- 2 



A second method is to f.dd to the chopnod nntcrir.l sor.io dohydratod preserva- 

 tive such r.s oat hulls or citrus pulp fortified v/ith molasses to absorb the 

 free moisture. It v/ill be noted in Table I tlir.t tv/o silos, L5, 1940 and Bl, 

 1938, were filled using this type of uroscrvative and that there was no leak- 

 age even with the high moisture green laatcrial. Corn meal and ground ear coi'n 

 are nov;- being tried as moisture absorbing preservatives, A third method 

 reported as practiced by middle vrestern farmers is to use a longer cut on the 

 chopper v/hen ensiling material of high moisture content. Along this same lino, 

 the Papoo Machine Company is advising its customers to vary the lengthy of Cut 

 with the condition of the green material, suggesting a 1/4 inch for lovf mois- 

 ture, 1/2 inch for average, and 1 inch for high moisture. This sounds 

 promising and should bo investigated under controlled conditionsr 



In some instances it may be desirable to rid a silo of free juice. 

 Therefore, considerable thought is being given to drainage systems for silos 

 and to preventing seepage at points other th'-'.n drains. In 1939 three drains 

 were placed in the walls of tvro 18 foot silos, 34 and B5, Table I, One of 

 the throe drains v/as a 1.5 inch pipe plc^ccd opposite the doorway and flush 

 with the inside wall and foundation. The other tv/o wore 2,5 inch pipes placed 

 about 6 inches above the foundation rjid opposite each other in the v/",ll midway 

 between the first drain and the doonvay. One silo was filled with. 188 tons of 

 phosphoric acid grass silage ^.nd the other was filled v.'-ith 198 tons of 

 molo.sses grass silage. The rvorago moisture content of the ensiled inatcrial 

 in each case was 68 per cent. The drainage loss from the acid silage v^vS 975 

 gallons of juice, representing 2,24 per cent by vroight of the ensiled material. 

 The drainage from the molasses silage was 3,990 gallons, representing a loss 

 of 9 per cent, A point of particular interest is th' t "11 of the juice lost 

 from the silos came through the drains. For 1940, using the sr-jno two silos, 

 one was filled with 333 tons of phosphoric acid grass silage '-.nd the other 

 with 318 tons of molasses gr^.ss silage, moisture content in each case being 

 approximately 77 per cent. The leakage loss from the acid silage rmounted to 

 almost 16 per cent, v^ile the loss from the molasses silage vrr.s about 18 per 

 cent of the total ensiled weight. The drains functioned but carried only 

 part of the leakage. Most of the loss occurred around the doorv/ay, not un- 

 expected because of the pressure panel construction, Soiae leakage through 

 the stave joints occurred up to a height of 18 feet in each silo« The joint 

 leakage in 1940 v/as associated wdth the higher pressures v.-hich amounted to 

 almost twice the values measured in 1939, A rock fill about 3 feet in 

 di^.meter with drain in the bottom was used in silo B6 in 194-0, Filled with 

 97 tons of phosphoric acid grass silage at 70 per cent moistxiro, the seepage 

 amounted to approxiraately one per cent, all coming through the drain. Other 

 tjHDes of floor drains and vertical v/all drains are to bo tried. 



The hoops on silos B5 and B8 v/ere tightened to produce a stress in the 

 steel of approximately 18,000 pounds per square inch so thr.t the staves might 

 bo held together with some force even after the silos were filled. Preliminary 

 observations indicate that prestressod hoops will limit the leakage through 

 the vortical joints of concrete stave silos but cannot bo expected to entirely 

 control the leakage problem because of the irregular joint surface found on 

 concrete staves. Horizontal joint leakage iTas more noticeable v/hen the vor- 

 tical joint leakage was rodxiced. In prestressing hoops, considerable diffi- 

 culty was encountered in holding the stress on intermediate hoops that do not 

 cross the door opening but are held by spreaders. Faulty design, particularly 



