SOILS — FERTILIZEKS. 135 



and magnesia in the soil, tlie action of increased applications of magnesium 

 and sodium salts on the growth of plants, lime content and soil reaction in their 

 relation to the need of lime in the soil, the action of different lime and mag- 

 nesia fertilizers on acid soils, and the determination of the acidity of soils. 



The soils used included clay loam, sandy, and loam soils. The crops grown 

 included buckwheat, oats, mustard, clover, and potatoes. Detailed data are 

 given for each crop. 



Correction of an excess of magnesia applied as fertilizer reduced the yield of 

 both buckwheat and oats. No definite relation between the yield of the crop 

 and the ratio of lime and magnesia in the soil was established. 



Magnesium sulphate, magnesium chlorid, and sodium chlorid, with a high 

 magnesia content in the soil, gave an increased yield with cereals but not with 

 hoed crops and forage plants. With the larger applications (2 per cent) the 

 action of the chlorids was more detrimental than that of the magnesium sul- 

 phate. The smaller the lime content and the lighter the soil the gi-eater was 

 the reduction of the yield. 



To determine the need of lime in a soil not only the lime content but also the 

 reaction of the soil is important. Neutral soils with low content of lime are 

 sometimes not benefited by applications of lime and the same is true of 

 acid soils with higher lime content, although the lime is beneficial In improving 

 bacteriological conditions. 



Calcium and magnesium carbonates had a beneficial effect on the yield of red 

 clover, mustard, and potatoes on an acid soil deficient in lime, whereas gypsum 

 reduced the yield. 



On the alleged refutation of the lime factor theory, O. Loew {Landio. 

 Jahrh., 39 {1910), No. 3, pp. 335-343) .—The author discusses recent work by 

 Hager, Gossel, Doyarenko (E. S. R., 15, p. 127) and de Ruijter de Wildt (E. S. 

 R., 18, p. 532), which led to conclusions contrary to his own views as to the 

 importance of a certain ratio between lime and magnesia in the soil. He ex- 

 plains why in his opinion the work of these investigators does not refute his 

 theory. 



Fertilizers and their use, J. T. Willard, C. O. Swanson, and R. C. Wiley 

 (Kansas 8ta. Bui. 169, pp. 37-97). — This bulletin gives the main provisions of 

 the state fertilizer law, reports analyses of 52 samples of fertilizers collected 

 for inspection in the State, explains the terms relating to fertilizers, describes 

 materials used in fertilizers, and discusses soil analysis and other means of 

 determining the fertilizer requirements of soils, including physical tests, study 

 of natural vegetation, and methods of making fertilizer experiments. 



The author is of the opinion that " a thorough chemical analysis of a soil is 

 indispensable to any comprehensive study of its condition and probable dura- 

 bility. Such chemical analysis may not be sufficient alone to give positive indi- 

 cations concerning the present productiveness of the soil, or its needs in respect 

 to fertilizers. Chemical investigation directed toward certain specific points 

 may be of great value in respect to a given soil. Laboratory tests of a purely 

 physical character afford little if any information that can not be obtained 

 better by examination of the soil in its natural condition and position. The 

 immediate fertilizer requirements of a soil are best ascertained by means of 

 systematic fractional fertilization of different crops." 



The bulletin also deals with the fertilizer constituents and requirements of 

 different crops, the valuation of fertilizers, fertilizing constituents in food con- 

 sumed by domestic animals, and the selection and home mixing of fertilizers. 

 Tables are included showing the composition of standard fertilizing materials, 

 data for calculating the fertilizing constituents in different mixtures and 

 the amounts of fertilizers to apply, and the relation between phosphorus and 



