168 PRODUCTION 



tensions are made in North America, they will probably be so in 

 conjunction with mixed farming in which animal industries will 

 be prominent. It is now recognised everywhere in the more 

 valuable agricultural lands of the temperate regions that the time 

 of successive ready-money crops, leading inevitably to soil ex- 

 haustion, has passed. This applies to cotton as well as to cereals. 



Another important fibre crop of temperate climates is flax, but 

 a much larger area is devoted to the production of linseed than 

 to the production of fibre, the respective annual averages being 

 about 14 million acres, and about 5 million acres. Of 

 the latter about 3J million acres have been in Russia alone. 

 The cultivation of flax for the fibre yields no by-product 

 of value for animal industries, so that the area thus occupied 

 is lost to food production. However, this area shows no 

 marked tendency to increase. Flax grown for linseed (culti- 

 vated mainly in North and South America and India) yields a valu- 

 able commercial oil, that at present enters in no way into human 

 foodstuffs or animal feedstuff s. On the other hand, linseed cake 

 and meal, resulting as a by-product of crushing the seed for oil, is 

 one of the richest concentrated feedstuffs for live-stock and is 

 suitable for different kinds of animals in a way that some others, 

 for example, cotton-seed cake, are not. 1 The total production of 

 linseed in recent years has been about 120 million bushels (average 

 of the years 1911-13), yielding about 1J million tons of feedstuffs. 

 Linseed is a crop more favourable to animal industries than cotton 

 is, owing to the greater value of the feed-cake residue, a higher 

 percentage of cake from a given weight of seed, and to the fact 

 that the whole available crop is milled, while much cotton-seed is 

 returned as fertilisers to the ground. 2 Moreover, cotton-seed oil 

 acts as a foodstuff in competition with animal fats, while linseed 

 oil does not. Since it does not seem possible to find efficient 

 substitutes for linseed oil in the arts and in manufacture, the 

 demand for the oil will probably determine the extent to which 

 the linseed crop is grown, and that may easily increase in the future. 



From the point of view of animal industries, land devoted to 

 linseed might perhaps produce a greater quantity of feedstuffs, 

 if sown to the typical feedstuff cereals or to some fodder crop 

 instead, but the difference is not very great. On the balance, 

 therefore, the cultivation of linseed on the present limited scale 

 offers no serious competition to animal industries, and the area 

 devoted to flax for fibre is comparatively small and is not likely 

 to increase rapidly in the future. 



1 Cotton-seed cake or meal is usually fatal to pigs. U.S. Dept. Agric., 

 Bureau of Animal Industry, Bulletin 47. 



2 In the New World linseed has been found especially suited to virgin soils 

 on which it yields a safer and a more rapid return to the pioneer farmer than 

 the common cereals. 



