### Instruction:

Extract the cause and effect entities from the following sentence:
Nitrogen supply from soil organic matter is not known accurately and introduces uncertainty (Ostle et al

### Assistant:

VARIABLE: Nitrogen supply
CONDITION: introduces uncertainty
CAUSE_1: Nitrogen supply from soil organic matter
AND: and
NOT_RELEVANT: (Ostle et al
EFFECT_1: is not known accurately
EFFECT_2: introduces uncertainty
NEGATION: is not

