ABSTRACT Soil quality can be understood as its capacity to provide several essential services within the ecosystem and has been used to understand the impact of different managements, providing information that proves the benefits and your maintenance of the agroecosystem. To understand the impact of different managements, this study aimed to compare the chemical, physical, and biological soil properties in pasture areas managed with different recovery times in an integrated crop-livestock system about perennial pastures and secondary forest. The following management systems were evaluated: Secondary Forest (SF), Perennial Pasture (PP), pasture recovered to five years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL5), and pasture recovered to eight years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL8). Different soil properties were evaluated, namely: Chemical: pH, H+Al, Al 3+ , P, K + , Ca 2+ , Mg 2+ , TOC, SB, CEC, V, and m; Physical: soil bulk density (Bd), total porosity (Tp), macroporosity (Ma), microporosity (Mi), soil resistance to penetration (Pr), and gravimetric soil water content (GWc); and biological: soil microbial biomass carbon (SMB-C), basal soil respiration (BSR), metabolic quotient (qCO 2 ), and microbial quotient (qMic). Perennial pasture and ICL8 areas were the ones that most contributed to the increase in nutrients (Ca 2+ , Mg 2+ , and K + ), TOC and sorption complex. The ICL8 area showed the best results in soil physical variables Ma, Tp, Pr, and GWc were the best results for the ICL8 area. Secondary forest and ICL8 areas presented the best results from SMB-C and qMic. Between periods of pasture recovery through the integration of crops and livestock, the longer the recovery time, the greater its beneficial effects on the different chemical, physical and biological soil properties, overcoming secondary forest and perennial pasture.

ABSTRACT. In Maranhão State, Brazil, soils are naturally acidic, nutrient-deficient, and prone to cohesion and erosion. Removing the natural cover to establish pastures causes physical, chemical, and biological changes in the soil. Therefore, this study aimed to evaluate the contents and stocks of carbon (C), nitrogen (N), and particle-size fractions of soil organic matter (SOM) in pastures with different years of recovery, and compare them with a secondary forest in the Legal Amazon. Four treatments were evaluated: secondary forest, perennial pasture, and perennial pastures recovered for five years and eight years, both of the latter through corn + brachiaria intercropping. The contents and stocks of total organic carbon, total nitrogen, C, and N from the soil organic matter particle-size fractions, as well as the carbon management indexes (CMI) of the 0.00-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.40 m layers were evaluated. The perennial pasture environment presented the highest total soil C and N contents; however, when observing the granulometric fractions and CMI, these increases were qualitative in relation to the secondary forest. Pasture recovery over eight years contributed to an improvement of soil quality similar to secondary forest, indicating that an increase in SOM quality, quantity, and recovery time related to increased pasture capacity to accumulate C and N in the soil.

RESUMO Objetivou-se avaliar as características produtivas e qualitativas de beterraba e chicória em função do manejo da palhada e da época de estabelecimento do consórcio. O experimento foi conduzido no setor de horticultura orgânica da UNIOESTE, em delineamento de blocos ao acaso, em esquema fatorial 2 x 5 e 2 x 8, com quatro repetições, sendo o primeiro fatorial constituído do manejo da palhada (sem e com incorporação da palhada de mucuna-cinza) e pelas épocas de estabelecimento do consórcio e do monocultivo de beterraba e chicória (0; 7; 14 e 21 dias após o transplante da beterraba). Sendo o segundo fatorial composto para avaliar as características da chicória com o manejo da palhada (com e sem incorporação) e pelo cultivo da mesma consorciada com beterraba e em monocultivo nas mesmas épocas. A chicória interferiu na produtividade da beterraba quando o transplante foi realizado na mesma época. A forma de cultivo da beterraba em consórcio contribuiu positivamente para o melhor aproveitamento da área nos dois sistemas de manejo, influenciando de forma positiva as características agronômicas da cultura, mas sem comprometer a qualidade comercial dos cultivos, sendo agronomicamente viáveis, considerando o índice de UET.

