Amendments of Severe Saline-Sodic Paddy Land: Optimal Combination of Phosphogypsum, Farmyard Fertilizer, and Wood Peat

We aimed to determine the optimal combination of amendments increase rice yields in saline-sodic soil. The effects different proportions phosphogypsum (P), farmyard fertilizer (F), and wood peat (W) across main growth period were studied. A total 14 treatments designed based on “3414” effect field experiment scheme, with 3 factors (P, F, W) 4 application levels per factor. Application a P, W reduced soil pH electrical conductance (EC) (p < 0.05), increasing yields. theoretical yield after treatment P2F2W2 (P 30, F 50, 30 t·ha−1) was 5819.20 kg·ha−1, which 32.52-fold higher than that P0F0W0 W, 0 t·ha−1). Panicle weight, number filled grains, grain seed-setting rate 9.76, 17.35, 32.11, 3.96 times those control treatment, respectively. Compared 0–5, 5–10, 10–15, 15–20 cm depth decreased by 12.69, 12.32, 11.18, 10.70%, respectively, EC 1.06-fold, 70.79, 49.30, 47.76% higher, Overall, we found 29.09–32.38 t·ha−1; 40.36–46.97 19.57–23.95 t·ha−1 this experiment.