PURCHASE AND USE OF FLvRTFUZKRS 



333 



grown, (3) wheat alternating with fallow, (4) barley continu- 

 ously, (5) potatoes continuously, (6) hay continuously, (7) ex- 

 periments on root crops. Most of the plots are about ^2 acre 

 each. The plots are very long and narrow and separated by 

 paths. 



The following is part of the plan of the wheat experiments on 

 Broadbalk field 1 with some of the results. 



Plot 



Application 



Average bushels 



wheat, 51 years, 



1851-1962. 



9 



10 



ir 



12 

 13 

 H 

 15 



16 



I? 

 18 



19 



nitrogen as ammonium 



nitrogen as ammonium 



nitrogen as ammonim 



Manure, 14 tons 



Nothing 



Minerals 2 



Minerals and 43 pounds 



sulphate 



Minerals and 86 pounds 



sulphate 



Minerals and 129 pounds 



sulphate 



Minerals and 43 pounds nitrogen as nitrate of soda - . 



86 pounds nitrogen as ammonium sulphate 



86 pounds nitrogen as ammonium sulphate. and acid 



phosphate 



Same as n, plus sulphate of soda 



Same as n, plus sulphate of potash 



Same as 1 1, plus sulphate of magnesia 



Mineral plus 86 pounds nitrogen as ammonium 



sulphate ( applied in autumn ) 



Minerals plus 86 pounds nitrogen in nitrate of soda- . 

 J Minerals alone or 86 pounds nitrogen as ammonium 



( sulphate alone in alternate years 



92.6 pounds nitrogen in rape cake 



35-7 

 13-1 

 14-9 



24.0 

 32.9 



37-i 



(27-3) 3 



20.7 



24.0 

 30.0 



3i-5 

 30.1 



30.6 



40. 4 

 (28.0)* 



Pennsylvania Experiments 6 at State College, were begun in 

 1882, on four fields of 144 plots of Y% acre, about i 1 /^ rods wide 

 by 1 6 rods long. A four-year rotation of corn, oats, wheat, and 

 hay of mixed clover and timothy is followed, each of the crops 



1 An Account of the Rothamsted Experiments, Hall. 



2 Minerals consist of superphosphate, with sulphates of potash, soda, 

 and magnesia. 



3 Average for 10 years only. 



4 Average for minerals. 



5 Average for nitrogen. 



6 Report 1910-11. 



