Agro-Ecological
SOIL BIOTA & INVESTMENT RETURNS
Soil biota and investment returns are probably two things you are not used to seeing mentioned in the same
sentence, in fact quite possibly in the same paper or article.
They are however strongly linked from the perspective of farmland investment.
A recent scientific paper in the Journal of Applied Ecology with the snappy title of ‘Soil biota enhance
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agricultural sustainability by improving crop yield, nutrient uptake and reducing nitrogen leaching losses’ ,
rather reemphasised this point and we thought we would share some of its more interesting insights with you.
Background
Firstly a little background on soil organisms. The activities of these microscopic members of the soil ecosystem
drive nutrient cycling and make nutrients available to plants, or store them in the soil. Furthermore soil biota
and their interactions are important for nutrient mineralisation and plant nutrition.
AMF
There is often a focus, particularly within ecological management systems on arbuscular mycorrhizal fungi
(AMF), a type/group of fungi that live in symbiosis with the majority of plants, including agricultural ones. AMF
mobilise nutrients from soil, transfer them to plants and improve plant nutrition. They can also reduce
phosphorus (P) loss from leaching.
Additional research indicates that interactions between soil fauna and AMF result in positive effects on plant
biomass and plant nutrition. Such interactions can also deliver highly efficient nutrient cycling and enhanced
mobilisation from soil resources with an effective pathway to plants. The promotion of internal nutrient cycling
reduces the need for external nutrient inputs (ie fertiliser). In short this in an agricultural context promotes
production performance and growth.
From the research:
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enriched soil life increased crop yield, nitrogen(N) and P uptake; and
strongly reduced leaching losses;
enriched soil life also increased P mobilisation from soil and overall increased nutrient-use efficiency.
Synthesis and Conclusion
Soil biota are a key factor determining resource efficiency in agriculture, through increasing the availability of
nutrient resource, reducing the need for nutrient input (fertiliser), reducing leaching (nutrient losses)and
delivering superior crop performance.
The research indicates that farming practices which favour a rich and abundant soil life e.g. reduced tillage,
organic farming and crop rotations, can reduce input cost, environmental impacts (and therefore
costs/limitations) and enhance crop yield.
In an investment sense this means management systems that support superior soil life in turn are more likely
to deliver superior investment returns.
References
1.
Bender, S. F. & van der Heijden, M. G. A. (2015). Soil biota enhance agricultural sustainability by
improving crop yield, nutrient uptake and reducing nitrogen leaching losses. Journal of Applied Ecology,
52(1), 228-239. http://dx.doi.org/10.1111/1365-2664.12351
www.agro-ecological.com
Glossary
Disclaimer
Soil Biota - Soil life, soil biota, soil fauna, or edaphon is
a collective term that encompasses all the organisms
that spend a significant portion of their life cycle
within a soil profile, or at the soil-litter interface. These
organisms include earthworms, nematodes, protozoa,
fungi, bacteria and different arthropods.
This document is not directed to, or intended for
distribution to, or use by any person or entity who is a
citizen or resident of, or located in any locality, state,
country or other jurisdiction where such distribution,
publication, availability or use would be contrary to law or
regulation or which would subject Agro-Ecological
Investment Management ("AEIM") to any registration or
licensing requirement within such jurisdiction.
Arbuscular mycorrhizal fungi - "Arbuscular
mycorrhizae" is the scientific way of referring to a
specific type of plant fungi of the Glomeromycota
phylum (one of six fungal phyla), which has had a
symbiotic relationship with at least 80% of vascular
plants. Arbuscular mycorrhizae may be the most
abundant type of fungus on Earth. The fungus helps
the plant absorb water and nutrients by vastly
increasing the surface area of the roots with its hyphae
— long, branching filamentous cells. In return, the
fungus gets valuable carbon and other essential
biochemicals. The singular form of "arbuscular
mycorrhizae" is arbuscular mycorrhiza.
The information contained in this document has not been
independently verified and no representation or warranty,
express or implied, is made to, and no reliance should be
placed on, the fairness, accuracy, completeness or
correctness of the information or opinions contained
herein. Prospective Investors should not construe the
contents of this document as legal, tax, investment or
other advice. Neither AEIM, their representatives, nor
their respective affiliates shall have any liability
whatsoever for any loss whatsoever arising from any use
of this document, or its content, or otherwise arising in
connection with this document.
What separates arbuscular mycorrhizae from other
forms of fungi that live within plants is the hyphae of
the mycorrhizae pierce the cell walls of the host plant.
Within the plant, branching structures called
arbuscules serve as the interface of nutrient exchange
with the plants. These go in and out of cells. The
symbiosis is so close that the expression of DNA of the
plant changes in cells where arbuscules are present,
the cell's cytoskeletons form around the arbuscules,
and the cell's vacuoles shrink to make room for the
structures.
Soil fauna – see Soil Biota above.
Mobilisation - is the process whereby plant nutrients
held within the soil, are released by the actions of
microbes, particularly arbuscular mycorrhizal fungi,
allowing them to be absorbed by plants.
Leaching - with reference to a soluble chemical or
mineral, to drain away from soil, ash, or similar
material by the action of percolating liquid, especially
rainwater.
Tillage – the act, process of cultivating land.
Agro-Ecological
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