In the science of agriculture the cropping of the land proceeds, like a banquet, by "courses." There is, however, this significant difference, that while in the feast each successive "course" leads on by steady and cheerful stages to the state of physical beatitude which to some people is represented by repletion, many cultivators make their "courses" items in the process of impoverishment.
"Rotation of crops" is a phrase that is supposed to contain a well of hidden meaning. Learn the theory of rotation, and you become a farmer (of a sort) straight away. You just move your crops about like pieces on a chess-board.
But before we see what happens, let us follow the fate of some beautiful chess theory that we have worked up. On the board of our brain the pieces move with automatic precision to our theory's triumphant end. The enemy obligingly moves his pieces just as he is wanted to, and becomes hopelessly entangled in the meshes which we have spread for him.
In actual play things are exasperatingly different. The enemy makes a lot of moves which we never anticipated, and by amazing luck (we are sure he does not really see our trap) keeps out of danger.
The automatic, theory-ridden farmer has an opponent to reckon with when he sits down to the board, whose name is Nature. This player (we generally allude to it as of the feminine gender) has her own particular moves, and they are generally ones that he never expected. So many are the surprises sprung upon him by this subtle strategist that he is often driven to his wits' end for expedients to hold his own, and, perhaps, at last has to throw all his lovely problems to the winds, and trust to his native wit to save the situation.
The rotation of crops in the garden, like that on the farm, is subject to influences which are not under the grower's control. A good system is a grand thing, and we should all do well to get a sound theory into our minds, for at the worst it gives us a standard to work to, but at its best it is not everything.
My chief objection to the theory of rotation of crops is that, set up to stand alone, it often leads to failure. There is a sort of suggestion that, as long as you shift your crops about from one year to another, you have done everything that need or can be done, and are sure of a satisfactory yield. It is a mischievous doctrine, and the man who follows it, whether he be farmer or gardener, has trouble ahead.
If rotation of crops is preached in conjunction with high cultivation, it becomes less objectionable, but at the same time less necessary, for highly cultivated ground will produce crops of the same kind continuously for many years. One of the greatest Potato growers who ever lived has stated that he has grown Potatoes on the same ground for many consecutive years, and the crop has not deteriorated in the slightest. I have grown Onions on the same piece of ground for five consecutive years, and the crop has improved annually. The same may be said of Scarlet Runners. Broad Beans and Peas thrive well on the same ground year after year, always providing the soil is properly cultivated.
Thick-and-thin supporters of change - cropping have a very awkward obstacle to get over in Asparagus. Here we have a plant which produces a great mass of fibrous roots, and is therefore a gross feeder, yet no one would dream of shifting an Asparagus bed every year. As a matter of fact, top-dressings will keep a bed going for periods varying from twenty to fifty years.
The object of these remarks is not to disparage change-cropping, which is right enough as a theory; it is to establish the fact that it is not the real key to success. You could do away with the change-course system altogether if your culture was good enough, but no amount of changing about would bring success if the culture was bad.
It is my desire to give encouragement to those who, having small plots of vegetable ground, are unable to bring into play those principles of rotation-cropping which some people advocate so eloquently. The theorist would aver that the principle is equally applicable to a piece of 10 rods and to one of as many acres; but in this he would only prove that he is a theorist, and nothing better. Practical experience proves that with very small plots of ground it is impossible to effect the changes that are easily effected on large ones. There is an overlapping that the utmost ingenuity cannot smooth away.