Impacts of sand amendment on rice (Oryza sativa L.) growth and yield in saline-sodic soils of North-East China

Information about using sand to ameliorate saline-sodic soils is scanty. Field experiments were conducted from 2008 to 2009 to explore the feasibility of using sand for reclamation of saline-sodic soils and to differentiate the effects on growth and yield of two Chinese rice cultivars ('Dongdao 2' and 'Changbai 9') at Da'an Sodic Land Experiment Station, North-East China. Four treatments, consisting of 1000 m(3)/ha sand alone (S), 1000 m(3)/ha sand plus 15 t/ha phosphogypsum (SP), 1000 m(3)/ha sand plus 15 t/ha phosphogypsum and 65 t/ha farmyard manure (SPF), and a control (no amendments added) were investigated. Application of sand and its combination with phosphogypsum/farmyard manure produced significant (P<0.05) improvements in plant growth, dry matter production and grain yield of both rice cultivars over control, but non-significant differences were found among S, SP and SPF treatments. On average of two years, the yield of 'Dongdao 2' for S, SP and SPF treatments increased by 557%, 689% and 463% compared to the control; for 'Changbai 9', the mean increment being 164%, 217% and 149%, respectively. The two cultivars responded similarly in the various treatments. Thus, sand alone, sand in combination with phosphogypsum/farmyard manure enhanced the salt tolerance and growth of rice, influenced the yield components positively and thereby increased rice grain yields. Sand application can be used as an effective strategy for the reclamation of saline-sodic soils and improve reclamation efficiency.