(a) Classify soil samples G, H and I provided into neutral, acid, and alkaline soil
(b) Outline briefly the procedure used in classifying the soil samples.
(c)(i) At what PH range is a soil said to be acidic?
(ii) State three adverse effects of soil acidity on soil reaction and plant growth.
(d) Mention one crop that does well in each of the soil types G, H, and I
Explanation
(a) Classification of soil samples:
- G - neutral soil;
- H - acid soil;
- I - alkaline l basic soil.
(b) Procedure used in classifying the soils:
- Add some water to the soil sample and test with litmus papers.
- Sample G - no change in colour of litmus paper;
- H - blue litmus paper turned or changed to red- Acidic:
- F - red litmus paper turned or change to blue Alkaline
(c)(i) A soil is said to be acidic at pH range of below 7 or 1- 6.9
(ii) Adverse effects of soil acidity are;
- The presence of hydrogen ions may have adverse effects on the roots of plants, hinder the absorption of mineral ions, reduce microbial population and cause certain nutrients to be present in toxic levels, e.g. manganese, iron.
- It also causes nutrient deficiency, especially calcium, phosphorus, and nitrogen.
- It depresses nitrification because of its adverse effect on soil microbes. Low pH reduces the activities of soil micro-organisms.
- Humus can be easily leached out of the soil and this results in lower rate decomposition of organic matter due to its adverse effect on soil microbes
(d) Crops that do well in each of the soil types are:
- G - neutral - cassava - yam
- H - acidic - oil palm - swamp rice, sugar cane, maize, rubber, cocoa, Banana / plantains.
- I - alkaline, millet, sorghum, coconut.