Environmental Engineering Reference
In-Depth Information
f
= Normality factor of N/100 H
2
SO
4.
W
=Weight of soil.
V
= Volume of extract used.
Available Phosphorous
Available phosphorus level was determined on oven dried soil samples by the method
described by Huq and Alam, 2005 modified from Olsen et al.
,
1954. Sample was analyzed
using spectrophotometer and subsequently calculated the results by applying following
formula:
S
V
1
50
ml
(
dilution
)
Available P (ppm)=
T
V
2
Where
S
= ppm from the standard curve.
V1
= 50 ml volume of extraction.
T
= Amount of soil in g.
V2
= volume of extract used.
Data Analysis
Tabular and graphical presentations as well as statistical analyses were applied on the
collected pooled seasonal data in order to see the changing pattern of different
hydropedological factors in different seasons of the year. Statistical analyses of the data
included a one-way ANOVA followed by Tukey HSD post-hoc test (when the assumptions of
normality and homogeneity of variances were satisfied) with a 5% significance level. Simple
correlation (r) and cluster analysis were made for assessing the relationship between the
hydropedological factors studied in the present research. All analyses were run in the SPSS
(v.11.5) and MINITAB (v.14) packages.
R
ESULTS
The monthly and seasonal mean values for different hydropedological factors of salt
marsh plant,
P. coarctata
bed were shown in Appendix A and Table 1. The sub-surface water
temperature in the vicinity of
P. coarctata
bed was significantly varied between seasons that
were ranged from 23.34ºC±2.76 to 31.05ºC±2.45 throughout the study period. Minimum
temperature (20.60ºC) was recorded during winter while the maximum temperature (34.44ºC)
was observed during premonsoon (Appendix A)). Variations in water temperature between
winter and premonsoon as well as the winter and monsoon were significant at the level of
p<0.05 (Table 1). Water temperature was found significantly higher in premonsoon and
monsoon than winter. Water temperature was decreased from monsoon towards winter
gradually. Afterwards it was increased during premonsoon sharply (Figure 3). Water
temperature was positively correlated with dissolved oxygen, total suspended solids, tidal
height, inundation period, soil temperature, % of sand, bulk density, particle density and the
exchangeable Ca of soil and negatively correlated with water transparency, water table depth,
soil organic carbon, organic matter, field water capacity at 1% level of significance. In
