There may not be a single farm where it will be possible to carry out to the letter these principles applying to the treatment and application of barn manures.
This is because climate, crops and conditions vary in different parts of the country and on different farms. Therefore we should study carefully our conditions and the principles and make our practice so combine the two as to produce the best and most economical results under the circumstances.
If we can get manure out in the winter it will very much lessen the rush of spring work.
In some parts of the country on account of deep snows, heavy rainfall and hilly fields, it is not advisable to apply manure in the winter. This will necessitate storing the manure.
If conditions are such that we can get the manure on to the land as soon as it is made, it should be applied to land on which a crop is growing or land which is soon to be planted. If land is not intended for an immediate crop, put a cover crop on it.
Composts are collections of farm trash or rubbish, as leaves, potato tops, weeds, road and ditch scrapings, fish, slaughter-house refuse, etc., mixed in piles with lime, barn manure, woods-earth, swamp muck, peat and soil.
The object of composting these materials is to hasten their decay and render available the plant food in them.
There are certain disadvantages in composting, namely:
Expense of handling and carting on account of bulk.
Compost heaps serve as homes for weed seeds, insects and plant diseases.
Nevertheless, all waste organic matter on the farm should be saved and made use of as manure. These materials when not too coarse may be spread on the surface of the soil and plowed under; they should never be burned unless too coarse and woody or foul with weed seeds, insects and disease.
[Illustration: FIG. 81.--SOY BEANS IN YOUNG ORCHARD.]
[Illustration: FIG. 82.--A YOUNG ALFALFA PLANT JUST COMING INTO FLOWER.]
Green-crop manures are crops grown and plowed under for the purpose of improving the fertility of the soil.
The main object of turning these crops under is to furnish the soil with humus. Any crop may be used for this purpose.
By growing any of the class of crops called Legumes we may add to the soil not only humus but also nitrogen. Cowpeas, beans, clover, vetch and plants having foliage, flowers, seed pods and seeds like them are called Legumes.