INDIANA HORTICULTURAL SOCIETY. 255 



forms of fertilizers should be used. In that case to obtain the immediate 



effect of the first formula given we would use- 

 Nitrate of soda 20 pounds 



Acid phosphate 250 pounds 



Muriate of potash 100 pounds 



The most conspicuous thing about the above formulas is the high 

 percentage of potash— more than ten times as much as is found in the 

 average "complete" fertilizer for general farm crops. 



A comparison of the plant food removed by fruit and wheat may show 

 the reason for this. 



Twenty crops of wheat, 15 bushels per acre, remove 660 pounds nitro- 

 gen, 324 pounds potash and 211 pounds phosphoric acid; twenty crops of 

 apples, 15 bushels per tree, 35 trees per acre, remove 1,337 pounds nitro- 

 gen, 1,895 pounds potash and 310 pounds phosphoric acid. 



The period when the wheat plant uses most of its food is during the 

 months of May and June, when moisture is usually abundant enough to 

 permit the wheat plant to utilize all the available plant food in the soil. 

 In the case of the apple the food is most needed during months when the 

 moisture is least abundant. Under these conditions the best course is to 

 provide an abundance, even an excess, of plant food so that during the 

 time when there is sufiicient moisture the plant may get its food' to the 

 best advantage. In the case of the first two formulas given there would 

 be no danger of loss of fertilizer ingredients from leaching and what was 

 not used one season would be ready for use the next. 



It will be noticed that the above formulas contain very little nitro- 

 gen. ■ There are several good reasons for this. The most important are 

 the high cost of commercial nitrogen, the danger of loss from leaching, 

 and the tendency of large quantities of quickly available niti'ogen to pro- 

 mote too rapid growth of the vegetative parts of the plant. 



The best source of nitrogen for orchards is farmyard manure and 

 clover or other leguminous plants. These furnish nitrogen in a form that 

 will gradually become available, and that is not liable to severe loss from 

 leaching. At the same time they* furnish a supply of organic matter to 

 the soil and this organic matter is of high value in maintaining a good 

 soil texture and in increasing the water-holding capacity of the land. Care 

 should be taken not to carry manuring to excess or to continue clovering 

 too long since we would then be likely to promote the excessive growth 

 of wood and foliage. I have no doubt that the amount per acre of fertil- 

 izer recommended above will at first sight appear excessive, especially 

 in those sections where fertilizer is used only on the wheat crop and 

 where the expenditure for fertilizer seldom exceeds $1.50 per acre. It 

 should, however, be kept in mind that one fertilization of an orchard pro- 

 vides plant food for several years. Moreover, if it is found that the profits 

 of an orchard are increased by the increase in the use of a fertilizer, then 



