4 DEPARTMENT OF AGRICULTUEE BULS. 351-3*75. 



* 



Department Bulletin No. 355. —Extension Course in Soils : Page. 



Lessons I. Origin, formation, and composition of soils 2 



II. The soil and plant growth. : 10 



III. Physical properties of the soil 17 



IV. The water supply of the soil 24 



V. Soil temperature and drainage 31 



VI. The nitrogen supply of the soil 41 



VII. The phosphorus and potassium of soils 47 



VIII. Manures and fertilizers 54 



IX. Soil acidity and liming 62 



X. Management of special soils ;■ . 68 



XI. Soil adaptation to crops 80 



XII. Crop rotations and soil fertility 84 



Appendix — 



Reference books 91 



List of apparatus and supplies required 91 



Department Bulletin No. 356. — Melk and Cream Contests: 



Introduction 1 



National contests 2 



Hew contests are conducted 4 



. Educational features 11 



List of exhibitions 12 



Average scores of recent contests 15 



Benefits of milk contests to dairymen 17 



Suggestions for production of contest milk 19 



Publications of United States Department of Agriculture relating to milk 



and cream 24 



Department Bulletin No. 357. — Alaska and Stoner, or "Miracle," 

 Wheats: Two Varieties Much Misrepresented: 



Introduction 1 



Alaska wheat 2 



Stoner, or "Mhacle," wheat 14 



Conclusions 27 



Publications of United States Department of Agriculture relating to cereal 



in^^estigations 29 



Department Bulletin No. 358.' — Studies of the Mexican Cotton Boll 

 Weevil in the Mississippi Valley: 



Introduction 1 



Longe^d.ty of adult weevils ^. . 3 



Food plants of the weevil 8 



Feeding hal^its on cotton leaves and terijiinals 11 



Sex of adults , 12 



Period from emergence to o^'ip^sition 12 



Period from first feeding on squares to oviposition 13 



Fecundity 13 



Oviposition period 23 



Rate of oviposition 24 



Maximum number of eggs per day 24 



Period from deposition of last egg to death 24 



Acti\dty of females in different parts of the day 25 



Cassation of o\'iposition by hibernated weevils 26 



Total development period ' . 26 



Effect of size of square on weevil development 30 



Generations 30 



Summary 31 



Department Bulletin No. 359. — Comparative Spinning Tests op the Dif- 

 ferent Grades op Arizona-Egyptian with Sea Island and Sakellar- 

 iD<is Egyptian Cottons: 



Introduction _ 1 



Purpose of the spinning tests 2 



Mechanical conditions 2 



Grade, staple, and price comparisons.... 3 



Waste comparisons 4 



Tensile strength comparisons 7 



Bleaching, dyeing, and mercerizing 11 



Difficulties in introducing a new variety of cotton 16 



