Effect of cadmium alone and in combination with butachlor on soil enzymes

Abstract

The ecological toxicity of cadmium (Cd, 10 mg kg(-1 )of dry weight soil) and butachlor (10, 50 and100 mg kg(-1 )of dry weight soil) in both their single and combined effects on soil urease and phosphatase was studied after 1, 3, 7, 14, 21 and 28 days exposure under controlled conditions in paddy and phaeozem soils. The results showed that Cd reduced the activities of urease and phosphatase at early incubation time (1-7 days), while the reduction almost disappeared at the end of the incubation. The effect of Cd on phosphatase was more pronounced than that on urease. The activities of urease and phosphatase were reduced by butachlor, while urease activity was significantly (P < 0.05 or P < 0.01) improved when the concentrations of butachlor were 10 and 50 mg kg(-1) at the end of the incubation. When Cd (10 mg kg(-1)) was combined with butachlor (50 and 100 mg kg(-1)), the activities of urease and phosphatase became lower than without combination at early incubation time, which indicated that the toxicity of Cd significantly increased (P < 0.05 or P < 0.01). However, when Cd (10 mg kg(-1)) was combined with butachlor (10 mg kg(-1)), the activities of urease and phosphatase became higher than those without combination at the end of the incubation, which indicated that the toxicity of Cd decreased. It was indicated that the combined effects depended largely on the incubation time and the concentration ratio of Cd and butachlor. In addition, it was showed that the combined effects of butachlor and Cd appeared different in paddy from phaeozem, which may be related to the different properties of these soils.

Soil Properties as Influenced by Long Term Herbicide with or without Organic Manure Application in Transplanted Rice-Rice System

“…The observation is in affirmation to that reported by Latha and Gopal (2010). The decrease in acid phosphatase activity in soil with application of herbicide is in conformity to the findings of Wang et al (2007), as the negative effect of butachlor on acid phosphatase is augmented in presence of cadmium. The urease activity was not affected by herbicide application compared to hand weeding, while addition of organic manure for partial N-fertilizer substitution significantly increased it over sole chemical fertilizer.…”

A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation

“…To prevent the substrate from escaping through the holes at the bottom, and the possibility of roots growing out of the pots (Hu et al, 2013), pieces of frost cloth were placed at the bottom before placing the substrate. Since the 100% WHC was determined prior to trial set-up, each pot containing the mixed substrate was initially watered with tap water to adjust soil water content to 60% WHC (Ruiz et al, 2009;Wen et al, 2004;Wang et al, 2007).…”

Response of soil enzyme activities to synergistic effects of biosolids and plants in iron ore mine soils

“…To prevent the substrate from escaping through the holes at the bottom and the possibility of roots growing out of the pots (Hu et al 2013a, b), pieces of frost cloth were placed at the bottom before placing the substrate. Since the 100 % water-holding capacity (WHC) of tailings was determined prior to trial set-up, each pot containing the mixed substrate was adjust to 60 % WHC using tap water and left to stabilize for 2 days (Ruiz et al 2009;Wen et al 2004;Wang et al 2007). Thereafter, 25 seeds (Grant et al 2002) of Cynodon dactylon were sown 2 cm deep (Du et al 2014) in each pot.…”