Page:Notes on five years' experiments on hop manuring conducted at Golden Green, Hadlow, Tonbridge.djvu/10

8 In 1899 our first dressing of nitrate went on at the beginning of January, and the last at the beginning of April. The actual dates of nitrate sowing in each of the last four years are shown in the following _table:—

The year 1899 has been a year of extraordinary natural productivity.

To illustrate this, it may be recalled that our A plot has received no nitrogenous manure of any kind since 1895, when it received an ordinary dressing of dung. Ever since, it has received every year either superphosphate or basic slag, with a dose of potash salts, but no nitrate or other nitrogenous manure. In 1897 and 1898 this plot only produced 7½ and 8¼ cwt. of hops per acre, while our best nitrated plot produced in the same two years 13½ and 15¼ cwt. per acre, there being, therefore, a difference of 6 cwt. and 7 cwt. per acre due to the use of nitrate in addition to the phosphates and potash. In 1899, however, this plot A, which might have been supposed to be, from a hop-growing point of view, in a state of nitrogen starvation, actually produced over a ton of hops per acre—though, as we shall see hereafter, of but poor quality. Now, a ton of hops per acre certainly cannot be grown without a very good supply of nitrogen from somewhere, and, as no nitrogen had been added to the soil since 1895, the natural capital of organic nitrogen in the soil and