Article Type : Research Article
Authors : Vazquez LL
Keywords : Microbiological products; Decentralization; Interactions; Habitat; Sustainability
There is a need to transit towards sustainability in the production and
use of bio products. To contribute to this, the agroecological transition is
addressed in the development of microbiological products. It focuses on the
importance of the decentralization of bio products towards local food systems.
It is argued that the sustainable development of bio products involves
facilitating functional interactions and improving the quality of the habitat
where they will be used. Also adopt new criteria to assess its sustainability.
The
history of technical products for crop nutrition and health has been
contrasting: those of mineral origin and natural bio preparations, which
predominated until the middle of the last century, were displaced by
agrochemicals. These have had a rapid development during more than 70 years of
intensive conventional agriculture (products, decision system and utilization
technology); however, its accumulated negative effects have put social and
scientific pressure in favor of the development of microbiological products
(MBP). The use of the latter, which have initially been valued as an
alternative with the same approach as the conventional product, is moving towards
their functional integration and the decentralization of production, which is
why they are considered sustainable biotechnologies for the food future. The
integration of MBP, which involves facilitating the synergy between bio
pesticides, bio fertilizers, bio stimulants and mycorrhizal inoculants, is in
high demand and puts scientific pressure on the methodological innovations
necessary to achieve their sustainable use, mainly to determine the
compatibility between the microorganisms used to develop them and their
interactions with the populations that cohabit in the rhizosphere and
phyllosphere of cultivated plants, as well as develop appropriate technologies
for their integration into crop practices and transform the design of the
agroecosystem as a quality habitat for these microorganisms [1]. Bio products
are a basic component of sustainable systems due to their contribution to
reducing external inputs, improving the quality and quantity of internal
resources, and their safety; furthermore, they can be generated from local
resources and promote endogenous regional development [2,3]. The agroecological
transition in the integration of MBP is a progressive process, which is
justified by contributing to the following functions: (a) reducing the toxic
load in agroecosystems, by replacing agrochemicals with bio products; (b)
facilitate the regeneration of the soil and crop microbiota, which was depleted
during intensive conventional agriculture and (c) contribute to the ecological
self-regulation capacity of the systems, through functional integration. Based
on recently published articles on decentralized biotechnologies and functional
integration of bio products, the current objective is to draw attention to the
need to move towards the sustainable development of MBP, in contrast to the
reductionist tendency to consider them simply as substitute products or
components of conventional technology packages.
The
different scientific and development institutions have their own research and
innovation systems to generate new bio products, position them in the markets
and achieve their use in agricultural production. However, although the demand
is still not satisfied and is growing, the progress made in recent years
suggests the need to move towards sustainability in the processes of mass
production and use by farmers. For intensive conventional agriculture, the
development of agrochemicals aimed to achieve their effectiveness in the
nutrition and health of crops; with the emergence of bio products during the
rise of organic agriculture, the purpose has been to replace agrochemicals with
biological products; however, the agroecological transition towards sustainable
agriculture conceives the decentralization of production processes and the
functional integration in their use, to facilitate the capacity for
self-management, the restoration of degraded natural resources and ecological
self-regulation in agroecosystems. The technological development of MBP (Figure
1) has two basic components: (a) mass production technology and (b) techniques
for use in agricultural production. As innovations advance towards validation
tests of the production process and its use in the soil-crop system,
biotechnologists and agricultural technicians are integrated into teams to
establish the characteristics of mass production and use, processes in which
adjustments are needed to different contexts with the participation of farmers.
This implies that the research and innovation processes for the development of
MBP are complex and require various scientific methodologies to carry out
transdisciplinary innovations. Mass production, which generally begins in
centralized facilities and is subsequently decentralized to territorial
production, also moves towards the adaptation of said technologies to different
socioeconomic contexts, a characteristic that leads to the generation of
different technological forms, be they industrial, semi-industrial and
artisanal. The generation of biotechnological products considers upward scaling
during the development process of a new product or technology, based on the
results of a smaller scale while, in decentralized biotechnologies, the
production process and the utilization system are scaled up in the territories
[4,5]. The sustainable production of fresh foods is moving towards contextual
self-management, a process that demands the decentralization of appropriate
biotechnologies; in turn, interactions are facilitated between actors who
obtain and use said products [6]. The practical use of bio products begins with
the substitution of chemical inputs, which is why the tendency is to use them
in the same way; however, due to their different characteristics (agrochemicals
are products of chemical synthesis and bio products are obtained through the
massive multiplication of microorganisms), they require integration into the
soil-crop system, achieving synergies between the different types of bio
products and moving towards habitat management (cropping and production system)
because they need certain conditions for their functioning as living organisms.
