Table 5-16. Analysis of variance for concentrations of Mehlich I-
extractable soil P, K, and Ca after harvest.

 Soil nutrients
Source D.F. Error term P K Ca

 ----- F value -----

Date 1 Rep(Date) a a a
 Rep(Date)+Pooled error 3.84b
Rep(Date) 2
Fert 4 Rep(Date)*Fert 2.17 1.07 < 1
Date*Fert 4 Rep(Date)*Fert < 1 < 1 < 1
Rep(Date)*Fert 8
Depth(Fert) 40 Pooled error 20.3** 5.55** 46.2**
Date*Depth(Fert) 40 Pooled error 1.88** < 1 < 1
Pooled error 80
Total 179

C.V. 25.5 76.1 17.6

Date = Planting date
Rep = Replications
Fert = Fertilizer scheduling
Depth = Depth of sampling

a Insufficient mean error square degrees of freedom for a valid F test.
b Mean error squares pooled to increase degrees of freedom in order to
 enhance validity of the F test.
*95 and **99% probability of significantly different treatment means.