52 



BULLETIN 699, U. S. DEPARTMENT OF AGRICULTURE. 



In 1889 the North Louisiana Experiment Station began a number 

 of experiments with corn.^ One of these had for its object the 

 testing of the effect of various phosphatic fertilizers alone and in 

 combination on the crop yields. This experiment was carried on for 

 five years, but the raw phosphates were not introduced until the 

 second year. The results obtained each year were published in 

 separate bulletins,^ but for the sake of brevity and clearness they are 

 here all incorporated in one table. As in the case of the cotton ex- 

 periments carried on at this same station, the size of the plots em- 

 ployed is not mentioned, and the only description given of the soil is 

 that it was poor. 



The land was plowed during tlie winter and fertilized in the 

 spring. The corn was planted in rows 5 feet wide and 3 feet apart in 

 the drill. The complete results are given below in Table XXVII. 



Table XXVII. — Results ohtained at CaUioun, 



(1889-1893). 



La., in 



the groioing o] 



corn 



Fertilizer. 



Applica- 

 tion per 

 acre. 





Yield per acre of corn. 





1880 



1890 



1891 



1892 



1893 





Pounds. 



56 



112 



336 



Bushels. 

 26.69 

 28.00 

 25.00 



Bushels. 

 2t.00 

 23.00 

 28.00 



23.14 



14.42 

 12.17 

 18.25 

 11.00 



18.13 



13.00 

 20.32 



20.78 



9.00 

 22.00 



} 21. 75 



9.10 



Bushels. 

 15.00 

 12.75 

 14.25 



12.75 



6.00 

 5.25 

 10.50 

 4.50 



13.88 



10.50 

 13.50 



17.25 



6.75 

 14.25 



15.75 



6.75 



Bushels. 

 13.60 

 25.20 

 32.80 



25.60 



10.80 

 17.20 

 18.80 

 8.40 



23.20 



11.20 

 29.40 



31.20 



13.60 

 28.40 



29.80 



14.00 



Bushels 

 16.00 



Dissolved bone black 



19.60 





22.00 



Do 



m } 22.00 





Dissolved bone black 



21.80 





56 

 112 

 420 



14.49 

 13.00 

 20.00 

 12.00 



8.80 





8.80 





16.80 





7.60 





420 



1 „„ .„ 





Acid phosphate 



112 ; ''■''' 



112 1 14.10 

 420 1 17.00 



24.00 





17.60 





21.60 



Do 







24.80 



South Carolina floats 



112 





15.60 



Basal mixture 



420 

 420 

 112 





20.40 



Do 







South Carolina floats 





22.40 







10.50 











The wider differences between the yields of the various plots re- 

 ceiving "basal mixture" show that this field was not of uniform 

 fertility. 



A careful study of Table XXVII will also show that the soil 

 seemed to respond much more readily to the nitrogenous than to 

 the phosphatic fertilizers, but the applications of the latter were 

 rather light, particularly for the- relatively insoluble phosphates. 

 With the exception of those treated with bone or dissolved bone black, 

 the plots on which phosphates were applied alone gave on the whole 

 little or no increase in yield over the unfertilized plots. While 

 tioats alone gave no increase in yield for the first three years of the 

 experiment, the crop produced the fourth year on this plot exceeded 

 the no-fertilizer plots by a considerable margin, indicating that 



iLa. Agr. Bxpt. Sta. Bui. No. 27 (1890). 



«La. Agr. Expt. Sta., Buls, Nos. 8, 16, 21 29 (new series). 



