Disease suppressive soil often results from ________.
A) adding organic materials to the soil that stimulate diverse microorganisms
B) fumigation with a volatile chemical
C) heating the soil by natural solarization or steam heat
D) repeated tillage to keep the soil bare for at least one full year
E) all of the above
Question 2
Many members of which group of soil microorganisms are anaerobic heterotrophs?
A) fungi
B) bacteria
C) actinomycetes
D) both A and C
E) all of the above