Chinese Journal of Agrometeorology ›› 2016, Vol. 37 ›› Issue (02): 131-142.doi: 10.3969/j.issn.1000-6362.2016.02.002

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Effects of Biochar and Straw Return on Mineral Nitrogen and pH of the Surface Soil in Farmland of the North China Plain

ZHANG Xing, LIU Xing-ren, LIN Guo-lin, ZHANG Qing-wen, ZHANG Qing-zhong,WANG Qin   

  1. 1.College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China; 2.Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agricultural Environment, Ministry of Agriculture, Beijing 100081; 3.Foreign Economic Cooperation Office, MEP, Beijing 100035
  • Received:2015-11-25 Online:2016-04-20 Published:2016-04-18

Abstract:

Based on the location experiment, which consisted of four treatments (CK, C1, C2, SR) with three replications: CK (single NPK fertilizer), C1 (biochar 4.5t·ha-1·y-1+NPK fertilizer) and C2 (biochar 9.0t·ha-1·y-1 + NPK fertilizer) and SR (straw return + NPK fertilizer). The effects of biochar and straw return on mineral nitrogen (N) and pH of the surface soil in farmland of the North China Plain in 2014 and 2015 were studied. Results showed that the dynamic trend of soil mineral N content (NO3--N, NH4+-N) were similar. Application of biochar and straw return significantly increased soil NO3--N (P<0.05). However, there were no significant effects on soil NH4+-N. Compared with SR treatment, C2 treatment was more helpful to increase soil NO3--N. The mineral N in the soil was dominated by NO3--N, and NH4+-N was kept at a low level. The contents of soil mineral N in the whole growth period of winter wheat was higher than in that of summer maize. Biochar significantly increased soil pH(P<0.05), and soil NO3--N was negatively correlated with soil pH(P<0.05), and soil NH4+-N was not correlated with soil pH. But soil NO3--N and NH4+-N were positively correlated with soil moisture content in each treatment(P<0.05). In short, adding biochar had greater potential in slowing N transformation, reducing N mobility and so on. The results can be used a scientific reference on improving soil quality and reducing soil N loss in farmland.

Key words: Biochar, Straw return, Mineralization, Nitrification, pH