112 MANUAL OF GARDENING 
acre; but on some lands, where the greatest results are demanded, 
sometimes as much as twice this application may be made. 
Phosphoric acid is got in dissolved South Carolina and Flor- 
ida.rock and in various bone preparations. These materials 
are applied at the rate of 200 to 400 pounds to the acre. 
Commercial nitrogen is secured chiefly in the form of animal 
refuse, as blood and tankage, and in nitrate of soda. It is 
more likely to be lost by leaching through the land than the 
mineral substances are, especially if the land lacks humus. 
Nitrate of soda is very soluble, and should be applied in small 
quantities at intervals. Nitrogen, being the element which is 
mostly conducive to vegetative growth, tends to delay the 
season of maturity if applied heavily or late in the season. 
From 100 to 300 pounds of nitrate of soda may be applied 
to the acre, but it is ordinarily better to make two or three 
applications at intervals of three to six weeks. Fertilizing 
materials may be applied either in fall or spring; but in the 
case of nitrate of soda it is usually better not to apply in the fall 
unless the land has plenty of humus to prevent leaching, or on 
plants that start very early in the spring. 
Fertilizing material is sown broadcast, or it may be scattered 
lightly in furrows underneath the seeds, and then covered with 
earth. If sown broadcast, it may be applied either after the 
seeds are sown or before. It is usually better to apply it be- 
fore, for although the rains carry it down, nevertheless the 
upward movement of water during the dry weather of the 
summer tends to bring it back to the surface. It is important 
that large lumps of fertilizer, especially muriate of potash and 
nitrate of soda, do not fall near the crowns of the plants; 
otherwise the plants may be seriously injured. It is a general 
principle, also, that it is best to use more sparingly of fertilizers 
than of tillage. The tendency is to make fertilizers do penance 
for the sins of neglect, but the results do not often meet one’s 
expectations. 
