THE BEET-SUGAR INDUSTRY IN THE UNITED STATES. 27 



vation and the satisfactory crops that the tillable area is capable 

 of producing when properly fertilized and tilled. Furthermore, a 

 considerable portion of the stable manure produced on most sugar- 

 beet farms is wasted or rendered only partially effective either by 

 not giving it proper care or by the method in which it is handled in 

 connection with crop production. In addition to the humus con- 

 tained in stable manure considerable quantities of plant food are 

 present, which if properly handled add to the fertility of the soil. 

 This plant food is largely soluble ; consequently the leaching process 

 to which the stable manure is in most cases subjected, owing to the 

 fact that it is usually exposed to rains and snows, frequently causes 

 much of the fertility to be lost. Again, stable manure is often 

 spread upon the fields and left exposed to the weather, until a large 

 part of the volatile plant foods have passed off into the atmosphere. 

 Much of the nitrogen is often lost in this manner. The best results 

 in utilizing stable manure- in connection with sugar-beet production 

 are obtained by applying the manure to the crop preceding the beet 

 crop ; this allows the manure to be thoroughly worked into the soil. 

 It is a common practice in many localities where manure spreaders 

 are not used to haul the manure from the feed yard or stable at times 

 when there is no urgent work to be done and to dump it in piles, to be 

 spread at some convenient time before the ground is plowed. This 

 is a wasteful method, especially if the piles are left for some days 

 or weeks without spreading, often resulting in much loss of valuable 

 material through leaching. However, this method is preferable to 

 spreading the manure and leaving it on the surface of the ground 

 exposed to the action of the sun and wind. If the manure is spread 

 and .the ground can not be plowed immediately, it should be disked 

 whenever practicable; that is, if the ground is not frozen. Fortu- 

 nately the manure spreader is becoming more and more conmion, and 

 where the number of live stock on the farm warrants it there is 

 probably no other implement of greater value to the farmer. The 

 full value of the spreader is not realized, however, unless the manure 

 is plowed under or worked into the soil immediately after spreading. 

 Green crops. — Green crops plowed under provide another source of 

 humus for soil improvement. Any vegetable matter plowed under and 

 worked into the soil will add humus, though certain crops are more 

 valuable for this purpose than others because of the plant food as 

 well as the vegetable matter which they contain. The so-called legu- 

 minous crops, such as peas, beans, clover, and alfalfa, are among 

 the best for supplying humus to the soil. These crops should be 

 plowed under in the fall, so that they will have abundant opportu- 

 nity to decay before the growing season begins the following year. 

 In irrigated countries the ground should be irrigated thoroughly, if 

 necessary, before plowing, so that there will be sufficient moisture 



