An agricultural ecosystem receives solar radiation at a rate of 2.4×106 kJ m−2 yr−12.4 \times 10^6\text{ kJ m}^{-2}\text{ yr}^{-1}2.4×106 kJ m−2 yr−1. Only 1.5% of this solar energy is captured by the crops as gross primary productivity (GPPGPPGPP). The crops lose 60% of this captured energy through cellular respiration (RRR), as illustrated in the energy flow diagram below.
What is the net primary productivity (NPPNPPNPP) of this crop ecosystem in kJ m−2 yr−1\text{kJ m}^{-2}\text{ yr}^{-1}kJ m−2 yr−1?
2.16×104 kJ m−2 yr−12.16 \times 10^4\text{ kJ m}^{-2}\text{ yr}^{-1}2.16×104 kJ m−2 yr−1
1.44×104 kJ m−2 yr−11.44 \times 10^4\text{ kJ m}^{-2}\text{ yr}^{-1}1.44×104 kJ m−2 yr−1
3.60×104 kJ m−2 yr−13.60 \times 10^4\text{ kJ m}^{-2}\text{ yr}^{-1}3.60×104 kJ m−2 yr−1
1.44×105 kJ m−2 yr−11.44 \times 10^5\text{ kJ m}^{-2}\text{ yr}^{-1}1.44×105 kJ m−2 yr−1