30 DRY FARMING IN THE GREAT BASIN. 



of hay during the fallow ^^ears." It is reasonable to believe that sim- 

 ilar results might follow attempts to grow alfalfa as an intertilled 

 crop, either with or without wheat in alternate years, in the Great 

 Basin, where conditions are in many respects similar to those in the 

 higher lands of North Africa in the vicinity of Setif, where this 

 method of growing alfalfa is in common practice. The quick re- 

 sponse of alfalfa to cultivation is shown in Plate II, figure 2, which is 

 reproduced from a photograjoh taken in the interior of a dry-land 

 alfalfa field some weeks after the first crop of the season had been cut. 

 The plants along the edge of the field next to the surface-tilled land 

 had made a good second growth, while the plants in the interior of the 

 field, where the available moisture had been exhausted by the first 

 crop, had made practically no second growth. 



There seems good reason for believing that sowing alfalfa in rows 

 far enough apart to f)ermit intertillage would be a profitable method 

 on the dry lands, even for forage production, while for seed produc- 

 tion it would almost certainly be more profitable. It is well known 

 that isolated alfalfa when allowed to mature on these dry lands pro- 

 duces relatively large quantities of seed. This is probably due, in part, 

 to a better illumination on all sides of the plant, resulting in a larger 

 number of flowers ; in part to the drier air surrounding these flowers 

 during the pollinating period, which appears to have some bearing 

 in seed production, and in part to the greater ease of access for insects 

 of various kinds that promote pollination. It is certainly true that 

 the partial isolation of the plants secured by row planting results in 

 greatly increased yields of seed per j^lant, and there is strong prob- 

 ability that the yields per acre would be larger, so that exi^eriments 

 to determine this point would be well justified. 



There is a strong tendency in the Great Basin, as elsewhere in the 

 western United States, to let alfalfa grow in a field as long as it will, 

 which is usually much longer than it is yielding its best returns. In 

 other words, it is not used as a rotation crop, in the ordinary sense of 

 the word. The beneficial effect of alfalfa upon the crop that follows 

 it is generally recognized, but a well-established alfalfa sod is hard 

 to subdue for the following crop, while alfalfa seed is expensive, and 

 it is not easy to get a good, even start on a new field. The temptation 

 is very strong, therefore, to leave alfalfa fields undisturbed, even 

 though the increased yields of succeeding crops are much desired. 



THIN SEEDING ESSENTIAL TO BEST RESULTS. 



Under ordinary conditions in a humid region or with irrigation, 

 farmers sow about 5 pecks of wheat or 75 pounds per acre, and from 

 15 to 20 pounds of alfalfa seed per acre. On the dry lands of the 



a Bul. 72, Part I, Bureau of Plant Industry, U. S. Dept. of Agriculture. 

 103 



