›› 2017, Vol. 29 ›› Issue (12): 1963-1969.DOI: 10.3969/j.issn.1004-1524.2017.12.02

• Crop Science • Previous Articles     Next Articles

Effects of application rate of biogas slurry on growth, grain yield and heavy metals contents of rice

SHAO Wenqi1, JI Li1, SUN Chunmei1, JIANG Xiaojian2, WEN Tinggang1, TANG Jinling1, ZHANG Ankang1, *   

  1. 1. Huaiyin Institute of Agricultural Sciences of Xuhuai Region in Jiangsu, Huai'an 223001, China;
    2. School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China
  • Received:2017-05-27 Online:2017-12-20 Published:2018-01-08

Abstract: To investigate the appropriate application rate and method of biogas slurry on rice, the pig manure from large-scale farms was fermented as fertilizer in the experiment to study the effects of different application rate of biogas slurry on rice growth, yield and heavy metals concentrations. It was shown that when the total amount of biogas slurry was below 750 t·hm-2, the height and tillering ability of rice were improved, while the height no longer increased and tillering ability significantly (P<0.05) decreased when the application amount was above 750 t·hm-2. The application of biogas slurry had little effect on the fluorescence intensity of rice leaf, but inhibited the photosynthetic intensity, such as net photosynthesis rate, stomatal conductance, transpiration rate. Compared with conventional fertilizer treatment, the biogas slurry treatments significantly (P<0.05) decreased rice seed setting rate, filled grain number per panicle and 1 000-grain weight, yet increased the total spike number. The application rate of 600 t·hm-2 was appropriate to improve rice yield and its components. However, the biogas slurry treatments had potential risks for heavy metals accumulation in rice straw, as the contents of heavy metals such as Hg, Cr, Cu, As were increased in rice straw compared with conventional fertilizer. But, this risk was not found in grains. Furthermore, the contents of heavy metals in grain had no significant changes and were all met with the national standard of GB 2762-2012. In general, the application of 600 t·hm-2 biogas slurry (basic fertilizer:topdressing=1:1) was appropriate for rice production.

Key words: biogas slurry, fertilizer effect, rice, heavy metal, food security

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