Across
- 3. the acidic water that forms when surface ater and air are exposed to iron sulfide
- 9. the cultivation of a single crop in a given area
- 11. an area of low-lying land which is flooded in wet seasons or at high tide, and typically always remains waterlogged
- 14. to prepare and cultivate land for crops
- 15. the most photosynthetically active zone of a lake
- 17. an area of low-lying, uncultivated ground where water collects, a bog or marsh.
- 18. all activities conducted by a farmer on a farm to produce agricultural products
- 21. still fresh water
- 24. a chemical that destroys fungus
- 25. he lowest ecological zone in a water body
- 26. land consisting of marshes or swamps
- 27. a low and marshy or frequently flooded area of land
Down
- 1. a cold and ordinary zone located below the range of effective light penetration
- 2. the science or practice of farming, including cultivation of the soil for the growing of crops and the rearing of animals to provide food and other products
- 4. the draining away of water from the surface of an area of land, a building or structure,
- 5. turn up an area of land with a plow, especially before sowing
- 6. water that exists underground in saturated zones beneath the land surface
- 7. aquatic organisms that do not have a spine
- 8. waste water and excrement conveyed in sewers
- 10. the supply of water to land or crops to help growth, typically by means of channels
- 12. unable to sustain crops or vegetation
- 13. rapidly moving fresh water
- 16. an area or ridge of land that separates waters flowing to different rivers, basins, or seas
- 19. a substance that pollutes something
- 20. a substance that is toxic to plants, used to destroy unwanted vegetation
- 22. a substance used for destroying insects or other organisms harmful to cultivated plants or to animals
- 23. part of a sea, lake, or river that is close to the shore