硒酸钠施用对小麦的富硒效应及其残效

Biofortification and Residual Effects of Selenate Fertilizer on Wheat

为明确外源硒酸盐对小麦各器官硒含量的影响以及硒酸盐的残效,通过两年连续盆栽试验,设置了0、0.02、0.04、0.08、0.16 mg·kg^(-1)五个施硒水平,第一年施硒,第二年不施硒且在原土中继续种小麦,测定和分析了两年小麦不同器官(叶、茎、籽粒和颖壳)和土壤硒含量及产量和生物量。结果表明,施硒当季能够增加小麦产量及地上部生物量,显著提高各器官硒含量,各器官硒含量与施硒量均呈显著的线性正相关。器官中叶片对硒的富集能力最强,其次为籽粒、茎和颖壳。小麦不同器官硒强化指数大小与富集系数表现一致,施硒量每增加1 mg·pot^(-1),叶片、籽粒、茎、颖壳的硒含量分别增加8.9、6.2、4.6和3.6 mg·kg^(-1)。外源硒酸盐具有残效,尤其在硒施用量较高时,小麦对外源硒的利用率两年均随施硒量的增加而增加,当季硒的利用率最高值为33.7%,两年累积利用率最高值为34.7%。施硒在第二年对小麦各器官硒的含量、土壤硒含量仍有显著的增加效应,尤其在施硒量较高时,但其对小麦硒含量的影响大于对土壤有效硒、总硒含量的影响。在农业生产应用中应选择适宜的施硒用量,关注硒肥的后效,实现高效安全的小麦硒强化。

In order to clarify the biofortification and residual effect of selenate on selenium content in wheat organs with the purpose of giving proper recommendation on improvement of wheat selenium in agricultural production,two years of pot experiments were conducted with five selenium treatments of 0,0.02,0.04,0.08 and 0.16 mg·kg^(-1).No Se was applied in the second year,and wheat was planted in the original soil.The results showed that Se application increased wheat yield and shoot biomass,and significantly increased Se content in wheat organs.The increment of Se concentration in wheat organs increased with the increase of Se application rates,with significant linear relationship.Among all organs of wheat,the leaf had the strongest selenium accumulation ability,followed by grain,stem and glume.The relationship between Se bioaccumulation coefficient and Se biofortification index was consistent.The Se content in leaves,grains,stems and glumes increased by 8.9,6.2,4.6 and 3.6 mg·kg^(-1) respectively with the increase of 1 mg·pot^(-1) of Se application.The results showed that selenate had residual effect,especially when the Se fertilization rate was high.The utilization percentage of selenate increased with Se application rate for two consecutive years.The highest utilization rate of selenium in first the season was 33.7%,and the highest cumulative utilization percentage in two years was 34.7%.In the second year after Se application,the concentration of Se in wheat organs and soil still increased significantly,especially when the Se application rate was high,but the increasing effect on the content of Se in wheat was greater than that on the content of available Se and total Se in soil.For agricultural production and application,we should choose the appropriate amount of selenate,and consider the residual effect of selenite fertilizer for improving wheat Se content efficiently and environmental friendly.