ROTATIONS TO PRODUCE FOOD 211 



albuminous ratio, and in order to make its consump- 

 tion economical, it is necessary to feed straw along 

 with highly albuminous foods. Under ordinary sys- 

 tems of farming, cake and meals, mostly of foreign 

 origin, are used for this purpose; but in the above 

 rotation, it will be noticed, a large bulk of home- 

 grown albuminous food, vetch hay, vetch silage, seeds 

 hay and ensilage, as well as " winter greens," is pro- 

 vided. Again. The " winter greens " are grown 

 twice in the rotation and by their consumption on the 

 land, preferably with sheep, the humus and vegetable 

 contents of the soil are maintained. 



This indeed, in corn growing areas, is a matter of 

 vital importance. Too often in corn raising areas the 

 humus contents of the soil are very deficient, the land 

 in consequence having a heavy nature, becomes sad 

 and difficult to till, whilst if the soil be light, the 

 exhaustion of its humus contents results in the land 

 becoming what the farmer terms weak — that is, un- 

 retentive of heat, moisture and plant food. The 

 chemical fertility of such land may be maintained by 

 the liberal use of artificial manures, but there is 

 nothing which will keep up the physical fertility, 

 except the application of natural manure or vegetable 

 matter. 



Indeed, the humus contents of soil in many corn 

 growing districts have become so depleted that it 

 would be better, for a few years at least, to turn in 

 the " winter greens " as green manure. Once the physi- 

 cal nature of the soil has been improved sufficiently 

 by turning in green manure, it would be more 

 economical to consume the winter green crops, pre- 

 ferably by sheep, and plough in the residue. 



In fact, the above rotation is probably as fine an 

 example of animal husbandry combined with human 

 food production as can be given. Furthermore, it per- 



