Page 4 - Molecular Soil Biology

Molecular Soil Biology (online), 2011, Vol. 2 No.1, 1-8
ISSN1925-2005 http://msb.sophiapublisher.com
- 1 -
Research Letter Open Access
The Classification Criteria for NO3
- Type Soil Secondary Salinization in
Cucumber Cultivated Greenhouse
Jinjin Zhang 1,2 , Xun Li 1,2 , Zengqiang Duan 1
1. The State Key Laboratory of the Soil and Agricultural Sustainable Development, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008,
P.R. China;
2. Graduate School of Chinese Academy of Sciences, Beijing 100049, P.R. China
Corresponding author email: szhzh2000@163.com; Author
Molecular Soil Biology, 2011, Vol.2 No.1 doi: 10.5376/msb.2011.02.0001
Received: 24 Feb., 2011
Accepted: 16 May, 2011
Published: 29 Jue., 2011
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Zhang et al., 2011, The Classification Criteria for NO3
- type Soil Secondary Salinization in Cucumber Cultivated Greenhouse, Molecular Soil Biology,
doi:10.5376/msb.2011.02.0001
Abstract The use of nitrogen fertilizers in intensive agricultural systems in China has dramatically increased for protected vegetale
farming in recent years. The excessive use of nitrogen fertilizer has obviously resulted in salinizing soil, namely soil secondary
salinization (short for SSS), which has become a significant environmental stress for crops, such as cucumber cultivated in
greenhouse, in the protected farming in China. Therefore it is urgent and necessary to propose some guidelines for farmers to manage
of the SSS problem in the areas of facility agriculture. In this study, the criteria of SSS classification based on the concentration of
NO3- was studied in cucumber cultivating greenhouses (Cucumis sativus L. cv. Dongfangmingzhu) in Taizhou, Jiangsu province,
neighboring Shanghai of East China. After the soils in the tested greenhouses were treated with different concentrations of nitrate, the
SSS levels expressed by electrical conductivity (EC) were detected at 0.89 ds/m for control, 2.78 ds/m for treatment 1 (T1), 3.65
ds/m for treatment 2 (T2), 4.66 ds/m for treatment 3 (T3) and 6.15 ds/m for treatment 4 (T4). The results showed that there were
significant relationships between NO3- contents and soil EC in the surface soil, which indicated that the changes of soil characters
resulting from the changes of nitrate concentrations in soil in the greenhouse should be used as criteria for classifying the ranks of the
NO3- type SSS. The ranks of the NO3- type SSS was significantly related with the plant height and yield of cucumber (p < 0.05). In
this research, we proposed the criteria of classification for NO3- type SSS in cucumber cultivated greenhouse in Delta of Yangtze
River with five ranks based on the effects of SSS on the plant height and yield of cucumber, that is: level Ⅰ: 0.89 ds/m < EC < 2.03
ds/m, level Ⅱ: 2.03 ds/m < EC < 3.76 ds/m, level Ⅲ: 3.76 ds/m < EC < 5.32 ds/m, level Ⅳ: 5.32 ds/m < EC < 6.15 ds/m, and level
Ⅴ: EC > 6.15 ds/m. This study might provide a practical guideline for evaluating NO3- type SSS in facility agriculture, and also
might be importance of the protected vegetable farming, particular in cucumber cultivated in greenhouse and plastic covering house,
to monitor and adjust salinity in soil for .
Keywords Soil secondary salinization (SSS); NO3- type SSS; Classification criteria; Protected farming; Facility agriculture;
Cucumber (Cucumis sativus L.)
Background
In recent years, The use of nitrogen fertilizer has been
dramatically increased in intensive agricultural
systems, particular in protected vegetable farming in
China, which results in soil salinization due to large
amount accumulation of nitrate in soil, that is
so-called soil secondary salinization (SSS) in the
protected farm (Kitamura et al., 2006). Nowadays,
SSS becomes one of the major negative factors that
hinder sustainable development of agricultural
production in the area of protected farming in China
(Yu et al., 2005). Cucumber (Cucumis sativus L.) is
one of the major vegetable crops cultivated in
greenhouse and protected farm, which is considered to
be a moderately sensitive crop to salinity (Ayers and
Westcot., 1985; Dorota, 1997). It was reported that
overuse of nitrate will retard the growth and
development of cucumber in the greenhouse (Yang et
al., 2010; Kotsiras et al., 2002). There are some
studies on the response of cucumber to salinity
reported (Trajkova et al., 2006). However, little
information involved in the classification of the NO3
-