Talks on Manures | Page 8

from the farm, must have a tendency to impoverish the land of the other elements of plant food. In other words, the use of superphosphate furnishing only, or principally, phosphoric acid, lime and sulphuric acid, must have a tendency to impoverish the soil of nitrogen and potash. Practically, however, it need do nothing of the kind. If the land is well cultivated, and if our low, rich, alluvial portions of the farm are drained, and if the hay, grass, clover, straw and fodder crops are retained, the more phosphates we use, the richer and more productive will the farm become. And I think it is a fact, that the farmers who use the most phosphates, are the very men who take the greatest pains to drain their land, cultivate it thoroughly, and make the most manure. It follows, therefore, that the use of phosphates is a national benefit.
Some of our railroad managers take this view of the subject. They carry superphosphate at a low rate, knowing that its use will increase the freight the other way. In other words, they bring a ton of superphosphate from the seaboard, knowing that its use will give them many tons of freight of produce, from the interior to the seaboard. It is not an uncommon thing for two hundred pounds of superphosphate, to give an increase of five tons of turnips per acre. Or, so to speak, the railroad that brings one ton of superphosphate from the seaboard, might, as the result of its use, have fifty tons of freight to carry back again. This is perhaps an exceptionably favorable instance, but it illustrates the principle. Years ago, before the abolition of tolls on the English turnpike roads, carriages loaded with lime, and all other substances intended for manure, were allowed to go free. And our railroads will find it to their interest to transport manures of all kinds, at a merely nominal rate.
Many people will be surprised at the recommendation of Sir John B. Lawes, not to waste time and money in cleaning poor land, before seeding it down to grass. He thinks that if the land is made rich, the superior grasses overgrow the bad grasses and weeds. I have no doubt he is right in this, though the principle may be pushed to an extreme. Our climate, in this country, is so favorable for killing weeds, that the plow and the cultivator will probably be a more economical means of making our land clean, than the liberal use of expensive manures. It depends, doubtless, on the land and on circumstances. It is well to know that manure on grass land, will so increase the growth of the good grasses, as to smother the weeds. Near my house was a piece of land that I wanted to make into a lawn. I sowed it with grass seed, but the weeds smothered it out. I plowed it, and hoed it, and re-seeded it, but still the weeds grew. Mallows came up by the thousand, with other weeds too numerous to mention. It was an eye-sore. We mowed the weeds, but almost despaired of ever making a decent bit of grass land out of it. It so happened that, one year, we placed the chicken coops on this miserable weedy spot. The hens and chickens were kept there for several weeks. The feed and the droppings made it look more unsightly than ever, but the next spring, as if by magic, the weeds were gone and the land was covered with dark green luxuriant grass.
In regard to the use of potash as a manure, we have still much to learn. It would seem that our grain crops will use soda, if they cannot get potash. They much prefer the potash, and will grow much more luxuriantly where, in the soil or manure, in addition to the other elements of plant food, potash is abundant. But the increased growth caused by the potash, is principally, if not entirely, straw, or leaves and stem. Nature makes a great effort to propagate the species. A plant of wheat or barley, will produce seed if this is possible, even at the expense of the other parts of the plant.
For grain crops, grown for seed, therefore, it would seem to be entirely unprofitable to use potash as a manure. If the soil contains the other elements of plant food, the addition of potash may give us a much more luxuriant growth of leaves and stem, but no more grain or seed. For hay, or grass or fodder crops, the case is very different, and potash may often be used on these crops to great advantage.
I am inclined to think that considerable nitrate of soda will yet be used in this country for manure. I do not suppose it