“In the course of a long residence,” continues Dr. Vœlcker, “in a purely agricultural district, I have often been struck with the remarkably healthy appearance and good yield of wheat, on land from which a heavy crop of clover-hay was obtained in the preceding year. I have likewise had frequent opportunities of observing, that, as a rule, wheat grown on part of a field whereon clover has been twice mown for hay, is better than the produce of that on the part of the same field on which the clover has been mown only once for hay, and afterwards fed off by sheep. These observations, extending over a number of years, led me to inquire into the reasons why clover is specially well fitted to prepare land for wheat; and in this paper, I shall endeavor, as the result of my experiments on the subject, to give an intelligible explanation of the fact, that clover is so excellent a preparatory crop for wheat, as it is practically known to be. “By those taking a superficial view of the subject, it may be suggested that any injury likely to be caused by the removal of a certain amount of fertilizing matter, is altogether insignificant, and more than compensated for, by the benefit which results from the abundant growth of clover-roots, and the physical improvement in the soil, which takes place in their decomposition. Looking, however, more closely into the matter, it will be found that in a good crop of clover-hay, a very considerable amount of both mineral and organic substances is carried off the land, and that, if the total amount of such constituents in a crop had to be regarded exclusively as a measure for determining the relative degrees in which different farm crops exhaust the soil, clover would have to be described as about the most exhausting crop in the entire rotation. “Clover-hay, on an average, and in round numbers, contains in 100 parts: Water 17.0 Nitrogenous substances, (flesh-forming matters)* 15.6 Non-nitrogenous compounds 59.9 Mineral matter, (ash) 7.5 ----- 100.0 ===== * Containing nitrogen 2.5 “The mineral portion, or ash, in 100 parts of clover-hay, consists of: Phosphoric acid 7.5 Sulphuric acid 4.3 Carbonic acid 18.0 Silica 3.0 Lime 30.0 Magnesia 8.5 Potash 20.0 Soda, chloride of sodium, oxide of iron, sand, loss, etc. 8.7 ----- 100.0 =====