INDOOR COMPOSTING FOR MUSHROOM CULTURE 11 
TABLE 3.—LHffect on yield of mushrooms of adding to the compost different amounts 
and combinations of potassium sulfate and calcium sulfate 
EXPERIMENTAL DATA 
Yield when amount of calcium sulfate added was— 
Potassium 
sulfate | Bed None 16 percent 1 percent 
added | No Waedts 2 etki s lie Ol ake fs ek aa ae aes Sums Mean 
(percent) : : F 
are Mean ethene Mean ee Mean 
———— | 
| Ounces 1 | Pounds? | Ounces! | Pounds? | Ounces! | Pounds? | Ounces: | Pounds 2 
1 366 392 44) 
ee Bel Aenea S34" 462/08 Soy 2135 ferlte 2.BL | 4453 2.31 
4 291 379 364 | 
ibe || 374 353 | 371 
Bemee Sees Fae ere |e a okes a a are Beale 2.200 e002 2.34 
4 350 |} 424 318 
iL || 394 447 435 
Ups, Jeet 2 | ae 2. 35 74 2. 43 ar 2.27| 4,516 2.35 
4 332 369 281 
1 392 406 387 
i cee ES STA 2238 aoe 2.41 oe 2.16| 4,430 2.30 
| 4 | 379 369 271 |} 
Sumse_-—— | Lens DSS lisse sea es GAI1GSE tae aeiees LS OP}. || 3 ae FOO le | St ae 
Vicari aw eee eae | cen ORIG Eee ree DUA) | eee cae DAS TO ere ones | heres 
ANALYSIS OF VARIANCE 
Pere Degrees of Sum of Mean 
Source of variation freedom squares square 3 
Between amounts of potassium sulfate____________________---_______- 3 410 137 
Betweenramounts of calcium sulfates —- === 2-8 ese 74.1 4,173 2,086 
Rotassiuni sulfate ><caleiumisnlfates = =) ss ee 6) 11, 536 1, 923* 
Beh Wiee hi DCGS: COlOCKS) seam ea ee ee ek Raa Ea cate 3 | 24, 464 Sel pha 
Beds treatments:(Crnon) = ase ee ee 33 | 26, 042 789 
Mota ene iS DUST S 2s ame ieetae eb az |e 66, 6200 | ene 
1 Per 10 square feet. 
2 Per square foot. 
3 *=Probably significant; odds between 19 to 1 and 99 to 1. 
=Probably significant; odds greater than 99 to 1. 
ANALYSIS OF VARIANCE AND DESIGN OF THE 
EXPERIMENTS 
In planning experiments to test the effect of different phases of the 
indoor composting process on mushroom yield, precautions were taken 
to reduce the uncontrolled variability and facilitate an analysis of 
variance. Uniformity trials have shown that bed levels may some- 
times be an important source of variability.? In view of this all treat- 
ments were randomized on each bed level. In effect then each of the 
four bed levels was handled as a randomized block. Variability within 
the blocks was reduced by thoroughly mixing the compost in each 
block before applying the treatments under consideration. 
The large mean square for block differences in table 3 illustrates the 
gain in precision sometimes obtained as a result of mixing the compost 
and arranging the experiment so that blocks correspond to bed levels. 
3 LAMBERT, E. B. SIZE AND ARRANGEMENT OF PLOTS FOR YIELD TESTS WITH CULTIVATED MUSHROOMS. 
Jour. Agr. Res. 48: 971-980, illus. 1934. 
