34 



EXPEEIMENT STATION RECORD. 



"(18) When undrained and kept in the native wild grass, and cut continuously, 

 these lands in some known cases greatly decrease in productiveness, so much so as to 

 hardly pay for cutting. 



"(19) In sowing to grain and seeding after corn, which has been kept clean, it 

 will generally be best not to plow, on account of the naturally loose character of the 

 soil. If plowing must be done and tin" ground is dry enough to do so, it will be best 

 to roll to increase the firnniess. 



"(20) When clover has winterkilled, leaving the timothy standing, the ground 

 may be seeded to clover very early in the spring by sowing on the surface and har- 

 rowing lightly." 



Percolation and evaporation from long columns of soil, F. H. 

 Ki\(! ( H7.srv>//.sv'/^ Sfa. Rpt. 7<S',9/>, j^>p. JIJ^-JIS). — In continuation of 

 prcviou.s studies (E. S. R., 10, p. 727), the author made observations 

 (1) on the rate of percolation from saturated sandy loam and cla}' loam 

 soil in brass cylinders 7 ft. long- and 3 in. in diameter, and (2) on loss 

 of water by evaporation from similar soils, mulched and not mulched, 

 in galvanized-iron cylinders 10 ft. lonjj;, having a cross section of 

 0.01011 sq. ft. 



In the first case the cylinder was made in sections 6 in. long, which 

 could be screwed together, forming water-tight joints. The top of the 

 cjdinder was provided with a closely titling screw cap and the bottom 

 with devices for collecting, maintaining at a uniform level, and remov- 

 ing the percolating water, with the minimum of evaporation. 



"The apparatus was filled with soil containing a good working amount of moistui-e, 

 and was introduced in small, uniform quantities at a time, tamping each quantity 

 added with the same number of strokes. When filled, the soil was completely sat- 

 urated with water by filling from the bottom under pressure until the water over- 

 flowed at the top. 



' ' The rate of percolation and the amount of it was obtained by weighing at 7 a. m. 

 each morning after the first rapid discharge had taken place, and the table below 

 gives the distribution of moisture by 6-in. sections, as found 60 days after percolation 

 was started." 



IHstribution of moisture in soil at different distances above standhuj ivatcr after 60 days of 

 percolation tmthout evaporation. 



There were several da3's during the course of the experiment in 

 which there was no percolation. These were usually days of lower 

 temperature and of higher barometer. 



