## 2 Soil-Borne Plant Pathogens and Microbiota Determine Disease Suppression  
Disease suppression can be conceptually simplified with a triangle consisting of three major determinants: plant, pathogen and environment [53]. As soil microbes and pathogens share a common space in the rhizosphere, their interactions have a great influence on plant productivity [54]. Since plants are the main providers of soilC stocks and are an energy source, plant diversity affects the composition and structure of microbial communities. The soil physicochemical properties such as texture and clay content, pH, electrical conductivity, soil nutrient, soil organic carbon (SOC) and soil organic matter (SOM) determine microbial activities for the growth and development of the microbiota, giving them an optimum habitat [34]. In addition, crop management practices such as the continuous and rotational cropping systems, tillage, fertilization, amendment by compost, mulching, weeding and irrigation can significantly manipulate the soil, affecting its own microbiome [55; 56; 57]. It is nearly an impossible task to study the roles of all factors independent of the disease suppression, and thus researcher needs to address them simultaneously in an integrated approach [58]. Understanding the disease model based on the mutual interactions between the host plant, virulent pathogen and environmental conditions favorable for disease development, it can be possible to study the complex systems of DSS for a pathogen/host system [53]. The environmental component needs to be manipulated, being specifically addressed to developing tailored DSSs by reducing their conduciveness even in the presence of the pathogen-host system [34]. Unless the soil properties have been significantly modified to the maximum suppresses level or the virulent pathogens have mutated into non-pathogenic strains, the persistence of disease suppression usually lasts long, even with the repeated introduction of pathogens into the suppressive soil [32]. Compost, rice straw, animal manure, green-waste, etc., are OAs that have disease-suppressive attributes against a wide spectrum of pathogens through their influence on soil microbiota [59; 60]. However, despite the amended soil showing satisfactory disease biocontrol properties either in the laboratory or under controlled conditions, there is still a major need to achieve the same results under field conditions [61; 62]. Such a response is attributed to the complex and specific interactions between the three components of the disease triangle model by better mixing of the compost-enriched bio-inoculants with the soil. Previous authors have reported that the degree of suppressiveness is linked with soil features such as physical conditions, fertility level, biodiversity and abundance of the biota and soil management practices. The use of animal manure modifies the soil's physical, chemical and biological parameters, affecting crop disease and survival of the pathogen, where _Pythium_ spp. suppression was linked to volatilization of ammonia from manure amendments [61; 62]. These authors also documented that application of liquid swine manure reduced the wilting occurrence of common scab in potato fields. Finally, they showed a more significant reduction in root disease of the red set site strawberry in the fields treated with steer/pultry and dairy manure compost than in the comparable manemended soil. DSS has been observed since the 1940s in suppressing Phytophthora root root in avocado plants (Queensland, Australia), which remained healthy after more than 40 years despite the soil was exposed to an environment highly favorable for disease development. Afterwards, others examples reported are _S. scabies_[63], _Pythium splendens_[64], _Pythium ultimum_[65], _Thielavopsis basicola_[66], _Phythothoma cinnamomi_[67], _Phythothoma infestans_[68], _Fusarium oxysporum_[69], _Rhizoctonia solani_[70], _Gaeumannomyces graminis_ var. _tritici_[71], _Ralstonia solanacarum_[72], _Aphanomyces euteiches_[73] and _Plasmodium brassinae_[74].