4(H) EXPERIMENT STATION RECORD. 



was coininenced in Dweiiiher, l!t()2, and was completed in February, 1903." It was 

 found to 1)6 impossible to obtain a gravity outlet for the drainage water, and a chain 

 jiunip operated by a water wheel was installed to remove the drainage water. The 

 total cost of ditching, tiling, and all incidentals except the cost of the pumji and 

 water wheel was $16.50 per acre. 



"About the first of March, 190:5, irrigation was connnenced. The laml was divided 

 into 30 checks, the size of each check de])en(ling upon the slope of the land. Tlie 

 largest checks, those on the level land, are about 2 acres in extent, while on the 

 steeper slopes they are less than half an acre. The f)bject was to divide tlie land in 

 such a way that it could all lie kei)t under water to a depth of 4 in., and the recla- 

 mation was to be accomplished by maintaining the water at this dejith until enough 

 alkali had been washed out of the soil through the drains to enable a crop to be 

 grown." 



When the drainage system was ixistalled 18 of the 20 acres contained too much 

 alkali to produce a croj). After 4j months of the treatment above described all of 

 the land, with the exception of small spots, amounting in the aggregate to less 

 than 2 acres, was considered ready for the sowing of alfalfa. On the basis of this 

 demonstration of the feasibility of reclaiming alkali land Ijy undenlraining and 

 flooding, the authors outline a general plan for the reclamation of the Fresno district, 

 at an estimated cost of $10 per acre. 



Soil temperatures at liincoln, Nebr., 1888-1902, G. D. Swezey {Xcbraska Sta. 

 Rpt. 1902, jjp. 95-129). — Observations on soil temperature have been made at the 

 station during 15 years beginning with May 1, 1888, with thermometers placed at 

 depths of 1, 3, 6, and 9 in., and 1, 2, and 3 ft. The readings for the years 1888 to 

 1893 have already been reported (E. S. R., 6, p. 123). A detailed tabular summary 

 of daily readings for the years 1894 to 1902 is given in this article. 



During 1891 readings were made 4 times daily during Feljruary and August for the 

 purpose of studying the behavior of the diurnal wave of temperature. The data 

 reported show "that the daily fluctuations in the air are nearly coincident in time 

 with those at the surface of the ground and are not very different from them in 

 amount; that the diurnal wave gradually progresses downward and at the same time 

 gradually grows less marked until it finally disappears. In winter the daily maxi- 

 mum is reached in the middle of the afternoon; at depths of 3 to 6 in. the maximum 

 occurs in the evening; at 1 ft. it is delayed till the following morning, below which 

 it is scarcely api^reciable, appearing, if at all, during the following day; the minimum 

 temperature, which occurs in the air in the early morning, is propagated downward 

 at about the same rate. In summer the daily range is considerably greater at all 

 depths, the changes are appreciable to a depth of at least 2 ft., and are retarded to 

 about the same extent as in winter." 



A study of the monthly normals leads to similar conclusions regarding the progress 

 of the annual temperature wave, that is, "the annual changes of temperature are 

 greater at and near the surface of the ground than in the air itself, and that the 

 annual range, like the diurnal, decreases with great regularity as we go down. The 

 data also show that on the whole the air receives heat from the soil rather than the 

 soil from the air; this follows from the fact that the soil is warmer than the air. 

 . . . The temperature of the soil to the depth of a few inches is higher during 

 every month of the year than is the air which lies upon it, and the deeper soil is 

 warmer on the average than the air. . . . How much of this excess is due to the 

 downflow of solar heat and how much to the upward flow of the internal heat of 

 the earth does not appear from -Qur data; we can only say that more of it comes 

 from above than from below, but how much more we can not say because our obser- 

 vations do not reach deep enough. ... At the depth of our deepest thermometer 

 the flow of heat is downward rather than upward." 



