**3.3 Production of arbuscular mycorrhizal fungi bio-fertilizers in arid lands**

Both conventional method and in vitro methods are practiced in arid areas to produce AMF bio-fertilizers. Several researches was focused on the increasing of plant production in arid land using AMF inoculum (**Table 2**), conventional method with AMF mixture was the most important technic of production adopted. Nevertheless, in vitro technic was also practiced such as by the energy and resource institute of India (TERI) [34]. They based on the faculty of Glomus genus to provide the possibility of using colonized roots as inoculum material with up to 80% of root colonization attained at 4 and 12 weeks [34, 39]. Despite, arid lands are often localized in underdeveloped country with low economical budget who cannot afford to allot enormous amounts in order to produce bio-fertilizers, so the conventional method remains the most appropriate technique under these conditions. In addition ecological conditions of arid lands give them specific characteristics that are not accommodating with all AMF strain. For that production of native AMF bio-fertilizers adapted to local conditions and to specific abiotic stress is essential [13]. Labidi et al. [39] developed a native AMF bio-fertilizer adapted to calcareous arid Tunisians soils. Abdelsalam et al. [38] produced AMF inoculum of desert saoudian areas using *Sorghum halepense* as trapping plant. Bencherif et al. [13] developed a specific AMF bio-fertilizer for arid saline soils. It is noted that in


**Table 2.**

*AMF bio-fertilizers produced in arid lands.*

all case, efficiency of AMF bio-fertilizers is related to the better combination AMF genotype/host plant genotype/adaptation to specific abiotic stress [13, 27].

### *3.3.1 On-farm method*

To have AMF bio-fertilizer produced at a large scale with low cost, studies has been developed to test the multiplication of AMF spores under field conditions, called the "on-farm method". These studies explore AMF colonization with strains isolates that are environmentally adapted to native environmental conditions, which potentially representing a low-cost alternative for farmers [26, 37]. This technic is based on sowing plants seeds or seedlings in intact soil cores or mixed soil samples for sufficient time to allow development of AMF symbiosis and then roots were sampled, processed and assessed to measure mycorrhiza formation [26]. Indeed, [41] showed that multiplication on-farm with *Rhizophagus clarus* and *Claroideoglomus etunicatum* grown in agro-industrial residues, such as sugarcane bagasse, is a good strategy for the multiplication of AMF, leading to excellent inoculum potential and large numbers of spores. As well as, the on-farm technic allows farmers and nursery workers to access inoculums with the most effective AMF strains for their culture and their soil and climate conditions; furthermore, they can produce seedlings already inoculated with adapted AMF strains, which enhancing their establishment of s in the field conditions. In addition Moreira et al. [26] produced AMF inoculum with *Rhizophagus clarus*, *Claroideoglomus etunicatum* species, and native AMF from pineapple and coffee plantations, using spores multiplied by the on-farm method to enhance the growth of pineapple and coffee plantlets. These authors concluded that AMF inoculum favorite growth of the commercial tested crops with a high viability of AMF spores. This method is recommended for arid land due to their specific AMF strain and low coast, it could be applied and generalized in order to developing agricultural practices in these areas. Furthermore, because fungi carry different amounts of nutrients for plants, they may affect the growth of plants differently [37], it is preferable to use mixed AMF strains adapted to native conditions which could maximize the absorption of limiting nutrients [26]. This phenomenon could provide more benefits compared to colonization with exotic AMF strains or with single AMF species. Moreover, the mixed inoculation of AMF might have the characteristic of complementarity, exploiting the best of each species that colonizes the plant [26–37, 41].

### **3.4 Formulation of AMF bio-fertilizers**

Formulation technologies largely take care of possible adverse environmental effects and factors that may render the inoculum ineffective [34]. In fact, biofertilizers are generally prepared as liquid suspension or more generally solid support containing different types of propagules: spores, fungal mycelium, mycorrhizal root fragments [7]. Generally AMF bio-fertilizers are presented with multi AMF species, which are closer to natural conditions; because in natural ecosystems it is rare to encounter only one species of mycorrhizal fungus. The presence of several fungal species allows the inoculum to respond to a greater diversity of culture conditions [13, 39]. Bio-fertilizer support can be composed of peat, vermiculite, lignite powder, clay, talc, rice bran, granulated rock phosphate, charcoal, soil, straw compost of rice or wheat otherwise a mixture of these materials. In current practice, for better framework life of the bio-fertilizer formulation, the support is selected on the basis of the viability of the microorganisms mixed with them. Likewise, the pre-sterilization of the support and its nutrient enrichment is the other strategy to improve framework, allowing AMF to be maintained

**85**

*Native Arbuscular Mycorrhizal Fungi and Agro-Industries in Arid Lands…*

in a non-competitive microenvironment. Sucrose, maltose, trehalose, molasses, glucose, and glycerol are additional nutrients and cell-protecting agents commonly used along with a support to ensure maximum cell viability and extended shelf life [4, 39]. After production, AMF bio-fertilizer may be in the form of granules,

• The micro granules, between 1 and 4 mm, are easily mixed with support of mycorrhizal plants or brought into the planting surface as close as possible to

• Very fine powders (particles <250 μm) make it possible to prepare a suspension which can be sprayed on growing media or injected into the soil at the base of plants already installed. This type of inoculum can also be used as a seed

• The tablets allow easy dosing of the inoculum to be placed in the plantation area. The inoculum provided is localized in one place and not distributed

• Associated with a praline, the inoculum is particularly suitable for plants with bare roots. In a single operation, the plant is inoculated and its roots protected.