ABSTRACT This study aimed to evaluate the productivity and quality characteristics of beet and chicory based on management of straw and intercropping period of establishment. The experiment was conducted in the organic horticulture sector of Unioeste, in a design of randomized blocks with four replications, where the treatments were arranged in 2 x 5 and 2 x 8 factorial schemes. The first factorial consisted of the straw mulch management (with and without incorporation of the gray velvet bean straw) and the intercropping period of establishments and beet and chicory monocrops (0; 7; 14 and 21 days after transplanting beet). The second factorial was composed of the straw mulch management (with and without incorporation) and the cultivation of chicory intercropped with beet and in monocrop at the same periods. The chicory interfered in beet's productivity when the transplant occurred at the same period. The beet cultivation in a intercropping contributed positively to the better use of the area in the two management systems, influencing in a positive way the agronomic characteristics of the crop, but without compromising the commercial quality of the crops, that were agronomically viable, considering the UET index.

RESUMOObjetivou-se avaliar os efeitos da altura de pastejo de Brachiaria ruziziensis na produção de palha, estabelecimento e rendimento de grãos da cultura da soja, em sistema de integração lavoura-pecuária, em Latossolo Vermelho distrófico típico, na Fazenda Experimental do Instituto Agronômico do Paraná (IAPAR), em Xambrê-PR. O estudo foi realizado entre setembro de 2010 e abril de 2012. O delineamento experimental utilizado foi em blocos ao acaso, em parcelas subdivididas no tempo, com cinco tratamentos e três repetições. Foram determinadas a massa de matéria seca da parte aérea de Brachiaria ruziziensis, massa de matéria seca de resíduo vegetal e massa de matéria seca total (massa da parte aérea de braquiária + massa de resíduo vegetal) e as variáveis relacionadas ao rendimento da cultura da soja (número de plantas por metro, altura das plantas e produtividade de grãos), nos anos agrícolas 2010/2011 e 2011/2012. A produção de palhada é maior em área sem pastejo de Brachiaria ruziziensis em comparação com as suas áreas pastejadas, com destaque também para a elevada produção nas áreas de maiores alturas de pastejo. O número final de plantas, a altura das plantas e a produtividade da cultura da soja não foram afetados pela altura de pastejo de Brachiaria ruziziensis.

ABSTRACTThe aim was to evaluate the effects of grazing height of Brachiaria ruziziensis on the production of straw, and the establishment and grain yield of a soybean crop, under an integrated crop-livestock system, on a typic dystrophic Red Latosol at the Experimental Farm of the Agronomic Institute of Paraná (IAPAR), in Xambrê, in the state of Paraná, Brazil (PR). The study was carried out between September of 2010 and April of 2012. The experimental design was of randomised blocks, in lots split over time, with five treatments and three replications. The following were determined for the Brachiaria ruziziensis: shoot dry matter weight, plant residue dry matter weight, and total dry matter weight (Brachiaria ruziziensis shoot weight + plant residue weight). Also determined were variables related to the yield of the soybean crop (number of plants per metre, plant height and grain productivity), for the crop years 2010/2011 and 2011/2012. Straw production is greater in areas of Brachiaria ruziziensis where there is no grazing compared to areas where grazing occurs; the high production seen in areas with greater grazing heights should also be noted. The final number of plants, plant height and productivity in the soybean were not affected by the grazing height of the Brachiaria ruziziensis.

