Contribution of arbuscular mycorrhizal fungi to the growth of Guazuma ulmifolia in degraded 'cerrado' soil

Ensaios foram conduzidos, em casa de vegetação, com solos de pastagem degradada reflorestada e cerrado preservado (controle) visando avaliar a contribuição de fungos micorrízicos arbusculares (FMA) autóctones no crescimento de mutambo (Guazuma ulmifolia Lamb.). As mudas foram transplantadas para sacos de plástico (2 kg) com substratos esterilizados na proporção 4:1 (solo:areia), e o tratamento inoculado recebeu 300 esporos de FMA por saco. A inoculação não proporcionou aumento significativo na produção da matéria seca da parte aérea, matéria fresca das raízes e altura da planta, sugerindo que a G. ulmifolia não é responsiva à micorrização.Experiments were carried out in a greenhouse, using reforested degraded pasture and preserved 'cerrado' (control) soil with the objective to evaluate the contribution of autoctone arbuscular mycorrhizal fungi (AMF) on the Guazuma ulmifolia Lamb. growth. Seedlings were transplanted to plastic bags with 2 kg of sterilized soil: sand substrate (4:1). Plants were inoculated with ca. 300 spores of AMF per replication; non-inoculated plants served as control. AMF did not improve significantly canopy dry matter, root fresh matter and plant height. G. ulmifolia showed no response to mycorrhizae

Associação micorízica em espécies arbóreas, atividade microbiana e fertilidade do solo em áreas degradadas de cerrado

The recuperation of areas used during the construction of the hydroelectric plant, especially in ‘borrowed areas', is a difficult and long process as all vegetation and fertile soil were removed. Interventions in these degraded areas could accelerate the revegetation process. The objective of this research was to evaluate the association of arbuscular mycorrhizal fungi (AMF) in tree species, microbial activity (basal respiration) and fertility of ‘cerrado’ degraded areas. Soil from two areas, pasture soil and exposed subsoil, were utilized. Organic compost and fertilizers, as well as limestone application were added to the pit for better development of seedlings’ initial growth, where 50 mL of preserved cerrado soil was applied as inoculum of microorganisms. Seedlings of 11 tree species were planted: Anadenanthera falcata (Benth.) Speg (‘angico preto’), Acacia polyphylla D.C. (‘monjoleiro’), Sthryphnodendron adstringens (Mart.) Coville (‘barbatimão’), Dimorphandra mollis Benth (‘faveiro’), Hymenaea stigonocarpa Mart. ex Hayne (‘jatobá-de-cerrado’), Dipteryx alata Vog. (’baru’), Machaerium acutifolium Vogel (‘jacarandá-do-campo’), Schinus terebinthifolia Raddi (‘aroeira pimenteira’), Magonia pubescens St. Hil. (‘tingui’), Lafoensia pacari St. Hil. (‘dedaleira’) and Tabebuia aurea (Manso) Benth. & Hook (‘ipê amarelo’). Twelve months later, root samples were colleted at the depth of 0-0.10 m and used for evaluations. The subsoil, as compared to pasture soil, was poor in organic matter and presented less microbial activity. The highest mycorrhizal colonization was seen in the species Aacia polyphylla D.C. (monjoleiro), Schinus terebinthifolia Raddi (aroeira pimenteira), Hymenaea stigonocarpa Mart. ex Hayne (jatobá-de-cerrado) and Sthryphnodendron adstringens (Mart.) Coville (barbatimão). These species could be indicated in revegetation projects in ‘cerrado’ degraded areas. Plants from both areas showed seedlings form high mycorrhizal colonization and low numbers of spores.A recuperação de áreas de obras das barragens, em especial de "áreas de empréstimos", é difícil e consiste em um processo lento, visto que toda a vegetação e a camada fértil do solo foram removidas. Intervenções nessas áreas poderiam acelerar o processo de revegetação. O presente trabalho teve como objetivo avaliar a associação de fungos micorrízicos arbusculares (FMA) em espécies arbóreas, atividade microbiana pela respiração basal e fertilidade em áreas degradadas de cerrado. Utilizou-se solo de duas áreas, solo de pastagem e subsolo exposto. Adubações orgânica e mineral, além da calagem, foram efetuadas nas covas, visando a um melhor crescimento inicial das mudas, assim como, 50 mL de solo de cerrado preservado como inoculante de microrganismos. Mudas de 11 espécies arbóreas foram plantadas ou seja: Anadenanthera falcata (Benth.) Speg. (angico-preto), Acacia polyphylla D.C. (monjoleiro), Stryphnodendron adstringens (Mart.) Coville (barbatimão), Dimorphandra mollis Benth (faveiro), Hymenaea stigonocarpa Mart. ex Hayne (jatobá-de-cerrado), Dipteryx alata Vog. (baru), Machaerium acutifolium Vogel (jacarandá-do-campo), Schinus terebinthifolia Raddi (aroeira-pimenteira), Magonia pubescens St. Hil. (tingui), Lafoensia pacari St. Hil. (dedaleira) e Tabebuia aurea (Manso) Benth. & Hook. (ipê-amarelo). Doze meses após a instalação do experimento, amostras de raízes foram coletadas na camada de 0-0,10 m para as avaliações. O subsolo, em relação ao solo de pastagem, continuou pobre em matéria orgânica e com menor atividade microbiana. As maiores porcentagens de colonização micorrízica por FMA foram observados nas espécies Acacia polyphylla D.C. (monjoleiro), Magonia pubescens St. Hil. (tingui), Hymenaea stigonocarpa Mart. ex Hayne (jatobá-de-cerrado) e Schinus terebinthifolia Raddi (aroeira-pimenteira). Tais espécies podem ser indicadas para projetos de revegetação em áreas degradadas de cerrado. As plantas das duas áreas exibiam altas porcentagens de colonização micorrízica e o solo ou subsolo baixo número de esporos de fungos micorrízicos arbusculares

