PNM EXAM 1 QUESTIONS WITH
DETAILED VERIFIED ANSWERS
Governing bodies of fertilizers Ans: AAPFCO, Association of American
Plant Food Control Officials
Association of Official Analytical Chemists, AOAC
IPNI, International Plant Nutrition Institute
Fertilizer Ans: is any substance that contains one or more recognized
plant nutrients, is used for its plant nutrient content, and is claimed to
have value in promoting plant growth
fertilizer exclusions Ans: unmanipulated animal or vegetable manures,
marl, liming material, sewage sludge other than finished sewage sludge
products, and wood ashes
Fertilizer grade Ans: is the guaranteed minimum content of water-
soluble (or slow-release) N, available (citrate-soluble) P, and available
(water-soluble) K, expressed as N-P2O5-K2O. Labeling of fertilizers is
highly standardized.
Mixed fertilizer Ans: is any fertilizer containing any combination of
fertilizer materials. In Wisconsin and many other states, the sum of N,
P2O5, K2O must be 24% or greater to meet this designation, else it can
be marketed as a 'specialty mixed fertilizer' or 'soil amendment'
Complete fertilizer Ans: any fertilizer containing all three of of the
primary nutrients, N, P, and K. Note that it is not a complete plant food
since it may lack Ca, Mg, S, and all the micronutrients.
Ballast Ans: or filler, in fertilizers is the non-NPK portion, such as
chloride in potassium chloride or calcium in monocalcium phosphate, the
active component of triple superphosphate
N sources: Ans: Urea [ (NH2)2CO ]