Table 1« Electrical Conductivity Standards for plant growth. 
487 
ELECTRICAL 
2 
Saturation 
extract 
CONDUCTIVITY mmhos/cm 
at 25°C 
1:5 soil to water 
suspension 
RELATIVE LEVEL OF 
SOLUBLE SALTS 
PLANT GROWTH RESPONCE 
2 
0.1 
Low non saline 
No injury to plants . 
2-4 
0.1-0.4 
Medium slightly 
saline. 
Very salt sensitive plants may 
be injured. 
cc 
1 
-cr 
0.4-0.75 
High moderately 
saline. 
Injurious to salt sensitive plants 
8 
0-75 
Excessive strongly 
Very injurious to many plants of 
any age only salt tone cant crops 
can grow. 
2. \vith regard to soils fertility in 
almost all of the soil profile sites samp 
led and analysed, the soils have a defici 
ency of sodium, potasium, calcium and ma 
gnesium. It is therefore necessary to 
raise the levels of the macronutrients by 
the application of fertilizers. From the 
soils analytical data, also the soils have 
reasonable amounts of available phosphorus, 
nitrogen and organic matter. 
3. The soils in the study area range from 
deep sand, excessively drained, (northwest 
part of the farm) to sandy clay loams (in 
the middle part of the farm). They were 
classified as canbic Arenosols, utric 
gleysols (mapping unit c). The Alluvial 
flood plain consists of deep poorly drai 
ned heavy clay soils. They were classified 
as Eutric Fluvisols, Utricgleysols and 
pellic Vertisols (mapping Unit A). 
REFERENCES 
CIDA, 1979. Coast Dar es Salaam Regions 
Water Master Plan Report Vol. B. Land 
Resource s. 
Goosen D, 1967. Aerial photointerpretation 
in soil survey SOIL Bui. 6 FAO Rome. 
Nyle C. Brady 1968. The Nature and 
Properties of soils. 
4. CONCLUSION 
1. 
From the analyti 
cal re 
sul 
t s 
, it can 
be con 
eluded tha 
t the 
f e r t i 1 
ity 
0 
f the 
soil i 
s 1 ok e s p e 
cially 
in th 
e c 
oa 
stal 
plain 
area. How r 
ever , 
d e pe nd 
ing 
u 
pon the 
crops 
to be plan 
ted t h 
e alluvia 
1 
plain 
area n 
eeds littl 
e fort 
ilizat 
ion 
• 
2. 
Due to the 
fine 
textur 
e 0 
f 
the soils 
in the 
alluvial 
flood 
plain, 
wa 
te 
r does 
not dr 
ain easily 
. Ser 
ious d 
ama 
ge 
may be 
caused 
to heavy 
soils 
by plo 
rgh 
in 
g when 
soil s 
are too w r e 
t. Th 
is c au 
ses 
i 
mpemeable 
pans , 
compac tion 
and s 
mearin 
g « 
ff 
ect of the 
soils. 
Therefor 
e i t i 
s reco 
mmend 
ed that 
proper 
farming methods 
, use 
of 
th 
e required 
f armin 
g machines 
and i 
mpleme 
nt s 
shotild be 
ad opte 
d in order 
to pr 
e serve 
go 
od 
soil 
struc t 
ure . 
( 
3. 
Soil manag 
ement 
practi 
ces 
«. g . 
instal 
lation of 
an und 
ergrou 
nd 
ti 
le d r a- 
inage system) aimed at improving the 
soils drainage would be necessary. 
4. Fairly accurate and economical soil 
surveys for agricultural development 
planning can be achieved by using aerial 
photographs. Tanzania has good aerial 
photography coverage lor natural resources 
inventories and exploitation. Therefore 
it is recommended that aerial photo inter 
pretation should be user! as a tool in soil 
surveys. 
enforced. 
It has to be emphasized and