42 



MISC. PUBLICATION 6 56, U. S. DEPT. OF AGRICULTURE 



spring if tobacco is to follow the next year. In this case the land 

 can be broken by simply reversing the beds — a practice followed by 

 many farmers in the flue-cured belt. 



Early seeding of winter covers and sufficient fertilization adds 

 greatly to their value, Seeclings that do not make adequate growth 

 may be useless in controlling erosion. In many cases late land prepa- 

 ration for seeding winter covers may cause more erosion than if the 

 area had been left undisturbed. Dense lush growth of winter covers 

 will give good protection from erosion and tend to increase crop 

 yields the next summer (fig. 26). 



THE USE OF MULCH 



Tests of straw mulch in Maryland proved that mulch was the most 

 effective method of erosion control on areas that are too steep or 

 irregular for the more usual and less costly methods of control. 



The value of tobacco grown on up-and-down-hill rows mulched 

 before transplanting with 4 to 6 tons of straw is compared in table 9 

 with the value of tobacco grown on ridged rows with 1 -percent grade. 



It can be seen that the mulch treatment gave good crop values in 

 the favorable tobacco seasons and in the excessively dry season. In 

 the seasons with excessive early rainfall, however, yields were de- 

 pressed on the mulched land. Average crop value for the 7-year 

 period was slightly better for the graded rows. Recent tests have in- 

 dicated, however, that growing conditions of mulched tobacco may 

 be improved by some subsurface tillage after protracted rainy 

 weather. Further studies on this phase of the problem and on eco- 



Table 9. — Effect of straw mulch on the value of tobacco during seasons 

 with favorable and unfavorable rainfall. The effect of mulching 

 ridged up-and-down-hill rows is compared with unmulched ridged 

 rows with 1 -per cent grade. 





Years 



Rainfall 



Value of crop per acre 



Type of season 



1-percent 

 grade 



Mulch 



Favorably distributed rainfall 



f 1941 

 1 1942 

 ] 1944 

 { 1946 



I riches 



14. 61 



15. 36 

 10. 34 



7. 49 



Dollars 

 \ 518 



Dollars 

 538 



Average 





11. 95 



16. 49 

 20. 61 







Excess rainfall early in season 



/ 1940 

 I 1945 



} 368 



230 



Average. 





18. 55 

 4. 17 







Too dry during last part of season. 



1943 



312 



363 



Average return from crop 







446 425 













