164 



EFFECT OF TILLAGE ON SOIL-MOISTURE. 



In two previous Bulletins * it has been shown of what very great 

 importance is the proper tilling of the soil. Cultivation not only makes 

 it easier for the roots to spread all round and get more food, but really 

 increases the amount of food in the soil. 



But tillage is also most useful in another way, especially in districts 

 subject to drought : it prevents waste of water from the soil, and so helpg 

 to store up moisture for the use of plants during dry weather. 



This is not merely opinion, but has been carefully tested and prov- 

 ed by scientific methods at many Experiment Stations. An instance 

 may be given from work carried on in Michigan, f 



Corn was grown on two series of four plots each. The soil of the 

 first series was a sandy loam somewhat gravelly below a depth of one 

 foot, while the soil of the second series was not quite so sandy at the 

 surface, and contained more clay below the first foot. In each series 

 plot one was not cultivated ; plots 2 and 3 were given three cultivations 

 with a weeder, seven with a Gale cultivator, and seven with a Planet 

 Jr. cultivator ; and plot 4 was cultivated five times with a Gale cultiva- 

 tor. The average percentage of moisture at different depths, and the 

 yields of the different plots are given in the following table: — 





Cultivation. 



Yield op Corn. 



Moisture Content op Soil. 



Green 

 Corn. 



Dry 

 Matter. 



First 

 Foot. 



Second 

 Foot. 



Third 

 Foot. 



A verage 

 for 3 feet 



First Series 





Pounds. 



Pounds, 



Per cent 



Per cent. 



Per cent. 



Per cent 



Plot 1 



None 



2,180 



723 



6.16 



4.70 



6.66 



5.84 



Plot 2 



Frequent, 3 in. deep 



13,207 



5,532 



715 



5.72 



8.23 



7.03 



Plot 3 



Frequent, 5 in deep 



12,687 



4,799 



7.45 



5.98 



7.83 



7.09 



Plot 4 



Ordinary, 5 in. deep 



12,167 



4,380 



6.28 



5.64 



8.44 



6.79 



Second Series. 













Plot 1 



None 



1,848 



620 



7.16 



6.36 



11.73 



8.42 



Plot 2 



Frequent. 3 in. deep 



12,258 



4,790 



8.41 



6.81 



12.74 



9.35 



Plot 3 



Frequent, 5 in. deep 



12.700 



4,728 



8.76 



7.36 



12.10 



9.40 



Plot 4 



Ordinary, 5 in. deep 



10,514 



3,849 



7.74 



8.26 



11.41 



9.14 



This table shows very clearly that there is much more water in the 

 soil in the plots that have been tilled than in those that have had no 

 cultivation. 



The weight of corn harvested fromtthe cultivated plots was 6 or 7 

 times as much as in the unfilled plots. 



The Agricultural College in Kansas J has also been experimenting 

 on the subject of soil moisture. An experiment reported in Bulletin 

 No. 68 showed that a dry soil mulch is quite as effective in conserving 

 soil moisture as a hay or straw mulch, and that by its application imme- 

 diately after a rain, a very considerable amount of moisture can be held 



* Bulletins, 1895 Aug., page 162 ; 1896 Nov. page 241. 



f Michigan Sta. Bull. 164, pp. 79-96. 



t Kansas State Agri. Coll., Bull. 89, pp. 12-22 



