Effect of inorganic amendments for in situ stabilization of cadmium in contaminated soils and its phyto-availability to wheat and rice under rotation

Abstract

Cadmium (Cd) toxicity is a widespread problem in crops grown on contaminated soils, and little information is available on the role of inorganic amendments in Cd immobilization, uptake, and tolerance in crops especially under filed conditions. The effect of three amendments, monoammonium phosphate (MAP), gypsum, and elemental sulfur (S), on Cd immobilization in soil and uptake in wheat and rice plants, under rotation, were investigated under field conditions receiving raw city effluent since >20 years and contaminated with Cd. Three levels of each treatment, 0.2, 0.4, and 0.8% by weight, were applied at the start of the experiment, and wheat was sown in the field. After wheat harvesting, rice was sown in the same field without application of amendments. Both crops were harvested at physiological maturity, and data regarding grain yield, straw biomass, Cd concentrations, and uptake in grain and straw, and bioavailable Cd in soil and soil pH were recorded. Both MAP and gypsum application increased grain yield and biomass of wheat and rice, while S application did not increase the yield of both crops. MAP and gypsum amendments decreased gain and straw Cd concentrations and uptake in both crops, while S application increased Cd concentrations in these parts which were correlated with soil bioavailable Cd. We conclude that MAP and gypsum amendments could be used to decrease Cd uptake by plants receiving raw city effluents, and gypsum might be a better amendment for in situ immobilization of Cd due to its low cost and frequent availability.

Silicon alleviates nickel toxicity in cotton seedlings through enhancing growth, photosynthesis, and suppressing Ni uptake and oxidative stress

“…Different actions have been taken to reduce heavy metal uptake and toxicity in plants including exogenous application of different materials such as humic substances Noman et al 2015), osmoprotectants (Adrees et al 2015c;Ali et al 2015b), soil amendments (Rehman et al 2015) and silicon (Rizwan et al 2012;Adrees et al 2015b;Keller et al 2015). Silicon (Si) is the second most abundant element of the earth's crust and is considered a quasi-essential element for plant growth and development (Epstein and Bloom 2005).…”

Effect of different amendments on rice (Oryza sativa L.) growth, yield, nutrient uptake and grain quality in Ni-contaminated soil

“…Recently, the use of a variety of organic and inorganic amendments has attained a considerable attention for remediation of heavy metal-contaminated soils (Usman et al 2013;Almaroai et al 2014;Adrees et al 2015b;Rehman et al 2015;Rizwan et al 2016b). Recently, a carbon-rich economically viable soil amendment like biochar (BC), produced by Communicated by: Elena Maestri pyrolyzing biowaste materials under limited oxygen supply, has attained significant interest to improve soil physical, chemical, and biological properties due to its high organic carbon content, surface area, cation exchange capacity, etc.…”

Influence of Organic and Inorganic Soil Amendments on Soil pH and Macronutrients

“…Therefore, to avoid losses of the organic matter that is quite beneficial to agricultural productivity, organic amendments act as positive remedies to carbon content, nitrogen content and soil structure stability among others [3]. The inorganic soil amendments are used to supplement the organic matter that is already present in the soil [5]. Due to scarcity of organic amendments, the inorganic materials have become increasingly popular in adjusting the soils physicochemical characteristics, enhancing growth and consequently promoting yields of crop [5].…”