174 



Journal of Agricultural Research 



Vol. V, No. 4 



Plot A received clean cultivation with a rye cover crop sown in late 

 summer and turned under in the spring. The average depth of plowing 

 has been 7 inches. Cultivation started in 191 3 on May i and in 191 4 on 

 May II. Rye at the rate oi i^i bushels per acre was sown for a cover 

 crop on August 20 in 191 3 and on August 15 in 191 4. The land was 

 cultivated seven times each season. 



Plot C was in grass, which was cut and allowed to lie w^here it fell, as 

 in plot D, but in addition a mulch of wheat straw was applied about the 

 same time that plot A was plowed, using one bale to a tree. The bales 

 averaged 93 pounds in weight. The litter w^as scattered around the 

 trees, forming a collar 12 to 14 feet in diameter. 



Plot D was in grass, which was cut and allowed to lie where it fell. 

 In the autumn of 191 2 plot D was seeded to a mixture of grasses in which 

 timothy largely predominated and may here be considered as a timothy 

 meadow. The grass was mowed for the first time in the middle of June, 

 1 91 3, largely to prevent weeds from seeding, as the amount of mulch 

 was negligible. The extremely dry summer of 191 4 was disastrous to 

 grass, and a cutting on July 10 returned to the land only one-fifth of a 

 ton of dry hay per acre. 



Space does not permit the publication of the complete temperature 

 records, but the weekly maximums and minimums are given in Table 11. 

 It will be seen that in April plot A began to forge ahead in holding the 

 highest minimum temperature, with plot D second and C third. This 

 condition prevailed until in the fall, when plot A cooled off quickly and 

 D less quickly, leaving C with the highest minimum temperature until 

 spring. The differences, however, in winter temperatures between the 

 plots were small. During the week of February 23, 191 3, plot A showed 

 a minimum temperature of 32° F. and plots C and D, 32.5° F. Plot A 

 continued to cool, until during the week of March 16 it reached 32°, 

 when plot D registered its lowest, 31°, and plot C was 33° F. The 

 following winter the three plots reached their minimum temperatures 

 during the week of January 11, that of plot A being 31°; D, 32.5°; and C, 

 34° F. 



Table II. — Records of soil temperatures under different cultural methods, May, 1913, 

 to May, 1915 



PLOT a: tillage with cover crop 



