Mitteilungen der Gesellschaft für Pflanzenbauwissenschaften Band 23

Mitt. Ges. Pflanzenbauwiss. 23: 238–239 (2011)
A soil survey for current fertility, pH and EC of greenhouses
with intensive vegetable cultivation in the North China Plain
Yuncai Hu 1 , Christoph Poschenrieder 1 , Zhiwen Song 2 , Wenlong Lu 2 and
Urs Schmidhalter 1
1 Chair of Plant Nutrition, Technische Universität München, Freising, Germany; 2 Tianjin Academy of
Agricultural Sciences, Tianjin, China. E-Mail: hu@wzw.tum.de
Introduction
The total area of vegetable crops planted under greenhouses or plastic film houses
was more than 2,500,000 ha in China in 2008, and China has become the country
that produces the most vegetable crops under greenhouses or plastic-film houses
(Yang et al. 2011). In order to obtain a high production, shallow-rooted vegetable
crops in greenhouses are intensively managed with high inputs of water and
nutrients, leading to degradation of soil quality and an increase in salt accumulation,
acidification and inducing nutrient imbalances and a high risk of nutrient losses to the
environment. Therefore, efficient management for nutrients is crucially important for a
sustainable vegetable production, and requires the understanding of the current
status of soil fertility pH and EC of greenhouses. Objective of this study was to survey
the soils in greenhouses for their status of current fertility, acidification and salinization
in Tianjin of the North China Plain (NCP). The NCP is the major area for the
vegetable production in China. Tianjin is located on the northeast of the NCP,
reached a vegetable growing area of 107,000 ha from total 420,000 ha arable land in
2010, and represents the typical intensive managed greenhouse vegetables in the
NCP.
Materials and Methods
Nine districts of Tianjin municipality were selected for the soil survey for greenhouses
and open fields in 2010, which cover all vegetable growing areas in Tianjin region.
163 soil samples from the depth of 30 cm were taken from greenhouses and open
fields to carry out to investigate the rapid nutrient accumulation, acidification and
secondary salinization of soils caused by excessive nutrient application for
greenhouse vegetables. Soil nitrate, CAL-P and CAL-K, pH and electrical conductivity
(EC) were analyzed.
Results and Discussion
This study demonstrates that soil NO3-N and P accumulation was very high for the
vegetable crops in greenhouse in Tianjin, which is in agreement with other studies in
the NCP in literature (Chen et al. 2004; Ju et al. 2006). In particular, soil available P
accumulation increased with the age of greenhouse. In contrast, our soil survey did
not find higher K and lower pH in the greenhouse vegetables compared with the
open fields. However, data here show that high nutrient accumulation in greenhouse
result in severe problem in salinity stress to most vegetable crops. 90% of the
investigated greenhouses have ECe of 2-8 dS m -1 , which affect yields of most
vegetable crops like green bean (most salt sensitive one), pepper, cabbage, carrot,
eggplant, lettuce, spinach, celery, cucumber and tomato. The similar findings of our
survey to the earlier reports in literature may suggest that there is an urgent need to
improve the farmers' current practices and strategies in fertilization management in