Sept. 9,1918 Deep Tilling and Dynamiting in the Great Plains 519 
Mississippi. —Ricks (6), reporting the results of subsoiling with plow 
and with dynamite at the Central Mississippi Station, shows the following 
corn yields: 
In 1913, not subsoiled, 31.8 bushels; subsoiled with plow, 25.5 bushels; 
subsoiled with dynamite, 27.7 bushels. In 1914 the yields were: Not 
subsoiled, 30 bushels; subsoiled with plow, 27.2 bushels; subsoiled with 
dynamite, 29.1 bushels. He says: 
These plats were on a Houston clay soil of medium fertility. The subsoiling was 
done in March of 1913. The check plats were broken about seven inches deep. 
.... Subsoiling for corn, as well as for any other crop gives us no returns. 
The same author (7) in describing the preparation of the soil for alfalfa 
says: 
Good deep plowing where there is good drainage has given us as satisfactory results 
as subsoiling with dynamite or with a subsoil plow. 
This is under an annual rainfall of about 60 inches. 
Texas. —Hastings and Letteer ( 2 ) in reporting on the experiments in 
subsoiling at San Antonio, Tex., covering three years, 1910, 1911, and 
1912, conclude that-^- 
(1) Subsoiling is an expensive practice and so adds to the cost of preparation for a 
crop that unless materially increased yields result it can not be profitably adopted 
as a regular farm practice. 
(2) Subsoiling has been tested at the San Antonio Experiment Farm for three 
years in rotation experiments with com, cotton, and oats for hay and for grain. 
(3) The yields of corn, cotton, and oats for hay and for grain have been either 
slightly increased or slightly decreased on subsoiled land. In no instance has the 
difference been significant. 
(4) The depressing residual effect of subsoiling on the yields of com and cotton 
was most marked when the crop was planted from 1 to 8 months after subsoiling; 
15 months after subsoiling but little depressing effect was noted. 
(5) In the soil-moisture studies so far made at San Antonio it has been found that 
subsoiling has not increased the moisture content of the soil. 
(6) The results of these tests indicate that since neither the moisture content of 
the soil nor the yields of com, cotton, and oats are increased by subsoiling, the prac¬ 
tice is not advisable in connection with the crops mentioned in the San Antonio 
region of Texas. 
Russia. —Rotmistrov ( 8 ), in discussing the state of the drouth ques¬ 
tion, says: 
Deep mellowing of the soil which all the writers on this subject unanimously regard 
as a matter of great importance with regard to fighting against drouth, has also very 
little real significance. On the Odessa field there have been more than 1,000 experi¬ 
ments made on the effect of deep plowing for winter and spring crops, and no differ¬ 
ence in favor of deep [10X inches] or even mediate [7 inches] plowing was obtained 
in the harvest. Investigations into the humidity of the soil also showed no differ¬ 
ence in that respect between deep and shallow [3X' inches] plowing. 
The argument in favor of deep plowing, that deeply mellowed soil imbibes more 
atmospheric residue [precipitation], falls through, because little residue settles on 
the steppes districts and it all enters the soil whether deeply plowed or not. On 
certain types of soil and in more northern regions deep plowing may have a beneficial 
effect for other reasons—airing the soil, etc.—but not as regards opposing drouth. 
[Translation.] 