An
interesting example is the biocontrol of harmful organisms in the soil, where
it is necessary to promote synergism to make the most of the benefits of
microorganisms, as shown by the results of the compatibility study between the
different bioregulators that are applied, such as: Trichoderma spp., Rhizobium
sp., Azotobacter, T. paurometabola, and Glumus clarum, suggests the possibility
of the combined use of some of these agents in the management of root-knot
nematodes [7,8]. Likewise, to control phytopathogenic fungi, bio preparations
are used from native strains of Trichoderma, previously selected as effective,
under preventive forms of use and established doses, according to the nature of
the pathogen and the type of crop compatible with bio fertilizers and
biostimulants [9-11]. It was determined that organic matter enhances the action
of the bio product, with higher yields due to the stimulation of plant growth
and protection against pathogens above 80-90% [12]. The synergistic integration
of microbiological biopesticides, bio fertilizers, biostimulants and
mycorrhizal inoculants is in high demand and puts scientific pressure on the
methodological innovations necessary to achieve their sustainable use, mainly
to determine the compatibility between the microorganisms used to produce them
and their interactions with populations. That cohabit in the rhizosphere and
phyllosphere of cultivated plants, as well as develop appropriate technologies
for their integration into crop technologies and transform the design of the
agroecosystem as a quality habitat for these microorganisms. The functional
interactions of MBP in the cropping system (phyllosphere and rhizosphere) are closely
related to the design and management of the cropping system and the integration
of auxiliary vegetation structures, due to their contribution to the regulation
of the microclimate and pedoclimate. That is, the cultivation system is the new
habitat where these microorganisms will function for the nutrition, growth and
health of the crop, which is why it is important for its integration to be
sustainable [13]. Innovation for the adoption of agrobiotechnologies requires a
holistic approach in their integration into agricultural production systems, so
that synergies and functional interactions are facilitated that also contribute
to the economic rationality of the transition towards sustainable systems. The
strategy of decentralized biotechnologies for the transition towards
sustainable agriculture and food means that the processes of obtaining and
systems of use of these products are appropriate for the different
socioeconomic and ecological-environmental contexts where they will be used.
During
the agroecological transition towards local food systems, MBP are valued in
three dimensions: (a) articulated local production, whether industrial,
semi-industrial and artisanal, carried out by local entities; (b) its
contribution to sustainable nutrition and the regeneration of natural resources
degraded by conventional agriculture and (c) the role of the local
agroecological knowledge management system, to achieve its sustainable
integration. The strategy of decentralized biotechnologies for the transition
towards sustainable agriculture and food means that the processes of obtaining
and systems of use of these products are appropriate for the different
socioeconomic and ecological-environmental contexts where they are going to be
used, so that they are feasible to create capacities so that these agro
biotechnologies are integrated into local value chains. These can be obtained
through industrial, semi-industrial and artisanal processes, in decentralized
facilities at different levels in the territory. Adopting agro biotechnologies
has various logistical, legal, financial, knowledge management, innovation,
biosecurity implications, among others; In turn, the territorial scaling for
obtaining and using it must be designed as an incremental transition process
(Vázquez 2023). Some agro biotechnological products are imported or obtained by
national entities, so that access through local agricultural production depends
on various external actors; however, decentralized biotechnologies mean an
approach to the places where primary agricultural production is carried out,
whose main advantages are: (a) facilitation of access by farmers; (b) greater
possibilities of exchange between biotechnologists and users; (c) production planning
according to crops and seasons of the year; (d) possibilities of using elements
of the local biota in some bio products (example: microbiological
biopesticides); (e) feedback on effectiveness to improve product quality; (f)
greater contribution to the transition process towards sustainable systems.
Despite the international crises that have an impact on agricultural
production, mainly economic, energy, climatic and technological, the approach
of "protecting" and "enhancing" cultivation with agrochemicals
(fertilizers, pesticides and others) still predominates as the only option and,
sometimes replacing these with other products with a lower environmental impact
(organic fertilizers, biopesticides, botanical pesticides, etc.), which also
contributes to the product approach that characterizes what is known as
"green revolution syndrome" [14].which was later popularized as a
"technology package", a reflection of the reductionist approach that
has led to the technological crisis of contemporary agriculture. These
narratives, which still predominate in agrarian socioecosystems, constitute a
factor that slows down the integration of MBP and other appropriate
technologies to move towards sustainable agriculture.
It
is difficult to fully understand the functioning of a biological system [15].
The complexity of plant-soil-microorganisms-environment interactions is varied.
