128 EXPERIMENT STATION RECORD. [Vol. 43 



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they become impregnated in slight or excessive degree with calcium or mag- 

 nesium bicarbonate derived frctm any one of the several forms of these two 

 alkali earths. Furthermore, excepting in the case of the Cumbei-land loam, 

 the excessive and impractical 32-ton and 100-ton CaO treatments, nothing that 

 has been developed would suggest the possibility that the lime, magnesia, or 

 their several chemical or mineral cai'bonate treatments have so altered the 

 original form of soil potassium as to render any residual portion of it more 

 available or beneficial to plant growth." 



A list of 34 I'eferences to literature bearing on the subject is IncUided. 



The lime factor in ijerniaiient soil iinprovemeut. — I, Rotations without 

 legumes, J. G. Lipman and A. W. Blair (Soil Set., 9 (1920), No. 2, pp. 83- 

 90). — In experiments conducted at the New Jersey Experiment Stations, lime! 

 in carbonate form was used on a loam soil at the rate of 1 ton per acre for" 

 the first five years and 2 tons for the second five years, in a 5-year rotation of 

 corn, oats, wheat, and two years of timothy. No legume crops were introduced. 

 Twenty \ -acre plats with different nitrogen treatment were thus limed, and ' 

 20 similar plats with parallel nitrogen treatment were left without lime. 



The total yields of dry matter and of nitrogen for the 10-year period were 

 essentially the same for the two sections. 



Analyses of the soil made soon after the work was started and again at the 

 end of each 5-year period showed that there was a loss of nitrogen from both 

 the limed and unlimed sections. However, the loss from the liminl section was 

 distinctly greater than from the unlimed section. Thus, at the end of the 

 10-year period there w^as a positive loss rather than gain from the use of lime. 

 From this work it would appear that the practice of using lime on light to 

 medium heavy soils, when leguminous crops are not grown in the i*«»tation, 

 may be questionable. Under such conditions it is quite possible that a slightly , 

 acid reaction may be desirable to prevent the too rapid oxidation of organic 

 matter. , 



A list of six references to literature bearing on the subject is included. 7= 



The lime factor in permanent soil improvement. — II, Rotations with 

 legumes, J. G. Lipman and A. W. Blair {Soil Sci., 9 (1920), No. 2, pp. 91- 

 114). — In this paper, continuing work noted above, an attempt is made to show 

 the influence of lime in four difEerent rotation systems, all of which include 

 some legume crops. In each 5-year rotation there were seven plats, one un-> 

 limed, one each that received 1,000, 2.000, and 4,000 lbs. per acre of calcium 

 limestone, and one each that received like amounts of magnesian limestone. 

 Legume crops were introduced in each rotation either as one of the main crops 

 or as a green manure crop between the main crops. Acid phosphate and 

 muriate of potash were nsed in liberal amounts. Light applications of com-- 

 inercial nitrogenous fertilizers were made. No farm manure was used. 



During the 10 years the limed plats, with only slight exceptions, yielded dis- 

 tinctly larger crops and more total nitrogen than the unlimed plats. In most 

 cases the yields were larger with the 2,000 and 4,000-lb. applications than with 

 the 1,000-lb. application. The two forms of limestone gave quite similar re- 

 sults. There appeared to be a slight difference in favor of the magnesium lime- 

 stone. In the majority of cases the percentage of nitrogen was higher in 

 crops from the limed than from the unlimed plats. The use of lime thus re- 

 sulted in a gain in both quantity of the crop produced and also in the quality. 

 Analyses of the soil showed, in a number of cases, a higher nitrogen content for 

 limed than for unlimed plats ; in other cases the two. were about on a level as 

 to nitrogen content, and in a few cases there was apparently a depletion of the 

 nitrogen in the limed plats. 



