ABSTRACT Parkia platycephala Benth. (Fava-de-bolota) found in areas of Cerrado-Caatinga transition, is a species with potential for feeding ruminants in arid regions. The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizal fungi (AMF) on the initial growth and nutrition of P. platycephala Benth. seedlings under water stress. The experimental design was a randomized block design in a 2 × 6 factorial scheme with five replications, consisting of two water regime conditions (with and without stress), four AMF strains (Gigaspora rosea, Gigaspora margarita, Acaulospora koskei, and Acaulospora morrowiae), one treatment with associated inoculum (Mix), and one control. At 120 days after sowing, the morphological variables height (H), stem diameter (SD), number of leaves (NL), root length (RL), total root volume (TRV), shoot dry mass (SDM), root dry mass (SDM) and total dry mass (TDM) were evaluated. Nutrient contents and mycorrhizal colonization rate were also evaluated. The variables NL, SDM and TDM presented significant interaction between inoculation with the fungi and the studied water conditions. For the contents of P, Mg and Mn there was also interaction, being the best results with the strains A. koskei, Mix, A. morrowiae and control, respectively, in the condition without water stress. Mycorrhizal fungi favored plant growth as well as the absorption of P, Mg, Mn and Zn.

ABSTRACT One of the great challenges in the post-nursery phase is to plant seedlings in the field. It is, therefore, important to produce them to a high standard of quality aiming to achieve an economically feasible and environmentally sustainable process. For this purpose, the use of organic residues in the composition of substrates, associated with biotechnologies available on the market, is a feasible alternative, which, however, requires further research for process optimization. Thus, the objective was to evaluate the morphophysiological characteristics, nutrition and quality of Copaifera langsdorffii seedlings in substrates formulated with organic residues and Fertbokashi premium®. The treatments were distributed in a randomized block design, with four repetitions, in a 5 x 2 factorial scheme, with four substrates (carnauba residue, goat manure, unprocessed and carbonized rice husks) and one control (soil) with or without applying bokashi. A part of the results, the highest values observed in the morphophysiological and nutritional variables, were for plants grown in the substrate with carnauba residue, followed by goat manure, both in association with bokashi. Among the residues studied, carnauba residue had the highest N and P contents and the lowest C:N ratio, raising the quality variables. The use of bokashi associated with the residues promotes the best results for most of the morphophysiological and nutritional parameters of the Copaiba seedlings. The substrates formulated with carnauba residue and goat manure are the most appropriate for seedling production. The regional residues can be used as a substrate to produce Copaiba seedlings to a high standard of quality.

ABSTRACT Sugarcane is one of the first activities of economic importance in Brazil. The understanding of the nutritional dynamics at different phenological stages of the sugarcane crop with the use of nitrogen-fixing bacteria has been one of the alternatives to decrease fertilizer consumption and increasing plant production. This study aimed to assess the morphophysiological attributes in the initial growth and nutrition of two sugarcane varieties inoculated with strains of diazotrophic bacteria, individually and in an association, in a greenhouse. The experimental design was a randomized block design in a 2 × 8 factorial arrangement with two cultivars (Co 1341-76 and RB 867515) and eight treatments consisting of bacteria inoculated individually with BR 11140T (Azospirillum amazonense), BR 11175T (Herbaspirillum seropedicae), BR 11192T (Herbaspirillum rubrisubalbicans), BR 11281T (Gluconacetobacter diazotrophicus), and BR 11366T (Burkholderia tropica), inoculation associated with the studied bacteria, N fertilization with 120 kg ha-1 of N, and absolute control without inoculation and nitrogen fertilization. Plants were conducted for 75 days after germination, and biometric variables and nutrient accumulation were measured. The sprouting rate index and root fresh matter were significant for inoculation (p<0.01). Inoculation with the strains BR 11192T (H. rubrisubalbicans), BR 11281T (G. diazotrophicus), and RB 11366T (B. tropica) showed the best results for root fresh matter regardless of the cultivar. The strains RB 11366T (B. tropica), BR 11192T (H. rubrisubalbicans), and BR 11175T (H. seropedicae) stood out regarding the sprouting rate index. Inoculation showed a significant effect for stem diameter (p<0.01), especially the strains BR 11140T (A. amazonense) and RB 11366T (B. tropica). All inoculations were efficient for the biometric variable related to leaf length. Nitrogen, Fe, and Zn contents showed a significant effect of the interaction between cultivars and inoculation. The inoculation with the strain RB 11366T (B. tropica), total N fertilization, followed by the other inoculations and the control stood out compared to the cultivar Co 1341-76 within the factor inoculation, indicating that the association of this strain with the cultivar Co 1341-76 is more efficient regarding the recommended commercial N dose for sugarcane. The cultivars Co 1341-76 and RB 867515 responded positively to the individual inoculation of strains of diazotrophic bacteria. The strains promoted improvements in some morphological and/or nutritional attributes of sugarcane plants. The strain B. tropica showed the best interaction with the tested cultivars for the biological N fixation, resulting in gains of biomass productivity and nutrient contents when not inoculated.

