Effects of the novel cis-nitromethylene neonicotinoid insecticide Paichongding on enzyme activities and microorganisms in yellow loam and Huangshi soils

Abstract

Soil enzyme activity and microbial population play important roles in maintaining soil fertility and ensure crop yield. Paichongding (IPP) is a novel cis-nitromethylene neonicotinoid insecticide, which was recently developed in China. In this study, in order to better understand IPP ecological toxicity, the impact of IPP on soil enzyme activity and microbial population in soils was investigated. The results showed that, urease activity was inhibited by IPP before 75 days incubation, after that this inhibiting effect gradually weakened. IPP had different stimulating effects on the activities of dehydrogenase, protease, and catalase. They were consistently stimulated from the initial time in soils. The results of microbial population indicated that the number of bacteria increased after IPP application compared with the control, fungal number increased before 45 days incubation and then decreased. While actinomycete number decreased during degradation period. DT50 (half-life value), k (degradation rate constant) of IPP in S1 (yellow loam soil), and S2 (Huangshi soil) were found 90 days and 173 days, 0.0077 day(-1), and 0.0040 day(-1), respectively.

Spray Retention on Coffee Leaves Associated With Type and Concentration of Adjuvants

“…Another undesirable parameter provided by excessive run-off is the risk of contamination of the soil water and air by pesticides (Pose-Juan et al, 2015). The amount of pesticide that reaches the soil may cause detrimental effects on soil microorganisms and modify the ecosystem (Cai et al, 2016). In this way, the most assertive application techniques of pesticides may reduce environmental problems and consequently, increase the performance of treatments.…”

Toxic effect of the novel chiral insecticide IPP and its biodegradation intermediate in nematode Caenorhabditis elegans

“…IPP is a novel chiral neonicotinoid insecticide with four stereoisomers (RR, SS, RS and SR-IPP) and it was widely used in China for insecticide control in agriculture. Cai et al reported that IPP could decrease soil enzyme activities, change soil microbial population, diversity and composition (Cai et al 2015a(Cai et al , 2016b(Cai et al , 2016c. The activities of microbial protease, catalase, urease and dehydrogenase in soil are both impacted after IPP application in crop (Cai et al 2015a(Cai et al , 2016b(Cai et al , 2016c.…”

“…Cai et al reported that IPP could decrease soil enzyme activities, change soil microbial population, diversity and composition (Cai et al 2015a(Cai et al , 2016b(Cai et al , 2016c. The activities of microbial protease, catalase, urease and dehydrogenase in soil are both impacted after IPP application in crop (Cai et al 2015a(Cai et al , 2016b(Cai et al , 2016c. The relative abundance of genus of Bacillus, Pseudomonas, Azohydromonas and Paenibacillus in soils with IPP application increased, the genus of Brevundimonas, Xanthomonadaceae, Massilia, Pedobacter, and Hydrogenophaga were newly appearance.…”

“…The relative abundance of genus of Bacillus, Pseudomonas, Azohydromonas and Paenibacillus in soils with IPP application increased, the genus of Brevundimonas, Xanthomonadaceae, Massilia, Pedobacter, and Hydrogenophaga were newly appearance. The bacterial species diversity and community structure in soils were remarkably different responding to IPP-sprayed (Cai et al 2016b(Cai et al , 2016c. Neonicotinoids have been considered to increase mortality in honey bees by impairing their homing ability and to reduce the reproductive success of bumble bees and solitary bees (Henry et al 2012;Whitehorn et al 2012;Woodcock et al 2017).…”

“…Previous studies have emphasized on the biodegradation pathway of IPP, its behavior in soils, and its effect on microbial community, soil enzyme activity etc. (Cai et al 2016a(Cai et al , 2016b(Cai et al , 2016c). However, little information is available on the toxicity of IPP and its biodegradation intermediates on protozoan in soils.…”