ABSTRACT Since the industrial revolution, human activities have emitted approximately 2,500 Gt of CO2, increasing the concentration of atmospheric CO2 by 50 % compared to pre-industrial levels. To better understand the potential for mitigating greenhouse gas (GHG) emissions through proper management of degraded pasture areas, we conducted a systematic literature review and identified 23 publications reporting carbon sequestration values for pastures managed under different conditions in the south and southeast regions of Brazil. From this dataset, 17 publications considered to be in line with the research premises were selected to estimate the potential for soil carbon sequestration (SEQ) through pasture recovery in the southern region of Brazil, using conservative and regenerative agricultural management practices. Results show that managed pastures can sustain carbon sequestration rates of around 2.50 Mg C ha-1 yr-1 over approximately 20 years. However, due to the numerous variables influencing SEQ rates, the limited number of publications, and the lack of data for some variables among them, a more extensive analysis of publications and data is needed to establish causal and preponderance relationships regarding the effect of each variable on the found SEQ rates. Under current pasture occupation conditions in Brazil’s south region, it is estimated these areas could sequester between 0.433 and 1.273 Gt CO2 at the end of 20 years if managed under appropriate practices. These numbers are not representative to reduce atmospheric CO2 concentration from legacy emissions and significantly mitigate physical impacts of climate change, reinforcing the importance of prioritizing the reduction of global GHG emissions as the primary mitigation strategy. On the other hand, from the perspective of mitigating the national agricultural sector’s annual GHG emissions, this potential cannot be considered negligible. Carbon sequestration by soils under agricultural management can play a vital role in mitigating climate change, integrating the set of necessary solutions and actions for a Paris Agreement goals compatible trajectory of limiting global warming to between 1.5 and 2 °C by the end of the century. revolution 2500 500 2,50 CO 5 preindustrial pre levels (GHG Brazil dataset 1 (SEQ practices 250 2.5 ha1 ha ha- yr1 yr yr- However them Brazils s 0433 0 433 0.43 1273 273 1.27 change strategy hand sectors sector negligible 15 1. century 2,5 25 2. 043 43 0.4 127 27 1.2 2, 04 4 0. 12

ABSTRACT Application of pig manure (PM) in agriculture can influence the amount and composition of soil organic matter (SOM). This study evaluated the changes in contents and stock of C in chemical fractions of SOM and the chemical and spectroscopic composition of humic substances (HS) in a Typic Hapludult (Argissolo Vermelho-Amarelo) after ten years of PM application. Experimental area received 90 and 180 kg ha-1 of N in the form of pig slurry (PS90 and PS180) and pig deep litter (DL90 and DL180), in addition to the control, without application (SA). Soil samples were prepared, and the chemical fractioning of SOM, elemental analysis, and Fourier Transform Infrared Spectroscopy of HS were performed. Applications of PM favored the accumulation of C in soil (up to 53 %), and PS180 increased humic acids (HA) (up to 185 %), while applications of DL favored the increase of hydrophilic substances extracted with HCl and humin (HU) (up to 10 times and 60 %, respectively). Applications of PS180 and DL180 promoted an increase in the aromatic and carboxylic character of the HS, increasing cationic exchange capacity. Therefore, PM applications, especially with DL, contribute positively to C fixation in the soil and the chemical composition of organic material. (PM SOM. . (SOM) (HS Argissolo VermelhoAmarelo Vermelho Amarelo Vermelho-Amarelo 9 18 ha1 ha 1 ha- PS90 PS (PS9 DL90 (DL9 DL180, , DL180) control SA. SA (SA) prepared analysis performed up 5 % %) PS18 HA (HA HU (HU 6 respectively. respectively respectively) DL18 capacity Therefore material (SOM PS9 (PS DL9 (DL (SA PS1 DL1

ABSTRACT Climate-smart agriculture (CSA) practices, mainly no-tillage (NT), cover cropping (CC), soil fertilization with organic amendments (OA), and crop-livestock (CL) and crop-livestock-forestry (CLF) systems, has been widely adopted in areas from Brazilian Cerrado. The CSA may partly offset former soil C losses and contribute to climate change mitigation. However, contradictory findings brought uncertainties about the effect of CSA on soil C. Here, by a systematic review of 87 papers and using 621 data pairs, we provided a pervasive biome-scale analysis of soil C stock changes associated with the adoption of CSA across Brazilian Cerrado. All CSA practices evaluated showed average positive rates of C stock change, indicating a general tendency of soil C accretion after its adoption. In areas under NT, CC and CLF, greater rates were estimated for the deeper soil profile evaluated (0.00-1.00 m) (1.24 ± 0.85, 0.54 ± 0.54 and 1.00 ± 1.47 Mg ha–1 yr–1, respectively), while OA and CL showed more soil C accretion when the assessment was limited down to 0.10 m depth (0.82 ± 0.60 and 0.59 ± 0.66 Mg ha–1 yr–1, respectively). Unfortunately, the lack of basic information precluded any attempt to statically compare our estimations. In this sense, we must be cautious in stating that soil C sequestration occurs at those rates after the adoption of CSA practices. Despite these limitations, the results clearly show that the diversification and intensification of agricultural areas in the Cerrado by the adoption of CSA is a promising pathway to increase soil C stocks, and consequently, contribute to climate change mitigation and adaptation. Finally, our findings emphasize the importance of efforts that stimulate farmers to adopt these practices on large scale, such as Brazil’s Low-Carbon Agriculture Plan, besides providing sound empirical evidence about the role of soil C sequestration in Brazil achieving its Nationally Determined Contributions commitments. Climatesmart Climate smart (CSA notillage no tillage NT , (NT) CC, (CC) OA, (OA) croplivestock crop livestock (CL croplivestockforestry forestry CLF (CLF systems However Here 8 62 pairs biomescale biome scale 0.001.00 000100 0.00 0 00 1 (0.00-1.0 1.24 124 24 (1.2 085 85 0.85 054 54 0.5 100 1.0 147 47 1.4 ha1 ha ha– yr1 yr yr–1 respectively, respectively respectively) 010 10 0.1 0.82 082 82 (0.8 060 60 0.6 059 59 066 66 respectively. . Unfortunately estimations sense limitations stocks consequently adaptation Finally Brazils s LowCarbon Low Carbon Plan commitments (NT (CC (OA 6 001 0.001.0 00010 000 0.0 (0.00-1. 1.2 12 2 (1. 08 0.8 05 5 0. 1. 14 4 yr– 01 (0. 06 0.001. 0001 (0.00-1 (1 (0 0.001 (0.00- ( (0.00 (0.0

