Heavy metal contamination in “chemicalized’ green revolution banana fields in southern India

Abstract

The present report is a general assessment of the level of nutrient and toxic heavy metals as an impact of "chemicalized" cultivation practices for decades in banana fields in the three south Indian states, Kerala, Karnataka, and Tamilnadu. The major objective was to critically analyze the status of metallic content in green revolution fields, where chemical fertilizers or plant protective chemicals remain the major source of heavy metal contaminants. Since soil series being a soil taxonomic category that includes slightly variant soils of similar origin and common parent materials, the 286 field samples of the broad south Indian region were further grouped into composite samples representing 47 different soil series for limiting the sample analysis. The quantitative assessment of ten metals done in these soils using the Atomic Absorption Spectrophotometer included Ca, Mg, Mn, Zn, Fe, Cu, Pb, Ni, Cr, and Co. The amount of Cu observed in many fields was higher than all the previous reports of the same in the "chemicalized" fields. Similarly, the amount of Co observed in 25 fields was above its threshold levels expected for normal soils. The amount of Pb observed in all the soils appeared quite normal. The amount of Ni observed in 14 soil series was higher than its threshold levels for normal soils, except in 4 soil series, where its amount exceeded the upper limit of contamination. Cr was detected in all the samples, but found higher than its threshold level in 31 soil series. Significant positive correlations were observed between the amounts of different metals in the study. PCA results indicated that variables were correlated to four principal components, and 74.36% of the total variance was justified.

Determination of Macro- and Microelements in the Inflorescences of Banana Tree Using ICP OES: Evaluation of the Daily Recommendations of Intake for Humans

“…Due to the indiscriminate use of fertilizers and pesticides for crop protection and pest control, fruits [12] and the banana tree are being contaminated by heavy metals [13]. High levels of Na, Pb, Cr, Fe, Mn, Cd, Zn, and Se in the banana may have been attributed to the repeated use and addition of residues as fertilizers in agricultural areas of banana [14].…”

Analysis of Heavy Metal Sources in the Soil of Riverbanks Across an Urbanization Gradient

“…The application of the traditional PCA-MLR method used to analyze heavy metal sources was reported widely [ 5 , 6 , 33 , 34 ]. This method classifies pollutants with similar sources into one group and then deduces the possible sources of heavy metals in the group according to the source of the specific pollutants in the emission list.…”

The inevitability of arbuscular mycorrhiza for sustainability in organic agriculture—A critical review

“…According to these authors, plants respond to heavy metals through specific stress-related protein molecules to tackle metal toxicities. Some heavy metals are naturally present in all soils, but toxic heavy metals accumulate in soils through anthropogenic means such as chemicalized agriculture (Sahodaran and Ray, 2018). Chemical fertilizers are notorious for heavy metal contaminants such as Cd, Cr, Ni, Pb, and the like (Alengebawy et al, 2021).…”

“…Moreover, intensive experimentations are also necessary to assess them individually, in combinations, and associated with diverse beneficial soil bacteria. (Sahodaran and Ray, 2018), and biocide residues in soils (Silva et al, 2019), affecting its productivity. Continued applications of agrochemicals in the fields cause pest resistance (Phillips, 2020), negatively impacting agricultural production's cost-effectiveness (Durham and Mizik, 2021).…”