ABSTRACT Management of Quilombola systems are primitive agricultural systems based on the ancestral knowledge of Afro-Brazilian enslaved people. Here, the aim was to understand the impact of these primitive farming methods on the distribution of available nitrogen (N) forms in the soil profile of two Brazilian Cerrado phytophysiognomies. The soil was sampled in Cerradão (high Cerrado) and Cerrado Stricto sensu (low Cerrado) at six soil depths (0-10, 10-20, 20-30, 30-40, 40-50, and 50-60 cm). The following management systems were considered: pasture (PP1 and PP2), maize cultivation (M1 and M2), citrus-cassava intercropping (T1), and citrus monoculture (T2). In addition, the soil was sampled in the native area of Cerradão (NC1) and Cerrado Stricto sensu (NC2). Three N forms were determined: i) available nitrogen (Av-N), ii) ammonium (NH4+-N) and iii) nitrate (NO3–-N) contents. The Av-N content decreased with increasing soil depth only in NC1 and NC2. The NO3–-N content was similar at all soil depths for maize and pasture, while the content decreased at soil depth for NC1, NC2, and T1. NH4+-N was similar in M2 and PP2, but it increased in T2, ranging from 6.17 mg kg–1 to 17.54 mg kg–1. Overall, the dynamics of available N forms varied according to the Cerrado phytophysiognomy and the management systems and NO3–-N was the most constant N form in the soil profile. Therefore, although the management of Quilombola systems is less intensive, they negatively affect the dynamics and N availability, mainly where management is less conservative, that is, in maize and citrus monocultures. AfroBrazilian Afro people Here (N phytophysiognomies high low 010, 010 0 10, 10 (0-10 1020, 1020 20, 20 10-20 2030, 2030 30, 30 20-30 3040, 3040 40, 40 30-40 4050, 4050 50, 50 40-50 5060 60 50-6 cm. cm . cm) considered PP1 PP (PP PP2 , PP2) M1 M (M M2, M2) citruscassava cassava T1, T1 T (T1) T2. T2 (T2) addition NC (NC1 NC2 (NC2) determined i AvN, AvN Av (Av-N) ii NH4+N NH4N NHN NH4+ NH4 NH (NH4+-N iii NO3–N NO3N NON NO3– NO3 NO (NO3–-N contents 617 6 17 6.1 kg1 kg 1 kg– 1754 54 17.5 Overall Therefore intensive availability conservative monocultures 01 (0-1 102 2 10-2 203 3 20-3 304 4 30-4 405 5 40-5 506 50- (T1 (T2 (NC (NC2 (Av-N 61 6. 175 17. (0- 10- 20- 30- 40- (T (0 (

ABSTRACT Leaf litter decomposition and the release of nutrients from macauba palm leaves play a major role in nutrient return to the soil in a conservation environment. This study evaluated macauba palm leaf decomposition, macronutrient contents and biochemical composition under contrasting water conditions in the Brazilian Cerrado. Macauba leaves were collected from plants in two different environments (low and high water table conditions), placed in litter bags and evaluated according to their decomposition, macronutrients, lignin, cellulose and hemicellulose for 420 days. In addition, green and dry leaves were collected for macronutrient analyses. Litter decomposition ranged between 49 % and 59 % up to 180 days. The half-life of litter ranged from 141 to 198 days. The leaf litter decomposition of macauba was practically stable during the dry season, whereas at the beginning of the rainy season, decomposition resumed. Nitrogen, P and S were higher in the green leaves, whereas the Ca levels were higher in the dry leaves. In addition, the K levels were twofold higher in the green leaves than in the dry leaves. Lignin release from macauba residues was slower than cellulose and hemicellulose. The decomposition rates of hemicellulose were higher initially due to its high solubility, although it gradually decreased with the decomposition process. Lignin decomposition was also higher at the beginning of the process but stabilized during the drought period. The study indicates that the decomposition process and nutrient cycling of macauba are influenced by its biochemical composition. environment Cerrado low conditions, , conditions) macronutrients lignin 42 days addition analyses 4 5 18 halflife half life 14 19 season resumed Nitrogen solubility period 1

