If the soil is of that nature which we have already[378] spoken of as “tender,”[379] after a crop of barley has been grown upon it, millet may be sown, and after the millet has been got in, rape. In succession to these, again, barley may be put in, or else wheat, as in Campania; and it will be quite enough, in such case, to plough the ground when the seed is sown. There is another rotation again—when the ground has been cropped with spelt,[380] it should lie fallow the four winter months; after which, spring beans should be put in, to keep it occupied till the time comes for cropping it with winter beans. Where the soil is too rich, it may lie fallow one year, care being taken after sowing it with corn to crop it with the leguminous plants the third year.[381] Where, on the other hand, it is too thin, the land should lie fallow up to the third year even. Some persons recommend that corn should never be sown except in land which has lain fallow the year before. CHAP. 53.—THE MANURING OF LAND. The proper method of manuring is here a very important subject for consideration—we have already treated of it at some length in the preceding Book.[382] The only point that is universally agreed upon is, that we must never sow without first manuring the ground; although in this respect even there are certain rules to be observed. Millet, panic, rape, and turnips should never be sown in any but a manured soil. If, on the other hand, the land is not manured, sow wheat there in preference to barley. The same, too, with fallow lands; though in these it is generally recommended that beans should be sown. It should be remembered, however, that wherever beans are sown, the land should have been manured at as recent a period as possible. If it is intended to crop ground in autumn, care must be taken to plough in manure in the month of September, just after rain has fallen. In the same way, too, if it is intended to sow in spring, the manure should be spread in the winter. It is the rule to give eighteen cart-loads of manure to each jugerum, and to spread it well before ploughing it in,[383] or sowing the seed.[384] If this manuring, however, is omitted, it will be requisite to spread the land with aviary dust just before hoeing is commenced. To clear up any doubts with reference to this point, I would here observe that the fair price for a cart-load of manure is one denarius; where, too, sheep furnish one cart-load, the larger cattle should furnish ten:[385] unless this result is obtained, it is a clear proof that the husbandman has littered his cattle badly. There are some persons who are of opinion that the best method of manuring land is to pen sheep there, with nets erected to prevent them from straying. If land is not manured, it will get chilled; but if, on the other hand, it is over-manured, it becomes burnt up: it is a much better plan, too, to manure little and often than in excess. The warmer the soil is by nature, the less manure it requires.