18 N. H. AGR. EXPERIMENT STATION. [Bulletin 12 



Plot 6. Cultivation and cover crop, with the following complete 

 fertilizer per tree: 



2 pounds nitrate of soda 

 4 pounds sulphate of potash 

 7 pounds basic slag. 



Plot 7. Cultivation and cover crop, with the following com- 

 plete fertilizer per tree: 



2 pounds nitrate of soda 

 4 pounds sulphate of potash 

 8J pounds acid phosphate. 



Plot 8. Excess phosphorus. Cultivation and cover crop, with 

 the following complete fertilizer per tree: 

 2 pounds nitrate of soda 

 4 pounds sulphate of potash 

 17 pounds acid phosphate. 



Plot 9. Excess nitrogen. Cultivation and cover crop, with 

 the following complete fertilizer per tree: 

 6 pounds nitrate of soda 

 4 pounds sulphate of potash 

 8J pounds acid phosphate. 



Plot 10. Excess potassium. Cultivation and cover crop, with 

 the following complete fertilizer per tree: 

 2 pounds nitrate of soda 

 10 pounds sulphate of potash 

 8J pounds acid phosphate. 



EXAMINATION OF DATA. 



Upon examination of this table it will be seen that the effect 

 of cultivation (which was begun 1908) was at once seen in the 

 growth of the twigs, Plots 1 and 2 not being tilled the first year. 



As would be expected, the trees in the sod plot (Plot 1) have 

 made about the same growth from year to year, and what slight 

 differences occur can probably be accredited to weather conditions. 

 These trees have averaged from a little more than four inches to 

 nearly six and a half inches of growth a year, and the average of 

 the eight years, 1909-1916, is 4.81 inches, which is an unsatis- 

 factory growth and not sufficient to keep the trees in a productive 



