Wednesday 31 May 2017

Padi Huma Taragang (Week 4)

For the final week of this mini project, we decided to revert the watering amount to 500 ml with the same watering frequency. Below is the result for the fourth week. 

Soil Sample
Number of Seeds Sowed
Germination Rate (%)
Mortality Rate (%)
W1
W2
W3
W4
W1
W2
W3
W4

A (sandy loam)
50
53
82
82
82
0
0
0
0

B (silt loam)
70
60
84
88
88
0
0
0
0

C (sand)
50
80
90
90
90
0
0
0
0

D (clay loam)
70
57
70
70
70
0
0
8.2
22.9

E (loam)
50
62
92
93
93
0
0
0
0


The data above also showed that Plot C has the highest germination rate on the first week. This is very likely influenced by the type of soil Pot C has, which is sand. Sand is known to be composed of very large and coarse particles which results in good aeration and porosity. Thus, this enables the seeds to sprout efficiently because the roots are able to penetrate freely and deeply into the soil making the root growth not limited. Pot E which has loam soil shows the second highest of germination rate on the first week. Loam is made up of medium-size soil particles and it is also a type of soil which has the best porosity and decent aeration.
On the contrary, Pot D showed the lowest germination rate on the first week. This may be because the type of soil in Pot D is clay loam which meant the soil is dominant in clay. Clay-ey soils tend to stick together, especially when wet. Also, Clay loam has very fine particles that are heavy result in poor porosity and poor aeration. In short, the roots in Pot D have very limited growth and cannot penetrate in to soil easily, as well as lacking in oxygen.


Plants data at about 2 weeks old:
Soil Sample
 Average Length (cm)
Fresh Weight (g)
Dried Weight (cm)
Whole
Shoot part
Root Part
A (sandy loam)
40.83
32.97
7.86
2.60
0.69
B (silt loam)
37.08
31.07
6.01
2.12
0.49
C (sand)
23.87
18.52
5.35
1.45
0.33
D (clay loam)
23.90
19.43
4.47
1.37
0.36
E (loam)
35.84
28.48
7.36
2.55
0.62

Plants data at about 4 weeks old:
Soil Sample
 Average Length (cm)
Fresh Weight (g)
Dried Weight (cm)
Whole
Shoot part
Root Part
A (sandy loam)
41.62
36.65
4.97
3.68
1.67
B (silt loam)
37.15
32.04
5.11
3.60
1.55
C (sand)
24.07
19.15
4.92
1.87
0.76
D (clay loam)
30.80
27.38
3.42
2.40
0.61
E (loam)
38.30
33.95
4.35
3.50
1.49


Figure 1: Average height of plants and their growth rate

From the data above, plants in Pot B have the highest growth week, while the lowest is plants growing in Pot D. There are several environmental factors that affect plants growth rate. The most important ones are temperature, moisture supply, soil aeration and structure, biotic factors, supply of mineral nutrients, absence of growth – limiting substances, as well as radiant energy. Each factor is correlated to each other, and can be a limiting factor. 

Temperature is the measure of heat intensity either on the plant’s surroundings or in the soil. It can directly affect absorption of water and nutrients. Nitrifying bacteria are inhibited by low temperature which could decrease soil pH during hot weather due to activities of microorganisms.Also, plant growth is restricted by low and high levels of soil moisture. However, it can be regulated by improving drainage and irrigation. Like temperature, good moisture content in soil improves nutrient uptake by plants. Radiant energy is the quality, intensity, and duration of light exposure to the light or sunlight.

On the other hand, Compact soils of high bulk density and poor structure are aerated poorly. Pore space is occupied by air and water so the amount of air and water are inversely proportional to the amount of oxygen in the soil. On well drained soils, oxygen content is not likely to be limiting to plant growth. Biotic factors include diseases, the influence of root knot nematodes, presence and growth of weeds which would compete for moisture, nutrients and light. Supply of mineral nutrients include the availability of macronutrients and micronutrients in the soil for plants to use. Those elements that are needed for higher plants to complete all life functions, and that the deficiency can be corrected only by the application of the specific element causing the deficiency.

Comparison of plants progress from Week 1 to Week 4:

Pictures are arranged according to week.
Top Left to Right - Week 1, Week 2
Bottom Left to Right - Week 3, week 4

Notes: the decrease of seedlings number in the pictures is because we dug 20 plants from each soil - 10 for 2-week-old, and another 10 for 4-week-old.


Pot A


Pot B


Pot C


Pot D


Pot E



Deficiency Symptoms
There were several deficiency symptoms observed in Pot C and Pot D.

