HardBiologyHigh School (9–10)GeneralBiology in Human Welfare › Improvement in Food ResourcesConceptual
Mahesh sprays a strong insecticide on his cabbage field every week and says this is the safest way…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Mahesh sprays a strong insecticide on his cabbage field every week and says this is the safest way to protect the crop. Give three problems with this, and suggest two ways to cut down the chemical.
Need a reminder? The key ideaShow
Weeds, insect pests and diseases lower the yield. Pesticides (herbicides, insecticides and fungicides) work but are poisonous. Safer methods are good field preparation, timely sowing, inter-cropping, crop rotation, resistant varieties and summer ploughing. Stored grain is lost to biotic and abiotic causes and is protected by cleaning, drying and fumigating.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Problems. The insecticide is poisonous. It can harm the soil, wash into the water and kill useful insects. A chemical that is not broken down can build up along the food chain and reach people.
Step 2. Ways to use less. Prepare the field well and sow in time. Use crop rotation or inter-cropping so that pests do not build up, grow a resistant variety, or plough deeply in summer.
Answer: it harms the soil, the water and useful animals, and it can build up along a food chain; he can rotate crops and use a resistant variety to cut down the spray.
Discussion (0)
Log in to join the discussion.
Loading…