ANNUAL REPORT, 1947-48 7 



The use of 3 HP on a 2-blade 40" propeller fan with 44" and 48" rings added, 

 but without a discharge tube, on an air scoop for drying baled hay permitted 

 the drying of bales on a mow floor without the use of a previously constructed 

 air distribution system. Bale width tunnels, two bales in height, leading from 

 the air scoop through the length of the pile of bales permitted air escape both 

 between and through the bales with heights up to eight tiers. Satisfactory dry- 

 ing was obtained with calculated water loadings up to 8000 pounds. Static 

 pressure developed within the air scoop at no time exceeded 3/8" and the cal- 

 culated delivery of the fan was never less than 22,000 cfm. 



Satisfactory drying is considered to be obtained when there is no mold develop- 

 ment and when during and after the drying operation the hay emits an aroma 

 rather than an odor. It is considered that the practical limit of water loading 

 for these fans has been reached, as the time required to reduce the moisture con- 

 tent of the hay to 25 percent with these loadings has been 4 days. 



Warm Room Brooding. (H. N. Stapleton.) The use of a hover-convector 

 shield with a wall-mounted pipe panel has indicated that with restricted ventila- 

 tion the temperature gradient across the floor of a narrow room can be made quite 

 uniform. With this equipment, crowding to 0.3 square foot per chick, with two 

 different ages in the room, was possible under warm room conditions. The 

 warm room, together with the crowding, was considered to give a slower rate of 

 both growth and feathering than was obtained with the same stock under other 

 brooding conditions. 



DEPARTMENT OF AGRONOMY 

 Dale H. Siding in Charge 



The Fixation of Phosphate by Iron and Aluminum and Its Replacement by 

 Organic and Inorganic Ions. (Dale H. Sieling, Richard M. Swenson, and C. 

 Vernon Cole.) It has been observed that hydrous oxides of iron and aluminum 

 and solutions of iron and aluminum salts will fix phosphate by chemically com- 

 bining with the phosphate at low pH values. The compounds formed were 

 shown to be the hydrated basic phosphates of iron and aluminum represented 

 by the formulas: Fe(H20)3 (0H)2 H2PO4 and A1(H20)3 (OH)2H2 PO4. The 

 conclusion that the compounds were basic phosphates rather than normal phos- 

 phates was based on the observation that for each iron or aluminum ion one phos- 

 phate and two hydroxyls were required for complete precipitation. If the normal 

 phosphate were formed, one phosphate and no hydroxjd would be required to 

 completely precipitate each iron or aluminum ion. 



The amount of phosphate which would combine chemically with one iron or 

 aluminum ion increased as the phosphate increased up to a value where one 

 phosphate was combined with one iron or one aluminum ion. In no instance was 

 the ratio of phosphate to iron or aluminum in the precipitated compound greater 

 than unity even when the amount of phosphate present was nine times that of 

 the iron or aluminum. 



Arsenate reacted with aluminum in the same manner as phosphate but was 

 found to be about one-fifth as effective in replacing chemically combined phos- 

 phate as was phosphate in replacing chemically combined arsenate. Fluoride 

 reacted with aluminum in the same manner as phosphate and arsenate and, when 



