1344 



RURAL ECONOMICS 



Furthermore, considering the extraordinary needs for phosphorus for 

 vast tracts of land in the United States, the writer thinks that the time has 

 arrived to make a careful estimate of the stores of phosphates in the United 

 States, and if need be, to restrict their export. 



IOI2 - Time and Method of Tillage on the Yield and Comparative Cost of Production 

 of Wheat in the Pelouse Region of Eastern Washington. — thorn c. c. and iioltzh. 



F., in State College oi Washin'^ton As,ricultmal Experiment Station, Bulletin No. 123, Pull- 

 man, Wash., Jiily 1915- 

 The data summed up in the appended Table result from a series of 

 comparative tests of cultural systems with biennial rotation and sj'stems of 

 tillage of the soil, for wheat growing in the region of Pelouse, in the east of 

 the State of Washington, U. S. A. These trials were carried out in such a 

 wav as to eliminate as far as possible the influence of factors other than 

 those inherent in the dii^erent methods of soil tillage, both as regards the 

 time and mode of carrying them out. 



System of cultivation 



Yield in bushels 

 per acre 



Gross 

 returns 

 per acre 



Cost 

 per acre 



Net 



returns 

 per acre 



I I 



I. Maize and wheat alternating, with an- ^ maize 30.0 ^ © ,5 24 

 nual autumn ploughing. \ wheat 37-8 C 



II. Alternate peas and wheat, with an- / peas 32.0 / 

 nual autumn ploughing ( wheat 33.7 \ 



III. Wheat and summer fallow, with 



auttmm ploughing after wheat ... wheat 49.4 



IV. Wheat and smnmer fallow, early ' 

 spring ploughing (April 3) and rolling wheat 49.0 



v. Summer wheat and fallow; early spring 



ploughing (April 3) without rolling . wheat 5 1. 7 



VI. Summer wheat and pasturage, with 



autumn ploughing after pasturage. . wheat 20.2 



VII. Summer wheat and fallow, with 

 late spring ploughing (June 10) and j 



rolling , wheat 38.5 1 



VIII. Summer wheat and fallow ; late | 

 spring ploughing (June 10) without ' 



rolling wheat 36.6 



IX. Summer wheat and fallow; early 

 spring disking (April 3), late spring 



ploughing (Jun^ 10), rolling wheat 42.4 ', 



X. Summer wheat and fallow; autumn ■ 

 harrowing, late spring ploughing (June | 

 10), rolling wheat 37.3 | 



XI. Svunmer wheat and fallow; autumn 

 ploughing, late spring harrowing (June 



10) wheat 49.7 



52.56 



39-50 

 39.20 

 4136 

 17.16 



31.00 



29.28 

 3392 

 29.84 

 39.7^ 



S 13-65 



17-35 



10.55 



10.35 



6.15 



8.80 



8,05 



9.70 



9.20 



9-45 



S 42-59 

 35-21 



29-! 5 

 28.65 

 31,01 

 1 1. 01 



21.23 



24.22 



20.64 



30.31 



