Sarkar S.,Arsenic Research Group |
Basu B.,Arsenic Research Group |
Kundu C.K.,Arsenic Research Group |
Patra P.K.,Arsenic Research Group
Agriculture, Ecosystems and Environment | Year: 2012
Farmers in arsenic (As) contaminated areas of West Bengal, India grow rice during dry months (January to April) and use underground water for irrigation with As concentration above WHO defined critical (0.01mgl -1) limit. In each season they add 50-150mgAsperm 2 soil area. Thus growing rice under deficit irrigation in these areas will reduce As load in soil-root-shoot-leaf-grain continuum of rice ecosystem. Suitable deficit irrigation system has to be screened so that As load will decrease with insignificant reduction in grain yield. With this objective, rice grown under four irrigation regimes (i) continuous ponding (CP), (ii) intermittent ponding (IP), (iii) saturation (SAT) and (iv) aerobic (AER) was tested to assess the arsenic load in soil and various parts of rice on 45 and 80 days after transplanting (DAT). Conditions described in treatments ii, iii and iv were imposed during 15-45DAT. Highest value (18.18 and 18.74mgkg -1) of soil arsenic was attained under CP followed by IP, SAT and AER. Root arsenic content under AER at 45 and 80DAT was at the lowest level (6.14 and 20.54mgkg -1) and this was 31 and 7.0% lower as compared to CP. As content in leaf and grain attained the lowest values under IP. Grain yield insignificantly differed under IP (4.33Mgha -1) over CP (4.69Mgha -1). Compared to soil As, As added through irrigation showed stronger relationship with As status of various plant parts. Imposition of IP only during vegetative stage was found to be optimum in terms of reduction of As content in straw and grain respectively by 23 and 33% over farmers irrigation practice with insignificant decrease in grain yield. © 2011 Elsevier B.V.
Majumder A.,Arsenic Research Group |
Bairagya M.D.,Arsenic Research Group |
Basu B.,Arsenic Research Group |
Gupta P.C.,Arsenic Research Group |
Sarkar S.,Arsenic Research Group
Science of the Total Environment | Year: 2013
Arsenic (As) toxicity of ground water in Bengal delta is a major environmental catastrophe. Cultivation of jute, a non edible crop after summer rice usually reduces arsenic load of the soil. However, during retting of jute As is present in the crop and thus increase its amount in surface water bodies. To test this hypothesis, a study was carried out in ten farmers' field located in As affected areas of West Bengal, India. As content of soil and variou the jute plant were recorded on 35 and 70days after sowing (DAS) as well as on harvest date (110DAS). During the study period, due to the influence of rainfall, As content of surface (0-150mm) soil fluctuates in a narrow range. As content of jute root was in the range of 1.13 to 9.36mgkg-1. As content of both root and leaf attained highest concentration on 35DAS and continuously decreased with the increase in crop age. However, in case of shoot, the As content initially decreased by 16 to 50% during 35 to 70DAS and on 110DAS the value slightly increased over 70DAS. Retting of jute in pond water increased the water As content by 0.2 to 2.0mgL-1. The increment was 1.1 to 4 times higher over the WHO safe limit (0.05mgL-1) for India and Bangladesh. Microbiological assessment in this study reveals the total bacterial population of pre and post retting pond water. Bacterial strains capable in transforming more toxic As-III to less toxic AS-V were screened and six of them were selected based on their As tolerance capacity. Importantly, identified bacterial strain Bacterium C-TJ19 (HQ834294) has As transforming ability as well as pectinolytic activity, which improves fibre quality of jute. © 2012 Elsevier B.V.