144 NATURE STUDY AND AGRICULTURE 
out injury, and the young seedlings will stand quite a hard 
frost. Oats and rye are even more hardy than wheat, but 
barley is less hardy, and flax and corn must be planted when 
all danger of frost is past, as the seeds will easily rot in the 
ground if too cold, and if frost strikes the seedlings after they 
are up it kills them. 
Cultivating. — All such grains as wheat, oats, barley, rye, 
and Indian corn should be gone over with a smoothing harrow 
after planting and again after they are up. This last harrow- 
ing destroys such weeds as may be germinating near the sur- 
face or have already come up, and it restores the dust mulch 
and thus helps to conserve soil moisture. Corn and potatoes 
are also cultivated between the rows several times during 
the early summer for the double purpose of preventing weed 
growth and preserving the dust mulch. 
EXERCISES AND PROJECTS 
1. List of field crops. — Make a complete list of all the field crops 
raised in your section of the country with the varieties of each, as 
Wheat: fife, blue stem, marquis, durum, etc. 
Oats: Swedish, white Russian, etc. 
Corn: (a) Dent — Northwestern dent, golden dent, Minnesota 
king, etc. 
(6) Flint — Jehu, squaw corn, Will’s Dakota, Longfellow, King 
Philip, etc. 
Potatoes: Early Ohio, early rose, rural New Yorker, Burbank, etc. 
2. The permanent exhibit. — Collect specimens of all the varieties 
of grain raised in your vicinity, as wheat, oats, barley, rye, etc. (a) A 
few heads of each variety and (6) a sample of the berry in a small bottle. 
The heads should be neatly mounted and the bottles should be of uni- 
form size so as to make an attractive arrangement for a permanent school 
exhibit. Include in the exhibit also an ear of each kind of corn and a speci- 
men of flax, millet, buckwheat, field peas, alfalfa, and any other kind of 
crop that can be kept in such a collection. 
