CROPPING AND SUMMER TILLAGE. 



15 



EXPERIMENTS WITH BARLEY. 



Plat A. Barley grown year after year on spring-plowed land by ordinary methods of 

 culture. 



Plat B. Barley grown year after year on fall-plowed ground by moisture-conservation 



methods of culture. 

 Plat C. Barley alternating with summer tillage. 

 Plat D. Summer tillage alternating with barley. 



By 11 ordinary methods" is meant plowing to a depth of about 3 

 inches in the spring just before seeding, harrowing once, and seeding 

 with a drill; no harrowing after seeding; no treatment of stubble 

 land after harvest except to cut weeds to keep them from seeding. 



By u conservation methods" is meant plowing to a depth of 8 

 inches immediately after harvest, thoroughly harrowing immediately 

 after plowing, keeping the soil in the best of tilth and free from weeds 

 or surface crust by frequent harrowings or diskings until seeding in 

 the spring, thorough harrowing at time of seeding, and light harrow- 

 ings at intervals to break crust and destroy weeds until the grain 

 reaches a height of about 6 inches. Under certain conditions, thor- 

 ough disking immediately after harvest and deferring the plowing 

 until the soil is in proper condition has been found to accomplish 

 the desired results more effectually than immediate plowing, and in 

 some cases this practice has been followed. 



By " alternate summer tillage" is meant treating the soil after 

 harvest as described under "conservation methods" until the fol- 

 lowing spring. Instead of then seeding it to crop, it is left bare or 

 fallow and is kept harrowed, disked, and free from weeds or surface 

 crust until midsummer. It is then plowed again and treated the 

 same as Group B thereafter, being seeded in like manner the following 

 spring, Group D being summer tilled and Group C being cropped 

 one year and Group C being summer tilled and Group D being cropped 

 the next, and so on indefinitely, alternately cropping and summer 

 tilling. 



The same variety and quantity of seed and the same drill are used 

 upon all the plats of the same series for all groups at each station. 

 It was found impracticable to use the same variety of each of the 

 grains at all of the stations, as it has not been found possible to 

 obtain any one variety of any of these grains adapted to so wide a 

 range of soil and climatic conditions as is found between Montana 

 on the north and Texas on the south. The rule has, therefore, been 

 to select the variety of each of the grains best adapted to the locality. 

 Durum spring wheat has been used at all stations. 



It was not practicable to use the same make of drill at all stations, 

 and there were other slight adaptations to local conditions, but the 



52345°— Bui. 187—10 2 



