Use and economic benefit of soft rock as an amendment for sandy soil in Mu Us Sandy Land, China

Desertification seriously threatens sustainable economic and social development. Soft rock has been used as a soil amendment for sandy soil in Mu Us Sandy Land. In this study, the effects of soft rock amendment treatments were examined in the cultivation of corn (Zea mays L.), with a focus on soil properties and economic benefits in a field site with sandy soil in 2012-2014, in Mu Us Sandy Land, China. Four crushed soft rock amendment treatments (four ratios of soft rock to sand, 0:1, 1:5, 1:2 and 1:1 by volume) were applied in 2012. The results showed sandy soil properties were well improved by adding soft rock. All soft rock treatments significantly (p < 0.05) increased grain yield and net revenue in all three years. Grain yield increases ranged from 67.8% to 160.1%, and 3-year net revenue increases ranged from 450% to 559%. The treatment with ratios of soft rock to sand of 1:2 showed the strongest effect among all treatments for soil aggregation and corn production averaged over three years. The 1:2 soft rock to sandy soil treatment (by volume) respectively produced 3,257, 633 and 382 USD ha(-1) higher net revenues than did the ratios of soft rock to sand of 0:1, 1:5, and 1:1 treatments over the three years. In general, the 1:2 soft rock to sandy soil treatment had a satisfactory effect on improving soil properties and enhancing economic benefit.