ABSTRACT Overliming is an effective way of neutralizing and reducing the toxicity of the hydrolysates generated from acidic pretreatment of lignocellulosic biomass for ethanol production and others biotechnological products. Overliming generates a solid residue whose inadequate disposal may represent an environmental problem. This work aimed at the chemical characterization of the solid residue generated during the detoxification of the sugarcane bagasse hemicellulosic hydrolysate and evaluation of its behavior in soil. The solid residue was submitted to physicochemical and granulometric analysis and determination of the contents of sugars, metals and toxic compounds (acetic acid, furfural, hydroxymethylfurfural and phenols). The potential of the residue as corrective of soil acidity was determined by analyzing the quality attributes of soil correctives (neutralizing power – NP, relative total neutralizing power – RTNP, Ca and Mg contents and granulometry). The residue was also evaluated for its influence on soil microbial communities and toxicity through bioassays with Lactuca sativa seeds. The residue contributed to the overall improvement of soil chemical attributes. The levels of Ca, Mg, C, OM and CEC were increased, nutrients such as Zn, Fe, Ni, Cr and Mn were detected, and microbial communities were stimulated. Besides, the residue showed no significant values of toxic compounds and no toxicity to L. sativa seeds. The residue was able to reduce the soil pH and to keep it stable throughout the study period. As a higher amount of the residue was necessary to reach pH 7 than limestone, it should be used as an auxiliary corrective of acidity.

Objetivou-se, com este trabalho, avaliar mudas de pepino e de tomateiro em relação a diferentes composições de substratos orgânicos, formulados com composto de resíduos do abate de aves, podas de árvores e areia. Os experimentos foram realizados em bandejas com 200 células, em blocos casualizados. Para mudas de tomateiro, os tratamentos foram: T0 (Plantmax® HT); T1 (composto); T2 (composto + areia, proporção 3:1 peso); T3 (composto + areia, proporção 1:1 peso) e T4 (composto + areia, proporção 1:3 peso). Para mudas de pepino, os tratamentos foram: T0 (Plantmax® HA) e as mesmas composições de substratos orgânicos adotadas para as de tomate. Avaliaram-se a emergência de plântulas (EP), o comprimento de raiz (CR), a massa seca de raiz (MSR) e da parte aérea (MSPA). Os substratos T0 e T4, que proporcionaram emergência rápida das plântulas de tomateiro, propiciaram maior CR. Mas os valores de CR nesses subtratos não diferiram daqueles observados em T2 e T3, aos 20 dias após a emergência (DAE). Houve aumento da MSPA do tomateiro, cultivado em T4, em relação à dos cultivados em T0 e T3. A MSR do tomateiro, em T2, T3 e T4, foi superior à observada em T0 e T1. Para a MSPA do pepino, aos 30 DAE, houve acúmulo de massa seca das plantas cultivadas em T3 e T4, em relação à dos tratamentos T0 e T1. Em relação à MSR, os substratos à base de composto proporcionaram resultados superiores aos de T0, destacando-se T3 e T4. Assim, para produção de mudas de pepino, recomendam-se os substratos T3 e T4 e, para tomateiro, o substrato T4.

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.

A utilização de esterco animal na agricultura, aliada ao cultivo de plantas de cobertura, pode conferir sustentabilidade ao sistema agrícola. Com o objetivo de avaliar o efeito de dois sistemas de culturas e de três fontes de nutrientes, na cultura do milho, conduziu-se um experimento, em Latossolo Vermelho, no município de Marechal Cândido Rondon (PR). O delineamento experimental utilizado foi de blocos casualizados, com quatro repetições, e, os tratamentos, dispostos em esquema fatorial 2 x 3, compostos por dois sistemas de culturas (sucessão trigo/milho e consórcio aveia+ervilhaca+nabo/milho) e três fontes de nutrientes (mineral, orgânica e organomineral). Em junho de 2006, implantou-se a cultura do trigo e o consórcio de plantas de cobertura. Em outubro de 2006, semeou-se milho sob os dois sistemas. As adubações orgânica e organomineral consistiram na aplicação de dejetos de suínos, unicamente, e combinada com fertilizante mineral, respectivamente. O consórcio de aveia preta, ervilhaca peluda e nabo forrageiro mostrou-se capaz de fornecer a quantidade adequada de biomassa, concretizando sua viabilidade para produção de cobertura vegetal ao solo, durante o inverno. O cultivo de milho em sucessão ao trigo proporcionou a maior absorção de N e K e a maior produtividade. A adubação mineral proporcionou maior absorção de N e maior produtividade de milho, em comparação com as adubações orgânica e organomineral com dejetos de suínos.