Resumo A aplicação de águas residuárias da bovinocultura (ARB) é uma prática usual, entretanto, carece de investigação acerca dos seus efeitos agronômicos para subsidiar a sua utilização sustentável. O objetivo deste estudo foi avaliar o reúso da ARB e da adubação mineral nitrogenada sobre os atributos morfológicos, bromatológicos e de produtividade da pastagem de Tifton 85 durante o inverno. Foram avaliados diferentes tipos de água aplicados por aspersão (I - água de córrego, II - ARB e água de córrego em proporção 1:1, e III - ARB) e dois níveis de adubação nitrogenada mineral (0 e 45 kg N ha-1) aplicados no início da rebrota. A irrigação foi semanal e totalizou 2.440 m3 ha-1. Aos 106 dias após a rebrota foram medidas a produtividade da forrageira, altura, razão folha/colmo, índice de área foliar, índice de nutrição de nitrogênio, proteína bruta, fibras insolúveis em detergente ácido, fibras insolúveis em detergente neutro e matéria mineral. A adubação mineral na dose de 45 kg N ha-1 não influenciou as variáveis avaliadas. Em média, o reúso da ARB elevou a produtividade de 2,50 para 5,12 t ha-1 e a proteína bruta de 12,35% para 14,58% comparado com a água de córrego. O reúso da ARB com ou sem diluição proporcionou produtividade, qualidade nutricional e acúmulo de nitrogênio pela pastagem superiores à irrigação com apenas água de córrego (p < 0,01), sendo o reúso com ARB diluída (1:1) e sem adubação é suficiente para sustentar a pastagem de Tifton 85 durante o inverno no Cerrado. (ARB usual entretanto sustentável morfológicos 8 I 11, 11 1 1, 1:1 0 ( 4 ha1 ha 2440 2 440 2.44 m ha1. 1. 10 forrageira altura folhacolmo folha colmo folha/colmo foliar ácido ha- avaliadas média 250 50 2,5 512 5 12 5,1 1235 35 12,35 1458 14 58 14,58 p 0,01, 001 0,01 , 01 0,01) (1:1 Cerrado 1: 244 44 2.4 25 2, 51 5, 123 3 12,3 145 14,5 00 0,0 (1: 24 2. 12, 14, 0, (1

Abstract The utilization of wastewater from livestock farming (WLF) represents a common agricultural practice, but the absence of research on its agronomic impacts hinders its sustainable implementation. This study assesses the reutilization of WLF combined with nitrogen fertilization on the morphological, bromatological, and productivity attributes of a Tifton 85 pasture during the winter season. The study involved the application of different types of water via sprinkler: (I) stream water; (II) mixture of WLF and stream water at a 1:1 ratio; and (III) undiluted WLF combined with mineral nitrogen fertilization (0 and 45 kg N ha-1) administered at the commencement of the regrowth period. Irrigation was applied on a weekly basis, totaling 2,440 m3 ha-1. At 106 days post-regrowth, parameters including forage productivity, height, leaf-stem ratio, leaf area index, nitrogen nutrition index, crude protein content, acid detergent fiber, neutral detergent fiber, and mineral matter content were determined. Mineral fertilization at the prescribed dosage (45 kg N ha-1) did not have any discernible impact on the parameters under investigation. On average, the reuse of WLF raised the productivity from 2.50 to 5.12 t ha-1 and the Crude Protein from 12.35% to 14.58% compared to stream water. The reuse of WLF demonstrated superior outcomes (p < 0.01) in terms of pasture productivity, nutritional quality, and nitrogen accumulation compared to irrigation solely with stream water. The reuse of diluted WLF (1:1) without fertilization proved adequate to sustain Tifton 85 pastures during the winter season in the Brazilian Cerrado region. (WLF practice implementation morphological bromatological 8 sprinkler I (I II (II 11 1 1: ratio III (III 0 ( 4 ha1 ha period basis 2440 2 440 2,44 m ha1. 1. 10 postregrowth, postregrowth post regrowth, post-regrowth height leafstem stem index fiber determined (4 investigation average 250 50 2.5 512 5 12 5.1 ha- 1235 35 12.35 1458 14 58 14.58 p 0.01 001 01 quality (1:1 region 244 44 2,4 25 2. 51 5. 123 3 12.3 145 14.5 0.0 00 (1: 24 2, 12. 14. 0. (1

