Heavy Metal Accumulation in Soil Amended with Roadside Pond Sediment and Uptake by Rice (Oryza sativaL.)

Abstract

The effect of addition of roadside pond sediments on heavy metal contents of flooded rice paddies was studied to investigate the yield of rice and uptake of heavy metal by rice straw and grain. Sequential extraction of heavy metals on sediments shows that the percentage contribution of metals in the labile fraction follows the order lead (Pb, 48%) > copper (Cu, 42%) > zinc (Zn, 31%) > cadmium (Cd, 16%) > chromium (Cr, 9%) > nickel (Ni, 6%). The risk assessment code (RAC) for pond sediment revealed that Cr and Ni were found in the low-risk zone, Zn and Cd in the medium-risk zone, and Cu and Pb in the high-risk zone. However, though the heavy metal concentration in rice grain does not exceed the range acceptable for human consumption, it still represents a significant additional source of heavy metals in the diet. The addition of pond sediment significantly increased the rice yield over control. Therefore, pond sediment would be a valuable resource for agriculture if it is properly used.

Evaluation of Composts from Agricultural Wastes with Fish Pond Sediment as Bulking Agent to Improve Compost Quality

“…Physico‐chemical properties of used agricultural waste are presented in Table 1. A profile of physico‐chemical properties along with different heavy metals present in fish pond sediment has been reported earlier 19.…”

“…The initial pH of the composting mixtures between 6.76 and 7.68, suggest its suitability for composting 54. The gradual decrease of pH was observed during the first week probably due to the generation of acid‐type organic compounds of low molecular weight produced during decomposition of the most labile OM fraction present in agricultural waste 55 and fish pond sediment 19). After composting for 7–14 days there was a rapid and significant increase in pH because of the thermophilic phase at this stage 47.…”

“…Significant differences of TOC between M1 and other composting mixture could be due to the presence of high carbon content in fish pond sediment. Karak 19 reported that, addition of fish pond sediment in rice field can change TOC in soil, dramatically. Concentrations of TOC decrease significantly within 1 wk of composting and this decrement was 57, 47, 28, 20, and 23% of initial carbon contents for M1, M2, M3, M4, and M5, respectively.…”

“…A very recent study revealed the feasibility of fish pond sediment as a valuable soil amending agent for rice cultivation, which has high nitrogen content with C/N ratio <12 18, 19. Therefore, due to lower C/N ratio and relatively high density, fish pond sediment could be used as a bulking agent to speed up the composting of agricultural waste as well as, to enhance the density of the matured compost.…”

“…Therefore, due to lower C/N ratio and relatively high density, fish pond sediment could be used as a bulking agent to speed up the composting of agricultural waste as well as, to enhance the density of the matured compost. Also, fish pond sediment contains essential plant nutrients like N, P, and K 19–22.…”