The purpose of this study was to determine whether Russian thistle (Salsola spp.) might have potential as either a protein source or a forage under conditions of restricted water. Salsola was chosen because it was reported to be a C4 plant which is efficient in water use, drought resistent, salt tolerant and because it had been used as a feed previously. In two seasons of field cultivation we find the following: (1) average percentage protein contents are 16% (range: 23-8.5%); (2) the protein is very well balanced with regard to amino acid content; (3) at water and nitrogen levels which provide maximal yields the nitrate content does not exceed 0.6%o of dry weight; (4) the average percentage of crude fiber content (acid detergent fiber-acid detergent lignin) is 23% (range: 27%-16%); (5) average yield of above-ground dry matter for 1975,over all water and nitrogen treatments, were 7781 kg/ha; (6) the same yield figure for 1976 was 8645 kg/ha; (7) under optimal treatments yields greater than 10,000 kg/ha were obtained; and (8) with 35 cm total applied water and 112 kg/ha of nitrogen, conditions giving optimal yields, water use efficiency was 329 g water/g above-ground dry matter. These results compare favorably with alfalfa, which is the most widely grown forage in New Mexico.

Project No. A-049-NMEX