Objetivou-se avaliar as etapas de produção de feno de capim Tifton 85 adubado com cinco doses de nitrogênio após cada corte sob a forma de ureia em cobertura. A desidratação da primeira colheita ocorreu durante seis dias em galpão, em função das condições climáticas, e a desidratação da segunda colheita ocorreu a campo durante dois dias. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas no tempo, sendo as parcelas (5m x 3m) as doses de nitrogênio (0; 25; 50; 75 e 100kg ha-1 colheita-1) e as subparcelas as etapas de produção de feno (corte, enfardamento e armazenamento). O nitrogênio aumentou a altura e produção de matéria seca por hectare, os teores de proteína bruta (PB) e de proteína insolúvel em detergente ácido (PIDA) e neutro (PIDN). A secagem em galpão durante seis dias foi insuficiente para que a forragem atingisse 850g kg-1 de MS no momento de enfardar. Entre a etapa de corte e 30 dias de armazenamento, o feno desidratado em galpão aumentou os teores de fibra em detergente neutro, de fibra em detergente de ácido, a PIDA, PIDN e a lignina e ocorreu um decréscimo de 18,9% nos teores de PB. Ocorreu redução da digestibilidade in vitro da matéria seca (DIVMS) em 32,72% entre a etapa de corte e 30 dias de armazenamento para o feno seco em galpão, enquanto que não houve alteração significativa na DIVMS e PB para o feno seco em dois dias a campo.

This study aimed to evaluate the stages of production of Tifton 85 hay fertilized with five rates of nitrogen after each cutting in the form of urea in coverage. The dehydration of the first harvest took place for six days in a shed due to weather conditions and the dehydration of the second harvest occurred in the field during two days. The experimental design was a randomized block design with split plot, and the plots (5m x 3m) were the doses of nitrogen (0, 25, 50, 75 and 100kg ha-1 crop-1) and the subplots steps hay production (cutting, baling, and storage). The nitrogen increased the height and dry matter production per hectare, the crude protein (CP) and acid detergent insoluble protein (PIDA) and neutral (NDIP). The drying in a shed for six days was insufficient for the material to reach 850g kg-1 DM at the time of baling. Between the stages of cut and 30 days of storage, the hay dehydrated in shed increased levels of neutral detergent fiber, detergent fiber acid, the PIDA, NDIP and lignin and decreased in 18.9% the CP levels. Ocurred a decrease in in vitro digestibility of dry matter (DM) in 32.72% between the step of cut and 30 days of storage for dry hay in the shed, while there was no significant change in IVDMD and CP for dry hay in two days in the field.

The objective of this study was to estimate the dehydration curve and occurrence of fungi and mycotoxins in Tifton 85 hay. The experimental design was randomized blocks in split plots with four replications and five levels of nitrogen (0, 25, 50, 75 and 100 kg ha-1) in the form of urea, two regrowth ages (28 and 35 days) and drying hay in the sun and in shed. After harvesting, the grass was sampled four times (0, 8, 23 and 32 hours) to dry in the sun and twelve times (0, 3, 18, 27, 42, 51, 66, 75, 90, 99, 114 and 123 hours) for drying in shed, turned over daily. The fungi were identified after seeding and growth in three steps of haymaking (cutting, baling and after 30 days of storage). To verify the presence of mycotoxins, 20 samples, composed of hay stored for 30 days, were collected, of which 10 samples were from sun-dried hay and 10 from hay dried in shed. It took 32 hours to produce hay at field conditions, with water loss rates up to 6.10 g g-1 DM-h during the first 8 hours after cutting. The average loss of water in this period was 2.0 g g-1 DM-h. Hays dried in the shed took 123 hours and the dehydration rates were less than 0.5 g g-1 DM-h due to environmental conditions. There was a predominance of three genera of fungi: Fusarium, Penicillium and Aspergillus. The largest population was the Fusarium, followed by Penicillium, at the steps of baling and storage. The fumonisin mycotoxin was found at a higher concentration and there was no difference in fumonisin concentration in the hay dried in the sun and in shed. Although it brings no hazard to animal health, the production of aflatoxin and zearalenone was significantly higher in the samples of sun-dried hay.

