Abstract:
This paper is the result of soil geochemical survey engineering.
Objectives Selenium(Se) is one of the essential trace elements for human body. The development and utilization of se−rich land and se−rich agricultural products have become a pivotal practice in rural revitalization. Nonetheless, it is challenging to accurately guide the local government to develop Se−rich land resources in accordance with nothing more than the content of Se in soil.
Methods The northwestern part of Longshan County, Hunan Province were selected as the explored area in this paper. The influencing factors of Se bioconcentration factors of rice were systematically and comprehensively explored on the basis of 1:5 land quality geochemical survey data and national land survey results data. Accordingly, the prediction model of Se bioconcentration factors of rice was established. Aside from that, the Se−rich land quality evaluation system was put forth by integrating with land fertility and ecological environment.
Results As evidently demonstrated by our research findings: (1) The soil Se content was 0.19~0.84 mg/kg, with an average value of 0.48 mg/kg. The Se content of rice seeds was 0.02~0.23 mg/kg, with an average value of 0.10 mg/kg, and the Se−rich rate of rice seeds was 82%. (2) The Se bioconcentration factors of rice seeds displayed negative association with soil Cd, S, and TC, among which the correlation coefficients were −0.617, −0.452, and −0.574, separately. (3) As suggested by the zoning results, the pollution−free medium−high yield cultivated land with Se enrichment in the explored area accounts for 78%; The pollution−free medium−high yield cultivated land, the pollution−free low yield cultivated land, the cultivated land of safe utilization, the cultivated land of prudent utilization account for 13%, 4%, 4% and 1%, severally.
Conclusions On the basis of scientific prediction of crop seeds Se content, a block scale Se−rich land quality evaluation system was innovatively constructed based on Se content of crops, land fertility and ecological environment in this paper. On this basis, this research is expected to offer paramount reference and demonstration significance for local governments to develop Se−rich land resources.
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