Characterization of edaphic fauna in different monocultures in Savanna of Piauí / Caracterização da fauna edáfica em diferentes monoculturas no Cerrado piauiense

Abstract Vegetation cover may show diversity and composition patterns of the soil invertebrate community, as a function of litter quantity and quality in a specific habitat. The objective of this work was to characterize the distribution of edaphic fauna in different monocultures. The study was carried out at Chapada Grande farm in Regeneração, PI. Four monoculture areas were chosen: no-tillage soybean, eucalyptus, pasture, and a preserved native cerrado forest. Soil fauna was collected in a dry and wet period by pitfall traps containing 4% formaldehyde. The edaphic fauna was evaluated by the number of individuals per trap per day, average richness and richness, Shannon diversity index and Pielou uniformity index. Data were submitted to analysis of variance and multivariate Principal Component Analysis (PCA). The highest number of individuals per day trap and of average richness were registered in the pasture, eucalyptus and forest areas in both periods, while soybean showed lower values with predominance of Coleoptera and Formicidae groups. The pasture and forest areas showed of higher Shannon index values in the two evaluated seasons, probably due to higher contributions organic residues in the soil that favors the shelter, feeding and reproduction conditions. Regarding the Pielou index, the soybean system showed higher values in this variable. The Aranae, Coleoptera, Formicidae and Diptera groups predominated in the humid period, while Coleoptera and Formicidae predominated in the dry period. Systems that generate greater accumulation of residues harbor a greater diversity of invertebrates of the edaphic fauna. Seasonality had an effect on all variables analyzed and the wet period showed more expressive values.

Resumo A cobertura vegetal pode mostrar padrões de diversidade e composição da comunidade de invertebrados do solo, em função da quantidade e qualidade da serapilheira em determinado habitat específico. O objetivo deste trabalho foi caracterizar a distribuição da fauna edáfica em diferentes monocultivos. O estudo foi realizado na fazenda Chapada Grande no município de Regeneração, PI. Foram escolhidas quatro áreas de monocultivos: soja em sistema de plantio direto, eucalipto, pastagem, além de uma mata nativa de cerrado preservada. Foram realizadas coletas da fauna do solo, em período seco e úmido, por meio de armadilhas do tipo pitfall contendo 4% de formol. A fauna edáfica foi avaliada pelo número de indivíduos por armadilha por dia, riqueza e riqueza média, índice de diversidade de Shannon e índice de uniformidade de Pielou. Os dados foram submetidos à análise de variância e à análise multivariada de Componentes Principais (ACP). O maior número de indivíduos por armadilha dia e de riqueza média foram registrados nas áreas pastagem, eucalipto e mata nos dois períodos, enquanto que a soja mostrou valores inferiores com predomínio dos grupos Coleoptera e Formicidae. As áreas de pastagem e mata mostraram maiores valores de índice de Shannon nas duas épocas avaliadas provavelmente em função de maiores aportes de resíduos orgânicos no solo que favorece as condições de abrigo, alimentação e reprodução. Em relação ao índice de Pielou o sistema com soja mostrou maiores valores nessa variável. Os grupos Araneae, Coleoptera, Formicidae e Diptera predominaram no período úmido, enquanto Coleoptera e Formicidae se destacaram no período seco. Sistemas que geram maior acúmulo de resíduos abrigam uma maior diversidade de invertebrados da fauna edáfica. A sazonalidade apresentou efeito sobre todas as variáveis analisadas sendo que o período úmido mostrou valores mais expressivos.

Soil phosphorus availability and uptake by mycorrhizal and non-mycorrhizal plants in an onion no-tillage system / Disponibilidade e absorção de fósforo no solo por plantas micorrízicas e não micorrízicas em sistema de plantio direto de cebola

ABSTRACT: Onion is an important vegetable crop, predominantly grown under conventional tillage system management. Alternatively, the vegetable no-tillage system uses cover crops to form a residue layer, which improves soil physical, chemical, and biological attributes. Aiming to understand the interaction of mycorrhizal and non-mycorrhizal cover crops, phosphatase activity, and soil phosphorus availability and uptake by plants, a no-tillage vegetable production system experiment with onion was carried out in Ituporanga, Southern Brazil. The treatments were black oats (Avena strigosa); rye (Secale cereale); oilseed radish (Raphanus sativus); rye + oilseed radish; black oats + oilseed radish, and a control with spontaneous plants. Additionally, two plots, a conventional tillage system area and a forest, both adjacent to the experiment, were evaluated. We measured cover crop biomass, onion yield, acid phosphatase activity, and resin-extracted phosphorus in the soil, shoot and root phosphorus content, and root colonization in cover crops, spontaneous plants, and onions. The treatments with cover crops had the highest plant biomass in winter and onion yield. Available soil phosphorus and acid phosphatase activity were higher in no-tillage plots than in the conventional tillage system area. The presence of non-mycorrhizal oilseed radish was associated with decreased colonization of rye and onion roots by arbuscular mycorrhizal fungi. No-tillage areas with cover crops or spontaneous plants in winter accumulated more phosphorus than conventional tillage system areas. The conventional tillage system showed adverse effects on most soil attributes, as shown by a Principal Component Analysis.

RESUMO: A cebola é uma importante cultura vegetal, cultivada predominantemente sob sistema de preparo convencional. Como alternativa, o sistema de plantio direto de hortaliças utiliza culturas de cobertura para formar uma camada de biomassa, o que melhora os atributos físicos, químicos e biológicos do solo. Com o objetivo de entender a interação de culturas de cobertura micorrízicas e não-micorrízicas, atividade da fosfatase ácida e disponibilidade e absorção de fósforo do solo pelas plantas, foi realizado um experimento em sistema de plantio direto de hortaliças com a cultura da cebola em Ituporanga, sul do Brasil. Os tratamentos foram: aveia preta (Avena strigosa); centeio (Secale cereale); nabo forrageiro (Raphanus sativus); centeio + nabo forrageiro; aveia preta + nabo forrageiro e um controle com vegetação espontânea. Além disso, duas outras parcelas, uma área em sistema de preparo convencional e uma floresta, ambas adjacentes ao experimento, foram avaliadas. Medimos a biomassa da cultura de cobertura, o rendimento de cebola, a atividade de fosfatase ácida e o fósforo extraído por resina no solo, bem como o conteúdo de fósforo da parte aérea e da raiz e a colonização das raízes em plantas de cobertura, plantas espontâneas e cebolas. Os tratamentos com plantas de cobertura apresentaram a maior biomassa de culturas de cobertura e rendimento de cebola. A atividade de fosfatase ácida e fósforo disponível no solo foram maiores nas parcelas de plantio direto do que na área convencional. A presença de nabo forrageiro, uma planta não micorrízica, foi associada a reduções na colonização de raízes de centeio e cebola por fungos micorrízicos arbusculares. As áreas de plantio direto com plantas de cobertura ou plantas espontâneas no inverno acumularam mais fósforo do que as áreas com preparo convencional. O sistema convencional de lavoura mostrou efeitos adversos para a maioria dos atributos do solo, como mostra a Análise de Componentes Principais.

