1. Summer Internship Project on: “Development of Climate
Adaptive agro-technologies for sustainable Wheat and
Corn production in eastern India”
The Potential Impact of Climate Change/Soils as a Part of the
Global C and N Cycles:
Soils are intricately linked to the atmospheric/climate system through the
carbon, nitrogen, and hydrologic cycles. Because of this, altered climate will
have an effect on soil processes and properties. Recent studies indicate at least
some soils may become net sources of atmospheric C, lowering soil organic
matter levels. Soil erosion by wind and water is also likely to increase.
Soils are integral parts of several global nutrient cycles. The two that are the
most important from the perspective of soils and climate change interactions
are the carbon and nitrogen cycles because C and N are important components
of soil organic matter and because carbon dioxide (CO2), methane (CH4), and
nitrous oxide (N2O) are the most important of the long-lived greenhouse gases.
The burning of fossil fuels, tilling of soil, and other human activities have altered
the natural balance such that we are now releasing more C and N into the
atmosphere each year than is taken up by global sinks. Human management of
soils can have a profound impact on the balance of C and N gas emissions from
those soils, and therefore influences global climate change.
Well-aerated soils are dominated by CO2 emissions, while anaerobic conditions
are associated with CH4 generation. The balance between C added to the soil
and C emitted from the soil determines whether the overall C levels in a given
soil increase or decrease. When C levels in a soil increase that C is taken from
the atmosphere, decreasing atmospheric levels, and when C levels in a soil
decrease that C is added to the atmosphere, increasing atmospheric levels.

2. Potassium for crop production: Potassium (K)
is an essential nutrient for plant growth. Because large amounts are absorbed
from the root zone in the production of most agronomic crops, it is classified as
a macronutrient. Minnesota soils can supply some K for crop production, but
when the supply from the soil is not adequate, K must be supplied in a fertilizer
program. This publication provides information important to the basic
understanding of K nutrition of plants, its reaction in soils, its function in plants,
and its role in efficient crop production.
Role in plant growth
The exact function of K in plant growth has not been clearly defined. Potassium
is associated with movement of water, nutrients, and carbohydrates in plant
tissue. If K is deficient or not supplied in adequate amounts, growth is stunted
and yields are reduced. Various research efforts have shown that potassium
 stimulates early growth,
 increases protein production,
 improves the efficiency of water use,
 is vital for stand persistence, longevity, and winter hardiness of alfalfa, and
 Improves resistance to diseases and insects.
Potassium uptake
Potassium uptake by plants is affected by several factors.
Soil Moisture: Higher soil moisture usually means greater availability of K.
Increasing soil moisture increases movement of K to plant roots and enhances
availability. Research has generally shown more responses to K fertilization in
dry years.
Soil Aeration and Oxygen Level: Air is necessary for root respiration and K
uptake. Root activity and subsequent K uptake decrease as soil moisture
content increases to saturation. Levels of oxygen are very low in saturated soils.

3. Soil Temperature: Root activity, plant functions, and physiological processes all
increase as soil temperature increases. This increase in physiological activity
leads to increased K uptake. Optimum soil temperature for uptake is 60-80°F.
Potassium uptake is reduced at low soil temperatures.
Tillage System: Availability of soil K is reduced in no-till and ridge-till planting
systems. The exact cause of this reduction is not known. Results of research
point to restrictions in root growth combined with a restricted distribution of
roots in the soil.
Potassium in soils
The total K content of soils frequently exceeds 20,000 ppm (parts per million).
Nearly all of this is in the structural component of soil minerals and is not
available for plant growth. Because of large differences in soil parent materials
and the effect of weathering of these materials in the United States, the amount
of K supplied by soils varies.
Three forms of K (unavailable, slowly available or fixed, readily available or
exchangeable) exist in soils. A description of these forms and their relationship
to each other is provided in the paragraphs that follow.
Unavailable Potassium: Depending on soil type, approximately 90-98%
of total soil K is found in this form. Feldspars and micas are minerals that
contain most of the K. Plants cannot use the K in this crystalline-insoluble form.
Over long periods of time, these minerals weather (break down) and K is
released. This process, however, is too slow to supply the full K needs of field
crops. As these minerals weather, some K moves to the slowly available pool.
Slowly Available Potassium: This form of K is thought to be trapped
between layers of clay minerals and is frequently referred to as being fixed.
Growing plants cannot use much of the slowly available K during a single
growing season. This slowly available K is not measured by the routine soil
testing procedures. Slowly available K can also serve as a reservoir for readily
available K. While some slowly available K can be released for plant use during a
growing season, some of the readily available K can also be fixed between clay
layers and thus converted into slowly available K.
Readily Available Potassium: Potassium that is dissolved in soil water
(water soluble) plus that held on the exchange sites on clay particles
(exchangeable K) is considered readily available for plant growth. The exchange

4. sites are found on the surface of clay particles. This is the form of K measured by
the routine soil testing procedure.
Plants readily absorb the K dissolved in the soil water. As soon as the K
concentration in soil water drops, more is released into this solution from the K
attached to the clay minerals. The K attached to the exchange sites on the clay
minerals is more readily available for plant growth than the K trapped between
the layers of the clay minerals.
The K status of soils can be monitored with either plant analysis or
routine soil testing procedures. Plant analysis can be used to either
confirm a suspected deficiency indicated by visual symptoms or
routinely monitor the effects of a chosen fertilizer program. An
interpretation for K levels in plant tissue is provided in Table 1:
Available K in soils is estimated by measuring the total of
solution K (water = soluble K) and exchangeable K. The
definitions for the relative levels of soil test K are
summarized in Table 2.

