Post-Harvest Eucalyptus Residue Removal Reduces Soil Aggregation and Biological Activities in Central-West Brazil

Tree residue removal from Eucalyptus plantations after timber harvest can reduce soil functioning by reducing the organic matter input. To assess the effects of residue management systems (RMS) on soil aggregation, carbon (C) and nitrogen (N) content, and biological activities, a field trial was conducted in a commercial Eucalyptus plantation (loamy sand soil) in Mato Grosso do Sul, Brazil. The study assessed three RMS: cut-to-length (CTL), tree-length (TL), and bare litter (BL), respectively. After 21 months, undisturbed soil samples were collected and physically isolated into three aggregate-size fractions: large macroaggregates (LM), medium macroaggregates (SM), and microaggregates (MI). Results showed that these soils are mostly composed of LM (54%), and that removing harvest residues from the growing site included total organic carbon (TOC) by 28%, microbial biomass-C by 20%, fluorescein diacetate hydrolysis by 17%, and β-glucosidase activity by 26%, when compared to CTL. TL outperformed CTL for the proportion of LM and LM-associated TOC. Across fractions, a higher microbial quotient was observed in SM and MI fractions, suggesting that the TOC has higher stability inside the LM. This study suggests that leaving harvest residues on the soil should be recommended for Eucalyptus plantations, especially in low-fertility sandy soils, as it helps in maintaining the soil structure and biological activities critical for soil health and ecosystem function

Biomass residues improve soil chemical and biological properties reestablishing native species in an exposed subsoil in Brazilian Cerrado

Revegetation of exposed sub-soil, while a desirable strategy in the recovery processes, often fails due to extreme soil chemical properties, such as low organic matter and pH levels inhospitable to biological activities such as nutrients cycling and plant establishment. This is the case for approximately 800 ha of the Cerrado biome in Brazil, where erecting the embankment of a hydroelectric dam in the 1960’s stripped vegetation, soil, and subsoil layers thereby distorting the soil properties. This work evaluates the effectiveness of restoration management (RM) treatments, to restore the soil quality, including biological activity and chemical attributes. In a factorial scheme, RM treatments include the addition of organic residue from aquatic macrophytes (AM) at 3 rates (0, 16 and 32 t ha-1), combined with ash from sugar cane bagasse of agroindustrial origin (BA) at 4 rates (0, 15, 30 and 45 t ha-1). RM samples contrasted samples collected from undisturbed Cerrado (CER) as well as a degraded area without intervention (DAWI). The mechanized RM plots received amendments and reforestation of 10 Cerrado native tree species. After 5 years, vegetation covered up to 60% of the surface in RM treatments receiving AM32 + BA45. AM and BA residues promoted height increases in the introduced plants. All RM treatments promoted lower levels of Al3+ than DAWI and CER. The combination of AM32 over the rates of incorporated ash increased soil pH and K values similarly to CER. Microbial-related variables, such as microbial biomass-C was the largest in CER, followed by the RM treatments, and the lowest in DAWI. The microbial quotient was no different between CER and RM treatments. The addition of residues such as AM and BA increased the vegetation covered, improved chemical and microbiological indicators. Thus, the residues used aided the recovery process of intensely degraded soils in the Cerrado area

AVALIAÇÃO COMPARATIVA DO ESTADO NUTRICIONAL DE MUDAS DE BARU (Dipteryx alata)

