502 FIELD AND GARDEN PRODUCTS 



to fill properly, the necessity of increasing the quantity of phos- 

 phates and potash is indicated. Frequently a complete fertilizer 

 containing the three important elements, nitrogen, phosphorus, and 

 potassium, may be necessary. Barley usually has large, heavy heads 

 and consequently requires a stiff straw to prevent the plant from 

 lodging. The fertilizer should, therefore, contain a higher per- 

 centage of potash and phosphorus than of nitrogen. 



Rotation. In the greater portion of the Unite.d States barley 

 has no fixed place in the rotation, but is generally sown without re- 

 gard to the preceding crop. The market demand and the necessity 

 for feed are the factors which usually influence the acreage. 



The preceding crop has considerable influence on the yield of 

 barley. At the Tennessee station it was found that winter barley 

 after cowpeas were turned under yielded 56 bushels, while after corn 

 the yield was only 41 bushels. This indicates that on clay soils in 

 the Southern and Central States, where the supply of humus is 

 usually deficient, a different rotation is necessary from that prac- 

 ticed on the rich prairie or alluvial soils where barley, after corn, 

 potatoes, or wheat, usually gives good results. 



A rotation which has given satisfaction in Minnesota consists 

 of one year of corn ; one year of barley, grass seed being sown with 

 the grain ; meadow and pasture as long as desired. Flax may take 

 the place of corn, or may immediately precede it. A rotation 

 planned to keep up the soil fertility consists of corn two years; bar- 

 ley one year, with grass or clover sown with it; hay two years, or 

 meadow one year, and pasture one or more years. The grass land 

 should be manured before breaking for corn. 



In the Dakotas barley frequently follows wheat, the wheat 

 stubble being disked and the barley drilled in. Where corn and 

 oats are grown it may follow either of these crops. It generally does 

 best, however, when following corn or where a leguminous or green- 

 manure crop has been plowed under the preceding year. On many 

 farms wheat is grown almost continuously, barley being grown only 

 where a change of feed is desired, or when the land becomes weedy. 



In Kansas, where alfalfa is grown, corn frequently follows that 

 crop, while barley or other small grains follow corn. In Montana, 

 where the growing of small grain predominates, a rotation which 

 includes two years of clover followed by three crops of small grain, 

 in the last of which clover is again sown, has given good results. 



Effect of Barley on the Land. Experiments conducted at thel 

 South Dakota station indicate that barley as a crop is exhaustive to 

 the land. A crop of barley of 40 bushels or 1,920 pounds of grain 

 and 2,200 pounds of straw removed from the soil 54.14 pounds of 

 nitrogen, 20.93 pounds of phosphoric acid, and 49.35 pounds of 

 potash, a total of 124.42 pounds. Comparing this with other crops, 

 we find that a 30-bushel crop of corn, weighing 1,680 pounds, re- 

 moved a total of 113.99 pounds of these three elements; a 15-bushel 

 wheat crop, weighing 900 pounds, removed 59.11 pounds; and a 

 45-bushel oat crop, weighing 1,440 pounds, removed 97.77 pounds. 



The comparative quantities of the elements removed from the 