The Effect of Soil Management on Pore Size Distribution and Water Infiltration

Abstract Water infiltration into soil varies significantly with soil type and management practices. Management practices alter soil physical properties, such as porosity and pore size distribution, which play an important role in infiltration. This study was conducted to assess the effect of the long-term use of two different soil tillage systems (conventional, CT, and no-tillage, NT) on soil structure and water infiltration to understanding of the relationship between physical conditions induced by tillage and water infiltration. The experiments were carried out on a Humic Cambisol in southern Brazil from 1995 to 2016. Soil density, porosity, aggregate diameter and soil water infiltration were evaluated under conventional tillage right after one plowing and two subsequent discings (CT0), and six months after these tillage operations (CT6). The results show that different management systems affect differently soil physical properties and, thus, water infiltration. By mechanical mobilization CT brings about modifications in soil structure which promote an increase in total porosity and mesopority, and a decrease in soil microporosity. This in turn results in an increase in the proportion of larger pores in the plow layer and a decrease in soil density, but also in a decrease in aggregate stability. The CT0 measurements showed the highest infiltration rates which were up to 15 times greater than in the NT treatment. The higher infiltration rate in CT0 wears off with time, but in the CT6 measurements six months after tillage it was still 2 times higher than under NT. Tillage, at least initially, increases total porosity and mesoporosity, while at the same time decreasing microporosity. This results in a larger saturated hydraulic conductivity (K). An increase in total porosity alone does not necessarily increase K, if there is an increase in small pores at the cost of decreasing the number of larger pores.

No-tillage:core strategies for sustainable development of ecological agriculture of Chinese materia medica / 中国中药杂志

Ecological agriculture is a crucial way for agriculture of Chinese materia medica, which emphasizes the application of ecological principles in the cultivation of traditional Chinese medicine. While long-term intensive farming and modern chemical agriculture have threatened soil health, the sustainable development of ecological agriculture of Chinese materia medica is constrained. No-til-lage can reduce both frequency and intensity of tillage. Compared with conventional agriculture, no-tillage can reduce soil disturbance, maintain no-tillage for a long or permanent period and keep mulching. The application of no-tillage has a long history. More and more studies have shown that no-tillage has many advantages over conventional tillage, and the ecological and economic benefits of no-tillage are particularly outstandingin long-term. The cultivation of Chinese medicinal materials adheres to the principle of not grabbing land from farmland, making full use of the soil resources under forests, mountains and wasteland. Reducing the risk of soil loss and sustai-nable utilization are the core issues in the process of new land cultivation. No-tillage application, which not only inherits the traditional Chinese concept of natural farming, but also integrates the laws of ecological agriculture, will become the core strategies of sustainable development of Chinese materia medica ecological agriculture. This study will introduce the basic concepts and development process of no-tillage, analyze their ecological benefits in ecological agriculture of Chinese materia medica, and put forward their application strategies.

Response of Conservation Agriculture on System Productivity and Carbon Sequestration in Rice-Based Cropping Systems

Low crop yields due to constant monocropping systems and deteriorating soil health in a smallholder farmers’ field of Indo-Gangetic plains of India have led to a quest for sustainable production practices with greater resource use efficiencies. The aim of the study was to elucidate the short term effects of conservation agricultural systems on productivity, soil health and carbon sequestration rate of soils in three different diversified cropping systems. The treatments consisted of two different tillage systems (conventional and reduced tillage), two mulch levels (no and straw mulch) and two levels of fertility (100 and 75% RDF) were compared in three rice-based cropping systems (rice-wheat; rice-vegetable pea-greengram; and rice-potato-maize sequences) for two years on an experimental field (clay loam) located at Norman E Borlaug Crop Research Center, Pantnagar, India. The resource conservation technologies (RCT) i.e. reduced tillage, mulch, and 100% RDF had recorded 2.5 and 3.0% higher system productivity and relative production efficiency in rice-vegetablepea-greengram and rice-potato-maize sequences, respectively in two consecutive years. Conservation tillage had sequestered three times higher carbon than conventional tillage while mulching acted four times higher than non-mulched condition in agricultural soils. Even though cropping system not significant significantly influenced on carbon sequestration, rice-vegetablepea-greengram sequence had recorded higher carbon sequestration rate and higher soil organic carbon stock noted in surface plough sole layer than any other cropping systems. Therefore, our results suggested that Indo-Gangetic farmers should consider adopting resource conservation practices together in indogangetic area because of benefits to soil health, carbon sequestration and system productivity.

Soil macrofauna associated with cover crops in an Oxisol from the southwest of Piauí state, Brazil / Macrofauna edáfica associada a plantas de cobertura em um Latossolo Amarelo do sudoeste do estado do Piauí, Brasil

The soil macrofauna is fundamental for the maintenance of soil quality. The aim of this study was to characterize the soil macrofauna under different species of cover crops, including monoculture or intercropping associated to two types of soil management in the southwest region of Piauí state. The study was carried out in an Oxisol (Latossolo Amarelo, according to Brazilian Soil Classification System) in the municipality of Bom Jesus, Piauí, distributed in 30 m2 plots. Testing and evaluation of the soil macrofauna were conducted in a 9 × 2 strip factorial design, with combinations between cover crops/consortia and soil management (with or without tillage), with four replications. Soil monoliths (0.25 × 0.25 m) were randomly sampled in each plot for macrofauna at 0‒0.1, 0.1‒0.2, and 0.2‒0.3 m depth, including surface litter. After identification and counting of soil organims, the relative density of each taxon in each depth was determined. The total abundance of soil macrofauna quantified under cover crops in the conventional and no-tillage system was 2,408 ind. m-2, distributed in 6 classes, 16 orders, and 31 families. The results of multivariate analysis show that grass species in sole cropping systems and no-tillage presents higher macrofauna density, in particular the taxonomic group Isoptera. No-tillage also provided higher richness of families, where Coleoptera adult were the second more abundant group in no-tillage and Hemiptera in conventional tillage.(AU)

