Investigations at Lincoln, Nebraska. 



41 



Both areas had been cropped for many years. The crop of the preceding 

 year in the upland was Sudan grass; the lowland area had lain fallow. The 

 cereals were sown in alternating strips, 100 feet long and 10 feet wide, with 

 planted discard areas between. On the upland the plats were all in dupli- 

 cate. The rate of seeding for oats, wheat, and barley was 56, 75, and 60 

 pounds per acre, respectively. Alfalfa and sweet clover were seeded at the 

 rate of 12 pounds per acre in plats 50 feet long and 10 feet wide. 



Table 9. — Chemical analyses of soils by digestion with hydrochloric acid (sp. gr. 1.115) for 



120 hours. 



Depth of sample. 



Insolu- 

 ble 

 resi- 

 due. 



Solu- 

 ble 

 salts. 



Vola- 

 tile 



mat- 

 ter. 



Iron 

 and 



alumin- 

 ium 



oxides. 



Cal- 

 cium 

 oxide. 



Mag- 

 nesium 

 oxide. 



Phos- 

 phorus 

 pent- 

 oxide. 



Nitro- 

 gen. 



Upland plats: 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



0.0 to 0.5 foot 



76.87 



17.12 



6.01 



13.20 



0.68 



1.19 



0.13 



0.159 



0.5 to 1.0 foot 



75.70 



18.58 



5.72 



14.25 



.70 



1.32 



.12 



.134 



1.0 to 2.0 feet 



76.17 



19.08 



4.75 



14.72 



.75 



1.68 



.12 



.079 



2.0 to 3.0 feet 



77.86 



18.46 



3.68 



14.03 



.86 



1.69 



.15 



.045 



Lowland plats: 



















0.0 to 0.5 foot 



79.34 



12.96 



7.70 



9.57 



.68 



.75 



.13 



.218 





79.63 



13.66 



6.71 



10.27 



.63 



.77 



.10 



.187 





78.11 



15.83 



6.06 



12.11 



.64 



1.01 



.08 



.135 



2.0 to 3.0 feet 



74.78 



19.82 



5.40 



15.20 



.76 



1.27 



.09 



.082 



Preparatory to seeding, both fields were plowed to a depth of 5 inches on 

 March 29 and repeatedly harrowed until a good seed-bed was formed. All 

 of the crops on the upland were planted on March 31, while the lowland 

 area, because of winter weather, was not seeded until April 9. At the time 

 of planting both fields were in excellent tilth. The seed was sowed broad- 

 cast by hand and hoed in to a depth of 1 to 3 inches. To assure uniform seed 

 distribution, each plat was subdivided into areas only 10 by 25 feet, and the 

 appropriate amount of seed scattered very evenly over each area. After 

 planting, no further attention was given to the cultivation of the crops, except 

 to pull out the larger weeds from the grain fields and keep the plats of legumes 

 clean in a similar manner. 



Oats, Avena sativa. 



The first examination of root development was made on May 1, in the 

 upland plats, 31 days after planting. The crop was evenly developed, with 

 an average height of 2 inches and a maximum leaf -length of 3 inches. About 

 half of the plants had only one leaf unfolded; on the rest the second leaf varied 

 from a few millimeters to over 2 inches in length. Some of the plants had 

 only 3 roots, but most of them had 5 to 7. The primary roots, or at least 

 one of them, reached a maximum depth of 7 or 8 inches; the younger roots 

 were only 1 to 4 inches in length. The working depth of the roots was about 

 5 inches. Where the seed had been planted more than 1.5 inches deep, a 

 pair of unbranched roots about 0.3 inch in length had arisen from opposite 

 sides of the node about an inch below the soil surface. On all of the other 



