No. 1, .In.Y 1920] .-><>ll BCIENCE 247 



crops grown were wheat, red clover, and blood turnip beel [*h< I .'id 



silty day, low in organic matter, and an aeid black p< ad high in organ io i 



loin) pounds of oalcite, magnesite and dolomite were applied to t < • > t i . 



similar. The differencea between the calcite, magni ind dolomite im nail 



for the wheat and clover, while magnt ium carbonate gave much larger incn 



beets. With a l2,(K)()-pound application, magni on the black toil 



increase in crop yield on clay soil. Although the magi much wheal incre 



in all, except the 12,000-pound magnesite application on <h<- blaok sand, then 



during vegetative growth a tendency toward tip burning wherever m applied. 



Magnesite favored nitrification more than calcite, < >n the yellon claj toil, magi 



favored better growth of aerobic and anaerobic bactei ia I b n did oalcite < m the I 



soil the reverse was true.—./. If. /; :■ on. 



it).")0. Ceockbk, Willi am. Soil acidity. [Rev. of : Habtwbll, B. I.. ufoF. i: Pens 

 The presence of aluminum as a reason for the difference in the effect of the so-called acid soil 

 on barley and rye. Soil Sci. 6: 259-279. / pi. 2 fig. 1918 [See Bot. Abe 2, En 

 1137).] Bot. (!az. 67: 519-1910.- Tlie reviewer notes thai this paper the con 



of the apparently simple problem of sod aciditj , and adds I hal he has not iced t bal "1 he hydro- 

 gen ion concentration found in acid soils by the gas chain method is generally only a fr 

 tion of the hydrogen ion concent rat ion necessary to reduce the growth rate of planl iter 



or sand cultures." — H. C. Cowles. 



1651. Funchess, M. J. Acid soils and the toxicity of manganese. Soilfi 7:66 

 Previously (Alabama Agric. Exp. Sta. Bull. 201) the author concluded t ; 

 plants of certain plots on the Alabama Agric. Exp. Sta. farm was due to soluble man] 

 produced by the action of nitrogenous fertilizers. Further studies indicate that the * 

 observed in these soils after incubation with a nitrogenous fertilizer and in their 

 probably due to uncombined acid or readily hydrolyzable Baits but not to in. . — 



W. J. Rabbins. 



1052. Hill, H. H. A comparison of methods for determining soil acidity and a study of 

 the effects of green manures on soil acidity. Virginia Agric. Exp. Sta. Tech. Bull l'.». 96 p. 

 1919. — The author points out thai as a rule Virginia soils ere very deficient in org 

 ter and that this deficiency may be overcome by the practice of green manuring. h of 



plants is alkaline and on decomposition exerts a marked influence in con 

 resulting from the incorporation of green crops with the soil. Plants remove calcium fr<>m 

 soil. Legumes remove more than non-legumes. The young plants contain Blightly m 

 lime than the mature ones. In turning under crops the calcium in the plant is i i to 



the soil thereby exerting a certain effeel in correcting soil acidity. The method of h in 



estimating soil acidity, though quite reliable, is long and tedious. The Jones i 

 and on comparison with the Veitch, fairly concordant result- are obtained and applii 

 of lime by its use have approached very near the actual field conditions. The Jon< B met 

 differentiates applications of phosphoric acid on plats which have produced corn over 1 

 periods. This distinction is very clear-cut. In pot experiments, with the lcadii - of 



Virginia soils, the incorporation or plant tissue produced a very slighl increase in soil acidity. 

 This, however, was not excessive. In pot experiments, green manures did not inhibit a vig- 

 orous nitrate development and plant growth was materially increased. In field exocrine 

 with soybeans, buckwheat, red clover and rye, with corn and wheat, no marked acidity 

 developed during a five-year period. The turning under of the green manure crops w 

 detrimental to a strong nitrate production, nitrogen fixation and plant growth. With lie!.] 

 experiments where the green crops were turned under at intervals of two weeks throughout their 

 development, no injurious effects were observed as a result of this practice and after the second 

 crop had been turned under the lime requirement of the soil was diminished rather than 

 increased. Rye shows a decided initial acidity but this condition quickly passes off. '1 

 indications are that this initial acidity is not of serious harm to the plant on account of its 

 transitory nature. The common belief that a green manure practice is a harmful one, is n 



