EXPERIMENTAL WORK WITH RAW ROCK PHOSPHATE. 



37 



At the beginning of these experiments limestone was applied on the 

 plots indicated at the rate of 5 tons per acre at Ewing and 6 tons 

 per acre at Ealeigh; no further applications were made during the 

 first five years of the experiment. Rock phosphate (finely ground) 

 was applied at the rate of from 500 to 2,000 pounds per acre on the 

 different series and kainit at rates varying from 200 to 800 pounds per 

 acre, with subsequent applications every four years. It is not stated, 

 however, which plots received the maximum and which the minimum 

 amounts of these materials. 



The average yield of each crop during the five years of the experi- 

 ment is given below in Tables XIII and XIV. 



Table XIII. — Average results of five years' loork on four series of plots at 

 Ewing, Franklin County — Four-year rotation, consisting of loheat, cowpeas {or 

 other legume), oats, and com. 





Average yield per acre. • 



Treatment. 



Wheat, 

 5 years. 



Cowpeas, 

 3 years. 



Clover, 

 1 year. 



Soy 

 beans, 

 lyear. 



Oats, 

 5 years. 



Com, 

 5 years. 





Bushels. 

 5.1 

 6.7 

 12.0 

 13.7 



4.3 



4.1 

 12.4 

 14.0 

 20.7 



5.7 



Tons. 

 0.63 

 .52 



.88 

 .98 



11.46 



Bushels. 

 1.2 

 2.4 

 3.2 

 4.0 



1.3 



Ton. 



0.20 



.24 



.40 



.81 



.19 



Bushels. 



.00 



.50 



1.08 



.75 



Ton. 

 0.31 



Ton. 



0.27 



.23 



.47 



.53 



Bushels. 

 2.0 



2.3 

 4.0 

 4.0 

 4.2 



2.0 



Bushels. 

 14.3 

 19.8 

 23.0 

 25.0 



14.6 



16.4 

 25.4 

 24.0 

 27.2 



16.9 



Bushels. 

 16.4 





23.3 





28.9 





30.3 



None .. 



18.0 





18.7 





29.7 





28.4 



Residues, lime, phosphate rock, potash... 

 None 



31.7 

 20.0 







1 One year only. 



Table XIV. — Average results of five years' work on four series of plots at 

 Raleigh, Saline County — Four-year rotation, consisting of wheat, cowpeas {or 

 other legume), oats, and corn. 



Treatment. 



Average yield per acre. 



Wheat, 

 5 years. 



Cowpeas, 

 2 years 



Clover, 

 2 years. 



Soy 

 beans, 

 1 year. 



Oats, 

 5 years. 



Com, 

 5 years. 



None 



Manure 



Manure, lime 



Manure, lime, phosphate rock 



None 



Residues 



Residues, lime 



Residues, lime, phosphate rock 



Residues, lime, phosphate rock, potash 

 None 



I One year only. 



Bushels. 



8.6 



7.4 



16.5 



17.8 



6.9 

 8.4 

 18.6 

 20.7 

 21.9 

 7.4 



Tom. 

 2.3 

 1.8 

 4.2 

 3.9 



1.7 

 Turned. 

 Turned. 

 Turned. 

 Turned. 

 11.1 



Ton. 

 0.33 

 .33 



.67 



1.23 

 Turned. 

 Turned. 

 Turned. 

 Turned. 

 (») 



Ton. 



0.28 



.30 



.26 



.23 



Bushels. 

 .7 

 2.5 

 2.5 

 2.7 

 1.8 

 .7 



Bushels. 

 11.7 

 11.7 

 19.9 

 19.0 



10.2 

 12.8 

 19.7 

 20.0 

 2L1 

 12.7 



Bushels. 

 17.2 

 24.3 

 34.9 

 33.8 



16.6 

 21.1 

 31.3 

 33.0 

 34.3 

 16.4 



* No weight. 