Resumo A utilização de materiais renováveis como fonte de nutrientes, além de ser uma interessante solução para destinação dos resíduos, pode também ser uma saída efetiva para a redução dos altos custos de insumos necessários para produção de mudas florestais. Este trabalho objetivou avaliar o crescimento de Anadenanthera colubrina (Vell. Brenan) (angico branco) cultivado em substratos orgânicos. Foi adotado delineamento em blocos casualizados e os tratamentos distribuídos em esquema fatorial 3 × 5, sendo três resíduos orgânicos: caule decomposto de buriti, bagana de carnaúba e composto orgânico misturados ao solo em quatro percentuais, 20% ,40%, 60% e 80% da composição do substrato e um tratamento testemunha apenas com solo sem incorporação de resíduo orgânico, com seis repetições. Aos noventa dias após a emergência, as mudas foram coletadas para determinação dos parâmetros de crescimento: diâmetro do coleto (DC), altura (H), dos índices: H/D, número de folhas (NF), clorofila total (CT), área foliar (AF), massa seca da parte aérea (MSPA), massa seca das raízes (MSR) e massa seca total (MST), H/MSPA; MSPA/MSR e de qualidade de Dickson (IQD). Os tratamentos que continham 60% e 80% de composto orgânico apresentaram as melhores respostas. Conclui-se que a produção de mudas de angico branco cultivadas com substratos acrescidos de 80:20 (composto orgânico: solo) apresentam os melhores resultados e tecnicamente viável de acordo com as características e os índices analisados.

Abstract The use of renewable materials as a source of nutrients, besides being a solution of interest for waste disposal, may also be an effective way to reduce the high costs of inputs needed for the production of forestry seedlings. The purpose of this study was to evaluate the growth of Anadenanthera colubrina (Vell. Brenan) (angico branco) cultivated in organic substrates. A randomized block design was adopted and the treatments were distributed in a 3 × 5 factorial scheme, with three organic residues: decomposed burity (moriche palm) stem, carnaúba straw and organic compost mixed with the soil in four percentages: 20%, 40%, 60% and 80% of the composition of substrate and a control treatment with soil only, without incorporating the organic residue, with six repetitions. Ninety days after emergence, the seedlings were collected to determine the growth parameters: stem diameter (SD), height (H), of the following indexes: H/D, leaf number (LN), total chlorophyll (T), leaf area (LA), dry mass of the aerial part (DMAP), dry mass of roots (DMR), total dry mass (TDM) H/DMAP: DMAP/DMR, and Dickson Quality Index (DQI). The treatments that contained 60% and 80% of organic compost presented the best responses. It is concluded that the production of angico branco seedlings cultivated with substrate with the addition of 80:20 (organic compost: soil) presented the best results and was technically feasible according to the characteristics and indexes analyzed.

ABSTRACT Besides being used in the wood industry, copaiba has medicinal properties. However, continuous and excessive extraction both of wood and of oil may impair the regeneration and make the product scarce. It is very important to produce quality seedlings, both for sustainable exploitation and for the recovery of degraded and disturbed areas. The purpose of the present study was to evaluate the initial growth and nutrition of Copaiba seedlings, incorporating organic residues into different classes of soils. The treatments were disposed in a design of entirely randomized blocks using the 5x4 factorial scheme, with four organic residues (rice husks in natura, carbonized rice husks, goat manure, carnauba residue), plus a treatment with soil only and four classes of soil (Latossolo Vermelho-Amarelo, Neossolo Quartzarênio, Gleissolo Háplico e Argissolo Vermelho-Amarelo), with four repetitions. At 90 days, the morpho-physiological variables of the seedling and macronutrient contents of the aerial part were evaluated. As to the morpho-physiological variables, the carnauba residue was outstanding among the residues tested in the present study. There was an increase in the quantities of P, K, Ca and Mg in the aerial part of copaiba seedlings resulting in the combination between the organic residues and the soil classes.

