Full Length
Research Paper
Soil
Micronutrient Variations in Paddy Fields of Honnali Taluk, Davanagere District, Karnataka
Somalingappa
B Palled[1]
and Prashanth Kumar. C.S
1-Department of
Botany, KSS College, Vidyanagar Masari,
Gadag, Karnataka, India.
2-Department of
Botany and Seed Technology, Sahyadri Science College,
Shivamogga, India
ARTICLE
DETAILS ABSTRACT
- Introduction
Indian
economy is agriculture. Supply of food is the major concern due to increasing
population and low per capita income. To fulfill the food need of the
population more and more efforts are put in to increase the productivity.
Maximum land is brought under agriculture, improved irrigation systems are
being developed and use of chemical fertilizer sand pesticides
is a common practice. It is being observed that over use of these chemicals
reduce the soil fertility and productivity. There are many ways to resolve soil
fertility problems and improve soil fertility. Use of Blue Green Algae (BGA) is
a common practice. The agricultural importance of BGA in rice cultivation is
directly related with their ability to fix Nitrogen and other positive effects for
plants and soil (Saadatnia and Riahi, 2009). BGA are known to
induce early germination and production of healthy plantlets. It was also
observed that the presence of BGA is soil increases the total organic carbon
and facilitated microbial growth in the rhizosphere
area that supports better plant growth (Rao and
Burns, 1990). Blue-green algae (BGA) are photosynthetic prokaryotic
microorganisms some of which are capable of nitrogen fixation. Such trophic
independence with regard to nitrogen and carbon, together with a great
adaptability to variations of environmental factors enables BGA to be
ubiquitous (Fogg et
al 1973). The paddy field ecosystem provides an environment favorable for
the growth of BGA with respect to their requirements for light, water, high
temperature and nutrient availability. This may account for the higher abundance of BGA in paddy soils compared to
other cultivated soils. The agricultural importance of BGA in rice cultivation
is directly related with the ability of certain forms to fix nitrogen.
- Materials
and Methods
For the investigation
of variation in micro-nutrients and other physico-chemical properties of soil
in Honnali Taluk 120 soil
samples were collected across the different villages. Soil sampling for all sites
was carried out according to a standard protocol. Soil samples were analyzed for
micro- nutrients and
various physico-chemical properties of soil samples using standard
procedures. The pH of the soil samples was determined following Jackson(1973). The oven dried soil sample weighing 12.5g was suspended in 25 ml of distilled water
and stirred continuously. The pH was measured using calibrated pH meter. It was
determined in soil water suspension using digital conductivity meter as
described by Jackson, 1973.The Organic carbon estimated by using the Walkley-Black (1934) Rapid Titration method i.e. wet combustion method.
DTPA offers
the most favorable combination of stability constants for the simultaneous
complexing of Zn, Cu, Fe and Mn (Lindsay and Norvell, 1978).And Determination of these micronutrients in
soil samples done using Atomic Absorption Spectrophotometer method. The Boran was analyzed by Azomethan H
Method (John et al.,1975).
- Results and
Discussion
Table1. Variation in micronutrient
sin soils of different villages of Honnali Taluk
|
Villages of Honnali Taluk |
pH |
Electrical conductivity (d
Sm-1) |
Organic carbon (%) |
Zinc (ppm) |
Copper (ppm) |
Iron (ppm) |
Mn (ppm) |
Boran (ppm) |
|
Ujjainipura |
5.37 |
0.231 |
0.23 |
1.205 |
0.546 |
30.13 |
12.55 |
0.933 |
|
Chikkabasur |
6.18 |
0.253 |
0.25 |
1.787 |
0.469 |
42.05 |
12.86 |
1.119 |
|
Beeragondanahalli |
7.28 |
0.140 |
0.14 |
0.887 |
0.357 |
13.29 |
5.37 |
0.749 |
|
Sadashivapura |
6.58 |
0.266 |
0.27 |
1.441 |
0.389 |
16.02 |
10.91 |
0.766 |
|
Hotyapura |
7.22 |
0.160 |
0.16 |
1.015 |
0.307 |
15.66 |
4.16 |
0.762 |
|
Rampura |
6.39 |
0.209 |
0.21 |
1.311 |
0.331 |
40.02 |
9.73 |
1.220 |
|
Benakanahalli |
5.91 |
0.278 |
0.28 |
1.908 |
0.397 |
33.52 |
13.75 |
1.419 |
|
Kambaraghatte |
5.65 |
0.317 |
0.32 |
1.541 |
0.523 |
51.92 |
14.07 |
1.435 |
Fig.1 Iron and Manganese variation different
villages of Honnali Taluk
Fig.2 Zinc, copper and Boron variation
different villages of Honnali Taluk
Fig.3 Soil reaction variation in different villages of Honnali Taluk
Fig. 4 Electrical conductivity (dSm-1) variation different villages of Honnali Taluk
Fig.5
Organic carbon variation different villages of Honnali Taluk
Fe
concentration in soil was attributed to accumulation of Fe and Al through laterization process under high rainfall region. Significant results were observed
through the study with respect to the micro- nutrient and soil properties and
data were presented in Table 1 and Fig. 1,2,3,4 & 5. Status of micro-nutrient
in Ujjainipra soil sample varied significantly, the
available Zinc content ranges from 0.68 to 3.10ppm with a mean of 1.2 ppm which
is high in range. The available Fe content recorded maximum of 70ppm with a
mean of 30.13 ppm followed by Mn (12.55 ppm), boron
