- 

 ing from one to three feet in height — the ma- 

 jority not more than two feet, and many of them 

 not a foot high. On the unman ured plot (No. 11,) 

 on the other side of the experiments, the plants 

 did a little better. "Why we cannot say. But even 

 here the sorghum presented a miserable appear- 

 ance, the plants being only from two to three 

 feet high, and many of them not that. As we 

 have before said, a row was left without manure 

 between each plot, and these rows, with the excep- 

 tion of here and there a hill which seemed to have 

 got a little food from the adjoining manured row, 

 the plants had the same starved, stunted and 

 shrivelled appearance. "With the exception of Mr. 

 Lawes' turnip experiments, and where one plot was 

 left continuously without manure for many years, 

 we have never seen such a marked difference be- 

 tween the unmanured and manured rows as in 

 these experiments on sorghum. 



On plot No. 9, dressed with ashes, superphos- 

 phate and sulphate of ammonia, there were 88 

 missing hills. In this case we have no doubt that 

 the manure injured either the seed or the young 

 plants. The hills that were left, however, were all 

 strong, green and healthy, and the plants seemed 

 to have more seed than on any other plot. 



On plot No. 2, dressed with sulphate of ammo- 

 nia, there were 78 missing hills. Here, again, un- 

 doubtedly, the manure, notwithstanding the great 

 care which was used to prevent such a result, had 

 injured either the seed or the young plants. It 

 should have been diffused more generally through 

 the soil* 



Assuming that none of the hills had missed, the 

 yield per acre would have been as follows : 



CALCULATED YIELD PER ACXE, IF NONE OF THE HILLS HAD MISSED. 



jy-0. Tons. Owt. Qrs, Lbs. 



1.— No manure, 1 7 20 



% — Sulphate ammonia, 6 17 1 15 



3.— Superphosphate, 10 5 3 15 



4._9ul. ammonia and superphosphate,. 9 9 8 11 



5.— Plaster (gypsum), 11 1 3 



6.-AsUes, 7 3 3 20 



7.— Ashes anrl plaster, 8 10 20 



8.— Salt, 4 3 3 23 



9. — Sul. ammonia, superphosphate and 



ashes, 8 7 3 12 



10. — Ashes and superphosphate, 8 



11.- -No manure, 1 12 2 22 



Whether we look at the actual yield, or at that 

 which would have been obtained it' none of the 

 hills had missed, the main features of the results 

 are the same. The effect of plaster (gypsum or 



* Borne may ask, " Why not have sown the manures broad- 

 east and harrowed Ihem in ?" Such a method would be better ; 

 but it is difficult to sow such manures broadcast by hand without 

 getting more or less of them on to adjoining plots. Under or- 

 dinary circumstances, we should certainly sow anamoniacal ma- 

 nures broadcast and harrow them in. 



sulphate of lime,) is perfectly astonishing. At the 

 time of the first hoeing (July 10) we wrote in our 

 note-book, "superphosphate and plaster the best. ,T 

 These two plots (Nos. 3 and 5) all through the sea- 

 son were obviously superior to any other, No, 4 

 gaining on them a little during September. 



The superphosphate used in these experiments 

 was made from calcined bones expressly for our 

 own use. It was a very superior article. But we 

 may here remark that the best superphosphate 

 that can be made contains over 50 per cent, of 

 plaster. The object of converting bones into su- 

 perphosphate is this: Phosphate of lime is in- 

 soluble in water. It contains 3 atoms of lime, 

 united with 1 atom of phosphoric acid. Super- 

 phosphate is soluble in water. It contains 1 atom 

 of lime, united with 1 atom of phosphoric acid. 

 Now to convert the insoluble phosphate of lime 

 into the soluble superphosphate, we have to take 

 away by chemical means two atoms of lime-. 

 This is done by adding sulphuric acid to the phos- 

 phate of lime in bones. Superphosphate is, then, 

 a mixture of soluble phosphate of lime and plaster. 



The 400 lbs. of superphosphate applied to plot 

 No. 3, probably contained about 200 lbs. of sul- 

 phate of lime or plaster. If our common plaster 

 contains 80 per cent, of sulphate of lime, the 250 

 lbs. applied to plot No. 5 would contain the same 

 quantity of real plaster as the 400 lbs. of super- 

 phosphate applied to plot No. 3. If 90 per cent., 

 it would get 25 lbs. more real plaster than plot 

 No. 3. 



The plots receiving superphosphate and plaster, 

 are the two best plots of the whole series. Plot 

 No. 5 is a little the best. It is probable that it 

 received a little more real plaster than plot No. 3. 



One thing is clear: the soluble phosphate of lime 

 in the superphosphate did no good. On the one 

 plot (No. 5) we have plaster alone; and on the 

 other plot (No. 3) we have plaster and soluble 

 phosphate ; and yet the crop is no better from the 

 two together than from the plaster alone. It is 

 evident, therefore, that the phosphate did no good. 



"What was it that caused such an immense in- 

 crease over the unmanured plot? Taking the best 

 of the unmanured plots, and adding all the missing 

 hills, we have still over six times as much produce 

 from the plastered land as where no manure was 

 used! To what is this owing? We frankly con- 

 fess we do not know. If we say the soil was 

 deficient in sulphate of lime, why is it that salt, 

 which contains none, more than doubled the crop; 

 and why did the ashes quadruple the yield? May 



