The Rothamsted Memoirs on Agricultural Chemistry and Physiology (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1893 edition. Excerpt: ...crops, grain and straw together. Thus, over the first period, the average amounts of soda in the total crop were, without any supply of either potash, soda, or magnesia, 840 lbs., and with the supply of all three, only 8'84 lbs.; over the second period, without the supply 15-21 lbs., and with the supply only 8-69 lbs.; and, lastly, over the third period, without the supply 11-85 lbs., and with the supply only 8-27 lbs. Thus, then, not only was there much more soda taken up, or retained, by the plant where it was not supplied than where it was, but it is evident that there was the more soda taken up the less the supply of potash. The amounts of soda retained in the grain are, however, seen to be but small; there is more, it is true, where there was a deficiency of potash, and where more soda was taken up. But, looking to the amounts of soda per cent, in the grain ash, or per 1000 dry substance of the grain, it would seem probable that the larger amounts where there was deficiency of potash, and more total soda taken up, were probably only due to larger amounts eliminated from the grain proper, and retained in the adherent paleae, or chaff. Whether, however, the soda has been of any avail, in the earlier, or merely vegetative stages of growth, as a carrier, or otherwise, may be a question..Next as to the phosphoric acid, of which there was the same annual supply on both plots. It is seen that whether we take its percentage in the ash, its proportion to the dry substance, or its average quantity per acre, the amounts are, in the comparable cases, comparatively uniform; the differences not being greater than can be supposed to be connected with the differences in growth due to the differences in the supply of other constituents. Lastly, as to...