AND COLLEGE, PUSA, FOR 1914-15. 8? 



by green manuring in the rate of ripening both of the oats 

 and of the tobacco were very marked. The effect of super- 

 phosphate in conjunction with green manure on the rabi 

 crop was marked in soil with good moisture, but inappre- 

 ciable in plots where the water content was low and the soil 

 itself poor. A large number of observations were made on 

 the changes going on in seeth during and after fermenta- 

 tion; it was concluded that the value of this material as a 

 manure depends upon numerous factors of which its 

 nitrogen content is the principal; at the same time great 

 differences in the results may be obtained by proper or im- 

 proper methods of preparation and application, especially 

 the latter, as large quantities of toxic bodies are produced 

 as a result of the semi -anaerobic conditions obtaining 

 during the early stages of its manufacture, and can totally 

 inhibit root growth if allowed to remain in the soil, being 

 specially injurious to plants in the seedling stage. The time 

 of application appears to be more important than the 

 manner of preparation although these should be inter- 

 dependent. In the meantime it will be necessary to crop 

 the plots for some time without individual treatment and 

 gain some knowledge of the extent of local variations 

 amongst them. This seems especially necessary in the case 

 of green manuring experiments the results of which are 

 not likely to become strikingly obvious as quantitative 

 differences in the succeeding crop of such an order as to 

 carry them indubitably beyond the range of experimental 

 error. 



Studies were made of the development of root nodules 

 on various leguminous plants with special reference to the 

 depth below the surface at which they are formed, the 

 effect of variation in the soil upon their vertical position, 

 and the relation between their development and the age of 

 the plant. With regard to this last, in the case of san- 

 hemp (Crotalaria juncea) it was clear that each nodule 

 had its own life-history independent of that of the plant, 

 forming, developing to maturity, and finally shrinking 

 and drying up to an empty shell; cultures and section* 

 from nodules at various stages showed coincident changes 



