A comparison was made between the digestibility of wheat and sorghum by pigs using three different methods of ration formulation, viz. grain alone, grain plus meatmeal, and grain plus skim-milk powder. For each type of ration, comparisons were made over the three body-weight ranges of 40-80 lb, 80-120 lb and 120-220 lb. Dry-matter and organic-matter digestibilities in the wheat rations were either slightly higher than or equal to these values in the corresponding sorghum ration. The sorghum rations had a correspondingly small advantage in the digestibility of nitrogen-free-extract. The major differences between the grains were in the digestibility of crude protein and crude fibre. Over all the body-weight ranges for all ration formulations the digestibility of the crude protein in the wheat ration was greater than that in the sorghum ration. The mean crude protein digestibility coefficients for the wheat and sorghum rations respectively were 92.3 and 72.2 for the grain-only rations, 89.6 and 77.9 for the grain plus meatmeal rations and 93.7 and 78.4 for the rations containing skim-milk powder. Differences in digestibility of crude fibre were even more marked, the levels being much greater in the sorghum rations. Mean coefficients for the wheat and sorghum rations respectively were 31.6 and 75.6 for the grain-only rations, 27.2 and 81.6 for the rations containing meatmeal, and 22.9 and 69.6 for the grain plus skim-milk rations.

Since their introduction, sudangrass-sorghum hybrids have found some use as a silage crop. However, their principal use for forage will probably continue to be for pasture and green chop. Several dual purpose and intermediate height hybrids offer some lodging resistance. These types have been the only hybrid forage sorghums to gain widespread usage in California. Tall growing types of hybrid forage sorghums should be used with caution. The development of a hybrid forage sorghum type with high yield capacity and lodging resistance continues to be necessary before greater use of sorghum silage can be expected in most areas of California.

Response to phosphorus fertilizer on a phosphorus-deficient Reddish-Brown soil was measured through 8 years. Yields, percent P in plant, and NaHCO₃-extractable soil P were followed through 2 cycles of alfalfa and 2 intervening crops of sorghum. Increased yields were obtained until P equal to the application was removed in harvested crops. Alfalfa yields were closely correlated with both percent P in hay and NaHCO₃-extractable soil P during the first 4 years. High yields were maintained in the second cycle of the rotation, but percent P in hay and NaHCO₃-extractable soil P were at levels associated with low yields during the first cycle. Sorghum following alfalfa was not affected by N fertilizer. Second-year sorghum benefited from N only where there was ample P.

SynopsisRelative root activity measurements using P³² uptake and soil-water depletion data show that approximately 90% of root activity of sorghum plants occurred in the top 3 feet. Root growth rates were from 0.75 to 2.0 inches per day.

SynopsisTeosinte produced more forage on a wet basis but less dry matter per acre than either corn or forage sorghum. Neither forage quality nor yield was sufficiently great to place teosinte with corn or forage sorghum as a silage crop in irrigated regions of the central Great Plains.