There are, however, numerous things constantly going to waste about the small place, which should be converted into manure. Fallen leaves, grass clippings, vegetable tops and roots, green weeds, garbage, house slops, dish water, chip dirt from the wood-pile, shavings—any thing that will rot away, should go into the compost heap. These should be saved, under cover if possible, in a compact heap and kept moist (never soaked) to help decomposition. To start the heap, gather up every available substance and make it into a pile with a few wheelbarrows full, or half a cartload, of fresh horse manure, treading the whole down firmly. Fermentation and decomposition will be quickly started. The heap should occasionally be forked over and restacked. Light dressings of lime, mixed in at such times, will aid thorough decomposition.
Wood ashes form another valuable manure which should be carefully saved. Beside the plant food contained, they have a most excellent effect upon the mechanical condition of almost every soil. Ashes should not be put in the compost heap, because there are special uses for them, such as dusting on squash or melon vines, or using on the onion bed, which makes it desirable to keep them separate. Wood ashes may frequently be bought for fifty cents a barrel, and at this price a few barrels for the home garden will be a good investment.
Coal ashes contain practically no available plant food, but are well worth saving to use on stiff soils, for paths, etc.
VALUE OF GREEN MANURING
Another source of organic manures, altogether too little appreciated, is what is termed "green manuring"—the plowing under of growing crops to enrich the land. Even in the home garden this system should be taken advantage of whenever possible. In farm practice, clover is the most valuable crop to use for this purpose, but on account of the length of time necessary to grow it, it is useful for the vegetable garden only when there is sufficient room to have clover growing on, say, one half- acre plot, while the garden occupies, for two years, another half-acre; and then changing the two about. This system will give an ideal garden soil, especially where it is necessary to rely for the most part upon chemical fertilizers.
There are, however, four crops valuable for green-manuring the garden, even where the same spot must be occupied year after year: rye, field corn, field peas (or cow peas in the south) and crimson clover. After the first of September, sow every foot of garden ground cleared of its last crop, with winter rye. Sow all ground cleared during August with crimson clover and buckwheat, and mulch the clover with rough manure after the buckwheat dies down. Sow field peas or corn on any spots that would otherwise remain unoccupied six weeks or more. All these are sown broadcast, on a freshly raked surface. Such a system will save a very large amount of plant food which otherwise would be lost, will convert unavailable plant food into available forms while you wait for the next crop, and add humus to the soil—concerning the importance of which see Chapter VII.
CHEMICAL FERTILIZERS
I am half tempted to omit entirely any discussion of chemical fertilizers: to give a list of them, tell how to apply them, and let the why and wherefore go. It is, however, such an important subject, and the home gardener will so frequently have to rely almost entirely upon their use, that probably it will be best to explain the subject as thoroughly as I can do it in very limited space. I shall try to give the theory of scientific chemical manuring in one paragraph.
We have already seen that the soil contains within itself some available plant food. We can determine by chemical analysis the exact amounts of the various plant foods—nitrogen, phosphoric acid, potash, etc.—which a crop of any vegetable will remove from the soil. The idea in scientific chemical manuring is to add to the available plant foods already in the soil just enough more to make the resulting amounts equal to the quantities of the various elements used by the crop grown. In other words:
)
Available plant food elements in (
the soil, plus > == Amounts of food elements
Available chemical food elements ( in matured crop
supplied in fertilizers )