A complete understanding of all the relationships involved is unlikely;
however, the beneficial effects of biological interactions that stimulate crop
yields and improve plant health can be evaluated and some general strategies of
the interaction become evident [16]. In nature, all microorganisms live in
associations and form natural consortia that are more stable than laboratory
monocultures [17]. A microbial consortium is a microbial association that
contains two or more microorganisms, which can be archaea, fungi, bacteria,
viruses and algae [18, 19]. At a biotechnological level, they have been
classified according to their construction into: I- natural microbial
consortia, which are found living symbiotically in nature; II-artificial
microbial consortia, made up of different wild microorganisms that can grow
together symbiotically in a closed system to generate valuable products; III-
semi-synthetic microbial consortia, in these consortia wild and modified
microorganisms are grown together for a common purpose; IV- Synthetic microbial
consortia: include the co-culture of microorganisms that are metabolically
modified to increase their function and productivity [20]. There is a lot of
scientific evidence in this regard. For example, studies on the rhizosphere
microbiome and its interaction with the plant have revealed that plants form
their own rhizosphere microbiome, coordinated by root exudates [21], a
phenomenon that varies with conditions. Environmental conditions and the age of
the plant [22].
The
interaction of rhizosphere microorganisms, such as arbuscular
mycorrhiza-forming fungi, fungi of the genus Trichoderma and bacteria of the
genus Pseudomonas, usually classified as biological control agents and plant
growth promoting microorganisms, depend on this type of factors to express its
potential beneficial effects; however, the interactions between microorganisms
are complex and synergistic effects may occur that enhance the benefits for the
plant or, on the contrary, antagonistic effects or simply no effect may occur
[23].
For
practical purposes, the interactions that are facilitated with the technology of
using MBP in the soil-crop system can be of three types, among others:
· Between bio products. When more than one
bio product is mixed, with the purpose of facilitating synergies in its
activity (nutrition, growth stimulation, health) or reducing the energy costs
of the intervention; also, when the incorporation into the soil or sprinkling
on the crop has a sequence, which is due to complementary effects between them.
· Between the bio products and the biota
that inhabit the soil-crop system. Mainlydue to the importance of contributing
to interactions with the rhizospheric and epiphytic biota.
· Between the bioproducts and the conditions
of the soil-crop system as habitat. When the soil-crop system has a temporal
(crop succession and rotation) and spatial (multiple crops) design, the
edaphoclimatic conditions for the activity and establishment of the
microorganisms that make up the MBP are improved.
Facilitating the functional interactions of MBP constitutes a challenge during the agroecological transition, because it involves making disruptive innovations in the methods of use (treatment of seeds and seedlings, incorporation into the soil, integration into the irrigation system, integration into filial spraying, among others) and the redesign of the soil-crop system as an appropriate habitat, so that it is expressed in greater sustainability.
Figure 1: Agroecological transition in the
sustainable development of microbiological products for crop nutrition and
health.
Although
the specific habitat where MBP interact is the soil-crop system, they also
receive influences from the rest of the production system, mainly from the
structural design of the crop composition and the integration of auxiliary
vegetation structures. Conventionally, the habitat is studied and managed
according to the species or groups of biodiversity, considering their
conservation and the ecosystem services they must provide; while, socioeconomic
development occupies vast territories in urban and rural areas, with increasing
artificiality and the consequent generation of pollutant emissions, among other
negative externalities that, as a whole, reduce the quality of the habitat for
biodiversity in general, including human settlements [24]. However, this
approach has proven insufficient and, today, attention is turned towards a more
functional approach, which tries to establish causal relationships between the
characteristics of the organisms present and the processes and services of the
ecosystems [25,26]. The quality of the agroecosystem as a habitat facilitates
the functions of the associated biodiversity and the synergies in the use of
bio products, which is evident in its capacity for ecological self-regulation,
because multiple cumulative effects occur that contribute to the regeneration
and conservation of the biota in the environment. Soil, recovery and
conservation of the associated biota (rhizospheric, epiphytic, natural enemies,
pollinators) and higher quality of food, with lower environmental impact, among
others [27]. The multifunctionality of microorganisms in agricultural systems
is expressed according to a series of biotic factors, such as competition with
other microorganisms, the biological composition of the soil, plant-microorganism
recognition and vice versa. Likewise, abiotic factors, such as climate,
physical and chemical characteristics of the soil, which directly influence the
type of interaction of these organisms and the expression of beneficial or
detrimental effects, determining the development of plant species [28,29].
Several ecological theories argue that the efficient functioning of
agricultural production systems does not depend only on the elements of
biodiversity that are introduced and inhabit it, since diversity is not always
something inherent to stability pointed out, connectivity and habitat quality
are essential [30-32].
