SOILS FEHIILIZEKS. 710 



humus, but which are frequently rich iu alkali (chlorids, sulphates, aud 

 carbonates) ; and (3) tlie intermediate chestnut soils containing 3 to 5 per cent 

 of humus. 



The value of excavated subsoil (Kuhlerde) for the agricultural improve- 

 ment of upland moor soils, B. T.vcKt; (Mitt. Vcr. Fonl. MoorkiiJtiir Unit. 

 Ix'ciche, .i.i [H'l.'f). Xo. .Li. pp. .ii).l-.',07). — The author brietiy describes the i)rocess 

 of excavatinj; and mixing the deep subsoil with the surface soil of the upland 

 moors in northwest (Jermany and reports crop experiments with oats, rye, and 

 potatoes on these soils with different manurial treatments. He states that the 

 moor soils are acid and poor iu plant food, but that the subsoils are well stocked 

 with plant food, which is made more or less available when intimately mixed 

 with the moor soil and subjected to proper manurial treatment and cultivation. 

 This process apparently ivquires several years time, however, as is shown by 

 nine years' of cropping experiments, but in the end important quantities of 

 potash and phosphoric acid are made available for plants. 



A simple method for determining' the critical moisture content of soils, 

 K. O. E. Davis (Jour. Iiidua. and J-Jii(jin. Chcm., 6 (1014), No. 12, pp. 1008-1010, 

 figs. 2). — The method proi)osed depends upon the rise of water by capillarity 

 a short distance in a column of dry soil and the subsequent distrll)Utiou of the 

 water in the soil. 



A brass tube 1 ft. long aud 1 in. iu diameter is tilled with the soil and sus- 

 pended in water until the water has risen several inches in the tube. The 

 tube is then removed and held in a horizontal j>ositiou until capillary move- 

 ment practically ceases, then moisture is deteiiuined iu the inch of soil at the 

 extreme iJoint to which water has advanced. The percentage so found is taken 

 to be the critical moisture content. To facilitate the operation the brass tubes 

 are split iu half, so that they can be separated and the entire soil column 

 obtained for examination, and have a slit covered with celluloid to permit of 

 observation of the movement of the water in the soil. 



The method is considered simpler and more accurate than older methods for 

 the purpose. 



Two equipments for investigation of soil leachings, C. A. Mooers and W. IT. 

 MacIntire (Tennessee Sta. Bui. Ill (1915), pp. S, plx. //).— Two types of 

 equipment for investigating soil leachings are described, and illustrated. 



The first, a pit equipment, consists of an oblong covered cement pit 81.5 ft. 

 long, 5.3 ft. wide, and 6.5 ft. high. Thirty-four heavy galvanized iron soil 

 drainage tanks are sunk in the ground on both sides of the pit. These are 1. 2, 

 4. and 6 ft. in depth, and are provided with block tin outlets which pass 

 through the pit wall and empty the drainage water into galvanizod-iron cans 

 inside. 



The second, a hillside equipment, is based upon a 6-ft. perpendicular concrete 

 wall built again.st the side of a terrace in which the soil drainage tanks are 

 .sunk. The tanks are made of 14-gage galvanized ingot iron, strengthened at 

 the top by means of a 3/10 by 3/4-in. wrought-irou band, and having a surface 

 area of 1/20,000 acre. There are two sets of these tanks, viz. 21 12 in. deep, 

 embedded 8 in. in the soil, and 23 24 in. deep, embedded 20 in. in the soil. 

 Block tin tubes connected with the bottom of the tanks pass through the 

 retaining wall and empty the drainage water into containers arraugeil along 

 the wall in a covered subway. This subway is open on the side opposite the 

 retaining wall, but is so arranged that the containers are protected from direct 

 sunshine and other extreme weather conditions. 



Ammonification and nitrification iu Hawaiian soils, W. P. Kixt.ey (Haiiaii 

 Sta. Bui. 37 (1915), pp. 52). — This bulletin rei)orts studies on ammonification 

 and nitrification in Hawaiian soils under a variety of couditions. 



