618 EXPERIMENT STATION RECORD. 



with their subsoil down to a depth of at least 4, but preferably li or 8 ft. . . . Simi- 

 larly, no irrigator should be ignorant of the time or amount of water it takes to wet 

 his soil to a certain depth. ... A definite knowledge of the rapidity with which 

 irrigation water penetrates downward and sideways in his soil should form a part 

 of the mental equipment of every irrigator, particularly in arranging his head 

 ditches. . . . Supposing the moisture to have reached the depths of the soil, whether 

 from rains or from irrigation, it is essential that proper means be employed for retain- 

 ing it in the land, and especially to prevent evaporation. That this is best accom- 

 plished by a mulch on the surface, and that the best mulch for the purpose, which 

 need not be hauled on or oft' and is always ready, is a surface layer of loose, well- 

 tilled soil, is now pretty well understood by all. ... In the East, where this prin- 

 ciple is well understood, it is considered that a surface layer 3 in. in thickness 

 is sufficient to afford effective protection. But what is adequate in the region of 

 summer rains is quite insufficient in California and in the arid region generally. It 

 takes fully twice the thickness mentioned, and preferably more, to afford protection 

 against the drought and heat lasting 5 or 6 months at a stretch." 



Determinations of moisture in the soil of apricot orchards lying side 

 by side, one cultivated and giving a good crop of fruit and growth of 

 wood and the other uncultivated and producing poor fruit and little 

 growth of wood, showed 244 lbs. more water per acre to a depth of 6 ft. 

 in the former than in the latter in July. 



Measurements of soil temperatures at Norwegian observation 

 stations, 1892-1897, J. Sebelien (Tidsskr. Norske Landbr., 5 (1898), 

 No. 7, pp. 295-318). — The observations here recorded and discussed 

 were begun in 1892. A report of the first year's work at Aas and 

 Jonsberg has already been noted (E. S. R., 6, p. 199). The stations at 

 Eotvold and Bodo (the former near Droutheim, both in Northern Nor- 

 way) were added in 1895. The soil at Aas and Rotvold is clayey, at 

 Bodo sandy, and at Jonsberg, black pulverized alum slate. Observa- 

 tions were taken at depths of 0.25, 0.5, and 1 meter, and (in case of Aas 

 since July, 1895) at 1.5 meters. The observations at Aas Agricultural 

 College are particularly complete and instructive, covering a period of 

 5 years. 



Mechanical and partial chemical analyses of the soil at the various 

 depths are given in case of each station, and the bearing of the results 

 on the temperature of the soil are discussed at some length. — f. w. WOLL. 



Observations on the management of sewage farms, O. 

 Pfetffeb, (Chem. Ztg., 22 (1898), No. 56, p. 560),— A brief discussion 

 of the amount of fertilizing constituents absorbed from sewage by soils 

 and the amount escaping in the drainage water, based mainly upon 

 observations made on the sewage fields of Magdeburg. It was found 

 that the potash was largely and the phosphoric acid completely 

 absorbed. The drainage water, however, contained a large amount of 

 nitrates and little organic nitrogen, thus indicating quite complete 

 nitrification and showing the danger of loss of considerable amounts 

 of nitrogen when the ground is not covered with crops to utilize the 

 nitrates. 



Nitric nitrogen produced by the pea, J. L. Beeson (Jour. Amer. 

 Chem. Soc, 20 (1898), No. 10, pp. 793-795).— Small plats of very fertile 



