Effects of Cd-resistant bacteria and calcium carbonate + sepiolite on Cd availability in contaminated paddy soil and on Cd accumulation in brown rice grains

2020 ◽  
Vol 195 ◽  
pp. 110492 ◽  
Author(s):  
Qian Li ◽  
Ping Zhang ◽  
Hang Zhou ◽  
Pei-qin Peng ◽  
Ke Zhang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Paddy Soil ◽  
Brown Rice ◽  
Resistant Bacteria ◽  
Cd Accumulation ◽  
Rice Grains ◽  
Cd Availability ◽  
Contaminated Paddy Soil

scholarly journals Co-Amendment of S and Si Alleviates Cu Toxicity in Rice (Oryza Sativa L.) Grown on Cu-Contaminated Paddy Soil

2018 ◽  
Vol 16 (1) ◽  
pp. 57
Author(s):  
Zhihong Lu ◽  
Xiao Yan ◽  
Zongqiang Wei ◽  
Jianfu Wu
Keyword(s):  
Paddy Soil ◽  
Oryza Sativa L ◽  
Brown Rice ◽  
Rice Root ◽  
Application Rates ◽  
Sulfur Addition ◽  
Cu Contamination ◽  
S Application ◽  
Cu Uptake ◽  
Contaminated Paddy Soil

With irrigation using waste water, application of sewage sludge, and development of mine exploration, copper (Cu) contamination in some paddy fields has become increasingly serious. A greenhouse pot experiment was conducted using a factorial design with three sulfur (S) application rates (i.e., 0, 0.013, and 0.026 g S kg−1 soil) and three silicon (Si) application rates (i.e., 0, 0.05, and 0.1 g Si kg−1 soil) to test the effect of co-amendment of S and Si on alleviating Cu contamination in paddy soil. There were significant interaction effects between S and Si on soil Cu speciation and Cu uptake by rice plants (except brown rice). Sulfur addition decreased the content of soil-exchangeable Cu, whereas Si addition decreased the content of soil-reducible Cu, suggesting that co-amendment of S and Si generally reduced Cu availability. Copper was biominimized in the soil-rice plant system and rice root had the greatest Cu concentration (163–285 mg kg−1). Co-amendment of S and Si decreased the translocation of Cu from soil to rice root, possibly due to decreased soil Cu mobility and enhancement of the formation of iron plaque on rice root. Co-amendment of S-Si at a rate of 0.013 (S)–0.1 (Si) g kg−1 soil, respectively, was the optimal among all treatments.

Mitigation of Cd accumulation in rice from Cd-contaminated paddy soil by foliar dressing of S and P

2019 ◽  
Vol 690 ◽  
pp. 321-328 ◽  
Author(s):  
Jiahao Liu ◽  
Hong Hou ◽  
Long Zhao ◽  
Zaijin Sun ◽  
Yifu Lu ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Cd Accumulation ◽  
Contaminated Paddy Soil

scholarly journals Nitrogen Application Practices to Reduce Cd Concentration in Rice (Oryza Sativa L.) Grains

2021 ◽  
Author(s):  
Qingyun Zhou ◽  
Hui Wang ◽  
Chao Xu ◽  
Shen Zheng ◽  
Meiyan Wu ◽  
...  
Keyword(s):  
Transport Coefficient ◽  
Oryza Sativa L ◽  
Brown Rice ◽  
Fertilizer Treatment ◽  
Rice Grain ◽  
N Application ◽  
Cd Accumulation ◽  
Rice Roots ◽  
Rice Grains ◽  
Cd Transport

Abstract Cd pollution in paddy soils creates challenges in rice grain production, thereby threatening food security. The effectiveness of different base-tillering-panicle urea application ratio and the combined basal application of urea and Chinese milk vetch (CMV, Astragalus sinicus L.) in minimizing Cd accumulation in rice grains was explored in a Cd-contaminated acidic soil via a field experiment. The results indicated that under similar N application rates, an appropriate amount of urea applied at the panicle stage or the combined basal application of urea and CMV decreased Cd absorption by rice roots and its accumulation in rice grains, as compared with that of conventional N application (control). Furthermore, under a 3:4:3 base-tillering-panicle urea application ratio or for basal application of CMV at high levels, Cd concentrations in brown rice were significantly lower (40.7% and 34.1%, respectively) than that of control. Cd transport coefficient from root to straw was significantly higher than that of control when an appropriate amount of urea was applied at the panicle stage or urea and CMV were applied basally, whereas the Cd transport coefficient from straw to brown rice was relatively lower. Moreover, soil pH, or the concentrations of CEC and CaCl2-Cd under different N fertilizer treatment was not significantly different. However, rice grain yield increased by 29.4% with basal application of a high amount of CMV compared with that of control. An appropriate amount of urea applied at the panicle stage or the combined basal application of urea and CMV decreased Cd absorption by rice roots and inhibited its transport from straw to brown rice, thus reducing Cd concentration in brown rice. Therefore, combined with the key phase of Cd accumulation in rice, a reasonable urea application ratio or a basal application of high amounts of CMV can effectively reduce Cd concentration in brown rice.

scholarly journals Effect of Liming with Various Water Regimes on Both Immobilization of Cadmium and Improvement of Bacterial Communities in Contaminated Paddy: A Field Experiment

2019 ◽  
Vol 16 (3) ◽  
pp. 498 ◽  
Author(s):  
Lei Shi ◽  
Zhaohui Guo ◽  
Fang Liang ◽  
Xiyuan Xiao ◽  
Chi Peng ◽  
...  
Keyword(s):  
Field Experiment ◽  
Contaminated Soil ◽  
Paddy Soil ◽  
Brown Rice ◽  
Growth Period ◽  
Residual Fraction ◽  
Soil Microbial Diversity ◽  
Water Regimes ◽  
Soil Microbial ◽  
Contaminated Paddy Soil

Cadmium (Cd) in paddy soil is one of the most harmful potentially toxic elements threatening human health. In order to study the effect of lime combined with intermittent and flooding conditions on the soil pH, Cd availability and its accumulation in tissues at the tillering, filling and maturity stages of rice, as well as enzyme activity and the microbial community in contaminated soil, a field experiment was conducted. The results showed that liming under flooding conditions is a more suitable strategy for in situ remediation of Cd-contaminated paddy soil than intermittent conditions. The availability of Cd in soils was closely related to the duration of flooding. Liming was an effective way at reducing available Cd in flooding soil because it promotes the transformation of Cd in soil from acid-extractable to reducible fraction or residual fraction during the reproductive growth period of rice. Compared with control, after liming, the concentration of Cd in brown rice was reduced by 34.9% under intermittent condition while reduced by 55.8% under flooding condition. Meanwhile, phosphatase, urease, and invertase activities in soil increased by 116.7%, 61.4% and 28.8%, and 41.3%, 46.5% and 20.8%, respectively. The high urease activity in tested soils could be used to assess soil recovery with liming for the remediation of contaminated soil. Soil microbial diversity was determined by the activities of soil acid phosphatase, urease and available Cd by redundancy analysis (RDA). The results indicated that the problem of Cd-contaminated paddy soil could achieve risk control of agricultural planting by chemical treatment such as lime, combined with various water regimes.

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