4. That as regards the distribution of the ash-constituents, lime, phosphoric acid, and magnesia are almost entirely found in the solid excrements; while the urine contains nearly all the potash.
5. That the best results can be expected only when the liquid and solid excreta are used together as a manure.
As the composition of the manure depends so largely on the nature of the food, a table will be found in the Appendix, Note VI.,[142] containing the manurial composition of some of the commoner feeding-stuffs.
3. Litter.
We have now to consider the third constituent of farmyard manure—viz., the litter, which generally consists of straw.
The uses of the litter, in addition to providing a dry and comfortable bed for the animal, may be briefly summed up as follows:—
1. To absorb and retain the liquid portion of the excreta.
2. To increase the quantity of the manure, and thus secure its more equal distribution when applied to the field than could otherwise be done.
3. To add to its value as a manure, both physically and chemically.
4. To retard and regulate the decomposition of the excreta.