Os organismos da macrofauna edáfica são fundamentais para a manutenção da qualidade do solo. O objetivo deste trabalho foi caracterizar a macrofauna edáfica sob diferentes espécies de plantas de cobertura, incluindo monocultura ou cultivo consorciado associados a dois tipos de manejo do solo no sudoeste do Piauí. O estudo foi realizado em Latossolo Amarelo (Sistema Brasileiro de Classificação de Solos) no município de Bom Jesus, Piauí, distribuídos em parcelas de 30 m2. O experimento e avaliação da macrofauna edáfica foram conduzidos em um ensaio fatorial em faixas 9 × 2, com combinações entre culturas /consórcios de cobertura e manejo do solo (com ou sem preparo), com quatro repetições. Os monólitos de solo (0,25 × 0,25 m) foram retirados aleatoriamente de cada parcela, para contagem da macrofauna, nas camadas de 0‒0,1, 0,1‒0,2, e 0,2-0,3 m de profundidade, inclusive liteira de superfície. Após a identificação e contagem dos organismos, foi determinada a densidade relativa de cada táxon em cada profundidade. A abundância total da macrofauna edáfica quantificada no experimento foi de 2.408 ind.m-2, distribuídos em 6 classes, 16 ordens e 31 famílias. Os resultados da análise multivariada revelaram que espécies de gramíneas em sistemas de cultivo solteiro e plantio direto favoreceram maior densidade da macrofauna, em especial do grupo taxonômico Isoptera. A ausência de preparo também proporcionou maior riqueza de famílias, destacando-se o grupo taxonômico Coleoptera adulto em plantio direto e Hemiptera em plantio convencional.(AU)

Does Dairy Liquid Manure Complementary to Mineral Fertilization Increase Grain Yield Due to Changes in Soil Fertility?

Abstract The main destination of manure is the application to croplands near livestock farms as nutrient source to enhance crop production. The aim of this study was to define the dairy liquid manure (DLM) dose, complementary to the mineral fertilizer, for higher crops yield, in rotation black oat-maize-wheat-soybean, and to identify the soil chemical variables improved by the manure that most affect the yield, in long-term. The experiment was conducted from 2006 to 2015, in no-tillage system, at Paraná State, Brazil. The soil was a Latossolo Bruno Distrófico típico, clayey texture. The treatments consisted by doses of DLM (0, 60, 120 and 180 m3 ha-1 year-1), complementary to the mineral fertilizer (applied in the same amount for all DLM doses). Crops yield and soil chemical variables were evaluated at six depths (0-10; 10-20; 20-30; 30-40; 40-50 and 50-60 cm). The DLM application increased the yield of all crops, but not in all harvests. The DLM even applied at soil surface improved the soil chemical variables in deep layers, resulting in high positive correlation between yield and exchange bases, P, Zn and Mn contents, and high negative correlation with Ca/Mg ratio and potential acidity at depth 0-10 cm. The DLM dose, complementary to the mineral fertilization, that provided higher soybean and wheat yield was about 130 m3 ha-1 year-1, while for maize this dose was equal to or greater than 180 m3 ha-1 year-1. This effect was not attributed to a single chemical variable but the improvement of all chemical variables evaluated.

Adaptation Approaches for Direct Seeded Rice to Reduce Greenhouse Gas Emission in the Perspective of Climate Change

A field experiment was conducted at research farm, Bihar Agricultural University, Sabour, India during 2017 and 2018 to gain insight crop phonology mediated greenhouse gas emission under different tillage and nitrogen management practices in direct seeded rice (DSR). The experiment was conducted in split plot design with two tillage viz. zero tillage (ZT) and conventional tillage (CT) as main plot and four nitrogen management practices viz. 100% nitrogen through neem coated urea (S1), SPAD based nitrogen management (S2), 75% through neem coated urea + 25% nitrogen through vermicompost, (S3) and ¼ nitrogen as basal and rest in equal three splits at 20, 40, 60 DAS (S4) as sub plot, in three replication. The highest yield (4.69 t ha-1), net return (Rs 46440 ha-1) and B:C ratio (1.44) were recorded from zero tilled DSR. Further, highest yield (4.82 t ha-1), net return (Rs 44880 ha-1) and B:C ratio (1.36) was obtained under split application of nitrogenous fertilizers among other subplot treatments. The range of methane (0.57- 1.47 mg m-2 hr-1) carbon dioxide (0.32- 0.61 mg m-2 hr-1) and nitrous oxide (19.58- 38.79 µg m-2 hr-1) emission was recorded lowest in zero tilled plots and split application of nitrogenous fertilizer also emitted lowest values of 1.59 mg m-2 hr-1 methane, 0.86 mg m-2 hr-1 carbon dioxide and 46.76 µg m-2 hr-1 nitrous oxide at maximum tillering stage of crop growth. Moreover, methane and nitrous oxide emission was gradually decreased from maximum tillering to harvesting stage. Zero tilled DSR with split nitrogen fertilizer application ascribed lowest greenhouse gas intensity among the other crop establishment and nitrogen management options. Thus, zero tilled method of crop establishment with split application of nitrogenous fertilizer could be a remunerative and environmentally stable method for direct seeded rice cultivation.

Soil organic matter and production of ears of green corn after four years under tillage systems and previous crops in costal tablelands / Matéria orgânica do solo e a produção espigas de milho-verde após quatro anos sob sistemas de cultivo e culturas antecedentes nos tabuleiros costeiros

The current study aimed to evaluate the effects of different tillage systems on soil organic matter (SOM) contents and green corn yield (total ear weight) of an Argissolo Vermelho-Amarelo(Ultissol) in Coastal tablelands of northeast Brazil. The experiment was arranged as a strip plot design with three replications. Three tillage practices [conventional tillage (CT), minimum tillage (MT) and no-tillage (NT)] were laid out as a whole plot each (830 m²). Then, each plot was equally split into 12 experimental units (60 m²), distant 1 x 10 m from each other, where in four cover crops [pigeon pea (Cajanus cajan (L.) Millsp.), sunn hemp (Crotalaria juncea L.), beans (Phaseolus vulgaris) and peanut (Arachis hypogeae) were seedling previous to corn cultivation. Neither cover crops, nor tillage practices affected SOM contents at 0.20 m depth. An exception was observed on beans plots in which CT resulted on the lowest SOM content (8.5 dag kg-1) at 0-10 cm soil layer. Regarding green corn ears yield, CT adoption also resulted in lower weight (4.11 t ha-1) than those on NT (7.65 t ha-1), regardless of cover crop. On the other hand, the influence of cover crops on green corn yield relied upon tillage practices. Peanuts and sunn hemp performed best to improve corn yield in CT; peanuts and beans increased by 14 % the green corn ears yield in MT, while sunn hemp resulted in the highest total ear weight (9.42 t ha-1). Linear correlation of Pearson was significant for SOM and productivity green maize ears in minimum tillage beans (p <0.001; r = 0.996). After four years of absence or reduced soildisturbance, there was no increase in SOM levels. The plowing appears to be important for increasing the entry of C soil and chemical protection SOM of Argissols mainly in the surface layer of Coastal tablelands in brazilian northeast. Although the NT did not provide higher levels of SOM, the yield of green maize incommercial was significantly higher when adopting conservation systems.

