## 1 Introduction  
The modern agricultural systems are characterized by intensive cropping systems, deep tillage, continuous monoculture and low organic matter content [1]. Inappropriate management practices have resulted in depletion of the topsoil (0-20 cm) with increased soil acidity and salimization, low soil nutrient content and hampered ecological services and functions [2, 3]. Plant diseases caused by soil-borne pathogens such as take-all decline, damping-off, root rot and wilting can cause substantial economic yield loss in the major crops, increasing the soil decline [4, 5, 6]. Among the biotic factors of soil, soil-borne pathogens are among the major agents that can limit the productivity of the agro-ecosystems, being relatively difficult to control with resistant host cultivars [7]. Soil-borne pathogens include overall strains and isolates of filamentous fungi, oomycetes and bacteria Diseases such as damping-off, root rot, stem collar and crown rots and vascular wilting occurring in the pre- and post-emergence phases can be found in many croppingsystems, being primarily caused by a wide spectrum of oomycetes (_Pythium_ spp. and _Plytophthora_ spp.) and fungi (_Rhizoctonia_ spp., _Sclerotinia_ spp., _Sclerotinia_ spp., _Sclerotinia_ spp., _Fusarium_ spp. and _Verticillium_ spp. ), and also by bacteria (_Ralstonia_ spp., _Pectobacterium carotovorum_, _Erwinia caroovora_ and _Streptomyces scabies_) [8; 9; 10; 11]. Pathogens such as _Fusarium granimearum_ and _Rhizoctonia_ spp. can infect cereals, oilseed crops and pasture plants, being difficult to control due to their ability to persist in crop residues and litters for longer times through resistant propagules such as scleroia of _Sclerotinia_ and _Sclerotinium_ and _microsclerotic_ of _Verticillium_[12; 13; 14; 15]. Soil-borne diseases such as root rot of pea caused by _Aphanomyces euteciles_ are difficult to control with fungicides, being able to develop plant resistance [16]. The synthetic fungicides and chemical fumigants are commonly applied to reduce inoculum abundance of pathogens [12; 13; 14; 15], but their impacts on sustainable agriculture should be carefully assessed before being used for balancing benefits and hazards [17]. However, with the increasing awareness of sustainable agricultural practices, several fumigants such as 1,3-dichloropropene and chloropicrin have been restricted due to their negative impacts on the environment. Even methyl bromide was banned in 2004 by the Montreal Protocol for its ability to deplete the ozone layer and increase global warming [18]. More issues are raised by using pesticides that are not effective enough against a wider spectrum of diseases due to their negative effects on beneficial soil organisms [19] or that kill non-target organisms such as insects (bees), fishes, birds and other wildlife organisms [20] or have direct impact on humans and foods [21]. The only practical method to reduce yield loss is to avoid or reduce field infestation even in the presence of pathogens. In such cases, soil related to disease suppression could potentially act in reducing the productivity loss [16]. Disease-suppressive soil (DSS) can be one of the most effective tools in sustainable agriculture, whose indigenous microbial community effectively protects host plants against infection by pathogens by activating several biocontrol mechanisms [22; 23]. Soil suppressiveness has already been related to a great number of pathogens [24]. The use of DSS does not refer to the complete eradication of the pathogen from the soil system [25], but it refers to those soils in which disease development can reach the minimum loading level, even in the presence of the virulent strain of the pathogen and the susceptible cultivar of the host plant under environmental conditions favorable to disease [26]. Although it is of primary importance to understand the functioning of the DSS [27], relatively few soils with suppressive property have been described well [28].