Agriculture Reference
In-Depth Information
harmful microorganisms provide a hygienized product that helps protecting the soil
and crops against soil-borne diseases and weeds. An advantage of the composting
process is the suppressive effect of compost on plant disease (Pascual et al.
2002
;
Bernal-Vicente et al.
2008
). Crops growing with compost amendments seem to be
less susceptible to disease than those grow without compost application (Suarez-
Estrella et al.
2007
).
Crop residues incorporation or their compost might have the same impact on the
environment; they have to be applied in right timing and under the right conditions.
If crop residues/compost is rich in soluble nutrients then in humid environment a
risk of leaching these nutrients, especially nitrate, into the groundwater is feasibly
possible. Also, if their C/N ratio were not in the optimum range then soil N might
be depleted due to microbial growth, which might negatively affect crop growth.
1.5
The Challenge of Ecological Intensification
Food security and safety, environmental pollution, biodiversity loss, climate chang-
es, water shortages, and non-renewable resources depletion are the global chal-
lenges for the future agriculture. As a response, inefficient use of land, water and
nutrients resources must be terminated or minimized maintaining increased crop
production (Foley et al.
2011
). Agroecological intensification approaches are under
investigation as suitable tools to face these challenges. In this framework, Agroeco-
logical practices might play a leading role as relevant part of the solution (Tscharn-
tke et al.
2012
). Organic agriculture has to improve and to renew its tools from
both scientific and technological point of view to attain economic, social and envi-
ronmental sustainability, increasing productivity using efficiently natural resource
(Altieri
2002
). The theoretical maximum yield is based on the crop's genotype and
on structural environmental parameters such as available photosynthetically active
radiation and temperature. Biotic and abiotic constraints such as nematodes, pest
and disease pressure, weeds competition, nutrients deficiency, water stress, lack of
pollination, soil quality and cropping history are the cause of obtaining lower yield
than the theoretical one (Bennett et al.
2012
). Although one sole factor may play a
relevant role, it is more likely that combinations of different factors mark the yield
decline. Conventional intensification aims to close this yield gap by conventional
methods with known negative externalities on the surrounding ecosystems and the
long-term depletion of the natural resources of the agroecosystem itself. On the
other hand, ecological intensification aims to improve the ecological services with-
out increasing the anthropogenic input. It could be achieved by two approaches,
which are not mutually exclusive: service replacement and service enhancement
(Bommarco et al.
2012
). In the case of on-farm composting and internal nutrients
and resources recycling, the replacement effect due to compost application is the
reduction of other off-farm sources of nutrients while, the service enhancement is
a replacement plus a boost effect of the soil nutrients supply service both increas-
ing the yield and reducing the adverse environmental impact of the agroecosystem.
