40 



Maine Agricultural Experiment Station. 1919. 



Application of Fertilisers Per Acre for Potatoes. 



Treatment No. 



Ammonia 



Phosphoric Acid 



Potash 



1 







240 







2 







192 



48 



3 



48 



192 







4 







144 



96 



5 



48 



144 



48 



6 



96 



144 







7 







96 



144 



8 



48 



96 



96 



9 



96 



96 



48 



10 



144 



96 







11 







48 



192 



12 



48 



48 



144 



13 



96 



48 



96 



14 



144 



48 



48 



15 



192 



48 







16 











240 



17 



48 







192 



18 



96 







144 



19 



144 







96 



20 



192 







48 



21 



240 











It was also desired to compare the usual potato formulas 

 of 5-8-7 and 3-8-10 goods, insoluble phosphate rock in the form 

 of finely ground floats with acid phosphate, and nitrogen in 

 the form of dried blood and in tankage with the mineral nitro- 

 gen used in the soil test. These 5 additional plots with 6 check 

 plots increase the number of plots to 32. 



The ingredients for the several fertilizer mixtures are 

 weighed out and thoroughly mixed by hand. To insure even 

 distribution each lot and plot are subdivided into fourths for 

 the application of the fertilizer on the oats and clover Series 

 and into sixths (as there are 6 rows in each plot) in the po- 

 tato Series. 



FIELD ARRANGEMENT OF PLOTS. 



It was thought that to overcome lack of uniformity in soil 

 each plot should be in triplicate. This makes a total of 96 plots. 

 As potatoes are the important cash crop of Aroostook County 

 it seemed important that potatoes should be grown annually. 

 As it was prohibitive to increase the number of plots much 

 above 100 because of the cost of caring for a larger number, 

 it was decided to grow the plots in a 3 year rotation of pota- 

 toes, oats and clover. This plan not only gives a potato crop 



