306 Missouri Agricultural Report 



be, before the processes are begun which start or renew life ^nd 

 produce growth, the seed must absorb moisture. Again, every seed 

 requires a favorable degree of heat before it will germinate, and the 

 presence of air is necessary in order to supply the "life-giving" 

 oxygen. A seed placed in a vacuum with the proper degree of heat 

 and moisture will not germinate, and the same results often occur 

 when seeds are placed in a very wet or water-logged soil, because 

 the air is largely excluded from a soil in such condition. 



In order to secure the ideal conditions for seed germination 

 and plant growth, a seed bed for planting all kinds of small seeds 

 should not be too deep and mellow, rather the soil should be mellow, 

 but finely pulverized, only about as deep as the seed is planted. Be- 

 low the depth at which the seed is planted the soil should be firm (not 

 too compact) , making a good connection with the subsoil, so that 

 the subsoil water may be drawn up into the surface soil. The firm 

 soil below the seed, well connected with the subsoil, supplies moisture 

 to the seed, while the mellow soil above the seed allows a sufficient 

 circulation of air to supply oxygan, and favors the warming of the 

 soil, gathering the heat of the sunshine during the day and acting 

 as a blanket to conserve the soil heat, thus maintaining a more uni- 

 form temperature in the soil during the night. Meanwhile, also the 

 m.ellow soil conserves the soil moisture, acting as a mulch to keep 

 the water from reaching the surface, where it would be rapidly 

 lost by evaporation, and the same condition favors the growth of 

 the young shoot upward into the air and sunshine, where, in the 

 presence of oxygen light, and a favorable degree of heat, the green 

 leaves quickly begin the work of assimilation and the soluble plant- 

 food elements absorbed by the roots are rapidly transformed into 

 protoplasm, starch and the various tissues which build up plant 

 structure, and the young plant grows and is soon firmly established 

 upon its own roots. 



With a deep, loose seed-bed the conditions are less favorable 

 for seed germination than in the "ideal" seed-bed described. The 

 mellow soil may be warm enough and well aerated, perhaps too well 

 aerated, causing the soil to dry out, but with the deep, mellow seed- 

 bed the moisture in the subsoil is not available for the use of the 

 germinating seeds, because the capillary rise of the water is checked 

 at the bottom of the mellow soil. Such a seed-bed is almost wholly 

 dependent upon rain for sufficient moisture to germinate the seed 

 and start the young plants, and even if such favorable weather con- 

 ditions prevail at seeding time so that seeds may germinate and the 

 crop start, yet at almost any time during the growing season, if 



