Organic Material Soil Amendment Effects on Root Rot and Sugarcane Growth and Characterization of the Materials

Abstract

Soil amendment with different organic materials was evaluated in greenhouse experiments for effects on root rot and growth of sugarcane. Materials included composts prepared from cotton gin trash, cottonwood bark, mixed hardwood bark, municipal solid waste, and municipal yard waste; municipal biosolids; and a sugar mill by-product, filterpress cake. Field soil, steam-treated field soil, and steam-treated soil infested with Pythium arrhenomanes were amended with nonsterile or steam-treated organic materials. A metalaxyl fungicide treatment was included for comparison. When added in nonsterile form, cotton gin trash compost, filterpress cake, and biosolids suppressed disease and increased plant growth in field soil and soil infested with P. arrhenomanes, but this ability was reduced after steam treatment. Bark composts were capable of suppressing root rot and increasing plant growth in field soil and Pythium-infested soil when added in either nonsterile or steam-treated forms. Plant growth in steam-treated soil was not promoted by nonsterile or steam-treated materials. Disease suppression provided by organic materials resulted in plant growth increases generally lower than those resulting from metalaxyl treatment in steam-treated soil infested with P. arrhenomanes, but some amendments resulted in growth increases comparable to those obtained with the metalaxyl treatment in field soil. Municipal waste composts had no effect or were detrimental to sugarcane growth. Differences in microbial community composition and chemical properties, including N content, C:N ratio, and other mineral nutrient levels, distinguished organic materials that may suppress disease and promote plant growth by different mechanisms. Microbial activity level of a material was an indicator of potential for disease suppression. The study results suggest that the severity of root rot in sugarcane may be reduced by amending soil with some organic materials.

Induction of suppressiveness to Fusarium wilt of chrysanthemum with composted sewage sludge

“…The induction of suppressiveness with the incorporation of sewage sludge should be mainly attributed to biological factors because the microbial activity and fungal and bacterial communities were greater in the substrates not thermally disinfested, which also correlated with greater suppressiveness. The increased microbial activity induced by the incorporation of sewage sludge and other organic residues was also observed by Chen et al (1988), Dissanayake & Hoy (1999), Cotxarrera et al (2002), Santos & Bettiol (2003), Abbasi et al (2004), Ghini et al (2007) and Lazarovits et al (2009).…”

Efeito do chorume líquido de suínos na podridão do colo e tombamento de plântulas de feijoeiro causadas por Sclerotium rolfsii

“…Além dos fatores citados, a quantidade e a forma dos nutrientes contidos nos compostos orgânicos podem interferir no efeito sobre as doenças de plantas (Dissanayake & Hoy, 1999). A supressão da podridão de esclerotínia na alface, obtida com lodo de esgoto compostado, foi associada com o aumento dos níveis de N, P, Ca e Mg no solo, como, também, ao aumento da atividade microbiana (Lumsden et al, 1986 2489,9; 1387,6; 375,37; 166,63; 104,48; 14,04; 21,07; 28,66 a temperatura mínima diária variou de 4,6 a 15,6°C, a temperatura máxima de 14 a 26,6°C, a temperatura média de 9,6 a 18,8°C, a umidade relativa do ar de 65,2% a 98,9% e a precipitação pluviométrica total foi de 148 mm.…”

“…Os Dissanayake & Hoy (1999) concluíram que o aumento da atividade microbiana, provocada pela aplicação de matéria orgânica ao solo, e a própria microbiota contida no material orgânico, foram os responsáveis pelo controle de doenças em pepino e cana-de-açúcar causadas por Pythium ultimum Trow e P. aphanidermatum, respectivamente. A atividade microbiana do solo é aumentada durante a decomposição da matéria orgânica e se traduz em ação antagônica entre os microrganismos, com mecanismos de ação de antibiose, competição e parasitismo (Millner et al, 1982).…”

Efeito de lodo de esgoto sobre patógenos habitantes do solo e severidade de oídio da soja

“…Diversos autores correlacionam a atividade microbiana com a supressividade aos patógenos do solo (3,7,8,12,14,23,24,33). No presente trabalho não foi possível realizar essa correlação para R. solani, pois apesar de outros estudos na mesma área demonstrarem aumento da atividade microbiana nas maiores doses de lodo de esgoto (7, 13, 17), os dados de tombamento e severidade apresentaram considerável variação.…”

“…de Bary (27,28) (28). O modo pelo qual o lodo de esgoto reduz a severidade das doenças está relacionado com o aumento da atividade microbiana no solo e à própria microbiota contida no material orgânico (14,18,33).…”