O presente estudo teve como objetivo avaliar o efeito de diferentes sistemas de cultivo nos teores de matéria orgânica do solo (MOS) e na produtividade do milho verde (peso total das espigas) emArgissolo Vermelho-Amarelo (Ultissol) nos Tabuleiros costeiros da região nordeste do Brasil.. O experimento foi disposto em faixas experimentais com três repetições.Três práticas de cultivo [cultivo convencional (CC), cultivo mínimo (CM) e plantio direto (PD)] foram arranjadas em faixas (830 m²). Então, cada faixa foi dividida igualmente em doze unidades experimentais (60 m²), distante entre si a cada 1 x 10 m, onde quatro culturas antecessoras [guandu (Cajanus cajan (L.) Millsp.) crotalária (Crotalaria juncea), feijão (Phaseolus vulgaris) e amendoim (Arachis hypogeae)] foram semeadas previamente ao cultivo do milho. As culturas antecessoras e as práticas de cultivo não afetaram os teores de MOS da profundidade de 0.20 m. Uma exceção foi observada nas parcelas com feijão no qual o CC resultou no menor teor de MOS (8.5 dag kg-1) na camada 0-10 cm. Em relação a produtividade das espigas de milho verde, a adoção do CC também resultou em menor peso (4,11 t ha-1) que no PD (7,65 t ha-1), independente da cultura antecessora. Por outro lado, a influência da cultura de cobertura sob a produtividade do milho verde foi dependente da prática de cultivo. Amendoim e crotalária saíram-se melhor para aumentar a produtividade do milho no CC; amendoim e feijão aumentaram em 14 % a produtividade das espigas de milho verde no CM, enquanto crotalária resultou no mais alto peso total das espigas (9,42 t ha-1). A correlação linear de Pearson foi significativo para a MOS e produtividade de espigas de milho verde com crotalária sob o cultivo mínimo (p <0,001; r = 0,996). Após quatro anos da ausência ouredução do revolvimento do solo, não houve aumento nos níveis de MOS. A aração parece ser importante para aumentar a entrada de C no solo e a proteção química da MOS em Argissolos, principalmente na camada superficial. Embora o PD não tenha fornecido níveis mais elevados de MOS, o rendimento de espigas comerciais de milho verde foi significativamente maior ao se adotar sistemas conservacionistas.

Soil chemical attributes variability under tillage and no-tillage in a long-term experiment in southern Brazi l / Variabilidade dos atributos químicos do solo em sistemas de plantio distintos em experimento de longa duração no sul do Brasil

Spatial variability of chemical attributes in soils tends to increase under the no-tillage system. However, data regarding this variability under this system for a long time are scarce. This study aimed to evaluate the spatial variability of phosphorus (P), organic matter (OM), pH, aluminum (Al), calcium (Ca), magnesium (Mg), potassium (K), base saturation (V%), sulfur (SO42-), and micronutrients: boron (B), iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) in soil with conventional tillage and no-tillage treatments for more than three decades in order to optimize fertilization and maintain soil conservation. Samples of Rhodic Hapludox were collected at 0.00­0.20 m depth. Sampling points were spaced 5 m apart, totaling 100 points. All sampling points were georeferenced according to the tillage system. Samples were analyzed chemically. Semivariograms and kriging were used in descriptive statistics and geostatistics analyses of the results. Only micronutrients and P presented distinct spatial variability between the treatments. Most of the analyzed chemical attributes presented spatial dependency in both tillage systems, which may help determine the best form of sampling and indicate adequate fertilization. According to semivariogram range values of OM, Mg, and K, the same sampling strategy may be adopted for analysis in both tillage systems, yet for Al, Ca, and pH the strategy should be specific

A variabilidade espacial dos atributos químicos tende a aumentar em solos sob sistema plantio direto. No entanto faltam informações sobre essa variabilidade em solos submetidos a esse sistema por longo período.Este estudo objetivou avaliar a variabilidade espacial do fósforo (P), matéria orgânica (MO), pH, alumínio (Al), cálcio (Ca), magnésio (Mg), potássio (K), saturação por bases (V%), enxofre (SO42-) e dos micronutrientes boro (B), ferro (Fe), cobre (Cu), manganês (Mn) e zinco (Zn) em plantio direto e plantio convencional adotados há mais de três décadas, como forma de otimizar a aplicação de fertilizantes e preservar a adoção do manejo conservacionista. Amostras de Latossolo Vermelho distrófico coletadas na profundidade de 0,00 - 0,20 m, e 5 m de distância entre os 100 pontos amostrados e georreferenciados por manejo, foramanalisadas quimicamente e os resultados submetidos à estatística descritiva e à geoestatística, através do estudo de semivariogramas e krigagem. Apenas os micronutrientes e o P apresentaram variabilidade espacial distinta entre os manejos. A maioria dos atributos químicos estudados apresentou dependência espacial em ambos os sistemas de manejo, o que pode determinar a melhor forma de amostragem e indicar a adubação adequada. De acordo com os alcances atribuídos aos semivariogramas, para MO, Mg e K pode-se adotar a mesma estratégia de amostragem para análise em ambos sistemas de manejo e para Al, Ca e pH deve ser específica

Long-term tillage and nitrogen management for improving productivity and profitability of a rainfed maize-wheat system in north western Himalaya

Aim: The study aimed to identify the optimum tillage and source of nitrogen for refining yields, yield sustainability and rainwater-use efficiency, and to develop predictive models explaining the relationship between crop yield and monthly rainfall with main goal of reduced cost of cultivation and increased profitability for long-term sustainability of maize-wheat system. Methodology: A long-term field experiment on maize-wheat system was conducted from 2000 to 2012 at Regional Research Station, Ballowal Saunkhri, Punjab Agricultural University, Ludhiana in split plot design with three replications. The treatment included three tillage practices, viz., conventional tillage (CT), reduced tillage (RT1) and RT1 + herbicide (RT2) in the main plots and three nitrogen (N) management practices, viz., 100% N from organic source (F1), 50% N from organic + 50% N from inorganic source (F2) and 100% N from inorganic source (F3) in the sub-plots. The parameters included maize and wheat yield, rainwater use efficiency, economics, sustainability yield index to develop predictive models. Results: Prediction models expressing relation between yield and monthly rainfall showed beneficial effect of rainfall in June, July and September months on maize and January and February in wheat on crop productivity. RT2 gave highest mean maize grain yield (2264 kg ha−1) with 13.8 and 1.8% yield superiority over RT1 and CT, respectively. However, in wheat, CT recorded highest grain yield (2110 kg ha−1) with 7.9 and 1.7% higher yield than RT1 and RT2, respectively. The RT2F3 gave highest net returns of US$ 222.60 ha−1 with benefit-cost ratio (B:C) of 1.88, rain water use efficiency (RWUE) of 4.78 kg ha−1 mm−1 and a sustainable yield index (SYI) of 60.7% in maize, whereas in wheat it provided net returns of US$315.45 ha−1 with B:C of 2.28, RWUE of 23.0 kg ha−1 mm−1 and SYI of 47.4%. Interpretation: The efficient rainwater use and optimum yields of rainfed maize-wheat system can be realised with reduced tillage + herbicide based weed management along with application of recommended nitrogen. The study suggests the shift from conventional tillage practices to reduced/conservation tillage practices.