The objective of this study was to evaluate the effect of fertilization with zinc or boron on the growth and dry matter production, nutritional value and accumulation of nutrients in white oats. The study comprised two experiments conducted in glasshouses, the first consisting of the application of four doses of zinc (0, 0.2, 0.4 and 0.6 mg/dm³) in the form of zinc sulphate (20% Zn), and the second consisting of the application of four doses of boron (0, 0.2, 0.4 and 0.6 mg/dm³) in the form of Borax (11% B). The experimental design in each case was a randomized block design, with five replicates. Fertilization with zinc and boron increased the growth of white oats, but had no significant effect on the nutritional value of the forage. Higher levels of absorption and accumulation of nutrients in plant tissues were observed following the application of boron and zinc at rates of up to 0.60 mg/dm³ of soil.

No sistema de integração lavoura-pecuária, o manejo inadequado da aveia pode resultar em baixo rendimento de biomassa. O objetivo deste trabalho foi avaliar o efeito do manejo de cortes na produção de biomassa, em cinco cultivares de aveia com potencial de uso no sistema de integração lavoura-pecuária. O delineamento adotado foi o de blocos completos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas pelas cultivares de aveia Preta Comum, IAPAR 61, IPR 126, FAPA 2 e FUNDACEP FAPA 43. A cultivar Preta Comum apresenta ciclo curto e as demais ciclo longo. As subparcelas foram representadas pelos seguintes sistemas de corte: corte único no florescimento, um corte na fase vegetativa e outro no florescimento, dois cortes na fase vegetativa e outro no florescimento e três cortes na fase vegetativa e outro no florescimento. As cultivares de ciclo longo (IAPAR 61, IPR 126, FAPA 2 e FUNDACEP FAPA 43) alcançaram alta produção de forragem, sem comprometer a posterior produção de palhada para a cobertura do solo, evidenciando aptidão para utilização no sistema de integração lavoura-pecuária. O manejo com três cortes no estádio vegetativo maximiza a produção de forragem, no entanto, para a produção de palhada, o melhor desempenho das cultivares foi obtido no manejo com até dois cortes na fase vegetativa, ou corte único no florescimento.

In the crop-livestock integration system, improper oat management can result in low biomass yield. This study aimed to evaluate the effect of cutting management systems on the biomass yield of five oat cultivars with potential use in the crop-livestock integration system. A completely randomized blocks design with four replications, in a split-plot scheme, was used. The plots were represented by the oat cultivars Preta Comum, IAPAR 61, IPR 126, FAPA 2, and FUNDACEP FAPA 43. The Preta Comum cultivar features a short cycle, while the others have a long one. The sub-plots were represented by the following cutting systems: one single cut in the flowering stage, one cut in the vegetative and other in the flowering stage, two cuts in the vegetative and other in the flowering stage, and three cuts in the vegetative and other in the flowering stage. The long cycle cultivars (IAPAR 61, IPR 126, FAPA 2, and FUNDACEP FAPA 43) reached high forage yield, without affecting the subsequent fodder yield for soil covering, pointing out its ability to be used in crop-livestock systems. The management systems with three cuts in the vegetative stage maximizes the forage yield, however, concerning fodder yield, the best results were obtained by using up to two cuts in the vegetative stage, or a single one in the flowering stage.

White oat and ryegrass were overseeded on Tifton 85 pastures for evaluation of dry matter yield (DMY), leaf:stem ratio (L:S), dehydration curves and nutritional value of forages. Dry matter intake and L:S ratio were analyzed using a completely randomized blocks design with five forage growth conditions (single Tifton 85 and intercropped with white oat or ryegrass, and white oat or ryegrass intercropped with Tifton 85), whereas for drying curves, ten dehydration times were tested (0, 4, 8, 24, 28, 32, 48, 52, 56 and 71 hours after harvest) by a 5 × 10 split-plot arrangement (growth conditions of forages as main plot and dehydration times as sub-plots). The nutritive value data were analyzed in a 3 × 3 split-plot trial with single Tifton 85, Tifton 85 - Oat and Tifton 85-Ryegrass as main plots and the three sampling times (before harvesting, at baling and 100 days after storage) as sub-plots. Oat and ryegrass showed higher L:S ratio, while the intercrops of Tifton 85 - Oat and Tifton 85 - Ryegrass presented lower DMY, but higher crude protein concentration and in vitro DM digestibility than single Tifton. Neutral and acid detergent fiber concentrations were higher for single Tifton 85. Ryegrass and white oat, overseeded on Tifton 85 pasture, improved the nutritional value of the hay produced; however, in a 100-day storage period, there was a reduction in in vitro dry matter digestibility and crude protein concentrations.