RESUMO O cultivo em sistema de plantio direto e a utilização de fertilizantes organominerais são práticas de manejo que amenizam a lixiviação e ciclam quantidades consideráveis de nutrientes, em virtude do aporte de matéria orgânica que proporcionam ao solo, e que podem melhorar o rendimento das culturas. Neste estudo objetivou-se avaliar o desempenho agronômico do repolho cultivado sobre diferentes resíduos de plantas coberturas e fontes de fósforo em sistema de plantio direto. O delineamento experimental foi de blocos ao acaso, em parcelas subdivididas, com oito tratamentos com plantas de cobertura na parcela principal: 1) Braquiária (B); 2) Crotalária (C); 3) Milheto (M); 4) B+C; 5) B+M; 6) C+M; 7) B+C+M; 8) cultivo convencional (preparo do solo sem planta de cobertura). Nas subparcelas avaliou-se as fontes de fósforo (P): 1) Fertilizante mineral (FM); 2) Fertilizante organomineral (FO); 3) Sem fornecimento de P, com quatro repetições. Avaliaram-se a produção de massa fresca (MF) e seca (MS) (t/ha) das plantas de cobertura; decomposição e ciclagem de nutrientes dos resíduos; MF e MS da cabeça (MFC e MSC) (g/planta) e a produtividade (PROD) (t/ha) do repolho. As maiores produções de MF e MS ocorreram nos consórcios das plantas de cobertura; Os consórcios de M+C, B+C apresentaram os resíduos com maior taxa de decomposição e ciclagem de P para o solo. Os maiores valores de MFC e PRODs do repolho ocorreram nas áreas cultivadas sobre resíduos do consórcio B+C, independentemente da fertilização utilizada. O FM utilizado como fonte de P proporcionou maior PROD do repolho quando cultivado sobre o resíduo de milheto. Quando em cultivo convencional do solo, a PROD do repolho foi superior quando utilizado o FO como fonte de P. culturas objetivouse objetivou se acaso subdivididas principal 1 B (B) 2 C (C) 3 M (M) 4 BC 5 B+M BM 6 C+M CM 7 B+C+M BCM 8 preparo cobertura. . cobertura) avaliouse avaliou (P) (FM) (FO) repetições Avaliaramse Avaliaram (MF (MS t/ha tha t ha (t/ha MSC g/planta gplanta g (g/planta (PROD MC M+C utilizada milheto (B (C (M (P (FM (FO

ABSTRACT No-till planting and the use of organomineral fertilizers are crop management practices that increase soil organic matter, thereby mitigating leaching and cycling a considerable amount of nutrients, with the potential to improve crop yield. This study aimed to assess the agronomic performance of cabbage grown under a no-till system, using different cover crops and phosphorus sources. A randomized block design was used, with the main plot consisting of eight split plots for different cover crop treatments: 1) Signal grass (SG); 2) Sunn hemp (SH); 3) Pearl millet (PM); 4) SG+SH; 5) SG+PM; 6) SH+PM; 7) SG+SH+PM; 8) conventional tillage (soil preparation with no cover crop), and phosphorus (P) sources in the sub-plots: 1) mineral fertilizer (FM); 2) organomineral fertilizer (OF); 3) no P, with four repetitions. The following characteristics were assessed: cover crop fresh (FW) and dry weight (DW) (t/ha), residue decomposition and nutrient cycling; and cabbage head FW and DW (HFW and HDW) (g/plant) and yield (YLD) (t/ha). The highest FW and DW were recorded in the intercropped cover plant treatments; PM+SH and SG+SH residue exhibited the highest decomposition rate and P cycling into the soil. The highest cabbage HFW and YLD occurred in the SG+SH treatment, regardless of the fertilizer used. The MF used as P source produced a greater cabbage YLD when grown in PM residue. Under conventional tillage, YLD was higher when OF was used as P source. Notill No till matter nutrients notill system treatments 1 SG (SG) 2 SH (SH) 3 (PM) 4 SGSH 5 SG+PM SGPM 6 SH+PM SHPM 7 SG+SH+PM SGSHPM 8 crop, , crop) (P subplots sub sub-plots FM (FM) (OF) repetitions assessed (FW (DW t/ha, tha t/ha t ha (t/ha) HDW g/plant gplant g (g/plant (YLD t/ha. . PMSH treatment (SG (SH (PM (FM (OF (t/ha

