1. Local Way Of Detecting Soil PH To Improve Agriculture7.
Local Way Of Detecting Soil PH To Improve Agriculture
Ihungo Secondary School
Redempotius Respicius and Baris Rajab
Abstract:
The aim of this experiment was to determine the local ways to detect soil PH. Soil PH is the acidity or alkalinity of the soil. In Tanzania, agriculture is taken as the backbone of economic development as more than eighty percent of citizens depend on subsistence farming. However, most of the farmers are lacking affordable simple techniques to detect the level of soil PH in addition to being un-aware of the influence of the soil choice in terms of PH on crop productivity. Using common local basic and acidic materials to identify PH using acid-base treatment with soils could help farmers understand the PH of their soils. By understanding the local ways of detecting the PH of the soil local small holder farmers specifically in the villages could practice proper soil choice for respective crops to increase productivity.
Method:
Material required
The following materials were used in this project: about 500g soil samples A,B, C and D, knife, local mortar and pestle, 10 lemons and 1000g of woods.
Method
Preparation of soil and reagents: soil samples A, B, C and D were prepared in beakers, of about 150 grams each. Lemons were cut transversely and a juice extracted using a traditional wooden mortar and pestle and a filter. This was labeled reagent 1. Then, woods were burnt to produce about 300g of ashes. Ashes dissolved in water and filtering gave a solution which was labeled reagent 2.
Detecting soil acidity: three spoons of each of the four soil samples were prepared from four different locations including Kasulu Kigoma (Sample A ), Kigoma (Sample B), Missenyi Kagera (Sample C) and Bukoba Municipality (Sample D). 50cm3 of reagent 2 solution were added in each of the four soil samples in a beaker as shown in the figure aside:
Detecting soil alkalinity: three spoons of each of the four soil samples were prepared from four different locations. 50cm3 of the reagent 1 solution were added in each of the four soil samples in a beaker as shown in the figure
Confirmatory experiment: three spoons of each of the four soil samples were prepared from four different locations. 10cm3 of distilled water were added in each of the four soil samples followed by 3cm3 of universal indicator solution. Color changes were observed in each soil solution.
The end colors were compared against the appropriate range in the standard universal indicator chart shown.
Results:
Detecting acidity: after adding 50cm3 of the reagent 2 in soil samples A, B, C and D the following results were obtained:
Detecting alkalinity: after adding 50cm3 of the reagent 1 in soil samples A, B, C and D the following results were obtained
Confirmatory experiment: after adding 10cm3 of distilled water in each of the four soil samples followed by 3cm3 of universal indicator solution, the following results were obtained
It was found out from this research project that acidic and alkaline soils could be identified locally using lemon juice and ashes solution. The test is based on the evolution of carbon dioxide gas (CO2(g) ↑) in acid-base reaction manner. Un-ripened lemon juice contains acidic organic compounds, acetic acid (CH3COOH(aq)) in large quantities while ash contains inorganic bases, Calcium carbonate (CaCO3(aq)) in large quantities.
S/ N
Soil Sample
Reagent added
Observation
Results 1 A 2
Many bubbles formed
Acidity was detected B
No changes observed
No acidity detected 3 C 4 D
S/N
Soil Sample
Reagent
Observation
Results 1 A
No changes observed
No alkalinity detected 2 B
A few bubbles formed
Alkalinity was detected 3 C
Many bubbles formed which filled three quarter of the beaker 4 D
No changes was observed
S/ N
Sampl e
Observation
Matching with the indicator chart PH scale
Results 1 A
Orange color formed
Between 4 and 5
Weak acid 2 B
Blue color formed
Between 8 and 9
Weak alkali 3 C
Purple color formed
Between 12 and 13
Normal alkali 4 D
Green color formed
Around 7
Neutral
Conclusion:
Ash solution which contained base reacted with sample A which contained acid to form bubbles. Lemon solution which contained acid reacted with samples B and C which contained base to form bubbles. The bubbles formed in each case were due to evolution of carbon dioxide gas. The neutral soil sample solution D had no reaction.
The question of whether the soil is basic or acidic can be answered by a local farmer. The method used in this experiment has proved the use of ash and lemon solutions to be effective in the determination of the soil acidity and alkalinity, respectively