Page:Our New Zealand Cousins.djvu/281

 for instance, takes a certain set of constituents from the soil. These must be given back in the form of manure, or the land inevitably becomes less able to grow wheat. Disease is at once a consequence and an evidence of insufficient nourishment. Hence many common crop diseases are Nature's protest against a direct infringement of her laws. It is probable that if lands round Camden, we will say, had been well-manured, or if farming by rotation had been practised, rust might never have put in an appearance in County Cumberland. Now, in the earlier times, wheat seemed to be the ultimate limit beyond which the mind of the farmer never rose. Even now the bucolic mind is desperately conservative, and it seems hard to make the ordinary farmer understand that if wheat will not pay, something else might. Instead of resolutely tackling the problem of experimenting, of availing himself of all the modern discoveries and improvements in the