Dercio Ceri Pereira

Produção de mudas de almeirão e cultivo no campo, em sistema agroecológico

Objetivou-se, neste trabalho, avaliar o desenvolvimento das mudas de almeirao em diferentes substratos orgânicos e verificar o comportamento em bandejas, apos o transplante no campo e na pos-colheita, constituindo tres experimentos. Foram avaliados o uso do substrato comercial e quatro misturas de proporcoes de composto, areia e po de basalto. Foram quatro fases de avaliacao: aos 13 e 26 dias apos a emergencia (DAE), aos 74 dias apos o transplante e na pos-colheita. Avaliaram-se o comprimento e a massa da materia seca de raiz e de parte aerea, numero de folhas por planta, diâmetro do coleto, area foliar e a conservacao pos-colheita. O composto orgânico e as misturas foram superiores ao substrato comercial, na maioria das caracteristicas avaliadas nos 13 e 26 DAE; entretanto, o substrato comercial superou os demais tratamentos para o comprimento de raiz. Os substratos orgânicos (T2 e T3) podem ser recomendados para a producao de mudas de almeirao com desenvolvimento satisfatorio em sistema de cultivo em bandejas e a campo e, de igual forma, em pos-colheita; o uso de composto orgânico como substrato para producao de mudas propiciou o desenvolvimento de mudas mais vigorosas e plantas mais resistentes no campo do que o substrato comercial.

Performance of four stabilization bioprocesses of beef cattle feedlot manure

The biological stabilization of beef cattle manure is crucial for promoting sanitation in feedlot pens. This study compared the performance of composting, vermicomposting, static windrows, and anaerobic digestion for stabilization of beef cattle feedlot manure based on the degradation of organic matter, nutrient retention, and stability of the final product in each process using uni- and multivariate analysis. The cluster analysis showed that composting and vermicomposting were the most similar processes. The principal component analysis showed that the more oxidative processes (composting and vermicomposting) degraded beef cattle feedlot manure more effectively (up to 45%) than static windrows and anaerobic digestion. Stabilization processes did not affect the amount of phosphorus, whereas potassium losses ranged from 3% (anaerobic digestion) to 30% (static windrow) and differed significantly across processes. Electrical conductivity decreased only in static windrow (30%). A decrease in the C/N ratio were observed in all processes, but the reduction was smaller in static windrow (5%). Larger reductions in C/N ratio were associated with greater increases in the humic to fulvic acid ratio. Composting and vermicomposting processes more effectively degraded beef cattle manure and produced stable organic fertilizers. Anaerobic digestion more effectively retained macronutrients (N and K) and converted organic N to ammonium. The use of static windrows is the least effective bioprocess for the stabilization of beef cattle feedlot manure.

Avaliação de substratos para a produção de mudas de tomate e pepino

The aim of this study was to evaluate the response of tomato and cucumber seedlings to different compositions of organic substrates formulated with compost of poultry slaughterhouse wastes, tree pruning residue, and sand. Experiments were performed in 200-cell trays in a randomized block design. The treatments for tomato seedlings were: T0 (Plantmax® HT); T1 (compost); T2 (compost + sand, proportion 3:1 weight); T3 (compost + sand, proportion 1:1 weight) e T4 (compost + sand, proportion 1:3 weight); and for cucumber seedlings were: T0 (Plantmax® HA) and the same composition of organic substrates used for tomato seedlings. Seedling emergence (EP), root length (CR), dry mass of the root (MSR), and shoot (MSPA) were evaluated. Substrates T0 and T4 provided a faster EP for tomato seedlings, thus increasing the CR. However, values of CR in these substrates did not differ from those in T2 and T3 on the 20th day after seedling emergence (DAE). There was increase in the MSPA of tomato seedlings from T4 comparing with those from T0 and T3. The MSR of the tomato seedlings from T2, T3 and T4 were higher than those from T0 e T1.The MSPA of cucumber of plants from T3 and T4 showed a higher accumulation of dry mass comparing with those from T0 e T1. The, treatments with compost had MSR higher than T0, especially T3 e T4. Therefore, the substrates T3 and T4 are recommended for cucumber seedlings and T4 for tomato seedlings.

Addition of cattle manure to sheep bedding allows vermicomposting process and improves vermicompost quality

Animal waste is usually a good substrate for vermicomposting. However, numerous animal husbandry systems use bedding that consists primarily of lignocellulosic substrates, which hinders earthworm and microorganisms development and thus, the entire bioconversion process. One possible solution is to mix the used bedding with other waste materials that are more amenable to earthworm ingestion and can provide better conditions for earthworm population growth. Here, we have aimed to examine the effectiveness of such procedure by mixing rice-husk-based sheep bedding with cattle manure in different proportions (0%, 25%, 50%, 75% and 100%). We have carried out vermicomposting experiments in benchtop vermireactors inoculated with 0.88kg of dry matter (sheep bedding+cattle manure). Data used in the Principal Component Analysis were the multiple vermicomposting variables (i.e., EC; pH; HA/FA and C/N ratios; P, K, cellulose, and hemicellulose content). The effect of the treatment on earthworm count was analyzed with ANOVA. We have observed that the addition of at least 25% of cattle manure to sheep bedding allows vermicomposting process but it is necessary 148days to obtain a stabilized vermicompost. However, increasing the proportion of cattle manure to sheep bedding, the vermicomposting time decreases proportionally to 94days. We concluded that vermicomposting can be considered a bioprocess to stabilize rice husk after being used as sheep bedding.

Substratos alternativos para produção de repolho e beterraba em consórcio e monocultivo

The aim of this study was to assess the efficiency of alternative substrates for the development of the root system in the shoots of beetroot and cabbage seedlings as well as their behavior in field under monoculture and consortium systems. Two experiments were performed in randomized block design with the use of the following treatments: T0 (Plantmax® substrate); T1 (100% of compost); T2 (50% of compost, 20% of sand, 20% of carbonized rice hulls and 10% of basaltic dust); T3 (45% of compost, 20% of sand, 20% of carbonized rice hulls and 15% of basaltic dust); T4 (40% of compost, 5% of sand, 15% of carbonized rice hulls and 20% of basaltic dust) and T5 (35% of compost, 5% of sand and 15% of carbonized rice hulls and 25% of basaltic). The first experiment was performed in trays of 200 cells and the second one in the field under monoculture system and in consort with the treatments composed of the substrates used in the trays. For the cabbage production in the field, substrates used in consortium and in monoculture showed similar results regarding the accumulation of dry mass in the shoot of the plant. As for the the beetroot, the diameter of the roots with commercial substrate was greater under consortium system when compared to monoculture system. For the production of beetroot and cabbage in monoculture and consortium systems, alternative substrate can be recommended.