208 MISCELLANEOUS FARM SUBJECTS 



The formation of soluble potash compounds from the decay of the 

 potash minerals did not keep pace with the amount removed as 

 plant food and that lost in soluble forms in the drain waters. 



(5) Systems of rotation, in which clover (and other legumes) 

 form an essential part and in which farm manures are used, should 

 be practiced to prevent depletion of the nitrogen and humus of 

 soils, because the humus takes such an important part, chemically, 

 physically and bacteriologically, in maintaining the fertility. 



Crop Rotation Simple and Practical. Crop rotation may be de- 

 fined as a systematic succession of the three general classes of farm 

 crops, namely, grain crops, grass crops, and cultivated crops, in such 

 a way as to provide large yields of grain, pasturage and forage needed 

 on the farm at the least expense of labor and fertility. 



Rotation systems must be adapted to each farm or class of 

 farms and to the particular condition of each farm. With a knowl- 

 edge of what it is desired to accomplish by rotation, namely an im- 

 provement in the condition of the soil and a corresponding increase 

 in the net income per acre, it is easily possible, knowing the charac- 

 ter of the farm, the climate, the line of farming desired and the 

 tastes of the farmer, to plan a systematic rotation for that farm which 

 will give the desired results. The essentials of a good rotation are 

 that the net yields in money per acre be maintained or increased, 

 that vegetable matter be kept in the soil, and that the land be kept 

 in good physical condition and reasonably free from weeds. Grass 

 crops must be grown or barnyard manure applied, or both, to keep 

 up the supply of vegetable matter. A cultivated crop occasionally 

 and good tillage are necessary to kill out weeds and help put the 

 soil in good tilth. These things are naturally brought about by 

 alternating the three classes of crops that is, one or more grass crops 

 should appear on each field every four to eight years. Corn or other 

 cultivated crops and manure should appear one or more years in 

 the same period, and the remainder of the time grain may be grown. 



This treatment cannot fail to keep the soil in much better con- 

 dition than can be done by growing any one crop continuously, 

 and it may be brought about by a very little planning, and without 

 very seriously changing the acreage devoted to each crop. Most 

 farms in the middle west have from one-eighth to one-half their till- 

 age area in corn, and from one-eighth to one-half in grass each year. 

 All the change that is necessary is to arrange these crops according 

 to some regular system of rotation instead of growing each on the 

 same field year after year. 



1. The best average yields of wheat have been obtained in 

 those rotations where that crop follows either corn or potatoes. Fol- 

 lowing these crops in the order of their merit as a preparation for 

 the growth of wheat comes summer fallow, millet, vetch, peas, wheat 

 and oats. 



2. The drier the season or the more unfavorable the condi- 

 tions for the production of a maximum crop of straw and grain, the 

 more important becomes the introduction of a cultivated crop into 

 the rotation. 