Resumo As mudanças climáticas têm implicações notáveis para a tomada de decisão dos agricultores em relação à irrigação suplementar no café cultivado em áreas com déficit hídrico. O objetivo do trabalho foi analisar o custo de produção e a rentabilidade do café arábica em diferentes regimes irrigado e de sequeiro nas áreas do Cerrado brasileiro. Foram avaliados quatro cenários: I. cenário anterior a eventos climáticos significativos e à pandemia; II. com efeitos da pandemia e eventos climáticos; III. com produtividade média nacional e produtividade média em áreas irrigadas, e IV - cenários de cafés especiais. No Cenário I, apenas o tratamento de sequeiro não apresentou viabilidade econômica por não apresentar valor presente líquido (VPL) positivo. No Cenário II, a taxa interna de retorno (TIR) apresentou valores superiores ao Cenário I. Os cenários de produção nacional e Cerrado mostraram-se viáveis para as condições de preços e taxas de juros avaliadas. O cultivo do café em sequeiro foi altamente atrativo para o cenário de grãos especiais (IV) em comparação aos demais cenários. A produtividade e o valor pago por saca de café são as variáveis que mais impactam a TIR da lavoura cafeeira. Portanto, uma análise econômica e técnica é importante para cada sistema de produção antes de investir na cafeicultura. hídrico brasileiro I II III irrigadas VPL (VPL positivo (TIR mostraramse mostraram se avaliadas (IV cafeeira Portanto cafeicultura

Abstract Climate change significantly impacts farmers' decision-making regarding the supplementary irrigation of coffee cultivated in areas experiencing water deficits. The aim of this study was to analyze the production cost and profitability of Arabica coffee under different irrigation and rainfed regimes in the Brazilian Cerrado. Four scenarios were evaluated: I. scenario before significant climate events and the pandemic, II. scenario with the effects of pandemic and climate events, III. scenario with average national productivity and average productivity in irrigated areas, and IV. scenario of specialty coffees. In Scenario I, only the rainfed treatment did not demonstrate economic viability because it did not yield a positive net present value (NPV). Scenario II showed higher internal rate of return (IRR) than Scenario I. The national production and Cerrado scenarios proved viable under the evaluated price conditions and interest rates. The rainfed sector was highly attractive for the specialty grain scenario (IV) than for other scenarios. Productivity and the amount paid per bag of coffee were identified as the variables that had the most significant impact on the IRR of the coffee crop. Therefore, economic and technical analyses should be conducted before investing in coffee farming to ensure the success of each production system. farmers decisionmaking decision making deficits I III IV coffees NPV. NPV . (NPV) (IRR rates (IV crop Therefore system (NPV

