Impact of irrigation and organic matter amendments on arsenic accumulation in selected vegetables

Abstract

The present study was set up to investigate the effect of irrigation with naturally arsenic (As)-contaminated water and addition of organic amendments on the As accumulation in frequently consumed vegetables in India (pumpkin, radish and cabbage). An arsenic-stricken village (Ghentugachi, Chakdah Block, Nadia, West Bengal, India; 23°02'N, 88°34'E, 9.75 m a.s.l.) was selected. Pot studies were conducted with the selected vegetables in contaminated soils collected from the selected village. Arsenic-contaminated water (spiked with varying concentrations of As III and As V ) was used to irrigate the pots. Use of irrigation water contaminated with arsenic (both As III and As V ) reduced the germination and inhibited photosynthetic pigmentation. As III contamination remained more harmful. The worst situation was encountered with As III contamination at 0.5 mg/L of irrigation water while As V contamination below 0.2 mg/L of irrigation water remained safe. Field experiments with the selected vegetables were undertaken in the arsenic-stricken village where irrigation water (0.32 ± 0.12 mg/L) and soil (total As 18.15 ± 2.12 mg/kg) were contaminated with arsenic, to characterize the arsenic contamination of the vegetables, to assess the risk of dietary exposure and to study the effect of organic amendments on such contaminations. Vegetable roots accumulated more As than other parts and the accumulation increased with age. Pond (surface) water emerged as safer source for irrigation than shallow tube well water. Organic amendments reduced arsenic contamination significantly and vermicompost was the most efficient in this regard. All the vegetables showed risk (> 100% provisional tolerable weekly intake) of dietary exposure to arsenic.

Evaluation of different extractants to estimate bioavailable arsenic in soil

“…Furthermore, when 0.2 M NH 4oxalate was tested with different shaking periods to determine As in soil, 0.17 h emerged as the best (Wenzel et al, 2001) with plant As. In most cases the extractant used for extracting bioavailable As from soil is 0.5 N NaHCO 3 (pH = 8.5) (Ghosh et al, 2021;Golui et al, 2017;Das et al, 2016). The amount of As extracted depends on the strength of the chemical used.…”

Production of Hull-less Mutant of Pumpkin Seed under Different Abiotic Conditions

“…Both middle and southern regions had considerably-higher soil organic matter (OM) (by about 78%) compared to the northern region (table 3), and that possibly had a positive influence on the yield. OM can enhance plant development with its role on soil sustainability (Marinari et al, 2000;Das et al, 2016), elevated photosynthesis (Amaya-Carpio et al, 2009;Antolín et al, 2010) and, consequently, biomass and seed yield. High organic matter levels are also routinely cited as a key determinant for high yielding pumpkin production (Dimsey, 1994).…”