Page:Notes on five years' experiments on hop manuring conducted at Golden Green, Hadlow, Tonbridge.djvu/12

10 In the ordinary course of things, the nitrates thus formed would have been to a large extent washed down through the soil into the drains during the winter and spring rains; but over a very large area of the hop-growing country the dry weather of several years had reduced both soils and subsoils to a very dry condition, and the rain that fell in the winter of 1898-99, and in the early spring months of the latter year, was not sufficient at any time—at Hadlow, at all events—to cause the drains to run. Ponds and ditches were dry during the greater part of 1899 that had not been dry for years before. Not only, therefore, must there have been an exceptionally large production of soil nitrates, but an unusually large proportion of the nitrates produced must have remained in the surface soil and in the upper subsoil, within reach of the crop of 1899, so that every hop garden, apart from any application of manure in 1899, must have been in the position of having received, by natural agency, an extensive dressing of nitrate. When these conditions were followed by good growing weather and by a most satisfactory scarcity of insect pests, it is after all not remarkable that even nitrogen starved land, like our Plot A, should produce a fine crop of hops, or that our Plot X, with its residues of unutilised dung to supply additional material for nitrification, should have given so excellent an account of itself.

An examination of our results for the year, however, will show that, even under the highly advantageous natural conditions that prevailed, nitrate of soda proved a valuable addition to the natural resources of the soil, the quantity of hops produced on the nitrated plots being from 2 to 4¼ cwt. per acre in excess of the crop produced without artificially applied nitrogen, while the good effect in quality, as will be seen later, was of even greater importance.