Resumo A evapotranspiração (ET) é um dos mais importantes processos do ciclo hidrológico, constituindo-se o principal responsável pelas perdas de água na superfície. Vários modelos de evapotranspiração utilizam informações da temperatura da superfície e índices de vegetação captadas por sensores remotos tais como o MODIS e a série LANDSAT para estimar o valor de ETc. O objetivo deste estudo aplicar o modelo SSEBop para estimativa da ETc da soja (Glicine max. L) em um campo experimental submetida a quatro regimes hídricos, utilizando imagens multiespectrais e termais de alta resolução coletadas com uso de aeronave remotamente pilotada. Mapas de temperatura da superfície e NDVI foram gerados como fontes para a estimativa da evapotranspiração. A partir de um script em Python, mapas de variabilidade espacial da ETc foram gerados para diferentes estádios fenológicos da cultura. A qualidade do modelo de estimativas de ETc foi realizada comparando-se os resultados da modelagem com os dados transpiração foliar medida no campo através de um analisador de gases por infravermelho, cujos resultados mostraram boa correlação (R2 = 0,76). Estes resultados demostraram a possibilidade de transferência de um modelo originalmente desenvolvido para processamento de imagens de satélite de baixa a média resolução para imagens de alta resolução espaço temporal adquiridos por RPA a partir de pequenas adaptações no algoritmo original, gerando um grande potencial para novos estudos em escala experimental e de campo. ET (ET hidrológico constituindose constituindo se Glicine max L hídricos pilotada Python cultura comparandose comparando infravermelho R2 R (R 0,76. 076 0,76 . 0 76 0,76) original 07 0,7 7 0,

Abstract Evapotranspiration (ET) is one of the most important processes in the hydrologic cycle, constituting the main responsible for water losses at the surface. Several evapotranspiration models use information from surface temperature and vegetation indices captured by remote sensors such as MODIS and LANDSAT to estimate the ETc value. The objective of this study is to apply SSEBop model to estimate ETc of soybean in a field experiment under four water regimes, using high-resolution multispectral and thermal images collected from remotely piloted aircraft (RPA). Surface temperature and NDVI maps were generated as sources for evapotranspiration estimation. From a Python script, spatial variability maps of ETc were generated at different phenological stages of the crop. The quality of the model for ETc estimates was performed by comparing the modeling results with leaf transpiration data measured in the field using an infrared gas analyzer, whose results showed a good correlation (R2 = 0.76). These results demonstrated the possibility of transferring a model originally developed for processing low to medium-resolution satellite images to high-resolution spatial-temporal images acquired by RPA with small adaptations in the original algorithm, generating great potential for new studies on an experimental and field scale. ET (ET cycle value regimes highresolution high resolution RPA. . (RPA) estimation script crop analyzer R2 R (R 0.76. 076 0.76 0 76 0.76) mediumresolution medium spatialtemporal temporal algorithm scale (RPA 07 0.7 7 0.

ABSTRACT This study aimed to evaluate the impact and duration of water stress on coffee growth, grain yield, and uniformity. The experiment was set up on Apr 2015 with water regimes denominated as follows: year-round irrigation with total water replacement (FI 100) and year-round irrigation with a 50 % reduction in total water replacement (FI 50); irrigation with application of water deficit from Apr to Sept with total water replacement (WD1 100) and irrigation with application of water deficit from Apr to Sept with 50 % of total water replacement (WD1 50); irrigation with application of water deficit from June to Sept with total water replacement (WD2 100), irrigation with application of water deficit from June to Sept with 50 % of total water replacement (WD2 50), and rainfed. A mechanized irrigation mobile Lateral Line sprinkler system was used. Irrigation management criterion was based on the climatological water balance and crop coefficients. Morphological variables, productivity, and fruit uniformity were evaluated. The growth variables had higher responses to water deficit treatment, with the highest reductions being recorded in rainfed treatments. The average productivity of the coffee tree in 2019 ranged from 14 to 120 bags ha–1. Even under low water availability, Iapar 59 was the most productive genotype, and E237 was the least productive genotype. Long periods of stress and 50 % reduction in water availability reduced plant productivity. Thus, the use of irrigation to complement rainfall is essential to the sustainability of coffee production systems in the Cerrado. yield 201 follows yearround year round FI 100 5 50) WD1 WD (WD WD2 100, , 50, used coefficients evaluated treatment treatments 1 12 ha1 ha ha–1 genotype E E23 Thus Cerrado 20 10 ha– E2 2

