## 4 Microbiota Disturbance Influences the Suppressive Properties
### Sustainable Agronotical Practices Re-Shape the Soil Microbiome
#### 4.2.3 Rotation, Crop Diversification, Intercropping and Cover Cropping  
By reviewing the most recent findings, authors have concluded that monoculture based on the most important horticultural and industrial crops has a significant relevance to the soil health-related concerns [99]. Monoculture may negatively impact on the multiple biotic and abiotic indicators of soil health, fertility, and crop yield. Long-term monoculture potentially can alter abundance, composition, richness, and diversity of the microbial consortia and enzyme activities. Monoculture can accelerate soil depletion by increasing the accumulation of toxic metabolites, salts and acids; reducing soil aggregation; altering the composition of soil aggregate-size classes; and decreasing mineralization, SOM, active carbon and nutrient contents. In contrast to monoculture, crop rotation can develop suppressive property, having a long history in the agronomical research [272]. It has been proved that crop rotation can increase yield [273] and support some of the essential ecosystem functions [81] such as SOC addition and its storage, nutrient cycling, and disease control [274, 275]. The types of crop used in rotation have strong implications in developing soil microbial structure. For example, maize is considered as a source of root exudation where 30% of the total photosynthetic is released in the rhizosphere in supporting soil microbe groups [190]. However, in order to elucidate the specific microorganisms from complex soil microbiota that predominantly contribute to suppression is difficult task. The increase in yield for crop rotation might be due to diversity that decreases soil pathogen abundance and virulence, although there are contrasting evidences as to the effect of crop rotation on disease control [193]. Another reason might be attributed to inclusion of non-host crops in the rotation cycle [276]. Crop rotation can enrich the soil of specific Rural communities that increase suppression [277]. For example, the increase of protozoan predation on bacterial communities can lead to enhanced 2,4-DAPG production, activating the disease suppression ability by the expression of biocontrol genes of rhizosphere associated _P. fluorescens_. [278, 279]. Crop rotation can also decrease microbial diversity with increasing crop diversity [193]. Some studies reported better disease control in monoculture than in crop rotation. For example, control of the take-all decline is better in wheat monoculture than in wheat rotation due to increased abundances of siderophore-producing fluorescent pseudomonads [280]. The benefits of crop rotation on disease control can be related to the diversification of the agronomical practices associated with the rotated crops, which could have selected specific microbiomes for pathogen suppression, as observed in an Italian area where long-term tomato monoculture was replaced by triannual rotation between durum wheat and cherry tomato in controlling fusarium wilt on tomato [113] by means of a specific group of microbiota positively correlated to wilk suppression. In contrast to monoculture, large-scale field experiments highlighted the importance of intercropping in increasing crop yield and reducing disease [281]. Intercropping can be a beneficial practice against the bacterial wilt of tomato [282] and fungal damping-off and root rot of lentil [283]. For example, pepper monoculture can lead to Phytophthoraobia flight outbreaks, but a maize-pepper intercropping system can reduce the spread of Phytophthoraobia might on pepper, which is attributed to the formation of \"root wall\" in maize root that acts as a physical barrier against theomycete [284]. Moreover, maize exudes a significant quantity of antimicrobial compounds that inhibit the growth and spread of _Phyophthora capsici_. Authors have studied the suppressive effects of peanut intercropped with the medicinal herb _Attractylodes lancea_ against fusarium wilt of peanut in China [285].