3.6.4
Harvesting
Harvesting has been done in 90 days after sowing, i.e. after
plants have shown the sings of maturity (when the foliage has started to
dry).
3.7. Data Collection
3.7.1 .Soil sampling
Soil samples were collected in each plot after demarcation and
bulked to obtain the composite sample for each treatment plot. In each plot the
auger samples were taken from each of the four corners and centre of the plot
and these were bulked to form a composite sample. The soil sampling was
repeated after crop harvesting.
3.7.2. Crop growth characteristics.
For crop growth measurement, three crop stands were selected
per treatment plot and their height determined in cm at after 30 days; 60 days;
and 90 days of crop sowing.
For the cop yield evaluation, three rows of crops were
systematically selected and harvested per treatment plot. The length and middle
diameter of the carrot tubers from each harvested plots were measured and the
weight of tuber per plot taken using weighing balance.
3.7.3. Yield
measurements
From the weight of the sampled plants per plot, the weight of
crop yield per plot was determined using simple arithmetic proportion.
Thereafter, the yield of crop was expressed in tons/hectare.
3.7.4. Laboratory
analysis
The soils samples at before sowing and after crop harvesting
were separately analyzed for PH; total exchangeable acidity; extractible
phosphorus; organic carbon; total nitrogen; calcium and magnesium contents.
Both water and KCl PH were determined by potentiometer method
using a solution of water or KCl mixed with a soil at a proportion of 1/2.5.
The measurement of p H was done using an electrode made for
this purpose (I.I.TA, 1981).
Total exchangeable acidity was determined by
titratimetric dosing of H+ and Al3+ percolated at a
normal solution of potassium chloride. The two ions were titrated together
using Sodium Hydroxyl 0.01N (I.I.T.A, 1981).
Extractible phosphorus was determined by photo calorimetric
method of BRAY II. The development of blue color was done ammonium fluoride
0.03N and Hydrogen Chloride 0.01N while percentage of transmittance was
measured using spectrophotometer at wavelength of 712nm (I.I.TA,1981).
Organic carbon was determined by WAKLEY and BLACK method or
oxidation method by moist way(Pansu et al,2003) .This method is based on
oxidation of carbon by potassium dichromate(K2Cr 2O7) in
the presence o sulfuric acid. After decantation, the carbon in solution is
measured by photometric method at 600nm.
The organic matter is estimated by multiplying the organic
carbon obtained by VAN BEMMELEN factor of 1.724 (I.I.TA, 1981).
Total nitrogen was determined by Khijeldhal method. This
method consists of mineralizing nitrogen contained in soil sample by
concentrated sulfuric acid with green catalyst specifically ammonium sulfate
formed by distillation. It is transformed to ammonia by action of a base (NaOH)
by vaporizing boric acid 2%.The quantity of nitrogen was obtained by titrating
the solution with sulfuric acid (H2SO4/70).
Calcium and Magnesium were extracted using a normal solution
of Ammonium Acetate and EDTA, at a p H of 7. The quantity of elements present
(Ca and Mg) were obtained using a standard formula. The quantity of biomass
from each plot was weighed and a sample from each plot was taken. After drying
on air, the samples were analyzed for phosphorus content in the plant
biomass.
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