1Which household material can make up a shortage of phosphorus in the soil?
2A maize plant has grown thin, with yellowing leaves. Which nutrient is its soil short of?
3What kind of leaf signals that the soil under a plant is short of potassium?
4Of potassium chloride, sodium chloride, DDT, aldrin, dialdrin and methoxy chloride, which are insecticides?
5Differentiate between chemical fertiliser and organic manure.
6Differentiate between chemical insecticides and bio-insecticides.
7The use of organic manure is friendly to the environment. Give the reason.
8The use of DDT powder brings imbalance to the ecosystem. Give the reason.
9What is NPK fertiliser? Write its importance.
10Write two examples each of fertilisers containing nitrogen, phosphorus and potassium.
11Two pots were sown with the same kind of seed, yet the plants of one pot are thick and tall while the other pot's are short and thin. Suggest the cause and ways to solve the problem.
12A farmer cannot decide whether to use chemical fertiliser to raise production. What suggestions would you give?
13What can be the alternative for a farmer who does not want to use chemical fertiliser? State the advantages of that manure.
14What is a chemical insecticide? Write two examples.
15What is a bio-insecticide? Write two examples.
16'The use of chemical insecticides should be replaced by the use of bio-insecticides.' Justify this statement with two reasons.
17Write the importance of using chemical fertilisers and insecticides.
18Commercial vegetable farming overuses chemical fertilisers and insecticides, harming human health. Write two slogans to spread awareness about this.
19Write two effects of the excessive use of chemical insecticides, with examples.
20Write two examples each of the alternatives to the chemical fertilisers and chemical insecticides used around you.
21Write any four precautions to be taken while using a chemical insecticide.
22What are the measures for conserving the quality of soil?
23Why should leaf litter never be burned on the field?