Research Article

Biomass and Yield of Peanut Grown on Tropical Soil Amended with Sewage Sludge Contaminated with Lead

Table 4

Dry matter of peanut as a function of Pb rates applied to soil with sewage sludge, time of sewage sludge application, mineral fertilization, and control.

Dry matter (g per pot)
TreatmentShootRootsPodsPod husksKernels

Additional treatments
 Control54.76a 3.59a32.61a13.91a18.10a
 Mineral fertilization46.31a 3.06a41.22a15.73a25.49a
Sewage sludge
 Pb rate (mg kg−1)
 367.99a 5.28a44.23a17.02a27.39a
 2166.81a 4.90a47.50a18.11a29.44a
 4274.65a 5.42a42.04a16.98a25.03a
 Time of application
 30 d before sowing77.14a 5.66a41.18a16.87a24.40b
 At the day of sowing62.49a 4.73a48.00a17.87a30.16a

Analysis of variance
Source of variationF test

Additional treatments NS NS NS NS NS
Pb rate NS NS NS NS NS
Time of application NS NS NS NS *
Pb rate × time of application NS NS NS NS NS
Sewage sludge × additional treatments * ** * * NS
CV (%)29.4623.6717.6612.1622.45

Means followed by same letter in column within additional treatments and each factor of factorial do not differ significantly by Tukey test at P < 0.05.
NS: not significant. *, **significant at P < 0.05 and P < 0.01, respectively.