Rice Straw 73

Rice Straw - 73
Project Leader and Principal UC Investigators R.A. Kepner, Machinery and Costs for Soil Incorporation of Rice Straw and Stubble (RM11) T.H. Burkhardt G.E. Miller F.E. Broadbent, Rice Residue Management by Soil Incorporation (RM7) R.S. Rauschkolb D.M. Brandon P. Sain J.B. Dobie, Residue Utilization Study to Determine Availability of Rice Straw as Raw Material for New Uses and Manufactured Products (RM12) J.R. Goss P.S. Parsopns B. Boyton H.B. Schultz R.G. Curley J.B. Dobie, Residue Utilizaiton (RM10) W.N. Garrett H.G. Walker (WRRL-USDA) J.L. Hull P.S. Parsons R.G. Curley	þ SOIL INCORPORATION At least in two soil types studied, incorporation was satisfactory when straw was chopped short (1 1/2-4 inches) and spread over the field. That was true in both the extreme wet season of 1972-73 and the drier season of 1971-72. Stubble should be short (not over 6-7 inches), either from the combine or from cutting in a later operation. Shear-bar choppers have been found more effective than impact shredders in shortening straw, and further, are just as effective with moist straw as with dry straw. A field chopper with a cutterbar header might be used to recut tall stubble as the windrow is picked up. Overall tillage operations remain about the same as with field burning. The only extra operation is chopping the straw. (RM11) Where stem rot is not a problem, spring incorporation of scattered straw has been followed by yields as high as those that followed fall incorporation or burning. Those findings were at two locations over a 3-year period. Straw decomposition is speeded by some type of tillage that provides contact with the soil. And any tillage is made easier and more thorough be chopping first. (RM7) USES OF STRAW Studies on information fundamental to any projected uses of rice straw, for feed or for manufactured products, have so far emphasized determination of what the basic problems might be: analysis of possible harvest systems for rice straw, annual capacity, handling systems, storage requirements, laboratory tests of physical characteristics affecting harvest, handling, storage, and the like. Well under way are studies of weather effects on the physical characteristics of straw, and the feasibility of harvest as projected by weather probabilities established from analysis of weather records. More optimistic forecasts of demands for rice straw seem required before such studies would be carried beyond this preliminary analysis of what would be involved. (RM12) STRAW AS FEED In studies on improving the palatability and feed values of rice straw for livestock, findings a year ago showed satisfactory results from an overwintering cubed ration containing 70-75% rice straw supplemented with other feed ingredients plus about 3% of a commercial binder. Rice straw did better than wheat straw by poorer than oat hay. Feed consumption and weight gains were best when the feeds were pelleted. Whether the improvement was due to the straw particle size of the physical from of the feed is now under study. Published during the year was information on the mechanics of cubing rice straw, and the use of rice-straw rations as livestock feed. These are results of considerable work in preceding years. (RM10)

Rice Straw - 73

Project Leader and Principal UC Investigators

R.A. Kepner, Machinery and Costs for Soil Incorporation of Rice Straw and Stubble (RM11)

T.H. Burkhardt

G.E. Miller

F.E. Broadbent, Rice Residue Management by Soil Incorporation (RM7)

R.S. Rauschkolb

D.M. Brandon

P. Sain

J.B. Dobie, Residue Utilization Study to Determine Availability of Rice Straw as Raw Material for New Uses and Manufactured Products (RM12)

J.R. Goss

P.S. Parsopns

B. Boyton

H.B. Schultz

R.G. Curley

J.B. Dobie, Residue Utilizaiton (RM10)

W.N. Garrett

H.G. Walker (WRRL-USDA)

J.L. Hull

P.S. Parsons

R.G. Curley

þ SOIL INCORPORATION

At least in two soil types studied, incorporation was satisfactory when straw was chopped short (1 1/2-4 inches) and spread over the field. That was true in both the extreme wet season of 1972-73 and the drier season of 1971-72. Stubble should be short (not over 6-7 inches), either from the combine or from cutting in a later operation.

Shear-bar choppers have been found more effective than impact shredders in shortening straw, and further, are just as effective with moist straw as with dry straw. A field chopper with a cutterbar header might be used to recut tall stubble as the windrow is picked up.

Overall tillage operations remain about the same as with field burning. The only extra operation is chopping the straw. (RM11)

Where stem rot is not a problem, spring incorporation of scattered straw has been followed by yields as high as those that followed fall incorporation or burning. Those findings were at two locations over a 3-year period.

Straw decomposition is speeded by some type of tillage that provides contact with the soil. And any tillage is made easier and more thorough be chopping first. (RM7)

USES OF STRAW

Studies on information fundamental to any projected uses of rice straw, for feed or for manufactured products, have so far emphasized determination of what the basic problems might be: analysis of possible harvest systems for rice straw, annual capacity, handling systems, storage requirements, laboratory tests of physical characteristics affecting harvest, handling, storage, and the like. Well under way are studies of weather effects on the physical characteristics of straw, and the feasibility of harvest as projected by weather probabilities established from analysis of weather records.

More optimistic forecasts of demands for rice straw seem required before such studies would be carried beyond this preliminary analysis of what would be involved. (RM12)

STRAW AS FEED

In studies on improving the palatability and feed values of rice straw for livestock, findings a year ago showed satisfactory results from an overwintering cubed ration containing 70-75% rice straw supplemented with other feed ingredients plus about 3% of a commercial binder.

Rice straw did better than wheat straw by poorer than oat hay. Feed consumption and weight gains were best when the feeds were pelleted. Whether the improvement was due to the straw particle size of the physical from of the feed is now under study.

Published during the year was information on the mechanics of cubing rice straw, and the use of rice-straw rations as livestock feed. These are results of considerable work in preceding years. (RM10)