11. The Hatch Act was driven by farmers'interest in knowing the constituents of early artificial fertilizer . 12. If the supply of manure or artificial fertilizer is limited, only the seedbeds are fertilized. 13. His father was a manufacturer of artificial fertilizer . 14. Without artificial fertilizers there would not be enough food to sustain a population of seven billion people. 15. Farming organically means using no artificial fertilizers . 16. Modern use of artificial fertilizers , containing nitrogen, phosphorus, and potassium, has affected the mouths of drainage basins. 17. Szekely spoke against herbicides, pesticides, artificial fertilizers , the increasing use of food processing, and the dangers of cigarettes. 18. In the first half of the century, the development of artificial fertilizer made global human population growth possible. 19. Growing world population pushes the need for artificial fertilizers or greater incorporation of organic systems within agricultural infrastructure. 20. He switched to sheep fattening, introduced artificial fertilizer , laid out strawberry and asparagus fields and grew fruit trees.
