6^ 



neglected and the soil impoverished by the continuous growing of 

 cultivated crops, such as cotton and corn. The two views very 

 clearl}' showed which orchard was on a paying basis and likely to 

 prove a profitable investment). It is needless to say that the crop 

 from such a poor, intercropped orchard would be meagre and unprofit- 

 able until the methods were changed. The growing of legumes to 

 furnish humus, and even the growing of winter cover crops, such .is 

 rye, to be plowed under in the spring, cannot be too strongly recom- 

 mended as soil improvers. 



When nut trees are grown in orchards, they can no longer be con- 

 sidered as forest trees to be left to take care of themselves until a 

 rich harvest of nuts is produced, but must be cared for just as much 

 as any other fruit tree or cultivated' crop or the harvest of nuts will 

 never be forthcoming. 



The fertilizing of nut trees, however, offers more difficulties than 

 do the annual crops. Experiments on this subject have been few and 

 the information obtainable is rather mea,gre. Consequntly, a few years 

 ago, the Office of Soil Fertility Investigation, which is conducting 

 fertilizer investigations on a large number of the annual crops grown 

 on the prominent soil types or soil regions of the United States, started, 

 in co-operation with the Office of Horticultural Investigations of the 

 Bureau of Plant Industry, a number of fertilizer ex23eriments on 

 pecan orchards, involving a study of several soil types suitable for 

 nut j)roduction and attempting to ascertain the proper fertilizer re- 

 quirements for the pecan on these soils. \\'hile these experiments 

 have been running only five years, which in jioint of time is very 

 small in the life of a pecan tree, yet the different fertilizers cmjjloyed 

 already show some highly interesting results, sufficient to indiicate that 

 certain fertilizer applications undoubtedly influence the growth of 

 the tree, its productiveness, and quality of the nut produced. 



The experimental fertilizer mixtures are all prepared here in 

 Washington in a fertilizer-mixing plant on the department's Arlington 

 I^'arm. on the Virginia side of the river. The fertilizer house is well 

 stocked w^ith all of the various fertilizer substances used in agriculture, 

 ready for mixing; nitrate' of soda from Chili, potash from France and 

 Germany, and our own far western states ; cottonseed' meal from the 

 South, tankage and dried' blood from the slaughter houses of Chicago 

 and Omaha, Tennessee or Florida pliosphates, and acid phosphate, 

 ammonium sulfate from the coke ovens of Pennsylvania, Thomas slag 



