222 EXPERIMENT STATION RECORD. 



plants; thus the products of the decompositiou of the humus, which on some 

 soils are of acid character, may in some cases he injurious to the plants. 



The fertilizing influence of sunlight, F. Fletcher {Nature [London], 83 

 (1910), No. 2110, pp. 156, 157). — The author gives some results of investigations 

 on " rah " on rice lands which he conducted in India a few years ago, and ques- 

 tions whether the benefit resulting from this practice is explained, as has been 

 suggested, by the work of Russell and Hutchinson on partial sterilization of the 

 soil. He suggests that the beneficial effects may be due to the destruction of 

 toxic compounds which he claims to have shown to exist in soils (B. S. li., 

 20, p. 521). He has shown that culture solutions which have been rendered 

 infertile by the growth of plants may be made productive by treatment with 

 volatile antiseptics such as toluene, benzene, chloroform, and carbon bisulphid, 

 which he claims render the toxic substances in the solution insoluble. 



Humidity of the soil in connection with the methods of its cultivation 

 under winter and summer cereals, K. G. Mankovski (In Itoghl Rabat Poltav- 

 slcitglw ()i)iiiiii(i(/li(> Poll/a :a Dradlzat Ljict. ISS6-1905. FoJtnni, 1908, vol. 

 1, pp. Ji3-209 ; App., pp. 33-111, fiys. 13). — The influence of time, depth, and 

 method of tillage was studied in detail in these experiments. 



A series of observations and experiments extending over a number of years 

 showed the advantage of surface tillage in absorbing and conserving the soil 

 moisture, the benefit being especially marked in case of early fall plowing. 

 Early tillage increased the supply of available plant food and so reduced the 

 amount of water necessary to the proper nutrition of the plants. Varying the 

 depth of tillage gave better results than tillage at a constant depth. The 

 marked influence of mulches in increasing the water supply of the soil was also 

 shown. 



Storing moisture in the soil, W. W. Burr and W. P. Snyder (Nebraska Sta. 

 Bui. 114, pp. 5-51, figs. 3, dgms. I'l, map 1). — This bulletin discusses the move- 

 ment of moisture in soils and the necessity of storing water in the soil during 

 periods of wet weather to be used during periods of drought, describes the type 

 of soil found on the substation farm at Noi'th Platte, Nebr., as well as the 

 methods of taking samples for soil moisture determinations, and reports a 

 series of moisture determinations in samples of soil taken to a depth of 15 ft. 

 The results are given in tables and diagrams illustrating the variation in mois- 

 ture content at different depths under various systems of tillage and cropping. 

 From the data reported the following conclusions are drawn : 



" Land which is under thorough cultivation absorbs water much more freely 

 than land not under cultivation or which is covered with grass or for any 

 reason has a hard surface. 



" Land under thorough cultivation loses but little water from below the first' 

 foot by surface evaporation so long as the mulch is kept in good condition. 



"A growing crop uses water from the land in proportion to the growth of 

 dry matter in the crop. 



" Land under summer tillage or thorough cultivation from May 1 to Septem- 

 ber 1 on the substation farm has accumulated from 5.5 to 7 in. more water in 

 the first 6 ft. of soil than similar land growing a crop. The water so stored 

 has been equal to from 40 to 50 per cent of the rainfall for the same period. 

 The moisture content on summer tilled land increases below the 6-ft. area 

 and is apparent to a depth of at least 10 ft. 



"Water stored in the subsoil to a depth of at least 6 ft. is available for the 

 use of farm crops, and alfalfa is able to draw water from much deeper areas. 



"Abundance of water in the subsoil is a great protection to the crop against 

 drought, and moisture in the surface soil, while it may favor the immediate 

 growth of the plant, does not protect it against prolonged drought. The pro- 



