AGRONOMY 



Experimental work in Agronomy has been carried on at the 

 Salt River Valley Farm near Mesa, the Prescott Dry Farm near 

 Prescott, and the Sulphur Spring Valley Dry Farm near Cochise, 

 Arizona. Demonstration work has been done on the University 

 Farm near Tucson. 



SALT RIVER VALLEY FARM 



JOHNSON GRASS ERADICATION 



The main project on the Salt River Valley Farm was the ex- 

 periment in Johnson grass eradication, which was carried on in the 

 same manner as last year. One hundred and twenty acres of the 

 farm were divided into six fields containing, 40, 20, 10, 10, 20, and 

 20 acres, respectively. 



In the first field, the south half of the east eighty acres of che 

 farm, the Johnson grass was quite well under control by the begin- 

 ning of the fiscal year, due to dry plowing in the summer of 1915. 

 However, a number of seedlings came up from seed which had been 

 left upon the land by the preceding infestation of Johnson grass 

 plants. These seedlings were readily destroyed by the use of a 

 weeder and by plowing in September, 1916, preparatory to seeding 

 to grains in the following December. Virtually no Johnson grass 

 was noted after the removal of the grains early in June of the pres- 

 ent year. Plowing in August left the land suf^ciently clean that it 

 was considered advisable to seed to alfalfa, which w^as done early 

 in November. The weed can easily be controlled in future by hand- 

 digging. 



The second field, which had been closely ])astured by shee]) 

 since June, 1916, by the fall of that year contained few Johnson 

 grass plants having rootstock of appreciable vigor. In Novem- 

 ber, 1916, the land was disked and seeded to barley to supply winter 

 pasture. The number of sheep having been somewhat reduced, the 

 growth of barley provided more than sufficient pasturage and about 

 $640.00 worth of grain was harvested from the twenty acres. The 

 land was plowed again in September, 1917, and at present virtually 

 no Johnson grass is to be seen. 