Modelación de los stocks de carbono del suelo y las emisiones de dióxido de carbono (GEI) en sistemas productivos de la Altillanura Plana / Modeling soil carbon stocks and carbon dioxide emissions (GHG) in production systems of Plain Altillanura / Modelagem dos estoques de carbono do solo e as emissões de dióxido de carbono (GEE) em sistemas de produção da Altillanura Plana

Resumen Los distintos manejos de los suelos afectan las existencias de C del suelo. El análisis multivariado de la modelación de los stocks de C del suelo (SOC0-T), las tasas de pérdidas (-ΔC) y/o ganancias de C del suelo (ΔC), las emisiones de gases de efecto invernadero (GEI) y remociones (-GEI) de CO2 atmosférico asociadas con algunas propiedades fisicoquímicas de los suelos en sistemas productivos de la Altillanura y otros de Piedemonte de la Orinoquia conformaron tres grupos bien definidos. El clúster I agrupó a pasturas mejoradas de Granada (S1) y sistemas agroforestales (SAFs) de café asociados con plátano y leguminosas de Villavicencio (S9), donde las ganancias de C (ΔC) y absorciones de CO2 atmosférico (-GEI) fueron medias variando de ≈ 0.11 a 2.37 t C ha-1 año-1 y de -1.60 a -8.70 t CO2eq ha-1 año-1; siendo que monocultivos en rotación también formaron parte de este grupo; el clúster II reunió a monocultivos de arroz de Villavicencio (S10) y de piña de Puerto López (S14) que presentaron las más altas pérdidas de C (-ΔC) del suelo y emisiones de CO2 atmosférico (GEI) de ≈ -2.08 a -2.35 t C ha-1 año-1 y de ≈ 7.62 a 8.62 t CO2eq ha-1 año-1; el clúster III agrupo a sistemas agroforestales SAFs de caucho y leguminosas de cobertura (S13) y sistemas silvopastoriles (SSPs) de Acacia mangium y pasturas mejoradas (S12) de Puerto López con las más altas ganancias de C del suelo (ΔC) y absorciones de CO2 atmosférico (-GEI) de ≈ 0.373 a 2.64 t C ha-1 año-1 y de ≈ -1.36 a -9.67 t CO2eq ha-1 año-1. Los sistemas agroforestales son una buena alternativa para el secuestro de C del suelo en la Altillanura Plana de Colombia.

Abstract The different soil management affects soil C stocks. Multivariate analysis of the modeling of soil C stocks (SOC0-T), soil C losses rates (-ΔC) and / or soil C gains (ΔC), greenhouse emissions (GHG) and removals (-GHG) atmospheric of CO2 associated with some physicochemical properties of soils in productive systems of High plains and other of lower mountains of the Orinoco region formed three distinct groups. Cluster I grouped improved pastures of Granada (S1) and coffee agroforestry systems (AFS) associated with banana and legumes of Villavicencio (S9), where gains of C (ΔC) and removal of atmospheric CO2 (-GEI) were averages ranging from ≈ 0.11 to -2.37 t C ha-1 yr-1 and -1.60 to -8.70 t CO2eq ha-1 yr-1; monocultures in rotation also were part of this group; Cluster II grouped rice monoculture of Villavicencio (S10) and pineapple of Puerto Lopez (S14) who had the highest losses of C (-ΔC) and soil atmospheric CO2 emissions (GHG) of ≈ -2.08 to - 2.35 t C ha-1 yr-1 of ≈ 7.62 to 8.62 t CO2eq ha-1 yr-1; Cluster III grouped to agroforestry system AFS of rubber and leguminous cover crops (S13) and silvopastoral systems (SSPs) of Acacia mangium and improved pastures of Puerto Lopez (S12) with the highest gains of soil C (ΔC) and removals of atmospheric CO2 (-GEI) of ≈ 0.373 to 2.64 t C ha-1 yr-1 and -1.36 to -9.67 ≈ t CO2eq ha-1 yr-1. Agroforestry systems are a good alternative for soil C sequestration in Altillanura Plana of Colombia.

Resumo A diferente gestão dos solos modifica os estoques do C orgânico do solo. A análise multivariada da modelagem do estoque de C orgânico (SOC0-T), as taxas de perdida (-ΔC) e / o aumento de C no solo (ΔC), as emissões de gases de efeito estufa (GEE) e remoções (-GEE) de CO2 atmosférico associado com algumas propriedades físico-químicas dos solos em sistemas produtivos da Altillanura e outras regiões de Piedemonte da região do Orinoco conformaram três grupos distintos. Cluster I agrupou pastagens melhoradas (S1) e sistemas agroflorestais (SAFs) de café associados com banana e leguminosas de Villavicencio (S9), onde o aumento de C (ΔC) e remoção do CO2 atmosférico (-GEE) eram médias que variou entre ≈ 0,11 até 2,37 t C ha-1 ano-1 e -1,60 até -8,70 t CO2eq ha-1 ano-1; as monoculturas em rotação também foram parte deste grupo; Cluster II agrupou a monocultura de arroz de Villavicencio (S10) e monocultura de abacaxi de Puerto Lopez (S14), que teve a maior perdida de C (-ΔC) no solo e as emissões de CO2 na atmosfera (GEE) ≈ -2,08 até - 2,35 t C ha-1 ano-1 e ≈ 7,62 até 8,62 t CO2eq ha-1 ano-1; Cluster III agrupou os sistemas agroflorestais SAFs de borracha e culturas de cobertura de leguminosas (S13), e sistemas silvipastoris (SSPs) de Acacia mangium e pastagens melhoradas (S12) de Puerto Lopez com o maior acumulo do C do solo C (ΔC) e remoções de CO2 atmosférico (-GEE) de ≈ 0,373 até 2,64 t C ha-1 ano-1 e de ≈ -1,36 até -9,67 t CO2eq ha-1 ano-1. Os sistemas agroflorestais são uma boa alternativa para o sequestro do C no solo na Altillanura Plana da Colômbia.

