Enhancing Soil Quality and Plant Health Through Suppressive Organic Amendments

Abstract

The practice of adding organic amendments to crop soils is undergoing resurgence as an efficient way to restore soil organic matter content and to improve soil quality. The quantity and quality of the organic matter inputs affect soil physicochemical properties and soil microbiota, influencing different parameters such as microbial biomass and diversity, community structure and microbial activities or functions. The influence of organic amendments on soil quality has also effects on crop production and plant health. The enhancement of soil suppressiveness using organic amendments has been widely described, especially for soil-borne diseases. However, there is great variability in the effectiveness of suppression depending on the nature of the amendment, the crop, the pathogen, and the environmental conditions. Although the effects of organic amendments on soil properties have been widely studied, relationships between these properties and soil suppressiveness are not still well understood. Changes in soil physicochemical parameters may modulate the efficacy of suppression. However, the parameters more frequently associated to disease suppression appear to be related to soil microbiota, such as microbial biomass and activity, the abundance of specific microbial groups and some hydrolytic activities. This review focuses on the effect of organic amendments on soil microbial populations, diversity and activities; their ability to enhance plant health through disease suppression; and which of the parameters affected by the organic amendments are potentially involved in soil suppressiveness

Organic Amendments to Avocado Crops Induce Suppressiveness and Influence the Composition and Activity of Soil Microbial Communities

“…Many studies have focused only on phylogenetic traits, but microbial activity and functional diversity might be as important as phylogenetic traits when studying disease suppression (24,27).…”

“…However, the specific nature of disease suppression is unknown in most cases, and the particular mechanisms involved have not yet been identified (23). To determine which amendments have potential suppressive capability, it is important to identify the microbial populations and associated processes that could account for disease suppression (24).…”

Enhancement of soil suppressiveness against Rhizoctonia solani in sugar beet by organic amendments

“…The addition of organic compounds to soil has been described as a method to stimulate disease suppression of soil-borne pathogens, including R. solani (Bonanomi et al, 2010;Bonilla et al, 2012). However, especially for R. solani the effects of organic amendments on suppression rates are rather unpredictable (Bonanomi et al, 2010;Termorshuizen et al, 2006).…”

<b>Agrosilvopastoral system enhances suppressiveness to soybean damping-off caused by <i>Rhizoctonia solani</i> and alters <i>Fusarium </i>and <i>Trichoderma</i> population density

“…Biological factors such as microbial biomass and activity, and the abundance of specific microbial groups have been frequently associated with suppressiveness to several pathogens (Bonilla, Gutiérrez-Barranquero, Vicente, & Cazorla, 2012), although the main factor involved in soil suppressiveness may vary according to the pathogen (Bonanomi et al, 2010). It is difficult to distinguish between primary and secondary factors that are responsible for suppressiveness, what makes difficult the extrapolation or generalizations of the results obtained when only one situation is studied (Höper & Alabouvette, 1996).…”