Fitzherbert, in deploring the gradual discontinuance of the practice of marling land, had alluded to the grievance familiar in modern times of tenants "who, if they should marl and make their holdings much better, fear lest they should be put out, or make a great fine or else pay more rent."
The following passage indicates the contemporary theory of manuring: - " In thy tillage are these special opportunities to improve it, either by liming, marling, sanding, earthing, mudding, snayl-codding, mucking, chalking, pidgeons-dung, hens-dung, hogs-dung or by any other means as some by rags, some by coarse wool, by pitch marks, and tarry stuff, any oyly stuff, salt and many things more, yea indeed any thing almost that bath any liquidness, foulness, saltness or good moysture in it, is very naturall inrichment to almost any sort of land."
The first half of the 17th century was a period of agricultural activity, partly due, no doubt, to the increase of enclosed farms. Marling and liming are again practised, new agricultural implements and manures introduced, and the new crops more widely used.
The author bespeaks the favour of those to whom he addresses himself in the following significant terms: - " Neither shall I affright you with hedging, ditching, marling, chalking, paring and burning, draining, watering and such like, which are all very good improvements indeed, and very agreeable with the soil and situation of East Lothian, but I know ye cannot bear as yet a crowd of improvements, this being only intended to initiate you in the true method and principles of husbandry."
He realized that with the enclosure of the waste lands and the absorption of small into large ho] dings, the commonfield farmer must migrate to the town or become a hired labourer; but he also realized that to feed a rapidly growing industrial population, the land must be improved by draining, marling, manuring and the use of better implements, in short by the investment of the capital which the yeoman farmer, content to feed himself and his own family, did not possess.
The chief processes for the improvement of soils which may be discussed here are: liming, claying and marling, warping, paring and burning, and green manuring.