]^38 EXPERIMENT STATION KECOED. [Vol. 36 



in the Arizona-Egyptian than in the Salcellaridis, which in turn was somewhat 

 more yellow than the Sea Island. 



Rab: A unique system of cultivating rice in western India, E. Buck 

 (Internat. Inst. Agr. [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 6 (WIS), 

 No. S. pp. 1111-1117).— This system is described and discussed with reference to 

 the effect of the different practices which it involves. 



It is pointed out that among the general features of the system the more 

 prominent ones are that the rice is transplanted from the seed bed to the field, 

 that the seed bed and not the field is manured, and that by burning the manure 

 its effectiveness is increased. The term " rfib " refers to manure burned on 

 the seed beds from which rice plants are transferred to the field, and at one 

 time the manure thus burned consisted mainly of branches and twigs of trees 

 and bushes of the surrounding jungle. The advantages of transplanting and 

 of the manuring of the seed bed are considered and an analysis of the heating 

 effect in its various aspects is presented. It is shown that one of the ad- 

 vantages of transplanting is the possibility of economizing in the use of 

 manures, since their application to the seed bed instead of to the field gives a 

 greater efficiency for a given quantity and incurs less expense in the application. 

 A study made by H. H. Mann et al. from 1909 to 1912 on the effect of heat 

 on the chemical, physical, and biological character of the soil, the effect of the 

 ash constituents on the plants, and the effect of heat alone compared with that 

 of the ash and of each with that of the complete application used in the " rS,b " 

 system, is briefly reviewed and the results summarized. In this study the 

 analysis of the water-soluble constituents of the soil before and after heating 

 sliowed a steady increase in the amounts of soluble minerals and organic mat- 

 ter with increase of temperature. An increase in permeability was found to be 

 proportional to the increase of temperature. A similar increase in permeability 

 brought about by the addition of gypsum was only able to effect an increase in 

 yield of about one-fourth of the amount produced by heating the soil. 



With regard to the biological effects of heat on the soil it was found that the 

 activity of the aerobic organisms as measured by the rate of absorption of 

 oxygen was very largely reduced on heating to 125° C. for half an hour, but 

 never wholly destroyed, and that after 7 weeks it greatly exceeded that in the 

 unheated soils. It is concluded that since the growth of the seedlings is great- 

 est immediately after heating when the aerobic activity is lowest, the fertility 

 of the soil is not dependent on the presence of large numbers of soil organisms 

 during the growth of the plants. It is pointed out that investigators have 

 shown that nitrogen in the form of ammonia is the most effective manure for 

 rice and that greater yields are obtained by applying it before planting than at 

 intervals during the growth of the crop, and from this fact it is concluded that 

 the heating effect of the rab system seems to produce ideal conditions in the 

 seed bed as it causes a temporary increase in ammonification of the soil at 

 the most favorable period in the development of the rice plant. 

 See also a previous note (E. S. R., 27, p. G41). 



The cost of producing sugar beets, F. W. Peck (Minnesota Sta. Bui. 154 

 (1916), pp. 3-35, figs. 11).— The results of a study of the cost of sugar beet pro- 

 duction showed that man labor constituted 49.5 per cent of the total cost of 

 production. Without contract help the growers required an average of 155.4 

 hours per acre to produce the crop. The average cost per acre for both con- 

 tract and noncontract labor was $23.61. The average rate per acre for pro- 

 fessional labor was .$17.19, or 20.6 cts. per hour. With contract or outside 

 labor the grower spent 34 per cent, and without it 11.5 per cent of his labor 

 In marketing the beets. 