Outstanding impact of soil tillage on the abundance of soil hydrolases revealed by a metagenomic approach

ABSTRACT The soil represents the main source of novel biocatalysts and biomolecules of industrial relevance. We searched for hydrolases in silico in four shotgun metagenomes (4,079,223 sequences) obtained in a 13-year field trial carried out in southern Brazil, under the no-tillage (NT), or conventional tillage (CT) managements, with crop succession (CS, soybean/wheat), or crop rotation (CR, soybean/maize/wheat/lupine/oat). We identified 42,631 hydrolases belonging to five classes by comparing with the KEGG database, and 44,928 sequences by comparing with the NCBI-NR database. The abundance followed the order: lipases > laccases > cellulases > proteases > amylases > pectinases. Statistically significant differences were attributed to the tillage system, with the NT showing about five times more hydrolases than the CT system. The outstanding differences can be attributed to the management of crop residues, left on the soil surface in the NT, and mechanically broken and incorporated into the soil in the CT. Differences between the CS and the CR were slighter, 10% higher for the CS, but not statistically different. Most of the sequences belonged to fungi (Verticillium, and Colletotrichum for lipases and laccases, and Aspergillus for proteases), and to the archaea Sulfolobus acidocaldarius for amylases. Our results indicate that agricultural soils under conservative managements may represent a hotspot for bioprospection of hydrolases.

Relationship between blast severity on seedlings and panicles of Brazilian oat cultivars / Relação entre a severidade de brusone em plântulas e panículas de cultivares brasileiras de aveia

ABSTRACT: Blast, caused by Pyricularia oryzae, threats black (Avena strigosa) and white (A. sativa) oats in Brazil. Little is known about the reaction of Brazilian oat cultivars to blast and if there is a relationship between the response of cultivars to the disease at seedling and adult plant stages. The goals of this research were to verify (a) the reaction of black and white Brazilian oat cultivars to infection of P. oryzae and (b) if the response to blast on seedling leaves and panicles was correlated. Seedlings and adult plants of 13 oat cultivars were inoculated with a conidial suspension of one P. oryzae isolate obtained from a black oat cultivar. The cultivars were classified according to blast severity on the leaf seedlings and panicles estimated by visual estimation. Two experiments were conducted for each one of the two evaluated stages. Cultivars with lower value to blast severity on seedling leaves were 'UPFA Gaudéria' (25.82%) and 'UPF 18' (24.88%) and, on panicles, 'BRS Centauro' (31.63%). Coefficients of Pearson, Spearman, and Kendall obtained from correlation analyses between blast severity on seedling leaves and panicles were -0.21232, -0.35714, and -0.30769, respectively (non-significant at 0.05). Lack of correlation between the responses of these oat cultivars to blast on seedling leaves and panicles be considered in the management of the disease in the field and the generation of new oat cultivars.

RESUMO: A brusone, causada por Pyricularia oryzae, ameaça as culturas da aveia preta (Avena strigosa) e branca (A. sativa) no Brasil. Sabe-se pouco sobre a reação das cultivares brasileiras de aveia à brusone e se existe relação entre a resposta destas cultivares à doença nos estádios de plântula e de planta adulta. Os objetivos deste trabalho foram: (a) verificar a reação de cultivares brasileiras de aveia à infecção de P. oryzae e; (b) se existe relação entre a resposta à brusone dessas cultivares nos estádios de plântula e de planta adulta. Plântulas e plantas adultas de 13 cultivares de aveia foram inoculadas com uma suspensão de conídios de um isolado de P. oryzae obtido de uma planta de uma cultivar de aveia preta. As cultivares foram classificadas de acordo com a estimativa visual da severidade da doença nas folhas das plântulas e nas panículas das plantas adultas. Dois experimentos foram conduzidos para cada um dos estádios avaliados. As cultivares com menor severidade de brusone nas plântulas foram a 'Gaudéria UPFA' (25,82%) e a 'UPF 18' (24,88%) e, nas panículas, foi a 'BRS Centauro' (31,63%). Os coeficientes de Pearson, Spearman e Kendall obtidos da análise de correlação entre os dois estádios avaliados foram -0,21232, -0,35714 e -0,30769, respectivamente (todos sem significância estatística à 0,05). A falta de correlação entre as respostas das cultivares de aveia à brusone, em plântulas e panículas, constitui-se em informação a ser considerada no manejo da doença, no campo e na geração de novas cultivares de aveia.

Soil management and application of agricultural gypsum in a Planosol for soybean cultivation / Manejo do solo e aplicação de gesso agrícola em Planossolo para o cultivo de soja

ABSTRACT: This study investigated the effects of soil management systems, tillage, and application of gypsum agricultural to soil, on soybean development in lowland areas. The experiment was carried out on an Alfisol in a randomized complete block design in a factorial arrangement. The two soil tillage practices were without deep tillage and with deep tillage. Gypsum treatments were no gypsum application, 500kg of gypsum ha-1, 1000kg of gypsum ha-1, and 1500kg of gypsum ha-1. Deep tillage resulted in less soil resistance to root penetration during ryegrass cultivation during the soybean offseason, 11 months after applying the management treatments, resulting in higher dry mass of ryegrass in the offseason and higher soybean yield in the following year.

RESUMO: O trabalho visou identificar o efeito de dois sistemas de manejo do solo, com e sem escarificação, associado à aplicação de gesso agrícola no desenvolvimento de plantas de soja em áreas de terras baixas. O trabalho foi realizado a campo, em Planossolo Háplico Eutrófico arênico, em esquema bifatorial (2x4) no delineamento experimental de blocos ao acaso composto por dois sistemas de manejo do solo: sistema sem escarificação do solo e sistema com escarificação do solo. Os tratamentos com gesso agrícola foram: testemunha sem aplicação de gesso agrícola, 500kg ha-1 de gesso agrícola, 1000kg ha-1 de gesso agrícola e 1500kg ha-1 de gesso agrícola. A escarificação do solo proporciona maior rendimento de grãos de soja em áreas de terras baixas com presença de camada compactada, independente do uso de gesso agrícola. Os efeitos da escarificação do solo resultam na menor resistência à penetração de raízes no final do cultivo do azevém na entressafra da soja, 11 meses após o manejo, resultando em maior massa seca do azevém em sucessão e produtividade da soja no ano seguinte.

