A Tree is a Living Thing 



Trees, however, are frugal with their 

 nitrogen. They do not waste it, but use 

 it over and over. A tree that is well 

 supplied with nitrogen has lush, dark- 

 green foliage, and its growth is luxu- 

 riant a tree deprived of nitrogen is 

 stunted and its leaves are pale green. 

 An overdose of nitrogen is also bad 

 for a tree. Conditions of nitrogen ex- 

 cess are extremely rare in nature, but 

 might occur occasionally, for instance, 

 in a tree grown in a chickenyard 

 where supply of nitrogen is in excess. 



How can you help a tree in its ni- 

 trogen nutrition? Growing nitrogen- 

 fixing legumes, such as clover, near 

 your trees will enrich the soil with ni- 

 trogen. The addition of leaf mold to 

 the soil would serve the same purpose. 

 Remember, too, that removing or 

 burning fallen leaves from around the 

 trees deprives the trees of the much- 

 needed nitrogen. If burning or remov- 

 ing must be done, it is wise to replace 

 the loss by applying some nitrogen 

 fertilizer. One word of caution in 

 feeding trees with nitrogen. Nitrate 

 fertilizers are leached rapidly from the 

 soil; they are not absorbed by the soil 

 as readily as, say, the phosphates. It is 

 advisable therefore to add nitrates in 

 small quantity and often, rather than 

 to apply a large quantity at one time. 



In applying fertilizer one should 

 keep in mind that trees do not grow so 

 fast as field crops, and thus their de- 

 mand for nitrogen and for other nu- 

 trients is comparatively small. 



BESIDES OXYGEN, hydrogen, carbon, 

 and nitrogen, which are obtained from 

 water and air, for proper functioning 

 a tree needs several other elements, 

 which it obtains from the minerals 

 found in the soil. 



Some of these mineral elements 

 potassium, phosphorus, and calcium 

 are needed in relatively large amounts. 

 Other elements magnesium, sulfur, 

 and iron are needed in relatively 

 smaller quantities. Still others, called 

 trace elements such as manganese, 

 copper, zinc, boron, or molybdenum 

 are necessary only in minute quantities. 



The need even of major elements is 

 very small indeed. The total amount of 

 the mineral elements in dry wood is 

 less than one-half of 1 percent, and the 

 need for the trace elements is so small 

 that generally they are found in suffi- 

 cient quantity in any soil. 



Occasionally there may be a com- 

 plete absence or too small a supply of 

 the trace elements in a particular soil. 

 In that case, a tree will not grow prop- 

 erly unless the lacking element is 

 introduced. Great care should be exer- 

 cised not to apply too much of the 

 trace elements, lest great damage be 

 done to the tree. For instance, while 

 potash or phosphorus may be added to 

 soil at the rate of, say, 1,000 pounds an 

 acre, about 5 or 10 pounds an acre of a 

 trace element is enough. More than 

 that might be harmful to the trees. A 

 specialist should be consulted before 

 any trace element is added to the soil. 



When wood is burned, all these and 

 many other elements are found in the 

 ashes, but some sulfur and phosphorus 

 and all nitrogen are lost in smoke. 

 Twenty-seven elements, including sil- 

 ver, titanium, and nickel, are found in 

 the ashes of white pine. That does not 

 mean that all these elements are neces- 

 sary for the life of the tree. Some min- 

 erals that may be found in a tree, such 

 as common salt, apparently are not 

 needed for its proper functioning. 

 These are absorbed by the roots sim- 

 ply because they happened to be in 

 the soil; the tree has no way of telling 

 the useful minerals from the useless 

 or even harmful ones. For example, 

 arsenic, though very poisonous to 

 the tree, is as readily absorbed as 

 phosphorus. 



Mineral elements are needed by a 

 tree to perform various vital func- 

 tions. Phosphorus is found in some 

 plant proteins; seeds and growing 

 points are especially rich in phospho- 

 rus. Lack of phosphorus often mani- 

 fests itself in purpling or bronzing of 

 foliage, which is easy to detect. Sulfur 

 also enters into the building of certain 

 proteins. It is well distributed through- 

 out the plant. Calcium apparently is 