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

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

Mycorrhizal association in tree species, microbial activity and soil fertility on "cerrado" degraded areas

A recupera\ue7\ue3o de \ue1reas de obras das barragens, em especial de \u201c\ue1reas de empr\ue9stimos\u201d, \ue9 dif\uedcil e consiste em um processo lento, visto que toda a vegeta\ue7\ue3o e a camada f\ue9rtil do solo foram removidas. Interven\ue7\uf5es nessas \ue1reas poderiam acelerar o processo de revegeta\ue7\ue3o. O presente trabalho teve como objetivo avaliar a associa\ue7\ue3o de fungos micorr\uedzicos arbusculares (FMA) em esp\ue9cies arb\uf3reas, atividade microbiana pela respira\ue7\ue3o basal e fertilidade em \ue1reas degradadas de cerrado. Utilizou-se solo de duas \ue1reas, solo de pastagem e subsolo exposto. Aduba\ue7\uf5es org\ue2nica e mineral, al\ue9m da calagem, foram efetuadas nas covas, visando a um melhor crescimento inicial das mudas, assim como, 50 mL de solo de cerrado preservado como inoculante de microrganismos. Mudas de 11 esp\ue9cies arb\uf3reas foram plantadas ou seja: Anadenanthera falcata (Benth.) Speg. (angico-preto), Acacia polyphylla D.C. (monjoleiro), Stryphnodendron adstringens (Mart.) Coville (barbatim\ue3o), Dimorphandra mollis Benth (faveiro), Hymenaea stigonocarpa Mart. ex Hayne (jatob\ue1-de-cerrado), Dipteryx alata Vog. (baru), Machaerium acutifolium Vogel (jacarand\ue1-do-campo), Schinus terebinthifolia Raddi (aroeira-pimenteira), Magonia pubescens St. Hil. (tingui), Lafoensia pacari St. Hil. (dedaleira) e Tabebuia aurea (Manso) Benth. & Hook. (ip\uea-amarelo). Doze meses ap\uf3s a instala\ue7\ue3o do experimento, amostras de ra\uedzes foram coletadas na camada de 0-0,10 m para as avalia\ue7\uf5es. O subsolo, em rela\ue7\ue3o ao solo de pastagem, continuou pobre em mat\ue9ria org\ue2nica e com menor atividade microbiana. As maiores porcentagens de coloniza\ue7\ue3o micorr\uedzica por FMA foram observados nas esp\ue9cies Acacia polyphylla D.C. (monjoleiro), Magonia pubescens St. Hil. (tingui), Hymenaea stigonocarpa Mart. ex Hayne (jatob\ue1-de-cerrado) e Schinus terebinthifolia Raddi (aroeira-pimenteira). Tais esp\ue9cies podem ser indicadas para projetos de revegeta\ue7\ue3o em \ue1reas degradadas de cerrado. As plantas das duas \ue1reas exibiam altas porcentagens de coloniza\ue7\ue3o micorr\uedzica e o solo ou subsolo baixo n\ufamero de esporos de fungos micorr\uedzicos arbusculares.The recuperation of areas used during the construction of the hydroelectric plant, especially in 'borrowed areas', is a difficult and long process since all vegetation and the fertile layer of soil were removed. Interventions in these degraded areas could accelerate the revegetation process. The objective of this research was to evaluate the association of arbuscular mycorrhizal fungi (AMF) in tree species, microbial activity (basal respiration) and fertility of 'cerrado' degraded areas. Soil from two areas, pasture soil and exposed subsoil, were utilized. Organic and mineral fertilization, and liming, were added to the pit for better seedlings' initial growth, where 50 mL of preserved cerrado soil was applied as inoculum of microorganisms. Seedlings of 11 tree species were planted: Anadenanthera falcata (Benth.) Speg ('angico-preto'), Acacia polyphylla D.C. ('monjoleiro'), Stryphnodendron adstringens (Mart.) Coville ('barbatim\ue3o'), Dimorphandra mollis Benth ('faveiro'), Hymenaea stigonocarpa Mart. ex Hayne ('jatob\ue1-de-cerrado'), Dipteryx alata Vog. ('baru'), Machaerium acutifolium Vogel ('jacarand\ue1-do-campo'), Schinus terebinthifolia Raddi ('aroeira-pimenteira'), Magonia pubescens St. Hil. ('tingui'), Lafoensia pacari St. Hil. ('dedaleira') and Tabebuia aurea (Manso) Benth. & Hook ('ip\uea-amarelo'). Twelve months later, root samples were colleted at the depth of 0-0.10 m and used for evaluations. The subsoil, as compared to pasture soil, was poor in organic matter and presented less microbial activity. The highest mycorrhizal colonization was seen in the species Acacia polyphylla D.C. (monjoleiro), Magonia pubescens St. Hil. (tingui), Hymenaea stigonocarpa Mart. ex Hayne (jatob\ue1-de-cerrado) and Schinus terebinthifolia Raddi (aroeira-pimenteira). These species could be indicated in revegetation projects in 'cerrado' degraded areas. Plants from both areas showed seedlings form high mycorrhizal colonization and low numbers of spores

