JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2020, Vol. 44 ›› Issue (6): 140-146.doi: 10.3969/j.issn.1000-2006.201912004

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Characteristics of soil salinity and its effects on poplar growth in a silting coastal area of Northern Jiangsu Province

CHU Dongsheng1(), ZHENG Xu2, QIN Shenghua1, SHEN Shuxiang1, SHEN Haiping1, TANG Luozhong2,*()   

  1. 1. Yancheng City Dafeng Forestry Farm of Jiangsu Province, Yancheng 224136,China
    2. Co-Innovation Center for the Sustainable Forestry in Southern China,College of Forestry,Nanjing Forestry University,Nanjing 210037,China
  • Received:2019-12-03 Revised:2020-03-24 Online:2020-11-30 Published:2020-12-07
  • Contact: TANG Luozhong E-mail:cds3419@sohu.com;luozhongtang@njfu.edu.cn

Abstract:

【Objective】This study was performed to understand the characteristics of soil salinity and its relationship with poplar growth in a coastal saline-alkali land of Northern Jiangsu Province. 【Method】We analyzed the soil salinity of poplar plantation (Populus deltoides ‘I-35’), farmland and uncultivated saline-alkali land, and determined the diameter at breast height (DBH), height and survival rate of poplar trees in Dafeng Forestry Farm, Yancheng City, China. 【Result】The salt content of different soil types varied considerably; soil salinity (mass fraction) of farmland was generally less than 0.1%, soil salinity of poplar plantation was mostly less than 0.2%, and soil salinity of uncultivated saline-alkali land was evidently the highest. Soil with high salinity had marked characteristics of salt accumulation in the topsoil layer. In this study, the pH value of soil generally ranged from 8 to 9, with an average value of 8.23, which depicts alkaline soil. There were significant positive correlations among soil salinity, electrical conductivity and pH values. The fitting effect of the quadratic polynomial equation between soil salinity and electrical conductivity was the best. Additionally, the fitting effects of the exponential equation between soil salinity and pH values, and soil electrical conductivity and pH values were the best. There were significantly negative correlations between the soil salt content and survival rate, DBH and poplar height, which could be fitted by exponential equation or power equation. 【Conclusion】There were considerable differences in the soil salt content and salt characteristics among different utilization types of soil. Soil salinity had a remarkable effect on the growth and survival rate of poplar 35 (Populus deltoides ‘I-35’). When soil salinity was more than 0.3%, DBH, height growth and survival rate of poplar were significantly lower. When soil salinity was less than 0.2%, DBH, height growth and survival rate of poplar were normal.

Key words: silting coastal area, soil salt content, electrical conductivity, growth of poplar, survival rate

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