RESUMO O plantio direto de hortaliças tem sido uma alternativa viável para diminuir as perdas causadas pela erosão e aumentar a disponibilidade de nutrientes no solo, pois a manutenção da palha na superfície protege o solo e, com a decomposição destes resíduos, ocorre a ciclagem de nutrientes. Esse fato pode proporcionar aumento da produtividade das culturas em sucessão. Neste estudo avaliou-se a produção e a decomposição dos resíduos de plantas de cobertura e o desempenho agronômico do brócolis cultivado sobre estes resíduos e com diferentes doses de adubação nitrogenada em sistema de plantio direto. O estudo foi conduzido em delineamento de blocos casualizados, em parcelas subdivididas (doses de N) e sub-subdivididas (tempos de decomposição), com quatro repetições. Foram avaliados sete tipos de cobertura, sendo 1) braquiária (B); 2) crotalária (C); 3) milheto (M); 4) consórcio B+C; 5) B+M; 6) C+M e 7) B+C+M. Foram avaliados também 4 doses de adubação nitrogenada em cobertura, sendo T1) sem aplicação de N (controle); T2) 60 kg/ha de N; T3) 90 kg/ha de N e T4) 120 kg/ha de N. Ainda, avaliamos cinco tempos de decomposição dos resíduos das plantas de cobertura, sendo: zero (manejo), 15, 30, 60 e 90 dias após o transplante das mudas de brócolis. Foram avaliados a produção de massa seca (MS) das coberturas, decomposição dos resíduos, massa fresca (MFC) e seca das cabeças (MSC) e produtividade (PROD) na cultura do brócolis. Crotalária e o consorcio B+C apresentaram a menor produção de MS e junto com a braquiária o menor T½ vida e maior taxa de decomposição dos resíduos. O melhor desempenho do brócolis ocorreu quando as plantas foram cultivadas sobre os resíduos de M, C e nos consórcios destas plantas como coberturas. A maior produção de brócolis ocorreu no cultivo sob os resíduos de crotalária, independente da adição ou não de adubo nitrogenado em cobertura, com MFC de 788 g/planta e PROD de 30 t/ha. sucessão avaliouse avaliou se casualizados subsubdivididas sub decomposição, , decomposição) repetições 1 B (B) 2 (C) 3 M (M) BC 5 B+M BM 6 CM 7 BCM B+C+M T1 T controle (controle) T2 kgha kg ha T3 9 T4 12 Ainda manejo, manejo (manejo) 15 (MS coberturas (MFC MSC (MSC (PROD 78 gplanta g planta tha t t/ha (B (C (M (controle (manejo

ABSTRACT No-till vegetable farming is a feasible alternative to reduce erosion-induced losses and to increase soil nutrient availability, because cover crop residue protects the soil and its decomposition promotes nutrient cycling, which can improve the yield of the subsequent crop. The present study assessed the production and decomposition of cover crops and the agronomic performance of broccoli grown on this residue using different nitrogen doses in a no-till system. A randomized block design was used, in a split-split plot arrangement of main plots (cover crops), sub-plots (N doses) and sub-sub plots (decomposition times), with four repetitions. Seven cover crops were studied, as follows: [1) signal grass (SG); 2) sunn hemp (SH); 3) pearl millet (PM): 4) SG+SH; 5) SG+PM; 6) SH+PM and 7) SG+SH+PM]; in addition to four doses of nitrogen topdressing [T1) no N application (control); T2) 60 kg/ha N; T3) 90 kg/ha N and T4) 120 kg/ha N]; and five cover crop residue decomposition times: zero (cutting), 15, 30, 60 and 90 days after transplanting (DAT) the broccoli seedlings. Cover crop dry weight (DW) production, residue decomposition, and the head fresh (HFW) and dry weight (HDW) and yield (YLD) of broccoli were assessed. Among the cover crops, sunn hemp and the intercropped SG+SH treatment exhibited the lowest DW production and, along with signal grass, the shortest half-life (T½) and highest residue decomposition rate. The best-performing broccoli plants were those grown using PM, SH and a combination of both as cover crops. The highest broccoli production was obtained using sunn hemp residue, regardless of nitrogen topdressing, with HFW of 788 g/plant and YLD of 30 t/ha. Notill No till erosioninduced erosion induced availability cycling notill system used splitsplit split , crops) subplots sub subsub times, times times) repetitions studied follows 1 [1 SG (SG) 2 (SH) 3 PM (PM) 4 SGSH 5 SG+PM SGPM 6 SHPM 7 SG+SH+PM SGSHPM SG+SH+PM] T1 T [T1 control (control) T2 kgha kg ha T3 9 T4 12 N] cutting, cutting (cutting) 15 DAT (DAT seedlings (DW (HFW HDW (HDW (YLD halflife half life T½ (T½ rate bestperforming best performing 78 gplant g plant tha t t/ha [ (SG (SH (PM [T (control (cutting (T