The study was conducted to estimate the dehydration curves, chemical composition, and occurrence of fungi in white oat hay (Avena sativa L. cv. Guapa BRS) and black oat hay (Avena strigosa Schreb cv. Common) at two cutting heights. Dehydration curves were studied under a randomized block design with a 2 × 2 factorial arrangement using split plots in time, considering two types of oats (white and black), two cutting heights (10 and 20 cm), and 17 sampling times (0, 4, 19, 24, 28, 43, 47, 52, 67, 71, 76, 91, 95, 100, 115, 129, and 124 hours after harvesting) with five replicates. For the chemical composition and occurrence of fungi, the experimental design comprised randomized blocks in a factorial 2 × 2 split-plot in time with two types of oats, two cutting heights, and three assessment periods: before cutting, during baling, and after 30 days of storage, with five replicates. The hay obtained by cutting of the black and white oats at heights of 10 and 20 cm showed similar dehydration curves. The crude protein values were higher in white oats only at the time of cutting (141.5 g/kg). The black oats showed lower nutritional quality, with higher levels of ADF and lignin. There was no effect of cutting height on the chemical composition, but the cutting height interfered with the production of dry matter and residue after cutting, with cutting at 10 cm leading to higher dry matter production and at 20 cm to increased waste production. The cutting heights of the oats interfere directly with the dry matter production and post-harvest residue without changing the chemical composition of the hay.

Objetivou-se avaliar características produtivas, estruturais e nutricionais dos capins Tifton 85 e Piatã e da leguminosa feijão-guandu em monocultivo ou em cultivo consorciado, com e sem aplicação de nitrogênio. Adotou-se o delineamento de blocos casualizados com parcelas subdivididas no tempo, com sete tratamentos nas parcelas principais e 3 tempos de avaliação nas sub-parcelas, com 4 repetições. Os tratamentos consistiram: Cajanus cajan cv. 'Super N' (feijão-guandu); Brachiaria brizantha cv. 'Piatã' solteira sem aplicação de nitrogênio (N); B. brizantha cv. 'Piatã' em associação com feijão guandu; B. brizantha cv. 'Piatã' solteira com aplicação de N (150kg ha-1); Cynodon sp. Tifton 85 em cultivo solteiro sem aplicação de N; Tifton 85 em associação com feijão-guandu e Tifton 85 com aplicação de N (150kg ha-1) e três períodos de avaliações. A associação dos capins Piatã e Tifton 85 com feijão-guandu proporcionou produção forrageira equivalente à adubação nitrogenada e incrementos com elevação nos teores de proteína bruta e redução nos teores de fibra em detergente neutro. O capim Tifton 85 se mostrou menos tolerante ao sombreamento imposto pelo feijão-guandu.

This trial aimed at evaluating characteristics as: production, structural and nutritional requirements of Tifton 85 and Piatã grasses and pigeonpea in single or intercropped tillage, with and without nitrogen application. The experimental plot in randomized blocks with plots subdivided through time, with 7 treatments in the main plots and three periods of evaluation on subplots with four replications. The studied treatments were: Cajanus cajan cv. Super N (pigeonpea), Brachiaria brizantha cv. single Piatã without application of nitrogen (N); B. brizantha cv. Piatã in association with pigeonpea; B. brizantha cv. single Piatã with application of N (150kg ha-1); Cynodon sp. Tifton 85 in a single crop without application of N; Tifton 85 in association with pigeonpea and Tifton 85 plus an application of N (150kg ha-1) and three cycles of evaluations. The association of Tifton 85 and Piatã grasses with pigeonpea provided forage production like nitrogen fertilizer and increase crude protein content and a reduction on neutral detergent fiber contents. Tifton grass was less tolerant to shading from pigeonpea.

