420 EXPERIMENT STATION RECORD. 



mainly from the monamino acid group. This increase in the production of 

 ammonia and the checking of nitrification were also observed in field soil on 

 which brush had been burned. 



Rice soils of Hawaii : Their fertilization and management, W. P. Kelley 

 {Hawaii Sta. Bui. 31, pp. 23). — Studies of the origin, composition, fertilizer 

 requirements, and management of these rice soils are reported. 



It is shown that the Hawaiian rice soils are of basaltic origin, but also 

 contain small amounts of coral limestone. They are generally clay loams con- 

 taining approximately equal quantities of fine sand, silt, fine silt, and clay. In 

 chemical composition the soils are quite uniform except those from the Waikiki 

 district, which contain abnormal amounts of magnesia, and those from the 

 Kaulaunui district, which are highly organic. In general, the nitrogen and 

 phosphoric acid are high, while the potash is low, due to leaching from the 

 soil. 



Fertilizer experiments carried on through seven crops showed that the appli- 

 cation of 150 lbs. per acre of ammonium sulphate produced notable increases in 

 the yield, but 300 lbs. per acre proved the more profitable. Potash and phos- 

 phoric acid were without effect. Application of ammonium sulphate to both 

 the spring and fall crops was considerably more profitable than application to 

 the spring crop only. The residual effects on the fall crop from the spring 

 application were small. The immediate effects from application to the fall 

 crop were about the same as those obtained with the spring crop. 



A complete fertilizer proved no more effective than ammonium sulphate 

 alone, whereas a mixture of ammonium sulphate and potassium sulphate was 

 less eft'ective than ammonium sulphate alone. Nitrate of soda alone gave poor 

 growth. Moreover, the nitrate was reduced in the submerged soils to nitrites, 

 which are poisonous to rice. Very little nitrification took place in the sub- 

 merged soils; ammonification, however, went on, not so vigorously as in 

 aerated soils, but sufllciently to supply the nitrogen needs of the rice, provided 

 sufficient organic matter was present. 



Conditions favoring aeration are not considered desirable because nitrifica- 

 tion sets in immediately after such conditions are produced and the nitrates 

 thus formed become converted into poisonous nitrites upon resubmergence, or 

 are lost through leaching. A rotation of crops, including the plowing under of 

 a legume, is recommended, but when no rotation is practiced it is better to leave 

 the land unplowed until just before planting the next crop. 



Introduction to the soils of California, G. E. Bailey (Los Angeles, Cal., 

 1913, pp. 171, fig. 1). — This book gives an elementary discussion of agricultural 

 geology, soil forming materials, land forms, processes of soil formation, soil 

 classification and its importance, soil particles, soil moisture, organic matter 

 in soils, subsoils, soil movement, and soil permanency and a description of the 

 soils of California as to their location, origin, and agricultural value, dividing 

 them into clay, adobe, silty clay, silt loams, loams, sandy adobe, fine sandy 

 loams, fine sand, hardpan, and alkali soils. 



The composition of the soils of south Texas, G. S. Fbaps (Texas Sta. Bui. 

 161, pp. 6J).— This bulletin, the third of a series (E. S. R., 23, p. 315), contains 

 a description of the soil types of about 33 counties in the southern portion of 

 Texas, notes on their present agricultural uses and productiveness, and also 

 chemical analyses of a number of samples of these types, together with an 

 interpretation of the results. 



Soil, D. J. HissiNK (In Dr. K. W. Van Gorkom's Oost-Indische Cultures. 

 Amsterdam, 1913, vol. 1, pp. 33-116, figs. 11). — This work deals with soil forma- 

 tion and composition, physical and chemical properties of soU, and soil biology, 