Pot C 
- leaves discolouration (turning pale green, almost light yellow)
- this type of deficiency is caused by shortage of sulphur supply.
- shortage of sulphur supply is rare, but are possible to occur when the pH is too high, or excessive amount of calcium in the soil.
- in this case, excessive amount of calcium in soil may be the cause. this is because based on the heavy metal analysis, soil sample C has the highest level of calcium in parts per million. 
- from the macronutrient analysis, soil sample in Pot C possesses the lowest amount of sulphur. 

Pot D
- growth is slow
- browning of leaves tips and margins.
- yellowing and browning of leaves are uniform, spreads from the tip.
- this type of deficiency is diagnosed as nitrogen deficiency.
- based on the macronutrient analysis, soil sample D has medium amount of nitrogen.
- also, soil sample in Pot D has the lowest pH which is 4.76. this could affect nutrient availability since most nutrients are taken up efficiently by the plants within the pH range of 5.5 - 8.5.

HEAVY METAL ANALYSIS

Table 1: ICP-MS result for soil sample A


Table 2: ICP-MS result for soil sample B


 Table 3: ICP-MS result for soil sample C
Sample ID
Element
Mean/Average(ppm)

Sample ID
Element
Mean/Average(ppm)
C1
Pb
0.004
C2
Pb
0.003
C1
As
0.025
C2
As
-0.006
C1
Cd
-0.001
C2
Cd
-0.001
C1
Ni
0.011
C2
Ni
0.002
C1
Cu
-0.052
C2
Cu
-0.040
C1
Mn
0.530
C2
Mn
0.285
C1
Fe
20.454
C2
Fe
9.018
C1
Zn
0.274
C2
Zn
0.078
C1
Mg
48.189
C2
Mg
26.561
C1
Ca
Saturated
C2
Ca
1320.218


Sample ID
Element
Mean/Average(ppm)

C3
Pb
0.011
     
C3
As
0.000
    
C3
Cd
-0.001
     
C3
Ni
-0.002

C3
Cu
-0.026

C3
Mn
0.145

C3
Fe
4.674

C3
Zn
0.054

C3
Mg
13.103

C3
Ca
730.298



  Table 4: ICP-MS result for soil sample D
Sample ID
Element
Mean/Average(ppm)

Sample ID
Element
Mean/Average(ppm)
D1
Pb
0.202
D2
Pb
0.169
D1
As
0.013
D2
As
0.014
D1
Cd
-0.002
D2
Cd
-0.002
D1
Ni
0.123
D2
Ni
0.106
D1
Cu
0.121
D2
Cu
0.101
D1
Mn
1.314
D2
Mn
1.135
D1
Fe
228.080
D2
Fe
208.107
D1
Zn
0.533
D2
Zn
0.432
D1
Mg
14.217
D2
Mg
11.331
D1
Ca
78.058
D2
Ca
9.081


Sample ID
Element
Mean/Average(ppm)

D3
Pb
0.073
     
D3
As
-0.010
     
D3
Cd
-0.001
     
D3
Ni
0.044

D3
Cu
0.038

D3
Mn
0.522

D3
Fe
100.045

D3
Zn
0.193

D3
Mg
4.534

D3
Ca
3.534



  Table 5: ICP-MS result for soil sample E
Sample ID
Element
Mean/Average(ppm)

Sample ID
Element
Mean/Average(ppm)
E1
Pb
0.291
E2
Pb
0.105
E1
As
0.019
E2
As
-0.001
E1
Cd
-0.001
E2
Cd
-0.001
E1
Ni
0.247
E2
Ni
0.098
E1
Cu
0.268
E2
Cu
0.098
E1
Mn
2.881
E2
Mn
1.192
E1
Fe
232.080
E2
Fe
83.698
E1
Zn
1.307
E2
Zn
0.577
E1
Mg
20.604
E2
Mg
7.948
E1
Ca
74.639
E2
Ca
36.578


Sample ID
Element
Mean/Average(ppm)

E3
Pb
0.095
    
E3
As
-0.005
    
E3
Cd
-0.001
   
E3
Ni
0.085

E3
Cu
0.084

E3
Mn
1.074

E3
Fe
73.634

E3
Zn
0.504

E3
Mg
7.082

E3
Ca
34.846


*Sample ID with 1 - diluted to 25 ml
*Sample ID with 2 - diluted to 50 ml
*Sample ID with 3 - diluted to 100 ml

Further discussion will be made in the full report.