32 EXPERIMENT STATION RECORD. 



Nitric acid and total soluble salts computed as sodium chlorid were 

 determined in soil nuilch and unstirred soil immediately below the 

 mulch on September 22. The results indicate some difference due to 

 the different depths of cultivation (2 and 3 in.), the nitric acid being 

 higher in the mulches formed by cultivating 2 in, deep than in those 

 formed by cultivating 8 in. deep. There appeared, however, to be 

 no such evident relation between cultivation once a week and cultiva- 

 tion once in 2 weeks. 



"The loose mulch develoi)ed in the cultivation of the several plats was measured 

 by collecting, weighing, samjiling, and determining the water content of the samples, 

 anil tlic results showed that about 42 per cent more loose soil was developed on the 

 :> in. cultivation than on the (Uiltivation 2 in. deep. The amount of nitric acid shown 

 to be in this mulch was a little more than 200 lbs. per acre." 



Determinations of nitric acid made April 15 in irrigated and unirri- 

 gated soil to a depth of 3 ft. showed, with one exception, "that the 

 ground which had been irrigated and which produced the largest 

 amount of dry matter showed a larger percentage of nitric nitrogen 

 in the soil." 



"It should be said in regard to irrigation that only so much water has been applied 

 a« it was thought the crop could use to advantage, and no water had been applied to 

 the irrigated ground since the preceding August; further, the plat has been in corn 

 continuously without fertilizers, since 1894." 



The character and treatment of s"wanip or humus soil, F. H. 

 King and J. A. Jeffeky {AVisconsiu Sta. Bui. 80, pp. 39.,ji(jH. H). — 

 Th(^ extent and character of swamp or humus soils in Wisconsin are 

 described, and experiments on their management, in continuation of 

 similar work in previous years (E. S. K., 10, p. 72S), are reported. 

 Accounts are given of plat and of pot experiments on soil of produc- 

 tive and unproductive areas of a reclaimed marsh with coarse, rotted, 

 and licjuid manure; cut and ground straw, ground oats, corn, and rye 

 (with and without addition of carl)onate of potash); green manure 

 (oats); gypsiun, sand, and ckw; magnesium carbonate and sulphate; 

 wood ashes; muriate, sulphate, nitrate, and carbonate of potash; and 

 nitrate of soda. The amount of soluble salts present (nitrates and 

 alkalis) and the effects of leaching, drainage, and adding drainage 

 water from hunuis soils were also studied. The crop grown was corn. 



Notwithstanding the presence of large amounts of nitrates in the 

 soil on May •!, barnyard manure produced a marked increase in the 

 crop, thus indicating that its benelicial effect was not due to increased 

 nitritication. 



Applications of sand and clay produced no benefit. Land plaster 

 reduced the amount of alkali present (see p. 31) but did not increase 

 the yield. 



In the pot experiments with magnesium salts the carbonate was used 

 in saturated solution at the rate of 511.1 lbs. per acre, the sulphate at 



