CONSERVATION PRACTICES FOR TOBACCO LANDS 



37 



Any benefits resulting from their use came after they were turned 

 under, usually from April through June, which is the period of culti- 

 vation. The benefits of nitrated ryegrass lasted through July because 

 of its resistance to decomposition. The turf of ryegrass was such that 

 land preparation for tobacco was difficult. 



Seeding winter covers actually increased soil loss during the period 

 of land preparation, seeding, and early growth in September and Octo- 

 ber. Serious erosion at this time frequently occurs in fall-seeded fields 



2.00 



AVERAGE ANNUAL SOIL LOSS 

 Tons per acre 



_4.6I 



3.97 

 Rye and Nitrate 3.77 



0.50 



Figuke 24. — Seasonal soil losses from tobacco plots with no winter cover, com- 

 pared with soil losses on plots with rye and nitrated rye winter covers. All 

 tobacco grown on l^-percent grade ridge rows, Raleigh, N. C, 1944—17. 



over the tobacco belts. This fall hazard tended to offset some of the 

 benefits occurring during the spring and summer. 



Benefits from these cover crops in erosion control seemed to be de- 

 termined by (1) the amount of growth produced, (2) the amount of 

 residue remaining on or near the surface, (3) the resistance of these 

 residues to decomposition. Adding nitrogen to stimulate the growth 

 of rye and ryegrass increased the beneficial effects of both cover crops. 

 Thus it is apparent that when cover crops are used they should be 

 seeded early and fertilized as much as necessary to secure adequate 

 growth. 



Tobacco yields and values from these plots are shown in table 7. 



Tobacco yields were increased when a sufficient amount of readily 

 decomposable cover-crop material was turned under, as in the case of 

 nitrated rye. A sparse growth of cover, as with the no-nitrate rye, had 

 little effect on the following tobacco crop. Material that decomposed 

 slowly, as did nitrated ryegrass, also had little effect on yield. 



In the studies of erosion-control practices for tobacco land at Belts- 

 ville, winter cover-crop mixtures of wheat and hairy vetch were used. 



