THE CORN CROP IN THE UNITED STATES. 97 



Study the important factors effecting the corn crop as : 



1. Elements usually deficient in our soils. 



2. The natural and artificial means by which nitrogen, phosphorus and 

 potassium are supplied for plant growth. 



3. Effects of clover, alfalfa and other legumes in preparing available 

 nitrogen for corn growth. 



4. Effects of manure and commercial fertilizers. 



Each of the .following topics should also be carefully con- 

 sidered in the following order: i. Thorough Draining. 2.. 

 Early Plowing. 3 Humus in the Soil. 4. Available Plant 

 Food. 5. A Sweet Soil. 6. Thorough Preparation of Seed 

 Bed. 7. Seed Selection. 8. Seed Testing. 9. Careful Plant- 

 ing. 10. Scientific Cultivation, n. Harvesting. 12. Feed- 

 ing and Marketing. 



PROBLEMS. 



1. In 1910 the total corn crop in the United States was 3,125,000,000 

 bushels ; what will be the size of a cube that will represent the same 

 number of bushels? 



2. If the population of the U. S. was 92,000,000 in 1910, what was 

 the average production of corn per capita? 



3. If the average wagon box holds 30 bushels of corn, how many 

 such boxes would have been necessary to hold the total corn crop of 1910? 



4. Allowing 30 feet for each wagon, how long a wagon train would 

 have been required to transport the product of 1910, and how many times 

 would this train of wagons have reached around the earth at the equator? 



5. How long a train of box-cars, each holding 1,000 bushels, would 

 be required to carry our average product of 2,500,000,000 bushels in the 

 U. S.? (Allowing 38 feet for each car.) 



6. The seven great corn producing states of the central west are: 

 Ohio, Indiana, Illinois, Iowa, Missouri, Kansas and Nebraska. These 

 states are known as the corn belt, and in 1911 they produced 1,753,835,000 

 bushels on 54,353,000 acres; what was the average production per acre? 



7. From the Year Book of the U. S. Department of Agriculture, 

 find the total corn crop of the U. S. for last year and also the total crop 

 in the corn belt and find the average production per acre in the U. S. and 

 also in the corn belt. 



8. What is the combined area of the seven states of the corn belt? 



9. What proportion is this of the land area of the U. S.? 



10. What part is this of the land area of the globe? 



11. What part is the corn production of the seven states of the 

 corn belt of the total corn production of the U. S.? 



12 What part is the corn production of the corn belt of the total 

 corn production of the world? 

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