Nutrient‐rich compost versus nutrient‐poor vermicompost as growth media for ornamental‐plant production

Abstract

A comparative study on the suitability of one compost and two vermicomposts, obtained from the same batch of tomato-crop waste, as growth media for ornamental plant production was carried out. Each material was mixed with Sphagnum peat at 100 : 0, 75 : 25, 50 : 50, 25 : 75, and 0 : 100 (peat control) proportions by volume. Two ornamentals (Calendula officinalis, Viola cornuta) were sown and grown in the 13 substrates. Substrates were characterized physically and chemically. Seed germination, total leaf chlorophyll (SPAD units), plant growth, and plant nutrient concentrations were determined. The compost and the vermicomposts were markedly different from peat. Compost and the vermicomposts had greater bulk density and lower total porosity than peat. Compost had larger aeration and lower water-holding capacity than vermicomposts and peat. Compost and vermicomposts were alkaline (pH = 8.8 on average) whilst peat was acidic (pH = 5.9). Electrical conductivity was low in peat (0.23 dS m -1 ) and vermicomposts (0.65 dS m -1 ), and high in compost (2.85 dS m -1 ) due to the high concentrations of K + and SO 2À 4 . Mixing compost and vermicomposts with peat produced substrates with intermediate characteristics. Physical properties were within adequate range for all mixes except for the compost ones. pH was within adequate range only in pure peat, and salinity was extremely high in the compost mixes. Compost was phytotoxic, as shown by the strong reduction of seed germination, chlorophyll content, and plant growth of both ornamentals. Vermicomposts did not affect seed germination but reduced plant growth, though much less than compost. Mixing these materials with peat improved germination and growth. The diluted materials (compost at the 25 : 75 and vermicomposts at the 50 : 50 and 25 : 75 proportions) produced good-quality plants.

Linking biochar properties to biomass of basil, lettuce and pansy cultivated in growing media

“…In the present study, lettuce and pansy biomasses were significantly negatively correlated with biochar pH, which reflects the high sensitivity of these crops to elevated pH, as already reported by previous studies (Kuehny and Morales, 1998;Logan and Lindsay, 1996;Roosta, 2011). By increasing pH of growing media, alkaline amendments such as biochar can decrease nutrient availability, mainly for P, Fe and Mn, resulting in lower yield (Belda et al, 2013). It must be noted that the negative correlations between lettuce and pansy biomasses and ash content most likely result from the strong relationship between ash content and basicity of biochars (Mukome et al, 2013).…”

Promotores de crescimento na propagação de caroba

“…Na produção de mudas de qualidade, é indispensável a utilização de substratos que ofereçam características físicas e químicas adequadas, com boa estrutura, consistência, alta porosidade e capacidade de retenção de água e nutrientes (Urrestarazu et al, 2008;Belda et al, 2013). Dentre os materiais disponíveis para a composição de substratos visando à propagação de mudas, o vermicomposto, ou húmus de minhoca, tem se mostrado uma excelente alternativa, contribuindo para um adequado suprimento de nutrientes, bem como para a melhoria dos atributos físicos do substrato (Steffen et al, 2010).…”

Use of Dry Dairy Manure Pellets as Nutrient Source for Tomato (Solanum lycopersicum var. cerasiforme) Growth in Soilless Media

“…The results for biomass and fruit production in this study are relatively consistent, suggesting that 25% to 30% manure pellet addition is the optimum range for manure pellet culture. Belda et al observed similar results growing ornamentals in mixtures of manure composts and peat: they found that 25% manure compost produced good-quality plants and that higher rates tended to be phytotoxic [18]. One potential reason for the reduced productivity is a lack of adequate N and K in the manure pellet treatments.…”