Organic-inorganic calcium lignosulfonate compounds for soil acidity amelioration.

Soil acidification is a problem widely occurring worldwide, which severely threaten food security and agricultural sustainability. Calcium lignosulfonate (CaLS), a cheap and ecofriendly compound, is used for the first time to amend acid soil by utilizing its unique organic and inorganic functional moieties simultaneously. Both column leaching and incubation experiments were conducted to investigate the comparative effects of CaLS (four rates at 5, 10, 15, 20 g kg) and compared with conventional amendments, including gypsum (5 g kg), lignin (5 g kg), L + G (each at 5 g kg), and control.