82 EXPERIMENTAL FARMS 



2-3 EDWARD VII., A. 1903 



Rotation (b) is well suited for the farm where it is desired to keep a large number 

 of cattle, and where there is more or less broken land to serve as pasture. 



Rotation (c) is adapted to the requirements of the average farmer and is one well 

 suited for general farming. 



Rotation (d) may be followed with some advantage where there is a moist climate. 

 The use of clover for a fertilizer merely is undoubtedly profitable where climatic con- 

 ditions permit of a good growth after the cover crop has been removed. 



Rotation (e) is probably even better suited than (d) for the average farmer anxious 

 to quickly put his farm in good lieart and keep it in that condition. This is more 

 especially true in sub-humid regions. 



Rotation (/) the longest, it is seldom or ever advisable to follow, includes one year 

 of timothy hay, which may recommend it to many farmers. The four year rotation (c), 

 however, has the same peculiarity, and is for various reasons to be preferred. 



In all save (a) it is understood that barn-yard manure is to be applied when roots 

 or corn or potatoes are grown. Experiment has shown over and over again that fre- 

 quent light applications of barnyard manure give better returns than heavy applications 

 at longer intervals. To illustrate, it has been proven that 10 tons per acre every third 

 year will give much better results than 20 tons per acre every sixth year. This fact 

 would seem to indicate very strongly the adoption of a short rather than a long rota- 

 tion by all who are anxious to improve their farms and get the greatest returns from 

 manure applied. 



The chief reason for surface cultivation and the adoption of such short rotations as 

 given above is to increase the quantity of, and place properly the chief factor making 

 for soil fertility, humus. 



Dead vegetable matter exposed to moisture and warmth soon breaks down to a 

 form called humus or black earth, the factor just mentioned. Our prairie and newly 

 cleared soils contain immense quantities of this material. Exposure to heat and the 

 intermixture of earthy matter serve to waste the same. Thus, repeated grain cropping 

 with deep ploughing pro\ade the conditions best calculated to dissipate this matter most 

 readily and most effectively. 



The functions of this common, yet easily lost, substance are varied and important. 

 Being, as every one can prove for himself, of the nature of a sponge, it retains the moisture 

 in a dry time, but will allow all superfluous water to rapidly and harmlessly percolate to 

 the lower soil layers in a wet season. It holds loose, porous soils together, and so other- 

 wise loose sands become stable and provide a good root hold for plants. It renders 

 dense, impermeable soils open and porous, permitting the free circulation of air and 

 water and allowing the weak rootlets to penetrate the erstwhile impenetrable space in 

 search of food. In brief, it is the chief factor making for good physical condition in 

 our soils. It contains much plant food, since it is really vegetable matter, and a large 

 percentage of this food is in available forms. It aids also in the conversion of the non- 

 available forms of the elements of fertility into available forms. Further, it retains 

 near the surface the dissolved plant food which must otherwise have sunk into the sub- 

 soil. 



Tlie most important sources of humus on the average farm are farm-yard manure 

 and crop residues. Upon the proper application or use of these materials depends the 

 future of Canadian agriculture. 



"O" 



Keep humus near the surface. — Where the supply of humus is limited its location 

 becomes a very important consideration. Now, most of our crops draw the greatest 

 part of their food from the surface soil, for, while some roots of most plants penetrate 

 to a considerable depth, most roots of all plants are found near the surface. Plants of 

 nearly all descriptions thrive best where the surface soil is mellow and rich in humus. 

 The great crops produced by newly cleared fields and prairie lands exemplify this, as 

 does also the rank growth of plants in our forests, where the subsoil is never stirred, 

 and where the annuals and smaller perennials must depend for their nourishment upon 

 the surface soil almost exclusively. It would, therefore, seem to be clear that available 



