Arsenic and selenium levels in rice fields from south-west of Spain: influence of the years of monoculture

Abstract

Rodrigo S., Santamaria O., Perez-Izquierdo L., Poblaciones M.J. (2017): Arsenic and selenium levels in rice fields from south-west of Spain: influence of the years of monoculture. Plant Soil Environ., 63: 184-188.There is a lack of information regarding the arsenic (As) and selenium (Se) concentrations in Spanish rice (Oryza sativa L.) fields and how soil conditions affect such concentration, especially those derived from the typical monoculture practiced in the studied area. To clarify these aspects, 76 soil samples and 95 grain samples were collected from 19 rice fields along the Vegas Altas area, the most important rice growing area of south-west of Spain. The results suggested a significant increase in the soil total As and Se concentrations as the number of monoculture years increased. While As concentration reached toxic levels in 12 out of the 19 locations, Se concentration in all the analysed fields could be considered as deficient. An increase of the As and Se concentration in soil produced a subsequent increase of the concentration of both elements in the rice grain. Therefore, it might be extremely important to control both levels. It would be necessary to establish different actions, including rotations with other crops, in order to remediate As accumulation and to increase Se intake.

Challenges and opportunities in productivity and sustainability of rice cultivation system: a critical review in Indian perspective

“…The intensive cultivation of frequent irrigation requiring crops like low land rice turned out one of the major factors responsible for the deposition of seleniferous material in the soil, leaving more than 100 ha area under selenium toxicity (Dhillon and Dhillon 1991). Sara et al (2017) observed that arsenic and selenium content of soil increased with duration of rice monoculture system. The increase in arsenic and selenium concentration in soil caused toxicity in rice grain.…”

“…Needless to say that intensive rice cultivation with puddling and flooding method projects the health risk associated with soil and grain toxicity in long-term. Sara et al (2017) recommended to control these elements with prior importance by employing the different actions including crop rotations, soil amendments, etc.…”

Rice quality improvement. A review

“…Selenium (Se) is another essential micronutrient that accumulates in rice in a lower concentration than in other staple crops, with negative health impacts on an estimated one billion people globally (Combs Jr 2001, also cited by Carey et al 2012;Boldrin et al 2013). Selenium concentration in brown rice in Spain was found to be closely associated with total and available Se in the soil (Rodrigo et al 2017). Unlike Zn, the Se in rice was more responsive to soil application than foliar Se (Boldrin et al 2013).…”

Tuning of the Amount of Se in Rice (Oryza sativa) Grain by Varying the Nature of the Irrigation Method: Development of an ICP-MS Analytical Protocol, Validation and Application to 26 Different Rice Genotypes

“…The determination of Se in rice has been the object of a number of valuable analytical methods based on different instrumental approaches: among others, it is worthy to cite the voltammetry [50,51], the HR-CS AAS (high resolution continuous source atomic absorption spectroscopy) [52], the ICP-OES (inductively coupled plasma-optical emission spectroscopy) [53], and the INAA (instrumental neutron activation analysis) [54]. Also ICP-MS (inductively coupled plasma-mass spectrometry) methods have been often used for this aim [33,[55][56][57][58][59][60][61][62][63] but-unfortunately-their overall reliability is not proven because these methods were often not fully validated.…”