Palisadegrass effects on N fertilizer dynamic in intercropping systems with corn

ABSTRACT Corn grain yield, nitrogen (N) fertilizer efficiency and distribution to corn alone and three forms of corn and palisadegrass (Urochloa spp.) intercropping implantation was investigated. A field experiment with 15N labeling fertilizer was performed in randomized block design. No form of palisadegrass intercropping implantation affected corn grain yield, total N accumulation and N use efficiency (NUE), which were 8.7 t ha-1, 205 kg ha-1 and 37% respectively. The palisadegrass produced on average 1.9 t of dry mass, absorbing a maximum of 6 kg ha-1 or 5.5% of N fertilizer during corn growing. Furthermore, the palisadegrass did not affect N fertilizer distribution in soil-plant system, in which 28.2% was recovered in the soil and 40.4% in the plants (corn + palisadegrass). The results show that for the three intercropping implantation methods the palisadegrass did not compete with corn for N fertilizer.

Ammonia and carbon dioxide emissions by stabilized conventional nitrogen fertilizers and controlled release in corn crop / Emissões de amônia e de dióxido de carbono de fertilizantes nitrogenados convencionais, estabilizados e liberação controlada na cultura do milho

ABSTRACT The market of stabilized, slow and controlled release nitrogen (N) fertilizers represents 1% of the world fertilizer consumption. On the other hand, the increase in availability, innovation and application of these technologies could lead to the improvement of N use efficiency in agroecossystems and to the reduction of environmental impacts. The objective of this study was to quantify agronomic efficiency relative index, ammonia volatilization, and CO2 emissions from conventional, stabilized and controlled release N fertilizers in corn summer crop. The experiment was carried out in a corn crop area located in Lavras, state of Minas Gerais, Brazil, without irrigation. All treatments were applied in topdressing at rate of 150 kg ha-1 N. N-NH3 losses from N fertilizers were: Granular urea (39% of the applied N ) = prilled urea (38%) > urea coated with 16% S0 (32%) = blend of urea + 7.9% S0 + polymers + conventional urea (32%) > prilled urea incorporated at 0.02 m depth (24%) > urea + 530 mg kg-1 of NBPT (8%) = Hydrolyzed leather (9%) > urea + thermoplastic resin (3%) = ammonium sulfate (1%) = ammonium nitrate (0.7%). Thermoplastic resin coated urea, ammonium nitrate and ammonium sulfate presented low values ​​of cumulative CO2 emissions in corn crop. On the other hand, hydrolyzed leather promoted greater C-CO2 emission, when compared with other nitrogen fertilizers.

RESUMO O consumo de fertilizantes nitrogenados estabilizados, de liberação lenta e controlada representa 1% do total de fertilizantes utilizados no mundo. Por outro lado, um aumento na disponibilidade, inovação e utilização dessas tecnologias pode levar a maior eficiência no uso do nitrogênio (N) na agricultura com menor impacto ambiental. O objetivo deste trabalho foi quantificar as perdas de amônia (N-NH3) por volatilização e as emissões de CO2 de fertilizantes nitrogenados convencionais, estabilizados e de liberação controlada na cultura do milho. O experimento foi realizado em condições de campo no município de Lavras (MG) no ano agrícola 2013/2014, sem irrigação. Os tratamentos foram compostos por fertilizantes nitrogenados aplicadas em cobertura na dose de 150 kg ha-1 de N. A perda acumulada de N-NH3 dos fertilizantes nitrogenados convencionais, estabilizados de liberação controlada em ordem decrescente foi: Ureia granulada (39% do N aplicado) = ureia perolada (38%) > ureia + 16% de S0 (32%) = mistura física de grânulos (blend) de ureia revestida com S0 e polímeros e ureia convencional (32%) > ureia perolada incorporada (24%) > ureia + 530 mg kg-1 de NBPT (8%) = hidrolisado de couro bovino (9%) > ureia + resina termoplástica (3%) = sulfato de amônio (1%) = nitrato de amônio (0,7%). O sulfato e nitrato de amônio e a ureia + resina termoplástica promovem a menor emissão de dióxido de carbono (C-CO2) em área de cultivo de milho. Enquanto que, o hidrolisado de couro promoveu a maior emissão total de C-CO2 para à atmosfera.

Chemical and microbiological indicators of quality in a yellow oxissol under conventional tillage of different ages / Indicadores microbiológicos e químicos de qualidade de um latossolo amarelo sob manejo convencional em diferentes idades

Brazil's agricultural production in Savanna soils has been highlighted due to significant yield gains in these areas. The present study aimed to evaluate changes in soil chemical and biological indicators of Piauí Savanna areas after 1 (PC1), 3 (PC3) and 6 (PC6) years under conventional tillage compared to a native Savanna forest (NF), used as control. Chemical (pH, P, Ca2+, Mg2+, K+, H+, Al3+ and organic carbon) and total organic carbon (TOC) and microbiological attributes (microbial biomass carbon (MBC), basal respiration, microbial quotient and metabolic quotient), were assessed. In PC6 and PC3 areas, Al³+, H+ + Al3+ and total organic carbon reduction and pH and nutrient content increase were observed in all layers evaluated. TOC was little influenced by time, since the change was gradual according to soil use. MBC and qMIC values were higher in the soil under natural vegetation, indicating adverse effects of monoculture managed with prolonged conventional tillage on these variables. PC6 soil had the highest qCO2 values in the depths of 0 to 0.20 and 0.20 to 0.40 m, which shows low efficiency of microorganisms in converting organic residue into microbial biomass in this system. Conventional management increased soil biological quality loss and favored chemical properties with its time of use.

A produção agrícola brasileira vem se destacando nos solos sob Cerrado devido aos ganhos significantes na produção e produtividade nessas áreas. Neste trabalho, objetivou-se avaliar as alterações nos indicadores químicos e biológicos do solo em áreas de Cerrado piauiense com 1 (PC1), 3 (PC3) e 6 (PC6) anos manejadas sob plantio convencional, em relação a uma mata nativa (MN) de Cerrado usada como controle. Foram avaliados atributos químicos (pH, P, Ca2+, Mg2+, K+, H+, Al3+ e carbono orgânico) e microbiológicos (carbono da biomassa microbiana, respiração basal, quociente microbiano e quociente metabólico). Nas áreas PC6 e PC3 foram observados, em todas as camadas avaliadas, redução dos teores de Al³+ e H+ + Al3+ e carbono orgânico total, e aumento do pH e teores dos nutrientes em relação aos demais sistemas. O COT mostrou-se pouco sensível com o tempo, visto que a mudança foi gradual conforme o uso do solo. Os valores de CBM e qMIC foram mais elevados no solo sob vegetação natural, indicando a ocorrência de efeitos adversos de monocultura manejada em sistema plantio convencional prolongado sobre essas variáveis. O solo sob PC6 mostrou o maiores valores de qCO2 nas profundidades de 0 a 0,20 e de 0,20 a 0,40 m que demonstra a baixa eficiência dos microrganismos em converter os resíduos orgânicos em biomassa microbiana neste sistema. O manejo convencional utilizado potencializou a perda de qualidade biológica do solo desses sistemas e favoreceu os atributos químicos com o tempo de uso.

