24 EXPERIMENTAL FARMS. 



GENERAL CONSIDERATIONS. 



While a period of six years in the testing of the efFects of manures on crops is 

 altogether too short to permit of drawing positive conclusions on any point, yet 

 when a considerable degree of uniformity is found in the results thi'oughout the 

 series they may justify an experimenter in calling special attention to them. 



The results obtained from plots 1 and 2 throughout the whole series in uni- 

 formly large average returns serves to confirm the correctness of the view generally 

 held as to the beneficial action of barn-yard manure. It is, however, worthy of 

 note in this connection, that in its application to wheat, Hjarley and oats, manure 

 used fresh from the barn has produced a higher average of grain than an equal 

 weight of manure which has been well rotted. In the barley plots the fresh 

 manure also gives a heavier weight of straw, while in the oat and wheat plots the 

 advantage, as far as the crop of straw is concerned, is slightly in favour of the rot- 

 ted manure. On the corn plots the fresh manure has given much the heavier crops 

 on the No. 1 series, while the rotted manure has a slight advantage in No. 2. In 

 the case of the roots the advantage is on the side of the rotted manure with the 

 mangels, with the sugar beets grown in 1891, and with the carrots after barley in 

 1892 ; but the fresh manure gives the larger returns with the turnips, also with all 

 the crops of carrots after wheat and oats and with the carrots after barley in 1893. 

 These facts when carefully compared indicate a considerable advantage thus far in 

 the use of fresh manure over that of rotted weight for weight, which is a most im- 

 portant point in the economy of manui-es, since, during the process of rotting, man- 

 nure loses about 40 per cent of its weight, and to this loss must be added the cost of 

 twice handling, and usually that of turning once or twice during the process of fer- 

 mentation. The explanation of this rather unlooked for result, probably lies in the 

 fact that the liquid portions of the manure, the richest in nitrogen, have much of 

 their most valuable constituent volatilized and lost during the process of rotting. 



The unmanured plots, Nos. 3 and 12, show fairly uniform results throughout, the 

 slight differences being easily explained by variation in soil. 



The crops given by plot 4 in all the series seem to show that mineral phosphate 

 untreated no matter how finely ground has little or no effect as a fertilizer, and that 

 the effects observable where nitrate of soda and wood ashes are used in conjunciion 

 with the untreated mineral phosphate are probably due entirely to the action of 

 these added fertilizers. There is however no doubt that the mineral phosphate 

 when treated with sulphuric acid and rendered soluble by being changed to the super- 

 phosphate is a most valuable addition to the fertilizing constituents of the soil. 



It would appear that, when the finely ground mineral phosphate is intimately 

 mixed with barn-yard manure in an active state of fermentation and composted for 

 several days, better results are obtained than would be expected from the pro- 

 portion of manure used and it is probable that under these circumstances some por- 

 tion of the mineral phosphate is rendered soluble by the action of the ferments in 

 the decaying manure. 



The addition of highly nitrogenous fertilizers, such as nitrate of soda and sul- 

 phate of ammonia, while usually producing a fair increase in the weight of grain, has 

 a more marked effect on the weight of straw, which is increased very considerabl3^ 



It is somewhat singular that the inferior quality of superphosphate of lime 

 known as No. 2 has given in nearly all the tests better average results than have 

 been obtained from the use of the more costly No. 1 quality : no explanation can yet 

 be offered for this unlooked for result. 



The experiments with the use of common salt alone, and land plaster or gypsum 

 alone, have resulted in better average yields than was expected. These results 

 are most probably due in large measure to the influence which both these substances 

 exert in libei-ating potash in the soil, by reducing insoluble potash compounds to 

 soluble forms and also of influencing the texture of the soil so as to enable it to 

 retain more moisture. The use of salt alone seems to be specially beneficial to the 

 barley crop. The tests made with sulphate of iron on grain crops have also given 

 better results on the average than was looked for. 



