Download Soil Microbial Community Crop production (yield)

The soil microbial community:
a key player in nutrient management
in agroecosystems
Amber Heijboer, Hein ten Berge, Peter C. de Ruiter, George A. Kowalchuk, Jaap Bloem
Background
Experimental setup
• The high loss of nitrogen (N) to the environment in agroecosystems is an
Brussel sprouts were grown in a pot
important issue in nutrient management.
experiment. Soil was mixed with
mineral and organic fertilizer (1:1).
• The challenge is to increase soil N retention capacity, while maintaining
Shown results are 6 months after
profitable crop production rates.
start of the experiment.
• Mixing mineral fertilizer with organic amendments has the advantage of
stimulating both crop production and N retention capacity.
Soil microbial community analysis:
• Soil microbial community structure plays a key role in decomposition
Phospholipid Fatty Acid (PLFA) analysis
processes and regulation of the N cycle.
• Quality of the organic amendment has a high impact on the soil microbial
5 treatments: 4 qualities of organic amendments + control
community structure, and determines to a large extent the success of the
nutrient management strategy.
Objective:
Assess
how
properties
(C/N
ratio;
digestibility)
of
Low digestibility
organic
amendments affect microbial community structure and hence soil N cycling.
High digestibility
Low C/N ratio
High C/N ratio
Manure
Straw
Lucerne silage
Maize silage
Control
(only mineral fertilizer)
Results
Straw
Manure
Luzern
Maize
Principal component analysis (PCA) of patterns in
phospholipid fatty acids (PLFAs) shows that different
qualities of organic fertilizer create distinct soil microbial
community structures.
Phospholipid Fatty Acids (PLFA)
Nitrogen storage in the microbial community
is impacted by the quality of organic fertilizer
Microbial N retention
Control
Organic amendments with a low C/N ratio
stimulate productivity of Brussels sprouts
Crop production (yield)
Soil Microbial Community
Microbial community structure
is treatment dependent
Low C/N ratio
High C/N ratio
Low C/N ratio
High C/N ratio
Conclusions
• The quality of organic amendments, added to the soil in combination with
mineral fertilizer, affects soil community structure.
• Combining mineral fertilizers with low C/N ratio organic amendments
increases plant productivity of Brussels sprout, compared to applying
only mineral fertilizer.
• Combining mineral fertilizers with high C/N ratio and/or a high digestible
organic amendments increases the amount of nitrogen stored in the
soil microbial community.
This experiment shows that applying mineral fertilizer in combination with
organic amendments changes soil microbial community structure. Those
changes are translated into effects on plant productivity and nitrogen
retention capacity, showing the important role of soil microbes in nutrient
References: Brussels Sprout www.grit.com; Soil bacteria - Courtesy the Research Center for Auditory and Vestibular Studies; PLFAs www.uic.edu
management.
Biometris, Wageningen UR
P.O. Box 100, 6700 AB Wageningen
Contact: [email protected]
T + 31 (0)317 481 431, M +31 (0)6 18 66 46 01
www.wageningenur.nl/biometris
Onderzoeksprogramma Biodiversiteit Werkt