642 



STATE BOARD OF AGRICULTURE. 



slightly rollinj]:. The soil con.«;if?ted of a snnrly loam. The ground had 

 been under alfalfa sod for several years, and from the plots, which were 

 to be left nncnltivated and cultivated, the vegetation was removed 

 long before the experiment was commenced. The plots were 20x15 feet 

 and the l)ulbs were placed about 5 feet apart from each plot. The 

 thermographs wei'e located on top of posts 4 feet high. 



The uncultivated plot was kept free from weeds, while the cultivated 

 plot was worked always immediately after a rain. The sod plot was 

 mowed the first of ^fay at the time when the bulbs were placed in the 

 soil after they were repaired. From this time on the vegetation was 

 never cut again. Throughout the growing season, the crop grew luxur- 

 iantly and was very dense. 



On account of space, the data of this experiment cannot be presented 

 as fully and as detailed as in the preceding experiments. In the fol- 

 lowing tables, therefore, is not shown the daily temperature but only 

 the monthly. 



MONTHLY AVERAGE TEMPEILVTURE. 

 TABLE 74— AVERAGE MONTHLY TEMPERATURE OF UNCULTIVATED, CULTIVATED, AND SOD LAND. 



December . 

 January. . . 

 February. . 

 March . . . . 



April . 

 May., 

 June. 

 July. 



August — 

 September. 

 October . . . 

 November. 



Name of month 



Uncultivated 



34.5''F 

 27.73 

 30.73 

 31.81 



42.24 



65.25 

 71.09 



66.60 

 63.48 

 50.24 

 39.77 



Cultivated 



20* 



3G.62°F 



62.00 

 66.94 



63.80 

 61.90 

 50.89 

 41.20 



34.84°F 

 27.79 

 29.42 

 30.60 



39.63 

 54.12 

 64.4 

 70.04 



66.24 

 62.80 

 50.46 

 39.50 



20' 



35.94''F 

 30.92 

 30.06 

 30.67 



37.10 

 50.88 

 60.64 

 66.61 



63.75 

 61.84 

 50.90 

 41.27 



Sod 



61.97 

 65.55 



63.39 

 59.60 

 48.46 

 39.85 



64.0 



63.74 

 61.40 

 52.43 

 45.07 



It will be seen that in December all the plots at the depth of 7 inches 

 had practically the same temperature. In January, the coldest month 

 of the year, the sod plot was about 1.5 F. warmer than the other two 

 plots, while the latter had nearly the same temperature. In the months 

 of February and March the temperature of all the soils was almost 

 the same with a small difference in favor of the uncultivated plot. In 

 April the uncultivated plot had the highest temperature and was fol- 

 lowed by the sod and finally by the cultivated. During the months of 

 June, July, August, and September, the uncultivated plot was the warm- 

 est, the sod the coldest, while the cultivated was intermediate. The 

 difl!'erence between the cultivated and uncultivated i)lots was not very 

 great, the highest variation occurred in Julv (1.05'' F.), followed by 

 June (.85°), September (68°) and August^ (.364°). The amplitude 

 between the sod and either of the bare plots was quite marked, ranged 

 in July as much as about 5° F. After October the order of warmth of 

 Ihese i)l()ts changed somewhat. The sod which since May had the lowest 

 temperature had now the highest, with the uncultivated and cultivated 