The use of animal wastes in agriculture coupled with the growing of cover crops can provide sustainability to the agricultural system. Aiming to evaluate the effect of two systems of crops and sources of fertilizer on the corn crop, was conducted an experiment on Oxisol in the municipality of Marechal Candido Rondon (PR). The experimental design used was of randomized block with four replications and treatments in factorial scheme 2 x 3, consisting of two culture systems (succession wheat/corn and oat+vetch+turnip/corn) and three nutrient sources (mineral, organic and organic mineral). In June 2006, was deployed to the wheat crop and intercropping of cover crops. In October 2006 was sowed corn on the two systems. The fertilizations organic and organic mineral consisted of application of pig manure alone and combined with mineral fertilizer, respectively. The consortium of oats, hairy vetch, wild radish has shown itself capable of providing good amount of biomass, showing its viability for the production of plant cover the soil during winter. Corn grown in rotation with wheat yielded the highest uptake of N and K and higher yield. Mineral fertilization gave higher N uptake and corn yield compared with the organic fertilizer and organic-mineral fertilizer based on pig manure

O presente trabalho teve por objetivo avaliar o desempenho do milho para produção de silagem e grãos, cultivado em diferentes sistemas e adubações. O delineamento experimental adotado foi de blocos inteiramente casualizados, em esquema fatorial 2 x 3, composto por dois sistemas de cultivo (sucessão e rotação de culturas) e três fontes de adubação (orgânica, mineral e organomineral), com quatro repetições. Para produção de silagem de planta inteira, os sistemas e as adubações não diferiram estatisticamente entre si (p < 0,05). Para produção de silagem de grão úmido, o sistema em sucessão e a adubação mineral mostraram-se superiores aos demais, produzindo 10.823 e 10.815 kg ha-1, respectivamente, não incrementando, contudo, qualidade à silagem. Já na colheita dos grãos, o sistema em sucessão produziu em média 6.820 kg ha-1 e foi superior ao sistema em rotação. A adubação mineral foi superior às demais, produzindo em média 7.277 kg ha-1, contudo apresentou 54,62% de plantas acamadas, fato este que resultaria em perdas significativas na produtividade, caso a colheita tivesse sido mecanizada.

The aim of this research was to evaluate the performance of the corn crop for silage and grain production, cultivated under different culture systems and fertilizations. The experiment was performed using a completely randomized design in a factorial scheme. The factors were two culture systems (no-tillage with crop succession and no-tillage with crop rotation) and three sources of fertilization (organic, mineral and organic-mineral), with four repetitions, totaling 24 plots. The results of production of fullplant ensilage in the systems as well as in the fertilization did not differ statistically. The results of humid grain production in the system in succession and in mineral fertilization were superior than the others treatments, producing 10,823 and 10,815 kg ha-1, respectively; however, they did not increase ensilage quality. Regarding the grain harvest, the system in succession produced 6,820 kg ha-1 on average, and was superior to the crop rotation system. The results of mineral fertilization were superior to the organic and the organic-mineral fertilizations, producing on average 7,277 kg ha-1; however, that system featured 54.62% of damped-off plants, which could have resulted in significant yield lost had the harvest been mechanized.