SOILS — FEKTTLTZEBS. 625 



Ztg., S7 (191S), No. 116, p. 1175). —Numerous investigations of flax and pea 

 sickness of soil showed that the repeated growing of flax or peas caused the 

 so-called germination fatigue, by which the seeds rotted before or during 

 germination. The ability of the seeds to resist this action was found to de- 

 pend more or less on the conditions of seed bed and soil, and on moisture and 

 temperature conditions, etc. Soils which were germination-tired for peas had 

 more or less the same effect on flax and vice versa. According to the author, 

 germination fatigue is different from growth fatigue, which was particularly 

 observed with flax. Well-cultivated plants grew poorly in healthy soil to which 

 about 15 per cent of flax-sick soil had been added. Similarly, a small addition 

 of good flax straw to the soil had a bad eft'ect on the growth of flax. 



While the germination fatigue disappears over winter, growth fatigue is 

 said to exist a longer time. It is stated that only by further investigation can 

 It be determined whether the germination and growth fatigue are due to the 

 activity of micro-organisms or to poisonous substances excreted by plants and 

 which may also be contained in straw. 



Essentials in the management of California soils, C. B. Lipman (Mo. Bui. 

 Com. Hort. Cal, S (1914), No. 1, pp. 19-26).— The author points out that the 

 deep soils of the arid region are due to the slow formation of clay resulting 

 from the relatively infrequent action of the leaching and weathering agencies. 

 He advocates as the six most important measures in maintaining the fertility 

 of California soils (1) deep plowing, (2) prevention of formation or breaking 

 up of plowsole, (3) irrigation in deep furrows, (4) deep incorporation of manure 

 and fertilizers, (5) frequent summer cultivation, and (6) green manuring and 

 the maintenance of the humus and nitrogen supply. 



The effect of treating- sand soil with moor soil, C. KRiicER {Mitt. Ver. 

 Ford Moorkultur Dent. Reiche, SO {1912), p. 402; ahs. in ZentM. Agr. Chem., 

 42 {191S), No. 10, pp. 651, 6.52).— Treatment of sand soil with different amounts 

 of moor soils and treatment of quartz sand subsoil with different amounts of 

 moor humus slightly increased the total yield of oats but decreased the per- 

 centage of grain in the total yield, and also the single grain weight. The 

 treated soils had always a higher water content than the untreated soils, but 

 relatively little of it was available to plants. It is thought that such treat- 

 ment in dry seasons without irrigation would result in a considerably decreased 

 yield. 



Gullying" and its prevention, F. H. H. Calhoun {South Carolina Sta. Circ. 

 20 {191S), pp. 86, pi. 1, figs. IS). — This circular contains a popular discussion 

 of the cause of erosion of farm lands, particularly through the agency of water, 

 the necessity for Its prevention, the means of checking the erosion, and the 

 methods of restoring eroded land to its original fertility. 



The disadvantageous results of unchecked washing of fields are pointed out as 

 (1) sheet erosion, which tends to strip the tops of the hills of fertile soil and in 

 time covers the lower slopes with less productive debris; (2) the formation of 

 gullies, which render cultivation diflicult, allow the escape of soil moisture, 

 humus, natural plant food, and commercial fertilizers; (3) the change of soil 

 texture from desirable loams to clays and sands; (4) the covering of fertile 

 bottom lands with material from gullies; (5) the filling of rivers, harbors, and 

 reservoirs with sediment; and (6) the depreciation of farm-land values. 



Means suggested and described for checking and remedying these harmful 

 results are (1) proper cultivation, (2) deep plowing, (3) preventing incipient 

 gullying, (4) hillside ditching, (5) proper terracing, (6) filling gullies by level- 

 ing or by obstructions, and (7) reforesting. 



Green manuring in California, C. B. Lipman {California Sta. Circ. 110 

 {191S), pp. S). — A brief popular summary of information on this subject 



