OTHER FARM CROPS 541 



expedient of the writer to roll his planting seed in Peruvian guano, 

 first thoroughly wetting the seed and using the fine, dry guano as a 

 drier. For this purpose 6 pounds were found to be ample for 1 

 bushel of seed. Not the slightest injury to the seed ever resulted 

 from the practice; but the dark green, vigorous appearance of the 

 plantlets was most remarkable. It was a good practice, resulting in 

 great saying of planting seed a desideratum when seeds of a desir- 

 able variety are scarce and high priced as well as in securing a good 

 stand of vigorous, healthy plants. 



A simple, easily constructed machine for "rolling" the seed 

 may be made in an hour by any carpenter: Take an ordinary iron- 

 bound whisky barrel. From the middle of one side, saw out a square 

 hole extending across two or three of the staves, or, say, 10 or 12 

 inches square. Batten together the pieces sawn out so as to form a 

 shutter for the opening, and fasten with thumb buttons. Run a 2 

 by 2 inch wooden axle through the center of the heads, with a com- 

 mon winch at one end; mount the barrel like a grindstone, on two 

 posts set in the earth. To operate it, put in 2 bushels of cotton seed 

 and an ordinary pailful of water. Turn the barrel slowly back and 

 forth a few minutes until every seed is wet. Let the superfluous 

 water drain away for a half minute. Then add about 12 pounds of 

 any suitable fine, dry powder, such as Peruvian guano, land plaster, 

 slaked lime, road dust, or sweepings from beneath a house. Turn 

 the barrel back and forth slowly a few times and the seed will be 

 found ready to plant, every one to itself. (F. B. 217.) 



Rotation of Crops. A rotation has been defined as a plan in 

 which a recurring series of different annual crops are grown upon a 

 given section. Investigators have found that various crops not only 

 require but absorb different quantities of the inorganic constituents 

 from the soil ; hence if a given crop is grown continuously for sev- 

 eral years the special elements required by that plant may become 

 depleted. 



By rotation of crops several purposes are accomplished, as fol- 

 lows: 



(1) The productive capacity of the land is increased and main- 

 tained. The cultivation of cowpeas, velvet beans, and other legumes 

 adds to the soil large quantities of nitrogen drawn from the air, 

 enabling the farmer to secure at slight expense an element which is 

 the most costly part of purchased fertilizers. 



The physical condition of the soil is improved, especially by the 

 addition of humus or vegetable mold, whereas continued cultivation 

 in cotton or corn rapidly exhausts the humus. The importance of 

 humus can hardly be overestimated. A soil rich in organic matter 

 is more easily cultivated than other soil. It suffers less from wash- 

 ing because the water is absorbed, and because of this water-holding 

 power it does not quickly become too wet, nor does it dry quickly; 

 hence, injury from drought is lessened. A soil rich in organic mat- 

 ter is richer in the beneficial bacteria and other organisms that take 

 part in rendering available to the plant the food hitherto locked up. 



