Effects of Chemical Fertilizer Application upon the Water Quality Parameters of a Rice–Eel (Monopterus albus) Coculture System

Figure 4

Changes of water quality parameters of rice field’s surface water and ring ditch water in the fertilization (RF) and non-fertilization (NF) treatment groups before (BF) and at 24 h (AF24), 48 h (AF48), and 72 h (AF72) after the ear granule fertilizer application (mean ± SE, n = 3). DO: dissolved oxygen, (T) temperature, TN: total nitrogen, TP: total phosphorus, TAN: total ammonia nitrogen, NO₂⁻-N: nitrite nitrogen, COD: chemical oxygen demand. (a), (c), (e), (g), (i), (k), (m), (0) Rice field. (b), (d), (f), (h), (j), (l), (n), (p) Ring ditch.

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