4 BULKETIN 320, IT. S. DEPARTMENT OF AGEICULTUEE. 



ditions with reference to farm labor and farm capital are the prin- 

 cipal factors in determining differences in practice. In the prepara- 

 tion of the seed bed the soil type is also an important factor, while 

 in intertillage the types of weeds to be dealt with have much to do 

 with prevailing practices. The reason why greater variation in re- 

 sults is not shown for the different methods and amounts of inter- 

 tillage is that, in the main, all the practices studied were adequate 

 for weed control in the growing crop in the regions where these 

 practices are employed. (Table I.) 



Previous investigations have shown that if weeds are eliminated, 

 any sort of intertillage becomes of minor consideration. 1 The whole 

 subject, therefore, is far more largely of economic than of agronomic 

 importance. What the farmer wants to know concerning seed-bed 

 preparation is: What is the cheapest method of making an adequate 

 seed bed under his conditions? An adequate seed bed may be de- 

 fined as land free from weeds and surface trash, sufficiently mellow to 

 permit easy penetration of the plant roots, sufficiently compact to 

 hold moisture and to be free from large air spaces, and sufficiently 

 fine in texture to bring many soil particles in contact 'with the seed 

 and thus to suppl} 7 an abundance of moisture to the germinating 

 plant. Land so prepared is also in good condition for subsequent 

 tillage. What he wants to know concerning intertillage is: What is 

 the cheapest method of controlling weeds which infest his growing 

 crops ? 



Table I. — Summary of tillage practices with corn, showing the averages of depth 

 of plowing, number of cultivations, price of land, commercial fertilizer used, 

 and normal yields per acre in twenty-one regions of the United States. 



Region covered (fig. 1). 



Key 

 letter. 



County and State. 



Depth 



of 

 plow- 

 ing. 



Workings 



after 

 plowing 



and 



before 



planting. 



Cultiva- 

 tions 

 after 



planting. 



Price 

 of land 

 per acre. 



Commercial fertil- 

 izer used. 



Farms 

 applying. 



Applied 

 per acre. 



Normal 

 yield. 



Tipton, Ind 



Montgomery, Ohio 



Mercer, N. J 



Moultrie, Ul 



Tama, Iowa 



Kalamazoo, Mich 



Maury, Term 



Hartford, Conn 



Bradford, Pa 



Christian, Ky 



Hamilton, Nebr 



Rockwall and Grayson 



Tex 



Scotland, N. C 



Augusta, Va 



Waushara, Wis 



Bates, Mo 



Alexander, N. C 



Oklahoma, Okla 



Pike, Ala 



Holmes, Miss 



Russell, Kans 



Inches. 

 6.7 

 7.1 

 6.3 

 5.4 

 5.1 

 6.7 

 7.7 

 7.4 

 6.1 

 7.1 

 5.8 



6.4 

 7.0 

 8.0 

 5.5 

 5.9 

 6.0 

 5.6 

 6.7 

 5.1 

 5.5 



2.8 

 3.6 

 3.5 

 3.2 

 3.0 

 3.3 

 2.7 

 2.4 

 2.5 

 3.0 

 2.5 



1.5 

 2.3 

 3.0 

 1.8 

 2.3 

 1.1 

 1.5 

 .6 

 1.4 

 



5.5 

 4.0 

 5.9 

 4.4 

 5.3 

 5.0 

 5.4 

 3.8 

 4.4 

 5.1 

 5.1 



3.9 



4.3 

 4.1 

 5.4 

 4.8 

 5.1 

 3.9 

 4.7 

 4.7 

 3.S 



146. 96 

 101. 87 

 198. 30 

 196. 40 

 101.40 

 110.38 

 138. 80 

 51.20 

 69.04 

 158. 38 



103.41 

 113.50 

 71.80 

 48.27 

 95.00 

 39.14 

 50.00 

 36.50 

 22.40 

 43.20 



Per cent. 



3.4 

 31.0 

 78.1 



















88.0 

 28.6 



3.8 









 100 

 42.9 









 78.9 





 90.5 



4.0 







Pounds. 



200.0 



217.2 



.331.7 



727.3 

 178.1 

 125.0 



575.7 

 161.3 



366.8 

 200.0 



Bushels. 

 57.4 

 52.3 

 51.1 

 49.5 

 46.6 

 41.5 

 40.9 

 39.9 

 38.2 

 36.9 

 35.0 



33.6 

 33.0 

 33.0 

 30.4 

 29.3 

 25.2 

 23.9 

 23.1 

 22.0 

 20.4 



1 See Bureau of Plant Industry Bulletin No. 257, already mentioned. 



