﻿CONTENTS 



Depaktment Bulletin No. 1376. — Nuttall's Death Camas (Zyga- 



DENUS NUTTALLIl) AS A PoiSONOUS PlANT: 



Introduction 



Description of the plant 



Experimental work 



Typical case of sheep 741 



Typical case of cattle 997 



Results of experimental work and conclusions 



Sjanptoms 



Time between feeding of plant and development of symptoms _ _ 



Duration of sickness 



Autopsy findings 



Toxic and lethal dosage 



Comparative toxicity of parts of the plant 



Animals susceptible to poisoning 



Probability of death of livestock 



Remedial measures 



Summary 



Department Bulletin No. 1377. — A Study of the Value of Crop 

 Rotation in Relation to Soil Productivity: 



Introduction ^ 



Primary objects of study 



Method of study 



Experiments selected for study 



Discussion of evaluation methods 



First method, involving assumptions 



Second method 



Third method 



Effects of crop rotation and of the use of fertilizers on crop yields 



Rothamsted experiments with wheat and barley 



Experimental data 



Rotation and the use of fertilizers conjoined 



Diagrammatic summary of Rothamsted results 



Columbia experiments with wheat, corn, and oats 



Experimental data 



Rotation and fertilization practiced independently 



Rotation and the use of fertilizers conjoined 



Wooster experiments with wheat, corn, and oats 



Experimental data 



Results when rotation and fertilization are practiced inde- 

 pendently 



Results when crop rotation and the use of fertilizers are 



conjoined 



Germantown experiments with tobacco 



Urbana experiments with corn 



Florence experiments with cotton 



Rotation and fertilizer efficiencies as affected by soil reaction 



Summary of relative values of crop rotation and of conjoint effects 



of rotation and the u.se of fertilizers 



Value of crop rotation and of the use of fertilizers in maintaining 



and increasing soil productivity 



Maintaining sfjil i>roductivity 



Increasing soil productivity 



Effect of soil reaction on rotation and use of fertilizers 



General discussion _ 



General surninary and conclusions 



Literature cited 



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