Document Type : Research Paper
Authors
1
Soil Science Department, Faculty of Agriculture, University of Tabriz, Iran.
2
Soil Science Depertment, College of Agriculture, University of Tabriz , Tabriz, Iran
3
Soil Science Department, Faculty of Agriculture, University of Tabriz, Iran
4
Tea Research Center, Horticultural Science Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Lahijan, Iran
5
Rice Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
Abstract
Conversion of rice straw and sewage sludge into hydrochars can reduce the organic matter decomposition rate soil and eliminate pathogens, pests and weed seeds. Present study aimed to investigate effects of rice straw, sewage sludge, and their hydrochars on agronomic traits and chlorophyll index in a Pb-spiked soil. The research was conducted as a factorial experiment in a completely randomized design with three replications and two factors of organic matter at 11 levels (control, rice straw, rice straw hydrochar, sewage sludge, sewage sludge hydrochar, rice straw + rice straw hydrochar, sewage sludge + sewage sludge hydrochar, rice straw + sewage sludge, rice straw hydrochar + sewage sludge hydrochar, rice straw hydrochar + sewage sludge, sewage sludge hydrochar + rice straw, and Pb at two levels of 0 and 500 mg/kg . The results showed that soil contamination with Pb significantly reduced leaf chlorophyll index, plant height, panicle dry matter, panicle length, leaf number, leaf width, and stem diameter. Application of sewage sludge and its hydrochar increased agronomic traits of rice and this increase was higher in presence of sewage sludge than its hydrochar. Rice straw application decreased panicle DW and leaf number and increased the ratio of shoot DW to that of root and had no effect on other traits. Rice straw hydrochar application reduced shoot and root DW, leaf number, and length. Integration of sewage sludge and its hydrochar with rice straw and its hydrochar can reduce negative effects of rice straw and its hydrochar and Pb toxicity.
Keywords
Main Subjects
)