Resumo: O objetivo deste trabalho foi avaliar a influência do remineralizador de solo finos de mica xisto (FMS) na fisiologia, na produtividade e na qualidade de grãos de soja (Glycine max) em diferentes regimes hídricos (RHs), no Cerrado brasileiro. O experimento foi conduzido em condições de campo durante dois anos, tendo-se utilizado quatro RHs e três tratamentos: mica xisto, adubação convencional e controle. Em 2017 e 2018, foram avaliados os seguintes RHs: RH1, RH2, RH3 e RH4, que correspondiam ao valor médio de 100, 65, 44 e 28% da reposição da evapotranspiração da cultura, respectivamente. A fotossíntese, a condutância estomática, a transpiração, a concentração interna de CO2, o rendimento quântico efetivo do fotossistema II (FSII) (Fv’/Fm’), o rendimento quântico (FSII) (ᶲFSII) e a taxa de transporte de elétrons reduziram em função do avanço da fase fenológica da soja e da redução do RH. A qualidade dos grãos foi afetada apenas pelo RH. O mica xisto foi estatisticamente semelhante à adubação convencional e ao controle em 2017 e 2018. A produtividade reduziu devido à antecipação da idade fenológica da soja e do RH, mas não houve diferenças entre os três tratamentos em 2017 e 2018. A redução da produtividade da soja é atribuída ao fechamento estomático, à perda da capacidade fotoprotetora e aos danos ao maquinário fotossintético causados pela seca.

Abstract: The objective of this work was to evaluate the influence of the soil remineralizer fine-graded mica schist (FMS) on soybean (Glycine max) physiology, yield, and grain quality under different water regimes (WRs) in the Brazilian Cerrado. The experiment was conducted under field conditions for two years, using four WRs and three treatments: mica schist, conventional fertilization, and control. In 2017 and 2018, the following WRs were evaluated: WR1, WR2, WR3, and WR4, corresponding to a mean value of 100, 65, 44, and 28% of crop evapotranspiration replacement, respectively. Photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, effective quantum yield of photosystem II (PSII) (Fv’/Fm’), quantum yield (PSII) (ᶲFSII), and electron transport rate reduced as a function of the advanced phenological stage of soybean and the reduction in WR. Grain quality was only affected by the WR. The mica schist was statistically similar to conventional fertilization and the control in 2017 and 2018. Yield decreased due to the anticipation of soybean phenological age and WR, but there were no differences between the three treatments in 2017 and 2018. The reduction in soybean yield is attributed to stomatal closure, loss of photoprotective capacity, and damage to the photosynthetic machinery caused by drought.

ABSTRACT: The Cerrado (Brazilian savannah) is a biome of great socio-economic and environmental importance to Brazil. The rapid agricultural expansion in the Cerrado biome areas promoted biogeochemical cycles that affect nitrogen and carbon dynamics, leading to increased greenhouse gas (GHG) emissions. In Brazil, nitrous oxide (N2O) is the main gas in agriculture, and agricultural practices increase emissions into the atmosphere. This review aimed to assess the influence of agriculture on N2O emissions in the Cerrado region, based on existing data in the literature, and extract patterns of direct N2O emissions in different agricultural systems in the Cerrado from existing data. A systematic review of data from 36 scientific publications in the Cerrado region with several crop systems revealed that N2O emissions varied from 0.15 kg ha-1 in native cerrado to 4.84 kg ha-1 in conventional tillage. Agricultural systems, nitrogen fertilizer application, and crop residues influence N2O emissions. One of the strategies to mitigate emissions is the sustainable intensification of farming systems. Cumulative N2O emissions in the Cerrado range from 0.001 to 4.84 kg ha-1 in different land-use scenarios. Soil under the conventional tillage system (CT) had the highest emissions, with an overall average of 1.58 kg ha-1 of N2O, compared to no-till system (NT) (0.82 kg ha-1) and native Cerrado 0.15 kg ha-1. Integrated crop-livestock (ICL) systems in the Cerrado had emissions with an overall average of 1.68 kg ha-1, integrated crop-livestock-forest systems (ICLF) had 1.20 ha-1, and eucalyptus plantations had 0.48 kg ha-1.

