Talks on Manures | Page 9

will pay as a rule, on wheat, corn and other standard grain crops. But the gardener, seed grower, and nurseryman, will find out how to use it with great profit. Our nurserymen say that they cannot use artificial manures with any advantage. It is undoubtedly true that a dressing of superphosphate, sown on a block of nursery trees, will do little good. It never reaches the roots of the plants. Superphosphate can not be washed down deep into the soil. Nitrate of soda is readily carried down, as deep as the water sinks. For trees, therefore, it would seem desirable to apply the superphosphate before they are planted, and plow it under. And the same is true of potash; but nitrate of soda would be better applied as a top-dressing every year, early in the spring.
The most discouraging fact, in Lawes' and Gilbert's experiments, is the great loss of nitrogen. It would seem that, on an average, during the last forty years, about one-half the nitrogen is washed out of the soil, or otherwise lost. I can not but hope and believe that, at any rate in this country, there is no such loss in practical agriculture. In Lawes' and Gilbert's experiments on wheat, this grain is grown year after year, on the same land. Forty annual crops have been removed. No clover is sown with the wheat, and great pains are taken to keep the land clean. The crop is hoed while growing, and the weeds are pulled out by hand. The best wheat season during the forty years, was the year 1863. The poorest, that of 1879; and it so happened, that after an absence of thirty years, I was at Rothamsted during this poor year of 1879. The first thing that struck me, in looking at the experimental wheat, was the ragged appearance of the crop. My own wheat crop was being cut the day I left home, July 15. Several men and boys were pulling weeds out of the experimental wheat, two weeks later. Had the weeds been suffered to grow, Sir John Bennet Lawes tells us, there would be less loss of nitrogen. The loss of nitrogen in 1863, was about twenty-four pounds per acre, and in 1879 fifty pounds per acre--the amount of available nitrogen, applied in each year, being eighty-seven pounds per acre. As I said before, the wheat in 1879 had to me a ragged look. It was thin on the ground. There were not plants enough to take up and evaporate the large amount of water which fell during the wet season. Such a condition of things rarely occurs in this country. We sow timothy with our winter wheat, in the autumn, and red clover in the spring. After the wheat is harvested, we frequently have a heavy growth of clover in the autumn. In such circumstances I believe there would be comparatively little loss of nitrogen.
In the summer-fallow experiments, which have now been continued for twenty-seven years, there has been a great loss of nitrogen. The same remarks apply to this case. No one ever advocates summer-fallowing land every other year, and sowing nothing but wheat. When we summer-fallow a piece of land for wheat, we seed it down with grass and clover. There is, as a rule, very little loss of nitrogen by drainage while the wheat is growing on the ground, but after the wheat is cut, the grass and clover are pretty sure to take up all the available nitrogen within the range of their roots. This summer-fallow experiment, instead of affording an argument against the use of summer-fallowing, is an argument in its favor. The summer-fallow, by exposing the soil to the decomposing influences of the atmosphere, converts more or less of the inert nitrogenous organic matter into ammonia and nitric acid. This is precisely what a farmer wants. It is just what the wheat crop needs. But we must be very careful, when we render the nitrogen soluble, to have some plant ready to take it up, and not let it be washed out of the soil during the winter and early spring.
We have much poor land in the United States, and an immense area of good land. The poor land will be used to grow timber, or be improved by converting more or less of it, gradually, into pasture, and stocking it with sheep and cattle. The main point is, to feed the sheep or cattle with some rich nitrogenous food, such as cotton-seed cake, malt-sprouts, bran, shorts, mill-feed, refuse beans, or bean-meal made from beans injured by the weevil, or bug. In short, the owner of such land must buy such food as will furnish the most nutriment and make the richest manure at the least cost--taking both of these objects into consideration.