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. 

Effects of soil management systems on soil microbial activity, bulk density and chemical properties

Este trabalho teve por objetivo estudar os efeitos de diferentes sistemas de uso e manejo na densidade do solo nas suas propriedades químicas e na atividade microbiana em um Latossolo Vermelho distrófico (Oxisol). As amostras de solo foram retiradas de parcelas dos seguintes tratamentos: cerrado denso preservado, pastagem de Brachiaria decumbens degradada (20 anos), plantio direto com rotação de culturas (8 anos) e sistema convencional com rotação de culturas anuais (10 anos). O delineamento experimental utilizado foi o inteiramente casualizado, com dez repetições. O uso contínuo de plantio direto resultou em mais alta taxa de C-biomassa microbiana e menor perda relativa de carbono pela respiração basal, podendo determinar, desta forma, maior acúmulo de C no solo a longo prazo. Proporcionou, ainda, melhoria na densidade aparente e nas propriedades químicas do solo. Assim, o sistema plantio direto, com manejo de culturas, mostrou ser uma alternativa para a conservação e manutenção das condições físicas e do potencial produtivo de solos de cerrado.The objective of this experiment was to study the effects of soil management systems on the bulk density, chemical soil properties, and on the soil microbial activity on a Latossolo Vermelho distrófico (Oxisol). Soil samples were collected from plots under the following management conditions: a) natural dense "cerrado" vegetation (savanna); b) degraded Brachiaria decumbens pasture, 20 years old; c) no-tillage treatment with annual crop sequence (bean, corn, soybean and dark-oat in continuous rotation), 8 years old; d) conventional tillage treatment with crop residues added to the soil, and annual crop sequence, 10 years old. The continuous use of no-tillage system resulted in an increase in microbial biomass and decrease in soil basal respiration, therefore displaying evident long-term effects on the increase of soil C content. The no-tillage system also provided an improvement in bulk density and chemical properties of the soil. Hence, the no-tillage management system could be an alternative for the conservation and maintenance of physical and chemical conditions and the productive potential of "cerrado" soils