ABSTRACT: The selection of wheat genotypes according to their drought tolerance is essential to off-season cultivation. The objective of this work was to characterize wheat genotypes through yield and components, morphological characteristics under water stress, and irrigated water use efficiency in the Cerrado region in Brazil. Genotypes were planted during the winters of 2016 and 2017 since there is no precipitation during this season and water levels can be measured. They were then submitted to four water regimes: WR1, WR2, WR3, and WR4, representing 100 %, 83 %, 50 %, and 30 % of evapotranspiration replacement. The following variables were evaluated: peduncle length (PL), number of ears m−2 (NE m−2), hectoliter weight (HW), thousand grain weight (TGW), drought resistance index (DRI), irrigated water use efficiency (IWUE) and yield. Most variables showed correlation with yield and can be a useful tool for breeding programs. PL and HW were best correlated with yield. BRS 264 (irrigated biotype) was productive in treatments receiving the greatest number of irrigation treatments. Given that WR1 registered the highest water level, it was not expected that the rainfed biotype (BR18) would show a higher yield than an irrigated biotype (BRS254). BRS404 (rainfed biotype) was the most productive under moderate stress treatment (WR3). Aliança (rainfed biotype) showed a higher yield under severe stress. Rainfed biotypes presented a higher DRI than the irrigated ones. These genotypes can be used as a reference in breeding programs under each water regime in which their performance was outstanding. None of the variables studied contributed to the selection of the most efficient wheat genotypes in the IWUE.

ABSTRACT The use of cover crop in agricultural fields has been well elucidated, especially regarding nitrogen fixation from legume crops and their function as weed protection. Furthermore, to cover crops can benefit the soil microbial community. This study aimed to evaluate and compare the benefits of mulching and cover cropping systems on soil microbial growth and activity, and their effects on plant mineral nutrition in pomelo (Citrus maxima ) and macadamia ( Macadamia integrifolia ) orchards. The treatments included: 1) control [Glyphosate herbicide (Roundup at 4 l per ha)], 2) manual weed control, 3) mulching with dead leaves from their respective trees (macadamia and pomelo), 4) millet, 5) faba bean, 6) millet + faba bean. All the treatments were applied for 120 days before soil and plant leaves were sampled for analyses. Plant mineral nutrition, soil microbial biomass C (MBC) and soil microbial biomass N (MBN); basal respiration (BRA), arbuscular mycorrhizal fungi (AMF) colonization (COL); number of AMF spores (SPO) in soil; total organic carbon (TOC) and total nitrogen (TN) were evaluated. Plant nutrition was not altered by the treatments; however, the MBC, COL and SPO markedly increased in response to mulching and faba bean + millet treatments. Especially in macadamia soils, these treatments had a great response to soil microbiology. Significant negative correlations were also detected for the COL, SPO, BRA and TOC with the Nutrient Balance Index (NBI). These results indicate that in short-term the cover cropping system is useful to improve the soil microbial growth and AMF formation in soils of pomelo and macadam orchards.

Resumo: O objetivo deste trabalho foi avaliar as frações de carbono no solo, sob plantas de cobertura cultivadas em sucessão ao milho (Zea mays), com ou sem adubação nitrogenada em cobertura, em um experimento de longa duração no Cerrado brasileiro. O experimento foi conduzido em delineamento de blocos ao acaso, em parcelas subdivididas, com três repetições. As parcelas consistiram das plantas de cobertura, e as subparcelas, da presença ou da ausência de adubação nitrogenada em cobertura para o milho. As seguintes plantas de cobertura foram plantadas, após a colheita do milho híbrido 30F53VYHR: guandu 'BRS Mandarim' (Cajanus cajan), crotalária (Crotalaria juncea), nabo-forrageiro (Raphanus sativus) e mucuna-preta (Mucuna aterrima). Após o corte das plantas de cobertura, amostras de solo foram coletadas às profundidades de 0,0‒0,10 e 0,10‒0,20 m. Após a colheita do milho, seus resíduos culturais foram coletados. As plantas de cobertura alteram as frações químicas e físicas do solo, principalmente o ácido fúlvico e o carbono orgânico particulado. A fertilização de N em cobertura no milho diminui o ácido fúlvico, mas aumenta a razão ácido húmico/ácido fúlvico e o carbono orgânico particulado na camada mais profunda do solo.

