In 1960 the ratio of food production to N fertilizer use was 40:15 or 2.7:1. By 2000 the ratio was 1:1. The efficiency of N use in agriculture _____.
Fill in the blank(s) with the appropriate word(s).
Answer: decreased—over time we have produced less food with the same amount of N fertilizer
Environmental & Atmospheric Sciences
You might also like to view...
Describe briefly how the map of Europe changed with the Treaty of Versailles in 1918
What will be an ideal response?
Environmental & Atmospheric Sciences
Jellyfish are ____
a. pelagic plankton b. benthic plankton c. benthic nektons d. pelagic nektons e. pelagic articulates
Environmental & Atmospheric Sciences
Which process is responsible for the oxygen in the atmosphere today?
A) Photosynthesis B) Outgassing of volcanoes C) Weathering of carbonate rocks D) Asteroid impact
Environmental & Atmospheric Sciences
By international agreement, what is the general term for all hurricane-type storms that originate over tropical waters?
A) typhoons B) hurricanes C) tropical storms D) tropical cyclones
Environmental & Atmospheric Sciences