FIELD CROPS 505 



soil by the grain and the straw of a 40 j bushel barley crop were 

 found to be as follows: Nitrogen, 28.99 and 25.15 pounds; phos- 

 phoric acid, 15.17 and 5.76 pounds; and potash, 9.22 and 40.13 

 pounds, respectively. From these figures it can be seen that the 

 grain removed 1.1 times as much nitrogen and 2.5 times as much 

 phosphoric acid as the straw. The straw, however, removed more 

 than 4 times as much potash as the grain. 



It has been estimated that under California conditions a 40- 

 bushel crop of barley removes 46 pounds of nitrogen from the soil, 

 or 1.15 pounds to the bushel. A 60-bushel crop of oats removes 55 

 pounds of nitrogen, while a 35-bushel crop of wheat removes 59 

 pounds. In South Dakota it was found that a 40-bushel crop of 

 barley removed 1.35 pounds of nitrogen per bushel, or 0.20 pound 

 more than in California. 



Drought Resistance and Water Requirements. With the ex- 

 ception of the hooded and hull-less varieties, barley is not generally 

 considered drought resistant. It is most affected when the plants 

 are small and when the heads begin to fill. This accounts for the 

 shortness of the straw following a dry spring and the poorly filled 

 heads after a dry period during heading. The hooded and hull-less 

 barleys will generally produce a crop with less rainfall than will 

 spring wheats, with the possible exception of those of the durum 

 type. 



Preparation of the Land. Barley is grown over such a wide 

 area and under such a diversity of conditions that definite rules for 

 its cultivation can hardly be given. The thorough preparation of 

 the seed bed is essential under all conditions, as on this depends a 

 large part of the success of the crop. Plowing should be done the 

 fall previous or a considerable time before seeding. This allows a 

 complete settling of the soil and improves its water-holding capac- 

 ity. Many failures have resulted from planting barley on newly 

 plowed ground, especially when a dry season followed. The crop 

 seldom does well on newly broken sod; but when sod land is to be 

 planted best results will be obtained if it is broken shallow and laid 

 flat rather than set on edge, as is commonly done. Breaking should 

 be done while the grass is fresh and green, as decomposition then 

 sets in rapidly and the vegetation and roots soon decay. Plowing 

 under vegetation when the plants and roots are tough is injurious, 

 as their slow decay renders the soil too open. 



No soil should be plowed when very wet. The shearing action 

 of the plow upon the bottom of the furrow is likely to form an al- 

 most impervious layer or "plowpan" by compacting the soil par- 

 ticles. Unless the depth of plowing is varied from year to year this 

 layer is likely to injure the growth of corps that follow. By grad- 

 ually changing the depth of plowing each year new soil is brought 

 to the top and mixed with the surface soil without injuring its yield- 

 ing capacity. 



In some portions of the United States the ground is seldom 

 plowed for barley where it follows a cultivated crop, but is simply 