Abstract: The objective of this work was to evaluate soil carbon fractions under cover crops cultivated after corn (Zea mays), with or without nitrogen topdressing fertilization, in a long-term experiment in the Brazilian Cerrado. The experiment was carried out in a randomized complete block design, in split-plots with three replicates. The plots were represented by the cover crops, and the subplots, by the presence or absence of N topdressing for corn. The following cover crop species were planted after the harvest of the 30F53VYHR corn hybrid: 'BRS Mandarin' pigeonpea (Cajanus cajan), sunn hemp (Crotalaria juncea), oilseed radish (Raphanus sativus), and black mucuna (Mucuna aterrima). After the cutting of the cover crops, soil samples were collected at 0.0‒0.10 and 0.10‒0.20 m soil depths. After corn harvest, samples of its residues were taken. The cover crops alter the soil chemical and physical fractions, especially fulvic acid and soil particulate organic carbon. Nitrogen topdressing for corn decreases fulvic acid, but increases the humic acid/fulvic acid ratio and particulate organic carbon in the deeper soil layer.

ABSTRACT: Soil management systems exert different effects on soil attributes, especially on the organic matter content, and, consequently, the soil aggregation. The aim of this study was to evaluate the impact of different land uses practiced by quilombola family farmers on water stable aggregates, glomalin and organic carbon in soil aggregates. Soil samples were collected at depths of 0-10 and 10-20 cm from areas cultivated under the following management systems: 1) conventional corn plantation (MA), 2) cultivation of citrus trees intercropped with annual crops (AC) (a conservationist approach), 3) pasture of Brachiaria (Urochloa spp.) (PA), and, as reference, an area of the Cerrado (CR) free of any anthropogenic interference. The studied areas were evaluated in a completely randomized design, with five replications, in a subplot scheme. The plots were the management systems and the subplots the depths. Soil macro-aggregates were predominant at both depths and the aggregate stability indices were higher than 90 % for all management systems. Total organic carbon in the two aggregate classes (micro and macro-aggregates) correlated with the MWD (mean weight-diameter), but not with the easily extractable glomalin (EEG) related soil protein. Soil micro and macro-aggregates, EEG and MWD discriminated management systems and are important soil quality indicators. The carbon content in both micro-aggregates (C-MIC) and macro-aggregates (C-MAC) of the intercropped system (AC) was higher than in the CR. The soil attributes that best separated the areas were C-MIC, MWD and EEG in macro-aggregates for the depth of 0-10 cm, and EEG in micro-aggregates, together with MWD and C-MAC for the depth of 10-20 cm.

Abstract Mycorrhizae are important components of agroecosystems and the diversification of crops stimulates the abundance of arbuscular mycorrhizal fungi and the participation of symbiosis in plant growth. This experiment examined mycorrhizal assessment, chemical and microbiological soil attributes in a maize-forage grasses intercropping compared to a maize-monocropping system. A complete randomized block design was used with crop systems installed under no-till management with three replicates, as follow: Maize (Zea mays L.); Panicum maximum Jacq. cv. Aruana; Urochloa humidicola (Rendle.) Schweickerdt.; Maize-P. maximum intercropping and Maize-U. humidicola intercropping. In 2015/2016 season, intercropping maize with Panicum maximum Jacq. cv. Aruana or Urochloa humidicola (Rendle.) Schweickerdt. promoted similar effects (Tukey test, p<0.05) to monocropped maize under no-till system on soil chemical and biochemical parameters related to carbon cycling in the soil surface layer, as well as the dynamics of arbuscular mycorrhizal symbiosis in tropical soils, managed for a period of more than six years. Similar grain yield was verified among maize crop systems. This result indicates that intercropping maize-tropical forage grasses represents an alternative for monocropped grains, a very common practice that is used in intensive management, being able to guarantee equivalent productivities and to combine grain production with crop-livestock systems. As a result, intercropping promotes the diversification of the property's income source, adding environmental gains, such as more efficient land use by cultivated plants, keeping soil constantly cultivated, storing carbon and contributing to minimize the impact of climate change on agricultural systems and the sustainability of food production.