RESUMO A utilização dos fertilizantes organominerais no cultivo das hortaliças vem sendo considerada como uma das tecnologias promissoras para fornecer nutrientes de forma lenta e gradual, diminuindo os problemas com adsorção de fósforo e lixiviação de nitrogênio e potássio, com fornecimento de alguns micronutrientes. Neste estudo objetivou-se avaliar o uso de diferentes doses de fertilizante organomineral (FO) como fonte fósforo (P) e micronutrientes no cultivo da alface crespa. No delineamento de blocos ao acaso, foram avaliadas cinco doses de FO: T1 = 0,0% (sem adubação com P2O5); T2 = 50% (75 mg/dm3 de P2O5); T3 = 100% (150 mg/dm3 de P2O5); T4 = 150% (225 mg/dm3 de P2O5); T5 = 200% (300 mg/dm3 de P2O5) da dose recomendada para a cultura, mais um tratamento adicional: T6 = adubação 100% fertilizante mineral (FM) (150 mg/dm3 de P2O5), todos com 4 repetições. Avaliou-se a matéria fresca (MF) e seca (MS) da parte aérea das plantas de alface, o teor de nutrientes no solo e o estado nutricional na planta no momento da colheita. Observou-se que as doses de 225 e 300 mg/dm3 de P2O5 via FO proporcionaram a mesma disponibilidade de P no solo que a dose de 150 mg/dm3 de P2O5 de FM; as doses de 225 e 300 mg/dm3 de P2O5 de FO proporcionaram teores superiores de boro e zinco no solo, em relação aos outros tratamentos utilizados; A adubação com FM se mostrou mais eficiente que a de FO na produção da alface crespa em ambiente protegido. gradual potássio objetivouse objetivou (FO (P acaso T 00 0 0,0 sem PO O 50 75 (7 mgdm3 mgdm mg dm3 dm mg/dm 100 (15 (22 200 (30 cultura adicional (FM P2O5, , repetições Avaliouse Avaliou MF (MF MS (MS colheita Observouse Observou 22 30 P2O 15 utilizados protegido 0, 5 7 ( 10 (1 (2 20 (3 2 3 1

ABSTRACT The use of organomineral fertilizers (OF) in the cultivation of vegetables has been considered a promising technology to provide nutrients gradually. The OFs can reduce the phosphorous (P) soil adsorption and leaching of nitrogen and potassium with the supply of some micronutrients. This study aimed to evaluate doses of OF as a source of P and micronutrients (boron and zinc) for curly lettuce cultivation. Five OF doses were evaluated: T1 = 0% (no P2O5 fertilization); T2 = 50% (75 mg/dm3 of P2O5); T3 = 100% (150 mg/dm3 of P2O5); T4 = 150% (225 mg/dm3 of P2O5); T5 = 200% (300 mg/dm3 of P2O5) of the lettuce recommended fertilization; T6 = 100% mineral fertilizer (MF) (150 mg/dm3 of P2O5). The fresh (FM) and dry mass (DM) of the lettuce shoot (aerial part), the soil nutrient level, and the plant nutritional status at harvest were evaluated. We observed that (i) the doses of 225 and 300 mg/dm3 of P2O5 via OF provided the same availability of P in the soil as the dose of 150 mg/dm3 of P2O5 of MF; (ii) the doses of 225 and 300 mg/dm3 of P2O5 of OF provided higher levels of soil boron and zinc compared to other treatments and (iii) the MF fertilization was more efficient than that of OF in the production of curly lettuce in a protected environment. (OF gradually (P evaluated T 0 no PO O P2O fertilization) 50 75 (7 mgdm3 mgdm mg dm3 dm mg/dm 100 (15 (22 200 (30 (MF P2O5. . FM (FM DM (DM aerial part, part , part) level i (i 22 30 15 ii (ii iii (iii environment 5 7 ( 10 (1 (2 20 (3 2 3 1

RESUMO Os milhos especiais são cultivados o ano todo e de forma convencional, contudo, quando cultivados sob sistema de plantio direto (SPD) pode aumentar a produtividade das culturas. O objetivo deste estudo foi avaliar o desempenho agronômico do milho doce e verde cultivados sob resíduos de diferentes coberturas e estádios de implantação do SPD. Dois experimentos foram conduzidos em delineamento de blocos casualizados, com quatro repetições, em cada uma das três áreas. Os experimentos consistiram da avaliação do milho doce e verde, simultaneamente, nas três áreas em diferentes estádios de desenvolvimento do SPD: inicial (1 ano), transição (7 anos) e consolidação (19 anos); Seis tipos de cobertura: braquiária (B), milheto (M), crotalária (C), mistura de B + C, B + M e M + C. Avaliou-se a produção de massa seca (MS) das coberturas, as produtividades de espigas empalhadas e despalhadas, de palha e rendimento de grãos. A crotalária teve a maior produção de MS entre as coberturas estudadas, em todas as fases do SPD. A produtividade de espigas com ou sem casca no milho verde não foi influenciada pela fase do SPD. O cultivo de milho doce em áreas de transição e consolidação do SPD apresentou melhores rendimentos quando comparado à fase inicial do sistema.

ABSTRACT Special corn is cultivated all year conventionally round; however, its productivity increases when grown under a no-tillage system (NTS). This study aimed to evaluate the agronomic performance of sweet and green corn cultivated under residues of different cover crops and the NTS implantation stages. Two experiments were carried out in the randomized block design, with four replications, in each of the three areas. The experiments consisted of evaluating the sweet and green corn, simultaneously, in three areas at different stages of development of NTS: initial (1 year), transition (7 years), and consolidation (19 years) with six types of cover crops: Signal grass (SG), Pearl millet (PM), Sunn hemp (SH), a mixture of SG + SH, SG + PM, and PM + SH. The dry matter (DM) production of the cover crops, the productivity of husked and unhusked ears, straw, and grain yield were evaluated. The SH had the highest dry mass production among the studied cover crops in all phases of the NTS. The phase of the NTS did not influence the productivity of ears with or without husk in green corn. The cultivation of sweet corn in transition and consolidation areas of the NTS showed better yields when compared to the initial phase of the system.

