Amendments to saline-sodic soils showed long-term effects on improving growth and yield of rice (Oryza sativa L.)

BACKGROUND: Saline-sodic soils are widely distributed in arid and semi-arid regions around the world. High levels of salt and sodium inhibit the growth and development of crops. However, there has been limited reports on both osmotic potential in soil solutions (OP(ss)) and characteristics of Na(+) and K(+) absorption in rice in saline-sodic soils under various amendments application. METHODS: A field experiment was conducted between 2009 and 2017 to analyze the influence of amendments addition to saline-sodic soils on rice growth and yield. Rice was grown in the soil with no amendment (CK), with desulfurization gypsum (DG), with sandy soil (SS), with farmyard manure (FM) and with the mixture of above amendments (M). The osmotic potential in soil solution, selective absorption of K(+) over Na(+) (SA), selective transport of K(+) over Na(+) (ST), the distribution of K(+) and Na(+)and yield components in rice plants were investigated. RESULTS: The results indicated that amendments application have positive effects on rice yield. The M treatment was the best among the tested amendments with the highest rice grain yield. M treatment increased the OP(ss) values significantly to relieve the inhibition of the water uptake by plants. Additionally, the M treatment significantly enhanced K(+) concentration and impeded Na(+) accumulation in shoots. SA values were reduced while ST values were increased for all amendments. In conclusion, a mixture of desulfurization gypsum, sandy soil and farmyard manure was the best treatment for the improvement of rice growth and yield in the Songnen Plain, northeast China.