Commercial fertilizers are often applied to agricultural land. Discuss the use of fertilizers on crops and their effect on other ecosystems.

a. adding fertilizer increases nitrogen/phosphate in soil/nutrient cycles ✔

b. adding fertilizer increases crop yield ✔

c. commercial fertilizers may not stay in ground as long as organic fertilizers/manure ✔

d. commercial fertilizers release compounds more rapidly than organic fertilizers/manure ✔

e. nutrients run off/leached from land into water/groundwater/lakes/streams ✔

f. «high concentrations of nitrogen/phosphate in water» causes eutrophication ✔

g. «high concentrations of nitrogen/phosphate» causes algae to multiply rapidly
OR
leads to algal blooms ✔

h. algae die and decomposed by bacteria ✔

i. «decomposers» require oxygen from water
OR
increased biochemical oxygen demand/BOD ✔

j. if oxygen levels drop too low fish/aquatic organisms die ✔

A fair number provided a complete and logical discussion including both the usage and the impact of fertilizers. Too many nevertheless discussed other issues, such as decrease of phosphorous availability (which addressed a question of a previous paper), or confused fertilizers with pesticides, sometimes also mentioning biomagnification.