Resumo Santa Catarina possui destaque nacional no cultivo da maçã, porém atualmente os dados de área cultivada são coletados através de metodologias subjetivas. Neste sentido, o presente trabalho tem como objetivo apresentar uma metodologia de estimativa de área utilizando técnicas de sensoriamento remoto. Além disso, através de dados SRTM e meteorológicos foi realizada a espacialização de um dos fatores essenciais ao cultivo da maçã, as horas de frio (HF), a qual determina a brotação e consequentemente a produtividade dos pomares. Os resultados mostraram que por meio das imagens orbitais foi possível um mapeamento com 93,4% de índice Kappa, fato este obtido principalmente pelo uso de imagens Sentinel-2 e Cbers-4. Cerca de 73% encontram-se em uma faixa de altitude entre 1.100 e 1.400 m. Em relação às Horas de Frio, pomares implantados entre 700 e 900 HF totalizam 71,3% da área de produção. A metodologia aplicada e os resultados alcançados no presente trabalho demonstram grande potencial para o mapeamento de outras regiões produtoras de maçã no estado.

Abstract Santa Catarina has national prominence in the cultivation of the apple, but currently the data of cultivated area are collected through subjective methodologies. In this sense, the present work aims to present an area estimation methodology using remote sensing techniques. In addition, through SRTM and meteorological data, the spatialization of one of the factors essential to apple cultivation, the chill hours (CH) was carried out, which determines bud break and consequently orchards productivity. Results showed that by means of orbital images a mapping with 93.4% of Kappa index was possible, fact obtained mainly by the use of Sentinel-2 and Cbers-4 images. About 73% are in an altitude range between 1,100 and 1,400 m. In relation to the Chill Hours, orchards implanted between 700 and 900 CH total 71.3% of the production area. The applied methodology and the results achieved in the present work show great potential for the mapping of other apple producing regions in the state.

Objetivou-se avaliar os teores de carbono orgânico total (COT) e carbono das frações oxidáveis em agregados biogênicos e fisiogênicos em áreas com aplicação de dejeto líquido de suínos (DLS) e cama sobreposta de suínos (CSS). Após 10 anos do uso de dejetos suínos (DS) na sucessão aveia/milho, coletaram-se amostras indeformadas de solo nas camadas de 0-5 e 5-10 cm, nos tratamentos sem aplicação de DS (testemunha), com aplicação de DLS e CSS em dose equivalente a uma e duas vezes a recomendação de N para o milho e aveia, respectivamente. Os agregados foram separados conforme a via de formação em biogênicos e fisiogênicos. Em seguida, estes agregados foram separados em macro, meso e microagregados. Nestes agregados determinaram-se o COT e apenas nos macroagregados para o C das frações oxidáveis (F1, F2, F3 e F4). A aplicação de DLS aumenta os teores de COT nos microagregados enquanto que o uso da CSS aumenta o conteúdo de COT nos macroagregados. O uso de CSS por longo tempo aumenta o carbono lábil (F1) e recalcitrante (F4) em comparação aos DLS e a testemunha. As frações de carbono oxidáveis permitiram evidenciar diferenças entre os agregados biogênicos e fisiogênicos, sendo maiores nos agregados biogênicos.

The objective of this study was to evaluate the total organic carbon (TOC) and carbon contents of the oxidizable fractions in biogenic and physicogenic aggregates in areas with pig slurry (PS) and deep litter (DL). After 10 years of use of pig manure (PM) in a crop succession with black oat/maize, undisturbed soil samples were collected in the 0-5 and 5-10 cm layers, in the treatments without PM (control) application, with application of PS and DL at a dose equivalent to one and two times the N recommended for maize and black oat, respectively. The aggregates were separated according to the biogenic and physicogenic formation pathway. Then, these aggregates were separated into macro, meso and microaggregates. In these aggregates the TOC was determined in the macro, meso and microaggregates and only in the macroaggregates for the C of the oxidizable fractions (fractions F1, F2, F3 and F4). Application of PS increases the TOC contents in the microaggregates while the DL increases TOC in macroaggregates. The use of DL for a long time increases the labile carbon (F1) and recalcitrant carbon (F4) in comparison to PS and control. Oxidizable carbon fractions showed differences between biogenic and physicogenic aggregates, being greater in the biogenic aggregates.

RESUMO O objetivo do estudo foi avaliara dinâmica de decomposição de resíduos de culturas num pomar de pereiras no Brasil. Resíduos de aveia, nabo forrageiro, azevém e vegetação espontânea foram adicionados em sacos de decomposição depositados à superfície do solo nas linhas de cultivo das pereiras. Após 0, 21, 36, 56 e 136 dias, a matéria seca e os teores de carbono, lignina, celulose, componentes não estruturais e nitrogênio (N), fósforo (P), potássio (K), cálcio (Ca) e magnésio (Mg) foram determinados. Os resíduos de vegetação espontânea apresentaram o maior tempo de semi-vida em comparação com as culturas de cobertura cultivadas, enquanto os resíduos de aveia apresentaram as taxas de decomposição da matéria seca mais rápidas (2-3 vezes maior). O nabo forrageiro e o azevém apresentaram os maiores teores de matéria seca remanescente (26-36%) e a maior liberação de nutrientes. Os resíduos de nabo forrageiro e azevém liberaram 85 kg N ha-1, 67 kg P ha-1, 48 kg K ha-1, 16 kg Ca ha-1 e 9 kg Mg ha-1. O nabo forrageiro poderá beneficiar a nutrição mineral de fruteiras, enquanto a vegetação espontânea poderá contribuir para proteger o solo da erosão e para aumentar o teor de carbono orgânico acumulado no solo num longo prazo.