(0.93 ppm) and copper (0.55 ppm). The concentration of Manganese ranges from 7.26 ppm to 16.69 ppm, whereas low
concentration of copper recorded among micro-nutrients which range from 021 ppm
to 0.78 ppm. It is interesting to note that concentration of boron is higher in
soils and ranges from 0.42ppm to 1.92 ppm which is considered as higher in
range. The higher levels of Zinc and boron in soils maybe due to application of
Zinc sulphate and boron to rice field where more adsorption of boron on surfaces
of Fe and Al oxides. The higher
available micro-nutrient (DTPA Extractable) status of high in the soils
of Chikkabasur. However, among the
micronutrients concentration of Fe and Mn recorded
maximum (42.05ppm &12.86ppm) followed by Zinc (1.79ppm), Boron (1.12ppm)
and Copper (0.47ppm). It clearly indicates that as the organic carbon contents
high the availability of micronutrient in soil increased in the soil
irrespective of soil pH. However there is no
correlation found between soil pH with available micronutrients in soil. The
DTPA Extractable micro-nutrients like Cu(0.21-0.69ppm),Mn(1.10-14.30 ppm), Zinc(0.39-1.72 ppm) and
Boron(0.34-1.02ppm) are medium in range except Fe(5.18-28.18ppm) which recorded
high in range. From the data of soil samples of Beeragondanahalli
revealed that Organic carbon positively correlated with Nitrogen, Zinc Iron and
Manganese. Availability of DTPA extractable Zinc (0.28-1.94ppm),Cu(0.13-0.62ppm), Mn (0.5-15.5ppm) and Boron (0.14-1.61 ppm) are medium in
range except Fe which recorded higher in concentration (6.48-37.44 ppm) with
mean of 15.66 ppm in soil samples of Hotyapura. The
higher concentration of Fe is due to parent material rich in Iron from which
soils formed are red sandy loam soils.
The DTPA
extractable Zinc, Cu, Mn and Boron ranges from medium
to high in samples of Benakanahalli. However the
available Iron and Manganese concentration recorded
higher in range with mean of33.52 ppm and 13.75 ppm respectively. Availability of Zinc Cu and
Boron with mean values of 1.91 ppm, 0.40 ppm, 1.42 ppm respectively. As
regard to micro-nutrients of Kambaraghatte soil
samples is concern the DTPA extractable Zn,Cu
Fe, Mn and Boron recorded higher concentrations.
However among the micro-nutrients mean value of Iron and manganese recorded
higher concentration (51.92&14.07ppm) followed by Zinc, boron and copper
(1.54 ppm,1.43 ppm & 0.52 ppm).
The
concentration of DTPA extractable Zinc, Iron, Manganese, Copper and Boron
content is high in Sadashivapura soil. However among
the micro-nutrients concentration of Fe and Mn
recorded higher concentration than other. The DTPA extractable Fe recorded
higher concentration and ranges from 10.36 to 74.30 ppm with mean of 40.02 ppm followed by Manganese
which recorded 4.90 to 16.38 ppm with mean of 9.73
ppm in Rampura soil. The concentration of Boron and
Zinc recorded medium in range with mean of 1.31 and 1.22 ppm. The lowest
concentration of Copper recorded in range of 0.1 to 0.75 ppm with mean of 0.33 ppm.
- Conclusion
Micronutrient refers to
the relative quantity of a nutrient that is required for plant growth. It takes
part in metabolic activities, enzymatic process/catalysts etc. Thus these all
directly and indirectly help in plant growth and development. There are 8
essential plant nutrient elements defined as micronutrients like boron (B),
zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), molybdenum
(Mo), chlorine (Cl) and silicon (Si). They constitute
in total less than 1% of the dry weight of most plants. Organic sources like
farm yard manure, compost, vermicompost etc. Micronutrients
for different soils and the effect of manipulating the soil physical
environment and its moisture regimes on plant available micronutrients need to
be generated. Continuous use of farmyard manure or of other organic sources
arrests the depletion of available micronutrient pools from soils. Development
of integrated micronutrient technology using available organic materials is needed
not only to increase micronutrient use efficiency but also to decrease the
pressure on the use of costly inorganic micronutrient carriers. Field
experiments have proved the superiority of zinc sulfate as a zinc carrier.
Increasing costs coupled with a shortfall in supply of zinc sulfate have necessitated
investigations on evaluating sparingly soluble zinc sources or ores combined
with zinc mobilizers. The residual availability of various sources of
micronutrients for a cropping system needs to be worked out.
- References
Jackson,M.L.,1973,Soil
Chemical Analysis, Prentice Hall of India Pvt. Ltd., New Delhi, p. 38-56.
John, M.K., Chuah, H.H. and Neufeld, J.H. (1975) Application of
Improved Azomethine-H Method to the Determination of
Boron in Soils and Plants.AnalyticalLetters,8,559-568.
Lindsay, W.L.
and Norvell, W.A. (1978) Development of a Dtpa Soil Test for Zinc, Iron, Manganese, and Copper. Soil
Science Society of America Journal, 42, 421-428.
Pandey, S. N. and Tripathi, A. K., 1988, Distribution of nutrient in Chilka lake, East Coast of India. Indian J. Marine. Sci., 18(4): 286-288.
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Burns, R.G., 1990, “The effect of surface growth of blue- green algae and
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