Characterization of edaphic fauna in different monocultures in Savanna of Piauí

Abstract Vegetation cover may show diversity and composition patterns of the soil invertebrate community, as a function of litter quantity and quality in a specific habitat. The objective of this work was to characterize the distribution of edaphic fauna in different monocultures. The study was carried out at Chapada Grande farm in Regeneração, PI. Four monoculture areas were chosen: no-tillage soybean, eucalyptus, pasture, and a preserved native cerrado forest. Soil fauna was collected in a dry and wet period by pitfall traps containing 4% formaldehyde. The edaphic fauna was evaluated by the number of individuals per trap per day, average richness and richness, Shannon diversity index and Pielou uniformity index. Data were submitted to analysis of variance and multivariate Principal Component Analysis (PCA). The highest number of individuals per day trap and of average richness were registered in the pasture, eucalyptus and forest areas in both periods, while soybean showed lower values with predominance of Coleoptera and Formicidae groups. The pasture and forest areas showed of higher Shannon index values in the two evaluated seasons, probably due to higher contributions organic residues in the soil that favors the shelter, feeding and reproduction conditions. Regarding the Pielou index, the soybean system showed higher values in this variable. The Aranae, Coleoptera, Formicidae and Diptera groups predominated in the humid period, while Coleoptera and Formicidae predominated in the dry period. Systems that generate greater accumulation of residues harbor a greater diversity of invertebrates of the edaphic fauna. Seasonality had an effect on all variables analyzed and the wet period showed more expressive values.

Resumo A cobertura vegetal pode mostrar padrões de diversidade e composição da comunidade de invertebrados do solo, em função da quantidade e qualidade da serapilheira em determinado habitat específico. O objetivo deste trabalho foi caracterizar a distribuição da fauna edáfica em diferentes monocultivos. O estudo foi realizado na fazenda Chapada Grande no município de Regeneração, PI. Foram escolhidas quatro áreas de monocultivos: soja em sistema de plantio direto, eucalipto, pastagem, além de uma mata nativa de cerrado preservada. Foram realizadas coletas da fauna do solo, em período seco e úmido, por meio de armadilhas do tipo pitfall contendo 4% de formol. A fauna edáfica foi avaliada pelo número de indivíduos por armadilha por dia, riqueza e riqueza média, índice de diversidade de Shannon e índice de uniformidade de Pielou. Os dados foram submetidos à análise de variância e à análise multivariada de Componentes Principais (ACP). O maior número de indivíduos por armadilha dia e de riqueza média foram registrados nas áreas pastagem, eucalipto e mata nos dois períodos, enquanto que a soja mostrou valores inferiores com predomínio dos grupos Coleoptera e Formicidae. As áreas de pastagem e mata mostraram maiores valores de índice de Shannon nas duas épocas avaliadas provavelmente em função de maiores aportes de resíduos orgânicos no solo que favorece as condições de abrigo, alimentação e reprodução. Em relação ao índice de Pielou o sistema com soja mostrou maiores valores nessa variável. Os grupos Araneae, Coleoptera, Formicidae e Diptera predominaram no período úmido, enquanto Coleoptera e Formicidae se destacaram no período seco. Sistemas que geram maior acúmulo de resíduos abrigam uma maior diversidade de invertebrados da fauna edáfica. A sazonalidade apresentou efeito sobre todas as variáveis analisadas sendo que o período úmido mostrou valores mais expressivos.

Management systems and soil use on fractions and stocks of organic carbon and nitrogen total in cerrado latosol / Sistemas de manejo e uso do solo sobre as frações e estoque de carbono e nitrogênio em latossolo de cerrado

Cerrado areas are agricultural frontiers of Brazil, being important to know the dynamics of carbon and nitrogen in agricultural production systems. The objective of this study was to evaluate the effects of management and soil use in fractions and stocks organic carbon and nitrogen in the Cerrado soil. The experiment was conducted in Latosol with four treatments: native Cerrado (CE), no-tillage 18 years (NT), coffee 10 years (CF) and integrated system for agriculture (ISA) three years, evaluating the fractions and stocks of organic carbon and nitrogen in three depths. Soil management systems, at all depths, were not able to recover the organic carbon, nitrogen and their stocks in relation to the Cerrado. In the surface layer there was a decrease in the organic carbon content of 21, 33 and 46% for NT, CF and ISA respectively. Also there was a reduction in the nitrogen content in the surface layer of 33, 36 and 59% for the NT, CF and ISA respectively. Organic carbon varied from 74.3 Mg ha-1 in the CE, 58.8 Mg ha-1 in NT, 56.4 Mg ha-1 in CF and 50.8 Mg ha-1 in ISA. It was concluded that the total organic carbon, nitrogen and its fractions were effective in demonstrating the effects of managements and soil use; that of no-tillage and coffee were not efficient in the recovery of stocks of carbon and nitrogen requiring managements with more carbon input and the integrated production system is still in consolidation process.

Áreas de cerrado são fronteiras agrícolas do Brasil, sendo importante conhecer a dinâmica do carbono e nitrogênio em sistemas de produção agrícola. O objetivo deste estudo foi avaliar os efeitos do manejo e uso do solo em frações e estoques de carbono orgânico e nitrogênio em solo de Cerrado. O experimento foi realizado em Latossolo Vermelho com quatro tratamentos: Cerrado nativo (CE), plantio direto 18 anos (PD), área com café 10 anos (CF) e sistema integrado de produção agropecuária (SIPA) 3 anos avaliando as frações e estoques de carbono orgânico e nitrogênio em três profundidades. Os sistemas de manejo do solo, em todas as profundidades, não foram capazes de recuperar o teor carbono orgânico, nitrogênio e seus estoques em relação ao Cerrado. Na camada superficial houve diminuição no teor de carbono orgânico de 21, 33 e 46% para PD, CF e SIPA, respectivamente. Também verificou-se redução no teor de nitrogênio na camada superficial de 33, 36 e 59% para o PD, CF e SIPA, respectivamente. Os estoques de carbono orgânico variaram de 74,3 Mg ha-1 no CE, 58,8 Mg ha-1 no PD, 56,4 Mg ha-1 no CF e 50,8 Mg ha-1 no SIPA. Conclui-se que o carbono orgânico total, nitrogênio e suas frações foram eficientes para demonstrar os efeitos dos manejos e uso do solo; que os sistemas de PD e CF não foram eficientes na recuperação dos estoques de carbono e nitrogênio necessitando de manejos com maior entrada de carbono e que SIPA ainda esta em processo de consolidação.