ABSTRACT Our objective was to evaluate the dynamics of decomposition of crop residues in a pear orchard in Brazil. Residues of oat, oilseed radish, ryegrass and spontaneous vegetation were placed in litter bags and deposited at surface soil in the inter-row spacing of pear trees. After 0, 21, 36, 56 and 136 days, the dry matter, carbon, lignin, cellulose, non-structural components, and nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations were determined. Spontaneous vegetation residues had the longest half residence time compared to the introduced cover crops, while oat residues presented faster dry matter decomposition rates (2-3 fold higher). Oilseed radish and ryegrass showed the highest final remaining dry matter (26-36%), and the largest nutrients release. Oilseed radish and ryegrass residues released 85 kg N ha-1, 67 kg P ha-1, 48 kg K ha-1, 16 kg Ca ha-1, and 9 kg Mg ha-1. Oilseed radish can potentially benefit mineral nutrition of fruit trees, whereas the spontaneous vegetation is recommended to protect the soil agains the erosion and to contribute to the soil organic carbon stock in the long term.

RESUMEN La información adecuada sobre la idoneidad de las tierras agrícolas para la viticultura es importante para la expansión de la actividad en las regiones productoras de vino, como el estado de Santa Catarina, Brasil. Esta información contribuye a mejorar la eficiencia de las evaluaciones, con la inclusión de diferentes niveles de gestión para el cultivo y la redefinición de los niveles límite de las condiciones de las tierras agrícolas. En este contexto, el objetivo de este trabajo fue adaptar el Sistema de Evaluación de la Aptitud Agrícola de las Tierras (SAAAT) a los cultivos de vid que se producen en las regiones de gran altitud de Santa Catarina. El SAAAT se modificó en función de las demandas y las gestiones de los cultivos, proponiendo la incorporación, eliminación, ajuste y actualización de los parámetros utilizados en el SAAAT. Los factores limitantes considerados fueron la topografía, la fertilidad, el exceso de agua o la deficiencia de oxígeno, la susceptibilidad a la erosión, los impedimentos a la meccanización y la profundidad efectiva del suelo. Estos rasgos se basaban en datos de estudios bibliográficos y se les atribuyeron cinco niveles limitantes: nulo, leve, moderado, fuerte y muy fuerte. Las clases de idoneidad agrícola como buena, regular, restrictiva e inapropiada resultaron de la interacción entre las condiciones agrícolas y los niveles de gestión de los productores de viticultura y posteriormente se elaboró un cuadro guía de idoneidad. La adaptación del SAAAT a los cultivos de vid que se realizan en condiciones de gran altitud en Santa Catarina incorporan y ajustan aspectos locales que son importantes para el sistema de producción de la vid. Por lo tanto, es una herramienta importante para la toma de decisiones en la implantación de nuevos viñedos y contribuye a un posible aumento de esta actividad en la región.

ABSTRACT Adequate information on agricultural land suitability for viticulture are important for the expansion of the activity in wine producing regions, as the state of Santa Catarina, Brazil. This information contributes to improve the efficiency of evaluations, with the inclusion of different management levels for the crop and redefinition of limiting levels of agricultural land conditions. In this context, the objective of this work was to adapt the Land Agricultural Suitability Evaluation System (LASES) to grapevine crops grown in high-altitude regions in Santa Catarina. The LASES was modified based on the crop demands and managements, proposing the incorporation, removal, adjust and update of parameters used in the LASES. The limiting factors considered were topography, fertility, water excess or oxygen deficiency, susceptibility to erosion, impediments to meccanization, and soil effective depth. These traits were based on data of bibliographic surveys and five limiting levels were attributed to them: null, mild, moderate, strong, and very strong. Agricultural suitability classes like good, regular, restrictive and inapt resulted from the interaction between agricultural conditions and management levels of viticulture producers, and later, a suitability guide table was developed. The adaptation of the LASES to grapevine crops grown in high-altitude conditions in Santa Catarina incorporate and adjust local aspects that are important for the grapevine production system. Thus, it is an important tool for decision making when implementing new vineyards and contributes to a possible increase of this activity in the region.

ABSTRACT Successive applications of swine manure can promote changes in soil physical attributes, with emphasis on the soil aggregation pathways. The objective of this work was to separate and quantify the aggregates according to their training path and to evaluate the stability of these aggregates in an area with a history of applications of pig slurry (PS) and deep litter (DL) in no-tillage system (NTS). After 10 years of use swine manure (SM) in oat/corn succession under NTS, undisturbed soil samples were collected in the 0-5 and 5-10 cm layers, in the treatments without SM (control), with application of PS and DL at doses equivalent to one and two times the recommended N for corn and oats (PS1X, PS2X, DL1X and DL2X, respectively). The aggregates were separated according to their morphological patterns and biogenic and physicogenic formation pathways. Then, weighted average diameter (WMD) of the aggregates and the distribution of the aggregates in the diameter classes for macroaggregates (8.0>Ø ≥2.0 mm), mesoaggregates (2.0>Ø ≥0.25 mm) and microaggregates (Ø<0.25 mm) in each type of aggregate were evaluated. The addition of SM increased the formation of biogenic aggregates. In the control area, the formation pathway of physicogenic aggregates prevails. The application of PS did not alter the WMD and the macroaggregates in relation to the control, while the application of DL increased these parameters when compared to the PS and control treatments.

