12B 

 TABLE I. 



Influence of Fertilization and Cultural Methods on Gi-owth. 



(Average Increases in Trunk-girth, 1908-'13, the first 6 years. 



Expt. 337) 



Average Gain over 



Plat Treatme nt Increase Normal Growth 



inches per cent, 

 (a) Fertilization 



1 Check (Unfertilized) 4.85 



2 Nitrogen and Acid Phos. 5.43 10.1 



3 Nitrogen and Potash 5.07 1.2 



4 Check 5.09 



5 Phosphate and Potash 5.79 6.2 



6 Complete Fertilizer 6.45 11.2 



7 • Check 6.19 



8 Manure 6.63 11.4 



9 Lime (and Ftlzr. 1912-) 6.21 7.8 



10 Check* 5.54 



(b) Cultural Methods Gain over lowest. 



per cent. 



11 Tillage and Covercrop 5.41 5.67 



12 Tillage and Intercrop 5.12 



13 Tillage alone 5.34 4.30 



14 Mulch 6^00 17.20 



*The average check equals 5.417 inches of increase. 



In connection with the average increases shown here, 

 it should be stated that plats 6 to 10 are situated slightly 

 lower than the others, and apparently more favorably. 

 Hence their actual gains are not so valuable for comparison 

 throughout the experiment as their percentages of gain over 

 the normal growth for the situation. On the latter basis, 

 it will be noted that certain forms of fertilization, — particu- 

 larly those containing nitrogen and phosphorus — are begin- 

 ning to show considerable influence. This is doubtless 

 connected with the fact that this particular soil type is often 

 unusually low in these elements, as young apple trees fre- 

 quently fail to respond appreciably to any application in- 

 volving plant food alone. 



This soil is also usually well supplied with moisture,— r 

 so much so in fact that drainage is generally its first need. 

 Even at that, however, it will be noted that the mulched 

 trees of plat 14, — a treatment especially fitted to conserve 