The experiment was carried out to evaluate the structural characteristics, biomass accumulation, chemical composition and in vitro digestibility of dry matter and crude protein of white oat (Avena sativa L. IPR 126) under different management systems. Grazing, cut at two heights (15 and 20 cm) and free growth were all evaluated in three periods (July, August and September) with a 28-day average interval between evaluations. In the free growth system, samples at 15 and 20 cm were also taken at the intervals chosen for cutting and grazing. The experimental design was in randomized blocks with three replications, arranged in a 3 × 2 factorial split plot design over time; systems of management and heights were the factors of plots, and time was taken as subplot. There was higher straw production under free growth, but, with decreased chemical quality from the first to the second period and from the second to the third one, with 236.4, 172.5, and 91.4 g/kg crude protein values, respectively. Regarding cutting and grazing systems, they showed structural changes in tillering, which was favored by the cut, but with some reduction in the periods. Nutritional quality values were close to cutting and grazing with high crude protein content (216.6 g/kg), adequate neutral detergent fiber (535.4 g/kg) content and high in vitro digestibility of dry matter (826.3 g/kg). Management heights promoted few changes in the characteristics evaluated. After the third period, cutting and grazing systems showed no suitable residual straw for ground covering and set a summer crop under no-tillage system, with 738.39 kg/ha of residual dry matter on average.

The objectives of this study were to estimate the curve of dehydration, bromatological composition and occurrence of fungi in Tifton 85 grass, submitted to four methods of dehydration. The curves of dehydration were studied in a completely randomized design with a 4 × 11 factorial scheme with four drying systems (1 conditioning + 1 turn-over; 2 conditionings + 1 turn-over; no conditioning + 1 turn-over and no conditioning + 2 turn-overs) and 11 sampling times (0, 3, 15, 18, 21, 24, 39, 42, 45 and 47 hours after the cutting), with six replicates. For the bromatological composition and fungi occurrence, the experimental design was completely randomized in a 4 × 3 factorial scheme with the four drying methods of Tifton 85 grass and three periods of evaluation (before the cutting, at the time of the baling and 30 days after storage) with six replicates. It was found that after the first hour after cutting and at the end of the period of dehydration, Tifton 85 plants that were treated with conditioners showed higher levels of dry matter. Stored hay that was treated with conditioners presented higher levels of acid detergent insoluble protein. Until baling, the drying methods did not alter the crude protein content of hay; however, after storage, the hay submitted only to turn-over showed crude protein content higher (13.90%) than those submitted to conditioners (9.94%). There was an increase in the occurrence of fungi after storage, but the application of conditioners and one turn-over resulted in lower CUF/g, compared with other treatments, enhancing the effect of conditioners on accelerating the dehydration rate and obtaining better hay storage conditions

Os objetivos do trabalho foram estimar a curva de desidratação em nove tempos (0, 3, 6, 9, 24, 27, 30, 33 e 46 horas após o corte), a relação folha/haste, número de folhas por haste de alfafa submetida a quatro manejos no processo de secagem. Também foram avaliadas a composição bromatológica e digestibilidade in vitro da matéria seca e parede celular do feno antes do armazenamento. Os métodos de secagem da alfafa foram: secagem a campo até 50% de MS e término da secagem em galpão arejado, secagem a campo sem nenhuma viragem; secagem com apenas uma viragem; secagem com duas viragens. O delineamento experimental foi inteiramente casualizado com quatro métodos de secagem e cinco repetições. A desidratação das folhas foi mais rápida em relação às hastes em todos os métodos de secagem. A secagem em galpão promoveu menor reidratação das plantas no período noturno, promovido pelo orvalho. Verificou-se que os fenos de plantas de alfafa que permaneceram ao sol e receberam as viragens apresentaram pior qualidade com redução nos teores de proteína bruta, aumento do FDN, FDA, NIDN e NIDA entretanto a digestibilidade in vitro da matéria seca e da parede celular não sofreram alteração com os diferentes métodos de desidratação (69,79 e 41,39%, respectivamente). Há acentuada queda de folhas e redução no número de folhas por haste com as viragens.