5. Photoelectric flame photometer:
A photoelectric flame photometer is a device used in inorganic
chemical analysis to determine the concentration of certain metal ions, among
them sodium, potassium, lithium, and calcium. Group 1 and Group 2 metals are
quite sensitive to Flame Photometry due to their low excitation energies.
Analysis of samples by Flame photometer
In principle, it is a controlled flame test with the intensity of the flame colour
quantified by photoelectric circuitry. The intensity of the colour will depend on
the energy that had been absorbed by the atoms that was sufficient to vaporise
them. The sample is introduced to the flame at a constant rate. Filters select
which colours the photometer detects and exclude the influence of other ions.
Before use, the device requires calibration with a series of standard solutions of
the ion to be tested.
Working Principle: The basis of flame photometric working is that, the
species of alkali metals (Group 1) and alkaline earth metals (Group II) metals are
dissociated due to the thermal energy provided by the flame source. Due to this
thermal excitation, some of the atoms are excited to a higher energy level
where they are not stable. The absorbance of light due to the electrons
excitation can be measured by using the direct absorption techniques. The
subsequent loss of energy will result in the movement of excited atoms to the
low energy ground state with emission of some radiations, which can be
visualized in the visible region of the spectrum. The absorbance of light due to
the electrons excitation can be measured by using the direct absorption
techniques while the emitting radiation intensity is measured using the emission
techniques. The wavelength of emitted light is specific for specific elements.

6. Parts of a flame photometer
1. Source of flame:
A burner that provides flame and can be maintained in a constant form and
at a constant temperature.
2. Nebuliser and mixing chamber:
Helps to transport the homogeneous solution of the substance into the
flame at a steady rate.
3. Optical system (optical filter):
The optical system comprises three parts: convex mirror, lens and filter. The
convex mirror helps to transmit light emitted from the atoms and focus the
emissions to the lens. The convex lens help to focus the light on a point called
slit. The reflections from the mirror pass through the slit and reach the filters.
This will isolate the wavelength to be measured from that of any other
extraneous emissions. Hence it acts as interference type colour filters.
4. Photo detector:
Detect the emitted light and measure the intensity of radiation emitted by
the flame. That is, the emitted radiation is converted to an electrical signal
with the help of photo detector. The produced electrical signals are directly
proportional to the intensity of light.

7. Procedure:
Weigh 5g of soil samples and is taken in a conical flask.
The conical flask is marked as per the soil type contained by it.
25ml of ammonium acetate is added and is added and is placed on a shaker.
We then filter the mixture using filter paper. The filtrate is then used for
analyzing the amount of potassium present in the soil samples by using flame
photometer.
Summary
Potassium is an essential major nutrient for crop production in Minnesota. The
supply of total K in soils is quite large. Yet, relatively small amounts are available
for plant growth at any one time. The three forms of K (unavailable, slowly
available, and readily available) exist in an equilibrium in the soil system.
The need for potash in a fertilizer program can be determined from plant
analysis and soil testing. Soil testing is the most reliable predictor of this need.
OTC – Open Top Chamber
OBJECTIVE
The purpose of Open Top Chamber (OTCs) is to study response of plants in high
CO2 and other gas in environment with precise control and regulation of desired
CO2, Temp and humidity inside the OTCs. Open Top Chambers (OTCs) is an
innovative and cost effective approach to investigate effects of elevated CO2,
Temperature and Humidity on the growth dynamics and yield response of plants.
In this approach, CO2 gas is supplied to the chambers through CO2 gas cylinders
and maintained at set levels using manifold gas regulators, pressure pipelines,
solenoid valves, sampler, pump, CO2 analyser, PC linked supervisory control and
data acquisition (SCADA). The data generated by OTCs are more realistic for
impact assessment analysis of rising atmospheric CO2 and temperature on
plants for developing models to predict the responses for future climatic
conditions. The accuracy of the results depends on the system adopted and its

8. maintenance of the required CO2 levels with near natural and variable
conditions for other parameters
STRUCTURAL DESIGN OF A TYPICAL OPEN TOP CHAMBER (OTC)
Open Top Chambers for elevated CO2 study are built with high quality multi
layered Polycarbonate sheets (4mm thickness) of 3X3X4mt. dimensions with
GI/MS structure with proper foundation and grouting. A suitable door of 6ft X3
ft. size is provided in each chamber. Multiwall clear polycarbonate sheet with 80-
85% light transmission level is used for OTC structure. Flat and angle aluminium
and rust free screws are used for mounting of polycarbonate sheet. Welding at
four corners and inclination of 30° at top is provided to protect against high winds
and moderate vibrations. Sealing of OTC is achieved using aluminium angles,
plates at the top, corners and centre along with gaskets. Door is sealed using “U”
type gaskets with overlapping of sheets to prevent loss of CO2.

9. Treatments:
Factor1: Environmental variation.
1) Open field
2) Ambient OTC, CO2 (380ppm)
3) Elevated OTC, CO2 (585ppm).
Factor2: Cultivation method
1) Direct seeded
2) Puddled transplanted
Factor3: Nitrogen management
1) CF100
2) CF150
3) CF75+ OF75
4) RTNM
Report Submitted by:
Meghna C.Dixit,
KIIT University.
Guided By:
Dr.D.K Swain,
Associate Professor,
Agricultural and Food Engineering Department
Indian Institute of TechnologyKharagpur.