RESUMO Aplicações sucessivas de dejetos suínos podem promover mudanças nos atributos físicos do solo, com ênfase nas vias de formação dos agregados solo. O objetivo deste trabalho foi separar e quantificar os agregados conforme sua via de formação e avaliar a estabilidade desses agregados em área com histórico de aplicações de dejeto líquido de suínos (DLS) e cama sobreposta de suínos (CSS), em sistema plantio direto (SPD). Após 10 anos do uso de dejetos suínos (DS) na sucessão aveia/milho sob SPD, coletaram-se amostras indeformadas de solo nas camadas de 0-5 e 5-10 cm, nos tratamentos sem DS (testemunha), com aplicação de DLS e CSS em doses equivalentes a uma e duas vezes a recomendação de N para o milho e a aveia (DLS1X, DLS2X, CSS1X e CSS2X, respectivamente). Os agregados foram separados conforme os seus padrões morfológicos e vias de formação em biogênicos e fisiogênicos. Em seguida, avaliaram-se o diâmetro médio ponderado (DMP) dos agregados e a distribuição dos agregados nas classes de diâmetro para macroagregados (8,00 > Ø ≥ 2,0mm), mesoagregados (2,0 > Ø ≥ 0,25mm) e microagregados (Ø < 0,25mm), em cada tipo de agregado. A adição de dejetos suínos aumentou a formação de agregados biogênicos. Na área testemunha prevalece a via de formação de agregados fisiogênicos. A aplicação de DLS não alterou o DMP e os macroagregados em relação à testemunha, enquanto a aplicação de CSS aumentou esses parâmetros quando comparada aos tratamentos DLS e Testemunha.

ABSTRACT Carbon (C) and nitrogen (N) content in granulometric fractions of soil organic matter (SOM) are sensitive indicators of soil quality changes caused by management systems. This study evaluated the C and N content in granulometric fractions of SOM of aggregates, an Inceptisol under onion grown in no-till vegetable farming systems (NTVFS) and conventional tillage systems (CTS), comparing them to a secondary forest. Treatments consisted of soil cover crops, monocropped and intercropped with onions grown under NTVFS: spontaneous vegetation, 100% black oats; 100% rye; 100% oilseed radish; oilseed (14%) + rye (86%) intercrop and oilseed (14%) + oats (86%) intercrop. The same evaluations were also performed in an area with onions grown under CTS for ± 37 years, and in secondary forest (± 30 years). Undeformed soil samples were collected from 0-5, 5-10, and 10-20 cm deep soil layers, and aggregates were subsequently separated (8.00 mm > Ø ≥ 2.0 mm). Organic C (OC) and N of the granulometric fractions contents were quantified in aggregates, which were subdivided into particulate fractions (POC and PN) and mineral-associated fractions (OCam and Nam). NTVFS promoted protection of SOM at the 0-5 cm depth compared to CTS, as a result of higher POC content. Intercropped oats+oilseed and spontaneous vegetation contributed to an increase in PN content compared to all other treatments under NTVFS. Monocropped and intercroppped oilseed radish caused an increase in Nam, which was more effective than OCam to indicate differences among the systems. Conversion of areas from CTS to NTVFS promotes increases in POC and PN content in the upper soil layer. NTVFS improves the quality of aggregates, and it may reduce damage caused by CTS.

RESUMEN El contenido de carbono (C) y nitrógeno (N) en las fracciones granulométricas de la materia orgánica del suelo (MOS) es un indicador sensible de los cambios en la calidad del suelo causados por los sistemas de manejo. Este estudio evaluó el contenido de Cy N en fracciones granulométricas de la MOS de agregados, en un Inceptisol bajo cebolla cultivada en sistema de cultivo de vegetales sin labranza (SCVSL) y sistema de labranza convencional (SLC), comparándolos con un bosque secundario. Los tratamientos consistieron en cultivos de cobertura del suelo, monocultivos y consorciados con cebollas cultivadas bajo SCVSL: vegetación espontánea, 100% de avena negra; 100% de centeno; 100% nabo forrajero; consorcio de nabo (14%) + centeno (86%), consorcio de nabo (14%) + avena (86%). Las mismas evaluaciones se realizaron en un área con cebollas cultivadas bajo SLC durante ± 37 años, y en un bosque secundario (± 30 años). Se recogieron muestras de suelo no deformadas de capas de suelo de 0-5, 5-10 y 10-20 cm de profundidad, y los agregados se separaron posteriormente (8.00 mm> Ø ≥ 2.0 mm). Las cantidades de C orgánico (CO) y N de las fracciones granulométricas se cuantificaron en agregados, que se subdividieron en fracciones particuladas (PCO y PN) y fracciones asociadas con minerales (COam y Nam). SCVSL promovió la protección de MOS a una profundidad de 0-5 cm en comparación con SLC, como resultado de un mayor contenido de POC. La avena consorciada con nabo y la vegetación espontánea contribuyeron a un aumento en el contenido de PN en comparación con todos los otros tratamientos bajo SCVSL. El nabo forrajero en monocultivo y consorciado causó un aumento en Nam, que fue más efectivo que el COam para indicar diferencias entre los sistemas. La conversión de áreas de SLC a SCVSL promueve aumentos en el contenido de PCO y PN en la capa superior del suelo. SCVSL mejora la calidad de los agregados, y puede reducir el daño causado por SLC.