This trial aimed at determining the dehydration curve at nine times (0, 3, 6, 9, 24, 27, 30, 33 and 46 hours after cuting of the plants); the leaf/stem ratio and number of leaves per stem in alfalfa submitted to four managements during the drying process. It was also evaluated the bromatologic composition and in vitro digestibility of the dry matter and cell wall of alfalfa hay before storage. The drying methods applied for alfalfa were the following: drying in the field until 50% DM and drying conclusion in an airy shed; drying in the field without turning; drying with only one turning and drying with two turnings. The experimental design was completely randomized with four drying methods and five replications. Leaf dehydration was faster when compared to the stems in all drying methods. Drying in the shed promoted the lesser re-hydration of the plants at night due to dew. It was also verified that alfalfa hays that remained under the sun and were turned showed the worst quality with reduction in crude protein contents and increase in NDF, ADF, NDIN and ADIN. However, in vitro dry matter digestibility and cell wall digestibility did not suffer any alteration because of the different dehydration methods (69.79 and 41.39%, respectively). There is a market fall of leaves and a reduction on the number of leaves per stem with the turnings.

Avaliaram-se os efeitos de diferentes tipos de cobertura morta de solo de origem vegetal sobre o crescimento, controle de plantas daninhas, produtividade e regime hidrotérmico do solo no cultivo da cenoura, cultivar Brasília, em um experimento conduzido no período de setembro a dezembro de 1998, em Marília, SP. O delineamento experimental utilizado foi o de blocos casualizados, com cinco tratamentos e quatro repetições em parcelas de 2 m². Estudou-se os seguintes tipos de cobertura: serragem de madeira, casca de arroz, maravalha (raspa de madeira), capim seco (Cynodon spp.) e controle (solo sem cobertura morta). A utilização da cobertura morta de solo mostrou-se como uma prática vantajosa para o cultivo de verão da cenoura, reduziu a temperatura em até 3,5ºC, aumentou a retenção de umidade do solo em até 2,3% em relação ao controle e melhorou o desenvolvimento das plantas de cenoura. Houve menor incidência de plantas daninhas com o uso de maravalha e capim seco que, juntamente com a serragem também aumentaram o número de plantas colhidas. Entre os tipos de cobertura morta utilizados, a casca de arroz e a maravalha se destacaram em relação ao solo descoberto como os materiais que proporcionaram maior produtividade (112,6 e 99,6 t/ha respectivamente). O uso de cobertura morta de solo mostrou-se vantajoso em vários aspectos para cultura da cenoura, sendo técnica e economicamente viável, principalmente, em pequenas áreas e em cultivos orgânicos.

The effects of different mulches were evalueted on carrot culture, cultivar Brasilia, in a experiment carried out at Marilia, São Paulo State, Brazil, from september to december/1998. The experimental design was a randomized block with four replications and size plots of 2 m². Wood dust, wood chips, dry grass (Cynodon spp.), rice straw and control (soil without cover) were tested and their effects on the soil hidrothermal regime, weed control, growth and yield of carrot were determined. Mulching materials showed better carrots plants development, mild soil temperature (3,5°C less control trait) and better soil moisture (2,3% high control trait). Dry grass and wood chips showed lower weed infestation and dry grass, wood chips and wood dust increased carrot stand. Mulches with rice straw and wood increased carrot yield (112,6 e 99,6 t/ha respectively). Mulching use is technically and economically viable for carrot growing, mainly in small areas and in organic farms.