n average of .72 per cent--_i.e._, 16.12 lb per ton.

Of mineral matter, however, straw contains a very much larger
percentage, proportionally, than of nitrogen; for, with the exception of
phosphates, there is a considerable quantity of inorganic fertilising
matter, in the shape of potash, lime, &c., present in

Composition of Straw.[144]
-----------------+---------------+------------------------+--------
| Ash. | Composition of Ash. |
+------+--------+------------------------+
| | | Lb. per ton. |
| | Lb. |-------+----------+-----| Number
| Per | per |Potash.|Phosphoric|Lime.| of
| cent.| ton. | | Acid | |Analyses
-----------------+------+--------+-------+----------+-----+--------
Wheat (winter) | 5.54 | 124.09 | 18.61 | 5.05 | 7.18| 8
Wheat (summer) | 5.14 | 115.13 | 25.76 | 6.47 | 7.12| 6
Rye (winter) | 5.33 | 119.39 | 20.61 | 5.89 | 9.73| 8
Rye (summer) | 6.14 | 137.53 | 42.41 | 6.73 |10.53| 1
Barley | 4.90 | 109.76 | 26.83 | 5.75 | 8.73| 8
Oats | 5.09 | 114.01 | 26.22 | 4.17 | 9.12| 4
-----------------+------+--------+-------+----------+-----+--------

it. Of total ash ingredients, on an average, there are generally about 5
per cent--or 112 lb. per ton. The largest percentage of the fertilising
matter in this 5 per cent is potash, which varies in the ashes of the
straws of the commoner crops from 30 to 15 per cent. The above table
will show the variation in composition of the straws of some of the
commoner farm crops, and may be valuable for purposes of reference. The
crops are wheat (winter and summer), barley, oats, and rye (winter and
summer), and the amount is also calculated in lb. per ton. The results
represent the average of a number of analyses.[145] From the table it
will be seen that the percentage of phosphates is, as has already been
noticed, very small.

But while straw is well adapted for the purposes for which litter is
used, it is not the only substance. Its almost exclusive use as litter
is largely owing to the fact that it is a bye-product of the farm.

_Loam as Litter._--Generally speaking, any substance which has great
absorptive as well as retentive powers for nitrogen and the soluble
fertilising matters present in farmyard manure, and whose p