NUESERY OPERATIONS. 27 



NURSERY OPERATIONS. 

 FERTILIZING. 



Although the soil of the nursery at first appeared to be abundantly- 

 fertile to support a good stand of small trees, its virgin fertility has 

 been dissipated, first, by the mixing of the surface soil with the 

 sterile subsoil; second, by watering, which has doubtless washed 

 out a good deal of the mineral fertility; and third, by the action of 

 the wind, which has to some extent moved the surface soil about. 

 Within two or three years the lack of humus in the soil began to be 

 felt, but it was not until 1908 that the use of manure for fertilizing 

 was begun on a large scale. Prior to this time some experiments 

 had been made with commerical fertilizers, such as dried blood, 

 bone meal, and phosphate, but these had had no appreciable effect; 

 possibly because they were quickly washed out of the sandy soil, 

 more likely because they did not change its physical composition. 

 Leaf compost has some advantage over manure, but is not obtainable 

 at Halsey in large quantities. 



The effects of the lack of fertility, and more particularly of the 

 lack of water-holding material in the surface soil, showed in several 

 ways: The trees were small and slender; the roots ramified to great 

 distances in order to obtain sufficient moisture and nutriment, and, 

 in hot, dry weather, as a direct result of insufficient moisture, the 

 trees were blighted. 



It was the physical composition of the soil that most affected tree 

 growth. An analysis of the soil from a number of nursery beds, 

 made at the University of Nebraska in 1905, showed that growth 

 of the seedlings was but little influenced by the small quantity of 

 humus in the soil, but that it was very directly controlled by the 

 quantity of moisture-retentive clay.^ The object in using manure, 

 therefore, is not so much to add to the quantity of plant food, which 

 may or may not be deficient, as to increase the water-holding capacity 

 of the soil by changing its physical composition. A small quantity 

 of clay would doubtless have about the same effect, and would be of 

 considerable value if it could be placed entirely below the depth of 

 cultivation, but experience has shown that clay in the surface soil 

 increases the difficulty of handling the trees. The extensive use of 

 clay, therefore, has not seemed advisable. This matter, however, 

 will be experimented with further. 



The proper quantity of manure to use depends, of course, on its 

 state of decomposition and the length of time that the soil has been 

 in use. At Halsey it has been the practice, when space would per- 

 mit, to grow trees on the ground for one or two years, then to manure 



1 Good growth was found where the percentage of alumina was from 2.05 to 2.76, and poor growth where 

 the percentage was from 0.76 to 1.01. In the sand hills a sample showed 0.84 per cent of alumina. 



