Peanut Plant (Week 3)

Peanut (Week 3)

Plants' progress:

This week, we have reduced the day watered the plant. All pots are watered twice day a week. The amount of watering the plant is 500 ml.

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	171.83	118.25	53.58	45.31
B	175.80	156.97	18.83	12.00
C	190.88	173.80	17.08	9.83
D	172.81	91.86	80.95	88.12
E	173.35	148.67	24.68	16.60

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

Nutrient Analysis

For the third week since the project was carried out, we conducted a macronutrient analysis for all five soil samples. The macronutrients analysis was Nitrogen (N), Phosphorus (P), and Sulphur (S) which are found in the form of Nitrate (NO₃^-), Phosphate (PO₄^3-), and Sulphate (SO₄²⁻). Readings were taken three times and the average values were tabulated as follow:

Soil Sample	Macronutrients			Overall soil nutrients availability
	Nitrate (NO3-), mg/L	Phosphate (PO43-), mg/L	Sulphate (SO42−), mg/L
A	1.93	1.00	117.33(over)	Excessive in sulphate
B	4.40	5.29(over)	86.30(over)	Excessive in phosphate and sulphate
C	1.03	0.89	28.67	Normal concentration for all nutrients
D	1.47	0.68	93.00(over)	Excessive in sulphate
E	4.47	0.57	94.00(over)	Excessive in sulphate

Plant Length

In order to measure the degree of growth of plant, 3 plants are chosen randomly from each pot. Their root length, shoot length, and overall length are measured and recorded. The fresh weight and dried weight (dry for a week) are measured and recorded. The results obtained are shown in a table below. The same method will be carried out again after the plants are about a month old. The reading differences will determine the growth rate of plants from each pot.

Data for plants of about 2 weeks old:

Soil Sample	Average Length (cm)			Fresh Weight (g)	Dried Weight (g)	Nodules
	Root	Shoot	Whole
A	-	-	-	-	-	-
B	7.83	25.57	33.37	2.97	0.87	-
C	6.63	23.17	29.80	2.35	0.61	-
D	5.00	21.40	26.40	3.63	0.66	-
E	6.45	30.10	36.55	1.11	0.43	-

Week 3 Plants Observations (11th of May 2017)

Pot A

1. Watering amount: 500 ml 
2. Germination rate: 0
3. Average plants' height: 0
4. Deficiency symptoms: none
5. Mortality rate: 0%

Pot B

1. Watering amount: 500 ml
2. Germination rate: 50%
3. Average plants' height:  18.76 cm
4. Deficiency symptoms: White on leaves
5. Mortality rate: 0%

Pot C

1. Watering amount: 500 ml 
2. Germination rate: 80%
3. Average plants' height: 15.23 cm
4. Deficiency symptoms: yellowing on leaves
5. Mortality rate: 0%

Pot D

1. Watering amount: 500 ml
2. Germination rate: 50%
3. Average plants' height: 17.58 cm
4. Deficiency symptoms: white on leaves
5. Mortality rate: 0%

Pot E

1. Watering amount: 500 ml 
2. Germination rate: 90%
3. Average plants' height: 25.33 cm
4. Deficiency symptoms: white on leaves
5. Mortality rate: 0%

Pot B, C, D and E are showing deficiency symptoms, especially pot C which showed the most yellowed leaves. This scenario is most probably because of moisture stress. There is a limited amount of the peanut plant space in each pot. This soil sample also have the highest pH which causing a condition called chlorosis.

  Discussions 

(1)    How does the amount of macro nutrients in the current soil use for growing peanut affect their growth?

Macronutrients are essential nutrients needed by crops in great amount. Each nutrient has distinct functions in ensuring good plants growth. Nitrate aids in the making of amino acids, which are the building blocks of proteins. It is important for making new cells and tissues. It is also directly involved in photosynthesis, and provides necessary component of vitamins. Deficiency in nitrate will results in plants’ stunted growth and thus it help in plant growth and development of peanut growth. Phosphorus is a main component of the complex nucleic acid structure of plants, which regulates the synthesis of protein. Therefore, it is important in cell division and the development of new tissues. Phosphorus is also involved in the complex energy transformation process in the plants. 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. Potassium is available to plants as K ion. Presence of K is vital for peanut growth because K is an enzyme activator that promotes metabolism. In process photosynthesis, K will maintain the balance of electrical charges at site of metabolism and at site of ATP production. K also will promote the translocation of photosynthesis for peanut growth or storage in roots. Another macronutrient which is affects the peanut plant growth is sulphur, which is available in plants as sulphate ion. Sulphate ion is essential in forming protein of peanut because it is constituent of certain amino acids. S aids in seed production, chlorophyll formation and stabilizing protein structure in development of growth in peanut plant.

(2)    How does water content of each soil affects peanut growth.

Based on the result of percentage water holding capacity, soil sample D has the highest percentage of water holding capacity among all soil samples while soil sample C has the least capability to store water. The soil texture for soil sample D is loamy sand while soil texture for soil sample C is sandy. This is because soils with smaller particles such as silt and clay have a larger surface area than those with larger sand particles, and a large surface area allows a soil to hold more water. In other words, a soil with a high percentage of silt and clay particles, which describes fine soil, has higher water content on it. Therefore, it will help to increase on the growth of peanut. 

(3)    How does different soil texture affects the peanut growth.

Based on the soil texture result, soil sample A, B, D and E are loamy sand while soil sample C is sand. The pH value of soil sample A, B, D and E are slightly acidic while the pH value for soil sample C is almost neutral. Loamy soil is generally contain more nutrients, moisture and humus than sandy soil, have better drainage and infiltration of water and air than silty soil. Therefore, it can store better water content than soil sample C. Apart from that, loamy soil also feature good aeration levels. It is suitable for farming activity. Sandy soils are often dry, nutrient deficient and fast-draining. They have little ability to transport water from deeper layers through capillary transport. Therefore, different soil textures have different water holding capacity where they can store nutrients as well.

(1)    How does soil texture effect peanut root growth.

Soil textures which refers to the properties of sand, slit and clay. Sand is the largest particles, slit is much smaller and clay is the smallest. The soil particle’s ability reacts with water and nutrient is related to the surface area of soil particles. In pot A, the plant does not growth up. Pot A which is clay has higher water-holding capacity and nutrient-holding capacity. Because of it is too high of water capacity, the soil is more moisture and it affects the growth of peanut. In pot B, pot C, pot D and pot E, the peanut is growth because the water-holding is suitable to the plant.