http://dx.doi.org/10.5902/1980509821095To a successful revegetation process, besides improving the edaphic area conditions, seedlings must have good quality, which can be assessed by nutritional status. This research evaluated the foliar contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn from Dipteryx alata seedlings produced under full sun or protected condition (30% of shade), using degraded soil as substrate, with or without organic residue added (32 t ha-1 macrophyte) and with different phosphorus doses (0, 100, 200 e 300 mg dm-3 P2O5), comparatively to seedlings and adult plants collected in the field. To each leaf sampling in the field, the soil was collected and analyzed for P, MO, pH, K, Ca, Mg, H+Al, SB and CTC. The same analysis was performed in the experimental units at the end of the experiment. The data showed that the Dipteryx alata presents low P requirement. The foliar levels, in seedling from field were higher than in adult plants, for N, P, K, and S, and lower for Ca, and the plant’s developing stadium did not affect the foliar levels of Mg, B, Cu, Fe, Mn and Zn. The organic residue was not enough to supplies the needed N to seedlings produced under experimental conditions. The cultivation under full sun provided higher foliar concentrations of N, P, Ca, Mg, B, Cu, Fe and Mn. The foliar levels of N, P, K, Ca, B, Fe and Zn were higher in the presence of organic residue.http://dx.doi.org/10.5902/1980509821095Para o sucesso de um processo de revegetação, além de melhorar as condições edáficas da área, deve-se dispor de mudas de boa qualidade, o que pode ser avaliado pelo estado nutricional. Neste trabalho, avaliaram-se os teores foliares de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn de mudas de Dipteryx alata produzidas a pleno sol ou em cultivo protegido (30% de sombreamento), utilizando como substrato solo degradado, condicionado ou não com resíduo orgânico (32 t ha-1 macrófitas) e com diferentes doses de fósforo (0, 100, 200 e 300 mg dm-3 P2O5), comparativamente às mudas e parte aérea de plantas adultas, coletadas em campo. A cada coleta de folhas em campo, o solo foi coletado e analisado para P, MO, pH, K, Ca, Mg, H+Al, SB e CTC. A mesma análise foi realizada nas unidades experimentais, ao final do experimento. Os resultados mostram que o Dipteryx alata é pouco exigente em P, que os teores foliares, nas mudas de campo, são superiores às plantas adultas em N, P, K e S e inferiores para Ca e que o estádio de desenvolvimento da planta não influenciou os teores foliares de Mg, B, Cu, Fe, Mn e Zn. O resíduo orgânico não foi suficiente para fornecer o N necessário às mudas produzidas. O cultivo a pleno sol propiciou maiores teores foliares de N, P, Ca, Mg, B, Cu, Fe e Mn. Teores foliares de N, P, K, Ca, B, Fe e Zn foram superiores na presença de resíduo orgânico. 

Influência da qualidade da água em experimento conduzido em vasos

Em experimentos conduzidos em vasos e molhados com água de abastecimento público, o solo pode apresentar modificações nas propriedades químicas. As alterações ocorrem em função da qualidade e quantidade da água, comprometendo, por vezes, os resultados. O objetivo deste trabalho foi avaliar as alterações ocorridas na fertilidade do solo, em experimentos conduzidos em vasos, em condições protegidas, após molhamento com água de abastecimento público. O experimento foi conduzido por oito meses, em Latossolo Vermelho Distrófico, textura argilosa, coletado na camada de 0-0,20 m, peneirado (2 mm) e acondicionado em vasos (2 L). Para o molhamento foi utilizado dois tipos de água (água purificada em deionizador e água de abastecimento público de Ilha Solteira - SP), empregando quatro volumes de água (0, 200, 400 e 600 mL), com três repetições. Durante o período experimental (240 dias), o solo foi amostrado a cada 60 dias para as análises de fertilidade. A água fornecida pelo setor público apresentou teores de cálcio (Ca2+), magnésio (Mg2+) e fósforo (P) de 81; 29; e 1,19 mg L-1 de água, respectivamente. Os resultados mostraram que a qualidade da água interferiu na fertilidade do solo, produzindo incrementos em P, Ca2+, Mg2+ e pH. Os molhamentos possibilitaram a lixiviação do K+ do solo, reduzido em 32-38%, em condições extremas (9.240 mm da lâmina d’água), o que equivale a 8 anos de chuvas em uma região com precipitação média anual de 1.155 mm

