surface 



EXERCISE 7 



HOW TO PLANT THE SEED 



Statement. The farmer wishes to have his seeds germinate promptly and produce rugged and 

 thrifty plants. He sows some kinds of seeds on the surface and covers them lightly. Other kinds he 

 plants at a depth of several inches. In the depth at which he plants his seeds the farmer is governed 



principally by the size of the seed, the nature 

 of the soil, and the season of the year. 



Object. To ascertain what factors deter- 

 mine the depth to which seeds should be 

 planted, and particularly to learn if there is 

 any relation between the size of a seed and the 

 depth to which it should be planted. 



Materials. Depth planting boxes (Fig. 9) 

 filled with clean, fine sand ; two dozen seeds 

 each of the following : timothy, millet, kafir, 

 wheat, cowpea, and corn. 



Directions. Fill a depth planting box with 

 sand, moisten the sand, lay the box on its side, 

 remove the glass, and plant the seeds next to 

 the glass and replace the glass. Plant four 

 seeds of each kind on the surface, one-fourth, one-half, and one inch deep, also two, four, and six inches 

 deep respectively. Cover the seeds planted on the surface with blotting paper and keep them moist. 

 Keep the soil moist and maintain a temperature suitable for the germination of seeds. As soon as 

 each plant appears at the surface, remove it and examine the seed under the magnifying glass to 

 observe the amount of food remaining to aid the plant in its further growth. Record results des- 

 ignating amounts as none, small, medium, and large. Make note of the size, color, and vigor of the 

 plants produced from each depth of planting. Record the number of seeds which produced plants at 

 each depth of planting. Note and show by drawings where the whorl of feeding roots appeared on 

 the plants from each depth. Allow the plants to grow for two weeks and note the differences in the 

 vigor of the plants from each depth of planting. 



Questions. Did the seeds tested germinate regardless of their size and the depth to which they 

 were planted? Did plants from all the seeds grow sufficiently to reach the surface regardless of the 

 depth to which they were planted ? Did seeds of any kind fail to bring plants to the surface from any 

 depth? Explain the reason. Did you notice any difference in the size and vigor of the different 

 plants when they came up? Explain. In sowing timothy, clover, or alfalfa should the seed be 

 covered as deep as the seed of oats, cowpeas, or lima beans? Why? Should seeds be planted as deep 

 when the soil is moist as when dry ? Should seeds be planted as deep when the soil is cold as when 

 it is warm, and why ? Should corn be planted as deep early in the season as later ? Explain. 



Reference. Waters, H. J. Essentials of Agriculture, p. 38. Ginn and Company. 



Fig. 9. A convenient device for studying the effect of depth of 

 planting on germination of seeds and early growth of plants 



14 



