Fig. 5

Fertiliser input for crop (rice, wheat, and maize) production systems from 2002 to 2021 in Yunnan Province (20 samples). The rice (a) total fertiliser rate, wheat (b) total fertiliser rate, and maize (c) total fertiliser rates were compared across the five-year intervals. Different nutrient inputs (d–f, nitrogen (N) fertiliser rate; (g–i) phosphorus (P2O2) fertiliser rate; (j–l) potassium (K2O) fertiliser rate) for crops (rice, wheat, and maize) production systems were compared across five-year intervals. Different lowercase letters represent statistically significant differences (LSD test, P < 0.05).