In
recent years, the need to pay greater attention to the effects of diversity on
the stability [33], and the occurrence of harmful organisms and their natural
enemies in agroecosystems [34] has been widely documented, as well as promoting
interactions that contribute to the ecological services of functional
biodiversity [35], including connections between production systems and natural
ecosystems [36]. The level of internal regulation of agroecosystems depends
greatly on the degree of diversity of plants and animals, and furthermore, this
agro diversity is the result of the interaction between the environment,
genetic resources and management, which modifies their functioning and allows
greater adaptability to extreme situations [37]. Property redesign attempts to
transform the structure and function of the agroecosystem by promoting
diversified designs that optimize key processes. The promotion of biodiversity
in agroecosystems is the key strategy in farm redesign, since research has
shown that [38]: (a) greater diversity in the agricultural system leads to
greater diversity of associated biota; (b) biodiversity ensures better pollination
and greater regulation of pests, diseases and weeds; (c) biodiversity improves
nutrient and energy recycling; (d) complex and multispecific systems tend to
have higher total productivity. Agroecology is a science that studies the
agroecosystem as a whole (holistically) and considers it as a complex system
[39], achieving a comprehensive approach to the processes that occur in it and
in this way, overcoming the simplistic view of industrial agriculture [40]. A
complex system can be described as a system composed of multiple elements that
interact in multiple ways, in which many properties depend on these
interactions and are known as emergent properties, of which the stability
(homeostasis) of an agroecosystem is a classic example and it does not depend
only on the identity of the components of biodiversity. The scaling of
biological control in Cuban agriculture has been fundamental in the
agroecological transition and greater sovereignty in pest management.
Furthermore, it has contributed to valuing the multifunctions of biodiversity
in the design and management of agricultural production systems, thus
generating new territorial dynamics and territorial governance [41].
After
the Second World War, agricultural production underwent a transcendental
technological change, which became the paradigm of productivism, based on the
intensive exploitation of land. This consisted of an accelerated process of
development of new technologies, mainly machinery and various implements,
fertilizers, pesticides and other agrochemicals, as well as technologies for
soil preparation and crop management, including genetic improvement to achieve
varieties with high response productive [42]. This hyper-technical
technological model established the limiting factors of its productive
efficiency, including the technical products that were needed for the growth
and health of the crops. Indeed, the intensification of agricultural production
implied greater productive efficiency and this was possible by subsidizing
crops with nutrients and eliminating harmful organisms that increased as a
consequence of the massive multiplication of their host plants. That is, it was
economically established that the main effect expected from technical products
is to increase the effectiveness of crop nutrition and health. These criteria,
established by agrochemicals, maintain their validity in the development of bio
products; because, the soil, the agricultural species and varieties and the
technologies of the cropping systems, which were generated during the rise of
conventional agriculture, are the same when the agroecological transition
begins. Therefore, they are farming systems that need these technological
subsidies. However, with the development of MBP, new decision-making and
application technology systems have been established, whose evaluation with
sustainability criteria considers the following criteria: (a) technical
efficiency in the control of populations of harmful organisms and nutrition of
crops; (b) synergistic integration between different bio products (effects,
energy savings); (c) its contribution to the reduction or elimination of the
toxic load caused by agrochemicals; (d) the facilitation of the functions of
the associated biota that inhabit the plant organs and the soil and (e) the
local capacity in access.
Unlike
agrochemicals, which are composed of specific molecules and additives, MBP have
reproductive structures of species or communities of microorganisms and the
substrate where they are preserved, which when used interact with the biota of
the agroecosystem, both to achieve greater effectiveness (nutrition, plant
growth, health), as well as to facilitate its persistence or establishment and
continuity of its positive effects. The recovery of soil biota (organic matter
decomposers, phytopathogen antagonists, rhizospheric biota, others); the
activity of the epiphytic microbiota that lives on the surface of leaves,
fruits and other aerial organs of plants; the activity of natural enemies of
pests (entomopathogens, antagonists, nematodopathogens), among others, with
evidence of sustainability in the integration of MBP. Several factors, which
are not important in the use of agrochemicals, negatively influence the effectiveness
of bio products, which in turn are determining factors in the sustainability of
the use of these biotechnologies [43], mainly the following: ( a) productive
specialization, including monoculture; (b) simple cropping system designs
(uniculture); (c) the integration of bio products and agrochemicals with
application substitution criteria; (d) direct exposure of the bio product to
direct solar radiation; (e) direct exposure of the bio product to surface air
currents; (f) low relative humidity in the soil and microclimate; (g) poor
quality of the bio product with respect to the concentration and viability of
the microorganisms that comprise it; (h) poor quality of water used to prepare
and apply suspensions; (i) prolonged exposure of the bio product to excess heat
before its use (transportation and preparation). Scientific centers and their
MBP development project teams generally focus on the same effectiveness
criteria of their similar agrochemicals, a situation that is logical because
the substitution of inputs demands this competition in effects [44]; however,
the research itself, mainly when it is transdisciplinary, incorporates new
sustainability criteria in its assessment by biotechnologists, technicians and
farmers.