ABSTRACT In semi-arid regions of developing countries worldwide it is necessary to develop low cost technology methods to acquire new water supplies. The objective was to evaluate the changes in the attributes of soil quality irrigated with treated sewage effluent. The treatments consisted of applying treated sewage effluent (TSE) and underground well water (UWW) in the following proportions: E0% (chemical fertilization and UWW), E25% (25% TSE and 75% UWW), E50% (50% of TSE and UWW), E75% (75% TSE and 25% UWW) and E100% (100% TSE). The sodium content did not differ significantly among the treatments, but the sodium input diminished as the percentage of residuary water in the irrigation grew. There was a greater increment of microbial biomass carbon in the E25% treatment. On the other hand, although treatments E50% to E100% have a greater nutrient input, they were no different from control treatments performed with well water. Treated domestic sewage effluent at a proportion of 25% is a feasible alternative for castor bean irrigation, however it is necessary to monitor the possible changes in the soil attributes over successive crops. Microbial attributes can be used as a quick, good indicator of changes in soil quality.

RESUMO Alternativas sustentáveis devem ser adotadas para minimizar os impactos ambientais negativos das atividades agrícolas. A utilização de águas residuárias assim como de resíduos orgânicos oriundos das atividades agrícolas ou encontrados naturalmente como o caule decomposto do buritizeiro, podem constituir uma alternativa sustentável para a produção de mudas para fins de reflorestamento de áreas em processos de degradação e desertificação, comuns no Piauí, Brasil. Objetivou-se neste trabalho, avaliar o crescimento e qualidade de mudas de Acacia mangium Willd cultivadas em substratos com diferentes proporções de caule decomposto de Mauritia flexuosa (CDB) e irrigado com água residuária da suinocultura (ARS). O delineamento experimental foi inteiramente casualizado, disposto em esquema fatorial 5 x 2, referentes a cinco proporções de CDB e solo (v/v, %: 0:100; 20:80; 40:60; 60:40; 80:20) e duas origens de água de irrigação (água de poço e ARS), com quatro repetições. Aos 100 dias após semeadura (DAS), as mudas foram coletadas para mensuração das variáveis relacionadas ao crescimento, qualidade e nodulação. A altura, o diâmetro do coleto, a massa seca da parte aérea, a área foliar e o acúmulo de nitrogênio na parte aérea, foram influenciados significativamente (p≤0,05) pela interação entre os substratos e a origem da água de irrigação. A ARS não influenciou significativamente o crescimento e qualidade das mudas de Acacia mangium Willd. A melhor relação entre o substrato CDB:solo foi a proporção 46:54, considerada a mais adequada à produção de mudas de Acacia mangium Willd.

ABSTRACT Sustainable alternatives should be adopted to minimise the negative environmental impacts of agricultural activities. The use of wastewater as well as organic waste, from agricultural activities or found naturally, such as the decomposed stems of the Buriti palm (Mauritia flexuosa), can be a sustainable alternative in the production of seedlings for the reforestation of areas in the process of degradation or desertification, common in the State of Piauí, Brazil. The aim of this study was to evaluate growth and quality in seedlings of Acacia mangium Willd grown in substrates with different proportions of decomposed stems of Mauritia flexuosa (DSB), and irrigated with wastewater from pig farming (WPF). The experimental design was completely randomised, arranged in a 5 x 2 factorial scheme, corresponding to five proportions of DSB and soil (v/v,% - 0:100, 20:80, 40:60, 60:40, 80:20), and two sources of irrigation water (well water and WPF), with four replications. At 100 days after sowing (DAS), the seedlings were collected to measure the variables related to growth, quality and nodulation. Height, root collar diameter, shoot dry weight, leaf area and nitrogen accumulation in the shoots were significantly influenced (p≤0.05) by the interaction between substrate and source of irrigation water. The WPF had no significant influence on the growth or quality of the Acacia mangium Willd seedlings. The best ratio between DSB substrate and soil was 46:54, considered the most suitable for seedling production in Acacia mangium Willd.