MUSHROOM CASING SOIL IN RELATION TO YIELD £ 



sufficient acid was added to the soil to increase the hydrogen-ion 

 concentration to pH 4.4. There was some doubt, however, whether 

 the reduced yield was due to an excess of sulphur or to hydrogen ions 

 in the acidified soil. 



To answer this question a naturally acid soil was used to make up 

 a series of soils of different pH values. When beds were cased with 

 these soils the yields shown in table 4 and figure 1 were obtained. 

 The poor yield from the acid soil and the beneficial effects of liming 

 are clearly indicated. 



Table 3. — Effect on the yield of cultivated mushrooms of treating casing soil with 

 sulphuric acid and with hydrated lime 



[Tests made in 1931] 



Material added per pound of soil and reaction of soil before casing 



Bed 

 No. 



Reaction 



Mar. 

 17 



May 

 15 



Yield 



per 10 



square 



feet 



Mean 

 yield 

 per 

 square 

 foot i 



20 cc N/1— sulphuric acid, pH 4.4. 



8 cc N/1— sulphuric acid, pH 5.2_ 



Untreated, pH 6.0 



Vi g hydrated lime, pH 7.2_ 



W2 g hydrated lime, pH 7.9_ 



pH 



4.7 

 4.3 

 4.8 



5.3 



5.4 

 5.1 



5.8 

 5.9 



7.0 

 fi.9 



pH 



5.8 

 4.9 

 4.8 

 5.4 

 5.2 

 5.7 

 5.4 

 5.5 

 5.7 

 5.4 

 5.6 

 5.7 

 6.2 

 6.0 

 6.1 

 7.0 

 7.0 

 6.9 

 7.0 

 6.9 

 8.1 

 7.9 

 8.0 

 7.9 

 7.8 



Ouncs 

 88 

 202 

 141 

 139 

 143 

 215 

 246 

 168 

 238 

 208 

 247 

 227 

 259 

 261 

 236 

 230 

 304 

 189 

 257 

 207 

 223 

 343 

 274 

 288 

 2f9 



Pounds 

 \ 0.9 



1.5 



1 Standard error of the mean yield of 5 plots is 0.09 pound per square feet. 



Table 4. — Effect on the yield of cultivated mushrooms of adding hydrated lime to an 



acid casing soil 



[Tests made in 1932] 



Hydrated lime added 



0.0 percent. 



0.2 percent. 



0.4 percent. 



Reaction 





Yield 

 per 10 



at time 



Bed No. 



of casing 





feet 



pH value 





Ounces 





f 1 









2 



67 



4.8 



\ 3 



63 





4 



26 





I 5 



7 





[ 1 



245 





2 



301 



6.7 



\ 3 



189 





4 



128 





I 5 



226 





f 1 



171 





2 



187 



8.1 



\ 3 



254 





4 



216 





I 5 



191 



Mean 



yield per 



square 



foot i 



Pounds 



0.2 



Standard error of the mean yield of 5 plots is 0.12 pound per square foot. 