Abstract Pedological surveys and physiographic characterization of a watershed are fundamental procedures for planning the soil use. Thus, the aim of this study was to characterize and map the soil classes of the Lajeado Pessegueiro watershed, located in Guarujá do Sul, Santa Catarina, Brazil. The types of land use and occupation, slope classes and physiography of the study area were delineated and described. Data were collected from 19 complete soil profiles and 9 extra samples. Physiographic analysis was performed using prior information on the photopedology of the terrain geomorphological characteristics, climatic conditions, vegetation, land use and geological conditions. The watershed has a predominant undulating relief (406.51 ha). The predominant land use is agricultural, with temporary annual crops (50.09%). The predominant physiography is colluvial erosional slope (35.53%), followed by erosional slope (27.13%), plateau slope (21.55%), alluvial colluvial valley bottom (10.51%) and erosional collu-vial slope (5.23%). The soil classes found were Red Nitosols (37.54%), Haplic Nitosols (8.22%), Haplic Cambisols (35.20%), Fluvic Cambisols (3.92%), Red Argisols (10.09%) and Litholic Neosols (5.04%). The data showed the importance of using the physiographic analysis of the area with geoprocessing techniques, assisting pedological surveys with presentation through thematic maps. These maps serve as a base material in studies evaluating land uses, and those aiming to contribute to a better planning of soil use.

Resumo Os levantamentos pedológicos e a caracterização fisiográfica de uma microbacia são procedimentos fundamentais para o melhor planejamento da exploração do recurso solo. Objetivou-se realizar a caracterização e o mapeamento das classes de solos da microbacia Lajeado Pessegueiro, Guarujá do Sul, Santa Catarina, Brasil. Fez-se a deli mitação e apresentação da área de estudo, dos tipos de uso e ocupação das terras, das classes de declividade e da fisiografia da área. Coletaram-se informações de 19 perfis de solo completos e mais nove amostras extras. A análise fisiográfica foi feita por meio do conhecimento prévio de fotopedologia das características geomorfológicas do terreno, das condições climáticas, da vegetação, do uso da terra e das condições geológicas. O relevo predomi nante da microbacia é o ondulado (406,51 ha). O uso da terra predominante é de culturas temporárias (anuais) com 50,09%. A fisiografia predominante é a encosta erosional coluvial (35,53%), seguido da encosta erosional (27,13%), encosta em patamar (21,55%), fundo de vale coluvial aluvial (10,51%) e encosta coluvial erosional (5,23%). As classes de solo encontradas foram Nitossolos Vermelhos (37,54%), Nitossolos Háplicos (8,22%), Cambissolos Háplicos (35,20%), Cambissolos Flúvicos (3,92%), Argissolos Vermelhos (10,09%) e Neossolos Litólicos (5,04%). Por meio dos dados gerados evidenciou-se a importância da utilização da análise fisiográfica da área junto às técnicasde geoprocessamento, auxiliando nos levantamentos pedológicos juntamente com a apresentação desses estudos através de mapas temáticos, servindo como material base para estudos de avaliação do melhor uso das terras, assim como estudos que possam contribuir para um melhor planejamento de uso do solo.

RESUMEN Se evaluaron los niveles de nitrógeno total (NT) y N de las sustancias húmicas (SH) de la materia orgánica en agregados de suelo cultivado con cebolla bajo siembra directa de hortalizas (SDH) y sistema de preparación convencional (SPC), comparando con un área de bosque. Los tratamientos evaluados fueron: vegetación espontánea; 100% avena; 100% centeno; 100% nabo; cultivos asociados de nabo (14%) + centeno (86%); cultivos asociados de nabo (14%) + avena (86%); área bajo SPC de cebolla (±37 años) y de bosque secundario de ±30 años). Cinco años después de la implantación del SDH fueran recogidas muestras no disturbados del suelo en las capas 0-5, 5-10 y 10-20 cm y obtenidos los agregados (entre 2,0 y 8,00 mm). En estos se determinaron los niveles de NT y el N de las SH, subdivididos en fracción ácidos fúlvicos (N-FAF), ácidos húmicos (N-FAH) y humina (N-HUM). La conversión de áreas de SPC a SDH favorece el aumento de los niveles de NT y N-HUM en la capa de 0-5 cm. Entre las especies de plantas de cobertura utilizadas en el SDH, los cultivos asociados de avena + nabo favorecieron el aumento del N-HUM (0-20 cm) en comparación a los demás tratamientos. La avena solo y el control con vegetación espontánea aumentaron los niveles de N-FAH y N-FAF, respectivamente, en la capa de 10-20 cm, en comparación a los demás tratamientos en SDH y SPC. El SPC con mijo como planta de cobertura aumentó los niveles de N-FAF (0-20 cm) en comparación con el SDH.

ABSTRACT The objective of this study was to evaluate the soil total nitrogen (TN), and N contents in humic substances (HS) of the organic matter in aggregates of soils cultivated with onion under no-till system for horticulture (NTSH) and conventional tillage system (CTS), comparing with an area of forest. The evaluated treatments were natural vegetation (control), 100% black oats, 100% rye, 100% oilseed radish, intercrop of oilseed (14%) + rye (86%), intercrop of oilseed (14%) + black oats (86%), area under CTS of onion for ±37 years, and area with secondary forest for ±30 years. Five years after the NTSH implementation, undisturbed soil samples from the layers 0-5 cm, 5-10 cm, and 10-20 cm were collected; these samples presented aggregate sizes between 2.0 mm and 8.00 mm. The TN, and N contents of the HS were subdivided into fulvic acids (N-FA), humic acids (N-HA), and humin (N-HU) fractions. The change from CTS to NTSH increases the TN and N-HU contents in the 0-5 cm soil layer. The intercrop of oats and oilseed radish, used as soil plant cover species in NTSH, presented a greater increase in N-HU (0-20 cm) than the other treatments. Black oats, and natural vegetation presented a greater increased in N-HA, and N-FA contents, respectively, in the 10-20 cm layer, than the other treatments in NTSH and CTS. CTS with millet as soil plant cover presented a greater increase in N-FA (0-20 cm) contents than the NTSH treatments.