• Liquid suspensions are suitable for coating seeds. These inocula can also be sprayed

The formulated AMF bio-fertilizers should be positioned near the roots, with avoiding the spreading products and favor the injection or burying method. Finally,

• Inoculated planting support, ready to use and particularly suitable for soil-less

○ Pre-inoculated plants (vine, chestnut, etc.) ready for planting and whose

○ Seeds coated with AMF propagules (mainly spores) which make it possible

○ Organic fertilizers and amendments containing AMF propagules [7].

The aim of our present study is to set up a production unit for AMF biofertilizers, which has the advantage of covering the biological deficit of arid soils, a problem which continues to degenerate more and more. Indeed, the installation of a bio-fertilizer unit must follow some criteria such as: appropriate production, location, construction space, equipment, machinery, other laboratory equipment and working capital. The bio-fertilizer production unit should be founded in a homogeneous area based on the interaction of soil characteristics, geomorphology and climate. This place should be qualified as a buffer to reduce the risk of contamination during the process of production and quality control. The overall architecture of the unit is the key element for the success of any economic project. In our case,

mycorrhization has been checked before marketing,

to spread and inoculate a plot in a single pass,

**4. Design of AMF bio-fertilizer production unit**

on growing media or injected into the soil at the base of plants [4–7, 39].

*DOI: http://dx.doi.org/10.5772/intechopen.94084*

powder, tablets, pralins, or liquid suspension:

the roots;

coating.

culture,

evenly over the roots.

it is also possible to produce "2 in 1" products:

#### *Native Arbuscular Mycorrhizal Fungi and Agro-Industries in Arid Lands… DOI: http://dx.doi.org/10.5772/intechopen.94084*

*Mycorrhizal Fungi - Utilization in Agriculture and Forestry*

species that colonizes the plant [26–37, 41].

**3.4 Formulation of AMF bio-fertilizers**

*3.3.1 On-farm method*

all case, efficiency of AMF bio-fertilizers is related to the better combination AMF

To have AMF bio-fertilizer produced at a large scale with low cost, studies has been developed to test the multiplication of AMF spores under field conditions, called the "on-farm method". These studies explore AMF colonization with strains isolates that are environmentally adapted to native environmental conditions, which potentially representing a low-cost alternative for farmers [26, 37]. This technic is based on sowing plants seeds or seedlings in intact soil cores or mixed soil samples for sufficient time to allow development of AMF symbiosis and then roots were sampled, processed and assessed to measure mycorrhiza formation [26]. Indeed, [41] showed that multiplication on-farm with *Rhizophagus clarus* and *Claroideoglomus etunicatum* grown in agro-industrial residues, such as sugarcane bagasse, is a good strategy for the multiplication of AMF, leading to excellent inoculum potential and large numbers of spores. As well as, the on-farm technic allows farmers and nursery workers to access inoculums with the most effective AMF strains for their culture and their soil and climate conditions; furthermore, they can produce seedlings already inoculated with adapted AMF strains, which enhancing their establishment of s in the field conditions. In addition Moreira et al. [26] produced AMF inoculum with *Rhizophagus clarus*, *Claroideoglomus etunicatum* species, and native AMF from pineapple and coffee plantations, using spores multiplied by the on-farm method to enhance the growth of pineapple and coffee plantlets. These authors concluded that AMF inoculum favorite growth of the commercial tested crops with a high viability of AMF spores. This method is recommended for arid land due to their specific AMF strain and low coast, it could be applied and generalized in order to developing agricultural practices in these areas. Furthermore, because fungi carry different amounts of nutrients for plants, they may affect the growth of plants differently [37], it is preferable to use mixed AMF strains adapted to native conditions which could maximize the absorption of limiting nutrients [26]. This phenomenon could provide more benefits compared to colonization with exotic AMF strains or with single AMF species. Moreover, the mixed inoculation of AMF might have the characteristic of complementarity, exploiting the best of each

Formulation technologies largely take care of possible adverse environmental effects and factors that may render the inoculum ineffective [34]. In fact, biofertilizers are generally prepared as liquid suspension or more generally solid support containing different types of propagules: spores, fungal mycelium, mycorrhizal root fragments [7]. Generally AMF bio-fertilizers are presented with multi AMF species, which are closer to natural conditions; because in natural ecosystems it is rare to encounter only one species of mycorrhizal fungus. The presence of several fungal species allows the inoculum to respond to a greater diversity of culture conditions [13, 39]. Bio-fertilizer support can be composed of peat, vermiculite, lignite powder, clay, talc, rice bran, granulated rock phosphate, charcoal, soil, straw compost of rice or wheat otherwise a mixture of these materials. In current practice, for better framework life of the bio-fertilizer formulation, the support is selected on the basis of the viability of the microorganisms mixed with them. Likewise, the pre-sterilization of the support and its nutrient enrichment is the other strategy to improve framework, allowing AMF to be maintained

genotype/host plant genotype/adaptation to specific abiotic stress [13, 27].

**84**

in a non-competitive microenvironment. Sucrose, maltose, trehalose, molasses, glucose, and glycerol are additional nutrients and cell-protecting agents commonly used along with a support to ensure maximum cell viability and extended shelf life [4, 39]. After production, AMF bio-fertilizer may be in the form of granules, powder, tablets, pralins, or liquid suspension:


The formulated AMF bio-fertilizers should be positioned near the roots, with avoiding the spreading products and favor the injection or burying method. Finally, it is also possible to produce "2 in 1" products:

	- Pre-inoculated plants (vine, chestnut, etc.) ready for planting and whose mycorrhization has been checked before marketing,
	- Seeds coated with AMF propagules (mainly spores) which make it possible to spread and inoculate a plot in a single pass,
	- Organic fertilizers and amendments containing AMF propagules [7].
