Compost and Manure Mediated Impacts on Soilborne Pathogens and Soil Quality

Abstract

Root rots of snap bean (Phaseolus vulgaris L.) and sweet corn (Zea mays L.) cause economic losses to farmers. This study was conducted to determine whether dairy manure amendments suppressed root diseases and to describe relationships between disease severity and soil characteristics. Field plots were amended with high or low rates of fresh or composted dairy manure solids in 2001 and 2002. Soils were collected at 2 and 12 mo after the first amendment and 2 and 6 mo after the second amendment. Greenhouse bioassays were conducted to assess severity of damping‐off (DO) of cucumber (Cucumis sativus L.) and root rots of bean and corn. Soils were analyzed for soil free (fPOM) and occluded (oPOM) particulate organic matter content, rate of hydrolysis of fluorescein diacetate (FDA), arylsulfatase activity, microbial biomass C, and water‐stable aggregation (WSA). Two months after amendment, all amendments (except the low rate of manure) reduced the severity of DO 30%, bean root rot 29%, and corn root rot 67%. Twelve months after amendment, amended soils were no longer suppressive. All amendments were suppressive after re‐amendment the following year and no longer suppressive 6 mo later. In Year 1, significant suppression was observed across all diseases when fPOM content was ≥12.1 g cm−3, FDA activity was ≥2.88 μg FDA min−1 g−1 dry wt, and microbial biomass was ≥91.6 μg C g−1 dry wt, and these levels were proposed as suppressive thresholds. Only the FDA threshold held up over all sampling times.

Risks and benefits of soil amendment with composts in relation to plant pathogens

“…The microbial activity of different composts or compost amended soils, determined by measuring the hydrolysis of fluorescein diacaetate (FDA), dehydrogenase activity, or CO 2 evolution rate, has been used as an indicator for suppression of Pythium and other root rots and damping-off diseases (Chen et al 1988;Dissanayake and Hoy 1999;Scheuerell et al 2005;Darby et al 2006;Giotis et al 2009). However, the technique of using FDA activity to predict disease suppressiveness has not been found to be consistently reliable (Quesnel et al 1997;Erhart et al 1999;Termorshuizen et al 2007;Rotenberg et al 2007).…”

Compost Use in Organic Farming

“…When composted dairy manure solids were applied at 28 and 56 t ha −1 (dry wt. ), they reduced the severity of Pythium damping-off of cucumber by 30%, of bean root rot by 29% and of corn root rot by 67% 2 months after amendment (Darby et al 2006). Such high amendment rates, however, cannot be applied year after year for environmental and economic reasons.…”

<b>Soil properties and cowpea yield after six years of consecutive amendment of composted tannery sludge

“…Previous studies showed that soil properties, soil organic matter, and crop yield could all be improved by the addition of different types of compost (Darby, Stone, & Dick, 2006;Mbarki et al, 2008;Arthur, Cornelis, & Razaghi, 2012). In particular, improving the organic matter in soil is known to promote many benefits, including increased soil fertility, improved soil structuration, and reduced soil bulk density (Lal, 2014).…”