Estado nutricional de mudas de baru (Dipteryx alata) em área de recuperação e remanescentes de cerrado

The Dipteryx alata is a tree specie with possibility of use in human and animal nutrition, and in the pharmaceutical industry. For reclamation of degraded areas, the revegetation has been an alternative, however, requires fertilizer addition. The objectives of this study were to evaluate the nutritional status and growth of Dipteryx alata seedlings, introduced in degraded soil under recovery process, with residues (organic and agroindustrial), compared to collected seedlings in preserved Cerrado, and evaluate the residues impact on soil chemical properties. In this work the degraded soil received the incorporation of residues, organic - RO (macrophytes) and agroindustrial - RA (ash derived from burning bagasse from sugarcane), with the following doses: 0, 16 and 32 t ha- 1 and 0, 15, 30 and 45 t ha-1 respectively. Within three months of incorporation of residues into the degraded soil, the D. alata seedlings were introduced in the experimental area, and 12 months later were evaluated for height, stem diameter, chlorophyll content and leaf contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. For purposes of comparison, the foliar concentration of those elements was determined in Dipteryx alata seedlings collected in preserved Cerrado area. Concomitant with the collect of leaves, at Cerrado and experimental area, soil was collected (0.0 - 0.20m deep) for evaluation of chemical parameters (P, OM, pH, K, Ca, Mg, H + Al, Al, Cu, Fe, Mn and Zn). Comparing the seedlings collected in the Cerrado with the seedlings from experimental area it is observed that the leaf concentration of N, P, K and Mg was higher in seedlings from preserved Cerrado in relation to those introduced in the experimental area. Fe, Mn and Zn, have lower foliar concentration in plants collected in the Cerrado, in the case of Mn the worst results occur in the absence of macrophytes indicating the importance of organic residue. The foliar concentration of Ca, S and Cu was similar in...O Baru (Dipteryx alata) é uma espécie arbórea do Cerrado com possibilidade de uso na nutrição humana e animal, e na indústria farmacêutica. Para recuperação de áreas degradadas a revegetação tem sido uma das alternativas, no entanto, demanda a adição de insumos. Os objetivos deste trabalho foram avaliar o estado nutricional e o crescimento de mudas de Dipteryx alata introduzidas em solo degradado, em processo de recuperação com incorporação de resíduos (orgânico e agroindustrial), comparativamente à mudas coletadas em Cerrado conservado, e avaliar a influência dos resíduos utilizados sobre atributos químicos do solo. Neste trabalho o solo degradado recebeu a incorporação de resíduos, orgânico - RO (macrófitas aquáticas) e agroindustrial - RA (cinza oriunda da queima do bagaço da cana-deaçúcar), com as seguintes doses: 0, 16 e 32 t ha-1 e 0, 15, 30 e 45 t ha-1 respectivamente. Transcorridos três meses da incorporação dos resíduos ao solo degradado mudas de D. alata foram introduzidas na área experimental e 12 meses depois foram avaliadas para altura, diâmetro do caule, índice de clorofila e teores foliares de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. Para fins de comparação, a concentração foliar dos mesmos elementos foi conduzida em mudas de Dipteryx alata coletadas em Cerrado conservado. Concomitante à coleta de folhas no Cerrado conservado e na área experimental, coletou-se solo (0,0 - 0,20m de profundidade) para avaliação de atributos químicos (P, MO, pH, K, Ca, Mg, H+Al, Al, Cu, Fe, Mn e Zn). Ao se comparar as mudas coletadas no Cerrado com as mudas da área experimental observa-se que a concentração foliar de N, P, K e Mg foi superior nas mudas obtidas no Cerrado conservado, em relação às que foram introduzidas na área experimental. Fe, Mn e Zn, apresentam menor concentração foliar nas plantas coletadas no Cerrado, no caso do Mn os piores resultados ocorrem na ausência de..