1 Nov., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 518 
SWEET POTATOES. 
We lately saw sweet potatoes being planted for the third time in succession on 
the same land. This is unquestionably bad farming. The only soil in which 
Sweet potatoes develop their best qualities and attain the largest size is a sandy 
or volcanic soil, in which there is not an over-abundance of nitrogenous matter. 
The tuber does well after a cleanly cultivated corn crop. When potatoes have 
been grown year after year on the same land, and the vines left to decay thereon, 
the soil is said to become “potato sick.” A heavy dressing of potash and 
phosphoric acid overcomes the sickness, but it is best to grow some other crop 
on the land for a while; 550 Ib. per acre of a fertiliser containing available 
phosphoric acid, 7 per cent.; potash, 9 per cent.; nitrogen, 4 per cent., will give 
good results. 
STABLE MANURE. 
Mrxep stable manure contains nitrogen, ammonia, potash, phosphoric¢ acid, and 
lime. When allowed to decompose by exposure to the air, it loses a portion of 
its nitrogen in the form of volatile ammonia. This loss can be prevented by 
scattering kainit over the surface of the manure heap as it accumulates. The 
amount of kainit which should be added to fresh stable manure to prevent loss 
of ammonia through heating, is 1 lb. per day for each cow or horse, or for eight 
head of sheep. The kainit will save more than its cost in the value of the 
nitrogen which it retains, and will possess its original value as potash food. 
The annual products of the farm (grain, grass, roots, milk, &¢.) remove 
from the soil large quantities of nitrogen, potash, and phosphoric acid. A 
portion of these food elements is returned to the soil in the form of stable 
manure, but the remainder have been lost, and the productive capacity of the 
farm can only be maintained by the use of commercial fertilisers. 
To illustrate this fact, let us suppose a farm, on which, during three years, 
crops of wheat, potatoes, and corn have been raised, and where 26,700 lb., or 
about 133 tons, of stable manure has been applied per acre. An examination 
of the composition of the crops removed and of the manure applied will show 
the following decrease in fertility at the end of the period :— 
Crops. Potash. | Phos, Acid. | Nitrogen. 
: Lb. | Lb. Lb. 
Wheat, 30 bushels (1,802 lb. grain, 2,671 1b straw) ... ais 30 | 22 44 
Potatoes, 300 bushels, 16,800 lb... Mb ce a oF 97 26 57 
Corn, 12 tons, 24,000 Ib. ... tr Ve: PA ee te ‘ 79 36 98 
Total plant food removed... me #3 oa a oft, 206 | 84 199 
Total plant food supplied by 134 tons stable manure ¥; 168 | 69 134 
Total loss of plant food... mr sf =, ne rte 38 | 1b 65 
The tops or vines of field potatoes are so seldom removed from the field, 
that they are here considered as having been returned to the soil. 
LARGE TREES. 
Tite largest tree in the world is to be seen at Mascali, near the foot of Mount 
Etna, and it is called “the Chestnut-tree of a Hundred Horses.” Its name rose 
from the report that Queen Jane of Aragon, with her principal nobility, took 
refuge from a violent storm under its branches. The trunk is 204 feet in 
circumference. The largest tree in the United States, it is gaid, stands near 
Bear Creek, on the north fork of the Tule River, in California. It measures 
140 feet in circumference. The giant redwood-tree in Nevada is 119 feet in 
circumference.—Ladies’ Home Journal. 