CRESCIMENTO DE MUDAS DE BARU E GONÇALO-ALVES EM SOLO DEGRADADO, SUPLEMENTADO COM RESÍDUO, EM ILHA SOLTEIRA - SP

The revegetation process represents an alternative to recovery of areas with exposed soil. The aim of this research was evaluate the growth of Dipteryx alata (baru) and Astronium fraxinifolium (gonçalo-alves) seedlings in degraded soil, compacted and not, supplemented with agro-industrial residue, and verify the possibility of using this as a chemical soil conditioner. The experiment was conducted at UNESP/Ilha Solteira Campus, under protected cultivation, with the following treatments: 3 doses of residue (0, 15 and 30 t ha-1), two densities (1.0 and 1.5 g cm-3) and two indicator plants (Dipteryx alata e Astronium fraxinifolium). The selected plants are arboreal species from ‘cerrado’ biome, which occur in the vicinity of the degraded area, where the soil was collected. The seedlings were evaluated 7 months after roughing, for height, diameter of stem, number of leaves, fresh and dry weight of shoots and roots, and the soil was evaluated for fertility. The results show that the agro-industrial residue (RA) has increased the pH, potassium, calcium and magnesium, and reduced the exchangeable aluminum. The Dipteryx alata fresh root weight, was negatively influenced by compaction and showed little demanding for nutrients added by RA. Fresh root weight and height of Astronium fraxinifolium were negatively influenced by compaction whereas the addition of agro-industrial residue increased the plant height, stem diameter, fresh and dry weight of shoot and root. The root morphology was affected by compaction, in both species. The used substrate presents a high capacity of particles reorganization, resulting in a high density, without force application.O processo de revegetação representa uma alternativa para recuperação de áreas com solo exposto. Este trabalho objetivou avaliar o crescimento de mudas de Dipteryx alata (baru) e Astronium fraxinifolium (gonçalo-alves) em solo degradado, compactado ou não, suplementado com resíduo agroindustrial e verificar a possibilidade de uso deste como condicionante do solo. O experimento, conduzido na UNESP/Campus de Ilha Solteira, em cultivo protegido, apresenta três doses de resíduo (0, 15 e 30 t ha-1), duas densidades (1,0 e 1,5 g cm-3) e duas plantas indicadoras (Dipteryx alata e Astronium fraxinifolium). As plantas, arbóreas de cerrado, ocorrem nas proximidades da área degradada, onde o solo foi coletado. As mudas foram avaliadas 7 meses após desbaste, para altura, diâmetro do caule, número de folhas, massa fresca e seca da parte aérea e do sistema radicular, e o solo foi avaliado para análise da fertilidade. Os resultados mostram que o resíduo agroindustrial (RA) elevou pH, teores de potássio, cálcio e magnésio, e diminuiu o alumínio disponível. O Dipteryx alata teve a massa fresca da raiz influenciada negativamente pela compactação e se mostrou pouco exigente quanto à adição de nutrientes pelo RA. O Astronium fraxinifolium teve a massa fresca da raiz e a altura negativamente influenciados pela compactação, enquanto a adição do RA favoreceu altura, diâmetro do caule, massa fresca e seca da parte aérea e do sistema radicular. A morfologia das raízes foi alterada pela compactação, nas duas espécies. O substrato utilizado apresenta elevada capacidade de reorganização, produzindo elevada densidade sem aplicação de força

CRESCIMENTO DE MUDAS DE BARU E GONÇALO-ALVES EM SOLO DEGRADADO, SUPLEMENTADO COM RESÍDUO, EM ILHA SOLTEIRA - SP

The revegetation process represents an alternative to recovery of areas with exposed soil. The aim of this research was evaluate the growth of Dipteryx alata (baru) and Astronium fraxinifolium (gonçalo-alves) seedlings in degraded soil, compacted and not, supplemented with agro-industrial residue, and verify the possibility of using this as a chemical soil conditioner. The experiment was conducted at UNESP/Ilha Solteira Campus, under protected cultivation, with the following treatments: 3 doses of residue (0, 15 and 30 t ha -1 ), two densities (1.0 and 1.5 g cm -3 ) and two indicator plants ( Dipteryx alata e Astronium fraxinifolium ). The selected plants are arboreal species from ‘cerrado’ biome, which occur in the vicinity of the degraded area, where the soil was collected. The seedlings were evaluated 7 months after roughing, for height, diameter of stem, number of leaves, fresh and dry weight of shoots and roots, and the soil was evaluated for fertility. The results show that the agro-industrial residue (RA) has increased the pH, potassium, calcium and magnesium, and reduced the exchangeable aluminum. The Dipteryx alata fresh root weight, was negatively influenced by compaction and showed little demanding for nutrients added by RA. Fresh root weight and height of Astronium fraxinifolium were negatively influenced by compaction whereas the addition of agro-industrial residue increased the plant height, stem diameter, fresh and dry weight of shoot and root. The root morphology was affected by compaction, in both species. The used substrate presents a high capacity of particles reorganization, resulting in a high density, without force application

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