Padi Huma Taragang (Week 2)

Determining Soil Sample Texture by Textural Triangle 

Glass jars containing all five soil samples, (Photo taken a week after the experiment was first conducted)

Soil Sample	Sand Height, cm	Silt Height, cm	Clay Height, cm	Total Height, cm
A (Red)	2.4	0.9	0.3	3.6
B (Dark Blue)	1.4	2.5	0.5	4.4
C (Yellow)	3.4	0.0	0.0	3.4
D (Green)	1.8	1.4	1.3	4.5
E (Light Blue)	2.0	1.8	0.5	4.3

The calculations are as follow:

From the calculations above, it can be concluded that:

Soil Sample A                       Soil Sample B                       Soil Sample C

Sandy Loam                            Silt Loam                                Sand

Soil Sample D                       Soil Sample E

Clay Loam                               Loam

Nutrient Analysis

For the second week since the project was carried out, we performed a macronutrient analysis for all five soil samples. The macronutrients analysed were Nitrogen (N), Phosphorus (P), and Sulphur (S) which are found in the form of Nitrate (NO₃^-), Phosphate (PO₄^3-), and Sulphate (SO₄²⁻). This experiment is crucial for us to better understand the relationship between the paddy growth and the nutrient availability in each soil sample. Readings were taken three times and the average values were tabulated as follow:

Soil Sample	Nitrate (NO3-), mg/L	Phosphate (PO43-), mg/L	Sulphate (SO42−), mg/L
A (FSSA compound)	6.50	1.19	31
B (Eco Campus Garden)	1.90	0.91	70
C (Sepanggar)	1.70	0.33	9
D (Eco Campus Lake)	3.00	0.90	46
E (Telipok)	7.00	0.97	15

Macronutrients are essential nutrients needed by crops in great amount. Each nutrient has distinct functions in ensuring good plants growth. Nitrogen is necessary for plant cell division which is vital for plant growth. It is also directly involved in photosynthesis, and provides necessary component of vitamins. Phosphorus on the other hand, promotes early root formation and growth, as well as plant enlargement. It also increases water-use efficiency of crops. Meanwhile, Sulphur helps in the development of vitamins and enzymes. Also, it promotes nodule formation on legumes, and aids in seed production.

Water Holding Capacity

The water holding capacity of the soil is determined by the amount of water held in the soil sample divided by the dry weight of the sample. This can be shown in the following formulae:

Soil Sample	Weight of Wet Soil, (g)	Weight of Dry Soil, (g)	Water Loss, (g)	Percentage of Water Holding Capacity, %
A (FSSA compound)	500	390	110	28.21
B (Eco Campus Garden)	500	460	40	8..69
C (Sepanggar)	500	450	50	11.11
D (Eco Campus Lake)	500	190	310	163.16
E (Telipok)	500	290	210	72.41

From the table above, it can be concluded that soil sample D has the highest water holding capacity among them, whereas, soil sample B has the least capability of retaining water in its soil particles. This is influenced by the texture type of each of the soil sample. 

Week 2 Plants Observations (5th of May 2017)

Pot A

i. Watering amount: 500 ml 

ii. Germination rate: 82%

iii. Tallest plant's height: 26 cm

iv. Average plants' height: 24 cm

v. Deficiency symptoms: none

vi. Mortality rate: 0%

Pot B

i. Watering amount: 500 ml 

ii. Germination rate: 84%

iii. Tallest plant's height: 29 cm

iv. Average plants' height: 27 cm

v. Deficiency symptoms: none

vi. Mortality rate: 0%

Pot C

i. Watering amount: 500 ml 

ii. Germination rate: 90%

iii. Tallest plant's height: 17 cm

iv. Average plants' height: 15 cm

v. Deficiency symptoms: none

vi. Mortality rate: 0%

Pot D

i. Watering amount: 500 ml 

ii. Germination rate: 70%

iii. Tallest plant's height: 24 cm

iv. Average plants' height: 21 cm

v. Deficiency symptoms: Yellowing of leaves

vi. Mortality rate: 0%

Pot E

i. Watering amount: 500 ml 

ii. Germination rate: 92%

iii. Tallest plant's height: 25 cm

iv. Average plants' height: 24 cm

v. Deficiency symptoms: Yellowing of leaves

vi. Mortality rate: 0%

Discussion based on Week 2 Observations

Both pot D and E are showing deficiency symptoms, especially pot D which showed the most yellowed leaves. This scenario is most probably because of moisture stress. These two soil samples also have the highest water holding capacity. Since, the texture types of the two soil samples also suggested that they have moderate to poor drainage, hence, the yellowing of leaves is most likely due to over watering. 

In order to determine whether over watering is the main cause of this problem, we decided to reduce the watering amount of every pot to 250 ml per session for the third week. Pots will be watered at the same frequency, twice a day (in the morning and in the afternoon) for every weekday.