40 



THE IRRIGATION AGE. 



ALFALFA GROWING IN CANADA 



An Address Delivered by Mr. Don H. Bark, at the Ninth Annual Convention of the Western Canada Irrigation Association, at Bassano, Alberta. 



Alfalfa has now been grown successfully 

 throughout Alberta for a sufficient number of 

 years so that it may be said to have passed the 

 experimental stage. There is no doubt but that it 

 now occupies a permanent place among the staple 

 forage crops of the province. This plant is easily 

 the King of forage plants, for no other forage con- 

 tains so many essentials of merit. It not only excels 

 all other forage plants both in yield and in feeding 

 value, but also in its beneficial effect on the soil. 

 Alfalfa produces more food value for less cost than 

 any other crop we can raise. Indeed, too much can 

 hardly be said in praise of this wonderful plant and 

 if history repeats itself, the time is not far distant 

 when it will become the predominating crop on 

 every irrigated farm in the province. As one of the 

 great benefits secured from alfalfa is its great im- 

 provement in the fertility of the soil, it seems well 

 in discussing the subject to deal for a moment with 

 the fundamental principles of soil fertility, in order 

 to show more clearly the beneficial influence of 

 alfalfa upon our arid soils. 



Principles of Soil Fertility 



Of the many elements found in the soil, four 

 only are used to any considerable extent by the 

 plants. These four are nitrogen, potash, phosphoric 

 acid and lime. Nitrogen itself is a gas and forms a 

 large part of the air we breathe, but plants can not 

 utilize it in this form. It must be combined with 

 other elements in the form of a salt (nitrate) be- 

 fore it becomes available as a plant food. The last 

 three mentioned plant foods are minerals formed 

 by the breaking up and decomposition of the parent 

 rock, of which the soil was originally formed. These 

 four substances are the principal or most important 

 of the plant foods. Crops not only need far more of 

 them than all the rest, but good yields cannot be 

 produced upon any soil in which one or more of 

 these elements are either deficient or entirely lack- 

 ing. The plants obtain these substances from the 

 soil in solution in the water absorbed by the plant 

 roots. Only such of these elements or compounds 

 therefore as are soluble in water are for the time 

 being available as 'plant foods, for the plants can 

 neither absorb solid particles of plant food into their 

 roots nor could they utilize them in this shape if 

 they could. 



All soil is primarily decomposed rock, the par- 

 ticles of which it is composed varying in size and 

 fineness from the coarsest gravel to particles so 

 small that sometimes forty thousand would have to 

 be laid side by side to make an inch. Soils as we 

 commonly know them, however, are more or less 

 mixed with vegetable matter in various stages of 

 decomposition. This decomposed vegetable matter 

 is commonly called humus, and is the principal 

 source of that most important plant food, nitrogen, 

 the mineral plant food being derived from the parent 

 rock. Now let us stop for a moment to note the 

 difference between the soils of a humid country and 

 of an arid or semi-arid one. The rains of centuries 

 in the humid belt have caused a luxuriant vegeta- 



tion to grow, which dying down each year, has 

 added a world of humus and nitrogen to these soils, 

 but these same rains have meanwhile leached out 

 enormous amounts of soluble mineral plant foods. 

 The soils of humid countries are therefore rich in 

 humus and nitrogen, but compan tively poor in the 

 mineral plant food, while the soils of arid and semi- 

 arid countries are almost diametrically opposite, for 

 it has never rained sufficiently to either grow the 

 luxuriant vegetation or to leach out the mineral 

 plant foods. The soils of the arid and semi-arid 

 regions are therefore rich in mineral plant foods, 

 for they still have all that was originally contained 

 in the parent rock, but they are quite liable to be 

 deficient in nitrogen. It can be seen therefore that 

 whenever the eastern or humid soils becomes worn 

 out or run down, the addition of mineral plant foods 

 is necessary. This can only be accomplished by the 

 purchase and application of expensive commercial 

 fertilizers. Arid and semi-arid soils, however, rarely 

 need the addition of such fertilizers, for they have 

 more mineral plant foods than the humid soils had 

 a million years ago, but thir supply of nitrogen and 

 humus is normally only sufficient to last for but a 

 few crops, when it must needs be replenished. And 

 we are indeed fortunate that this can be so easily 

 and cheaply done through the growing of that val- 

 uable plant alfalfa. 



If we take pains to keep up the supply of nitro- 

 gen in our soil, we are far better off on an irrigated 

 farm in Alberta than any one can ever possibly be 

 on a farm in the humid belt, for with our soil far 

 richer in the necessary plant foods, with our longer 

 days of sunshine, and our ability to control the sup- 

 ply of moisture to the crops, giving them just what 

 they need, and, above, all, when they need it, we 

 can always grow larger crops and secure larger 

 profits than can be secured anywhere in the humid 

 belt, for the farmers in this belt have neither the 

 rich soil, the same amount of sunshine, nor the 

 ability to control the amount of moisture in the soil, 

 which is so necessary to maximum crop production. 

 We must, however, grow alfalfa, for as I shall ex- 

 plain later on, it adds more nitrogen to the soil than 

 any other crop we can grow. 



The Type of Soil Required 



Alfalfa has been known to grow and do well on 

 a very large variety of soils. It, however, has its 

 preference, and usually does better on the lighter 

 soils consisting of the sandy loam and clay loam. 

 Even in districts having the heavier soils most farms 

 contain one or more classes of soil, and in such cases 

 the alfalfa should be planted on the lighter or more 

 sandy soil. I should not hesitate, however, in 

 planting alfalfa even though my farm consisted of 

 all heavy soil. The one thing that alfalfa will not 

 stand is wet, soggy soil. Though it requires con- 

 siderable precipitation or irrigation water through- 

 out the season, it prefers a well drained soil. If 

 those desirous of planting alfalfa upon heavy soils 

 will select the higher and better drained portions 

 of their farm for this crop, but little difficulty will 



