EXPERIMENTAL WORK WITH RAW ROCK PHOSPHATE. 45 
TABLE XX.—Average yields of corn, wheat, and lequmes obtained in a 10-year 
experiment on three series of plots at Littles, Pike County, Ind. (1906- 
1975). 
| Average yield per acre. 
Legume 
Treatment, Corn, 8 crops. Wheat, 10 crops. 3 crops. 
Ear corn.| Stover. | Grain. Straw. Hay. 
See ST RNR See Meee AN Ws (oS SA Wh Ser 
; Bushels. | Pounds. | Bushels. | Pounds. | Pounds. 
LI ULES oe oo SRR ee eee eRe a a Se a 41.8 3, 298 13.3 1,149 3, 987 
Aeidepnosphates150 pounds lee... cote a tanec ence 41.9 3, 288 15.0 1,407 4,353 
uek phosphate, Pion) Lh 1.222. ic bi cctce eee ee ece 39.2 3, 030 14.7 1, 293 3,913 
IN GHAI GES Boe Cee SS SOC OE OIRO Ce Eee ae ar aera e 37.7 2,990 13.7 1,122 3, 767 
Rock phosphate, 1 ton; manure, 10 tons! ...........| 46.9 3, 435 18.6 1,769 4, 930 
ju VAT TG es OF Ce a 47.4 3, 698 18.4 1, 769 4,043 
Nothing .......... SScocnecsdocdscaccaGsesnesoeccasese 41.0 3, 427 14,9 1,491 3, 793 
1 Per rotation. 
2 Rock phosphate applied at the above rate twice during 10 years. 
TABLE XXI.—Average yields of corn, wheat, and legumes obtained in a 10-year 
experiment at Scottsburg, Scott County, Ind. (1906-1915). 
Average yield. 
Treatment, Corn, 8 crops. Wheat, 10 crops. nea 
Ear corn.} Stover. | Grain. Straw. Hay. 
| Bushds. Pounds. | Bushels. | Pounds. | Pounds. 
IN @UITES . 2 ccc hens Soece doce cacnoSdoeeoUcCoSEuaEoec] 25.1 2,366 9.2 862 749 
Acid phosphate, 150 pounds!..-_.--- 2.22. cece eee 34. 3 2,81? 15.6 1,392 1,412 
UA eKaPNOSP Mabe wl OOM ae eke oclewe oma ceesscciinese=s | 40. 4 2, 988 13.9 1,311 1,396 
INOtHING = ate aseccncso she Oar SE eeN Ee SaaS EC ee res | 30. 5 2,578 10.2 992 1,291 
Rock phosphate, 1 ton; 2 manure, 10 tons!. ........-.. | 51.2 4,114 20.8 2,138 - 3,151 
[Mamtirer nt OL ONS tae maaan sono sae ston cis asic cicccensasic| 50. 5 4,025 20. 0 2,073 3, 065 
30.5 2, 583 10. 4 1,061 1,523 
Ie pints awececsdoe occa ees acces See Ee 
1 Per rotation. 
2 Rock phosphate applied at the above rate twice during 10 years. 
The average results of 10 years’ work on the Littles field are not 
very satisfactory, since the difference between-the average yields of 
certain check plots is greater than the difference between the checks 
and the plots treated with phosphates. Moreover the yields of all 
crops (except the legumes) on some of the checks were practically as 
. good and in some cases better than the yields on the plots treated with 
phosphates alone, indicating that the soil was not very responsive to 
phosphate treatments. Only in the case of the legume hay did acid 
phosphate seem appreciably more beneficial than raw rock; in fact, 
it was on this crop only that the former appeared at all effective. 
More significant increases in the yields of legumes were obtained, 
however, on plots receiving manure reenforced with phosphate rock. 
On the Scottsburg field the effect of phosphate treatments seemed 
much more marked, the average yields of the fertilized plots being 
