Making soil biodiversity matter for agriculture - Microbial Ecology in Sustainable Agroecosystems - page 274

biodiversity to reduce pests and pathogens can be useful and should be considered for
the maintenance and sustainability of agriculture worldwide.
Progress on biocontrol can and is being made, but to achieve sustainability, other dis-
ciplines must recognize the crucial importance of the belowground-aboveground con-
nection. The development of plants with genes to withstand drought or other targeted
characteristics is not useful unless the interactions of the belowground organisms common
to the soil type are included. The Global Soil Map ( http://www.globalsoilmap.net ) (see
Barrios et al., 2012), a digital soil map of the world that is freely accessible online, is provid-
ing new chemical and physical soil data on Africa's degraded and fertile soils to encour-
age better land use and soil conservation. Sachs et al. (2010) have called for this effort to
be part of an agricultural monitoring network. However, unless an understanding of soil
biodiversity underpins this monitoring, control of pests and diseases will likely continue
to be through synthetic chemical application. A pilot project is examining soil biodiversity
in a few countries to coincide with the abiotic data of the Global Soil Map Project (D.H.
Wall and N. Fierer, unpublished data, 2012). This will provide information on soil habitat,
plant and animal pests and pathogens, as well as multitrophic levels of organisms that are
responsible for long-term, sustainable soil fertility. The value of linking projects such as
the Global Soil Map with soil biodiversity is the ability to design new ways for agriculture
to reach the potential to feed people and to cope with climate change in the future (Ostle
et al., 2009; Woodward et al., 2009; van der Putten et al., 2010). In the absence of interna-
tional climate change policy, Woodward et al. (2009) urged scientists to move forward with
research addressing biological uncertainties, one of which, carbon sequestration, involves
the soil food web in both natural and agricultural ecosystems.
10.5 Concluding comments
Many of the most pressing and globally recognized challenges to human societies are tied
to soil and soil organisms. Human activities are irreversibly impacting Earth's ecosystems
at a rapid pace, and these activities are having major global impacts on soils. Sustaining
soils, their biodiversity, and their ability to provide ecosystem services is now one of
society's major global challenges, as evidenced by numerous environmental governance
policies that include soil. Hans Jenny, a consummate early soil scientist and pedologist,
included soil biota as a soil-forming factor key to the study of soil science. However, in
recent years, the use of fertilizers and the need for strategies to reduce greenhouse gases
have somewhat marginalized the study of soil invertebrate-microbial interactions from
much of soil science. What is yet to be resolved by the scientific community as a whole,
and politicians and funding agencies, is that addressing these environmental challenges
will require increased understanding and integration of the physical aspects of soil sci-
ence with soil biology and ecosystem services (Woodward et al., 2009; van der Putten et al.,
2010). While soil biodiversity alone will not provide solutions, including understanding of
its interactions with biocontrol, climate mitigation, and water quality may encourage new
scenarios of landscape management. We need to make better use of what we know, gener-
ate key new knowledge, and expand our use of this knowledge and technology. Beyond
this, there is a need to agree on measures and standards for quantifying ecosystem services
provided by soil organisms and to implement these into sustainable management strate-
gies and ecosystem monitoring assessments at landscape scales. Gathering the evidence
and deciding on the essential new knowledge to reduce uncertainties in response to mul-
tiple global change drivers of climate change and loss of species on ecosystem processes
require that we move quickly to include the soil biological processes and their services.