Objective  Effects of different types of saline-alkali soil that are selenium (Se)-rich on the absorption, transport, and accumulation of Se in rice grown on them were studied.

  Method  Saline-alkali-tolerant Ningjing 45 seedlings were grown on soils in the Yellow River irrigation area of Ningxia province that were mildly saline (Treatment A), mildly alkaline (Treatment B), and moderate-severely alkaline (Treatment C). Se uptake, accumulation, and quality of the seedlings grown on the pots were determined.

  Result  (1) The Se contents in the roots, stems, leaves, and grains of the rice plants ranked as Treatment C＞Treatment B＞Treatment A, and at maturity, roots＞stems＞leaves＞grains. The contents in mature grains were 0.17 mg·kg⁻¹ under Treatment A, 0.217 mg·kg⁻¹ under Treatment B, and 0.24 mg·kg⁻¹ under Treatment C. They all met the enrichment standard set for rice; however, Treatment C produced a significantly higher level of the metal element in the plants than the other two treatments (P＜0.05). (2) The Se accumulation in rice peaked at heading stage but varied in the organs at maturity with the ranking of milled rice＞stems＞leaves＞roots＞glume. (3) In seedling to heading stage, Se transported basically from the roots to the stems and leaves, but in heading to maturity, mainly from the stems and leaves to the spikes. (4) The Se absorption and primary transport coefficients of the roots increased with increasing salinity and alkalinity in soil. Thus, the effect was the greatest under Treatment C, followed by Treatment B and Treatment A. In contrast, the secondary transfer coefficient decreased with the increases to reverse the ranking order.

  Conclusion  It appeared that Se-enrichment for rice grown on a saline-alkali soil that had an ample supply of the metal element could be realized if the soil had a pH ranging between 8.41 and 9.51, salt content between 1.74 g·kg⁻¹ and 3.62 g·kg⁻¹, and Se content of 0.23 mg·kg⁻¹. And, interestingly, moderate and heavy saline-alkali soils bolstered the absorption, transport, and accumulation of Se in rice, and therefore, the normally considered undesirable conditions would enhance, rather than hinder, the use of like land masses.