Abstract This research evaluated the monthly variation of plant mineral nutrition in six species of fruit trees over a year. Leaf samples were taken from the fruit trees and nutritional status (N, P, K, Ca, Mg, Fe, Zn, Cu, Mn, and Mo) was determined in the leaves in a month basis from April until November for apple, persimmon and peach. Mandarin mineral nutrition was monitored for one year, and grape and fig from May to November. Using this data, the Diagnosis Recommendation Integrated System (DRIS) was also calculated to evaluate the nutrient balance in the plants. The concentration of N and P had seasonal differences, especially in apple and peach, which reached the peak during the summer. Apple, fig, and grape trees had large ranging on their mineral contents over the year, especially with the P and K levels reaching the minimum during the harvesting season. However, the seasonal changes in leaf micronutrient concentrations were not uniform and not affected by phenological stage. The DRIS data demonstrated that mandarin had the best nutrient balance compared to others and that K was the most limiting element among the fruit trees. In summary, the current data suggest the occurrence of a significant seasonality in mineral nutrition in these six fruit trees, especially in temperate ones.

Resumo: O objetivo deste trabalho foi avaliar a dinâmica do crescimento das plantas de cobertura amaranto (Amaranthus cruentus), quinoa (Chenopodium quinoa) e milheto (Pennisetum glaucum) em Latossolo Vermelho, sob diferentes regimes hídricos no Cerrado. O cultivo foi realizado no inverno, com pluviosidade reduzida, o que facilitou a aplicação de lâminas de irrigação nas diferentes culturas. No experimento foram avaliados regimes hídricos intitulados de inferior, médio inferior, médio superior e superior, correspondentes à aplicação respectiva de 217, 386, 563 e 647 mm de lâminas de água, por meio de uma barra irrigadora composta por aspersores de diferentes vazões. O crescimento das plantas foi quantificado mediante coletas com periodicidade semanal. O amaranto foi a planta mais responsiva à água. A quinoa apresentou o melhor desempenho no tratamento com nível de água médio superior entre as espécies avaliadas. O milheto apresentou sensibilidade térmica ao cultivo no inverno, o que inviabilizou a produção de grãos; porém, mostrou excepcional aptidão quanto à produção de biomassa, inclusive no tratamento com maior deficit hídrico.

Abstract: The objective of this work was to evaluate the growth dynamics of the cover plants amaranth (Amaranthus cruentus), quinoa (Chenopodium quinoa), and millet (Pennisetum glaucum) in a Typic Acrustox, under different water regimes in the Brazilian Cerrado. The cultivation was carried out in the winter, with reduced rainfall, which facilitated the application of varying irrigation depths to the different crops. Water regimes denominated lower, lower middle, upper middle, and upper - corresponding to 217, 386, 563, and 647 mm water depths, respectively - were tested by means of an irrigation bar composed of sprinklers with different flow rates. Plant growth was quantified by weekly collections. Amaranth was the most responsive plant to water. Quinoa showed the best performance in the treatment with the upper-middle water level among the other evaluated species. Millet showed thermal sensitivity for cultivation in the winter, making grain production unfeasible; however, it showed exceptional ability to produce biomass even in the treatment with higher water deficit.