Soil deep tillage performed before soybean cultivation on the rice cultivation in the following harvest / Efeito remanescente da escarificação do solo realizada antes do cultivo da soja, sobre o cultivo de arroz na safra seguinte

ABSTRACT: Soil decompaction is an alternative for soybean cultivation in rice areas, but it can affect the growth of irrigated rice in rotation. The objective of the study was to evaluate the effects of soil deep tillage performed before soybean cultivation on rice irrigation water, grain yield, and operational parameters of rice sowing carried out in the following crop season. Soil scarification was implemented in September 2017, prior to soybean crop season in the 2017/18 crop, and the rice experiment was conducted in the 2018/19 season. Treatments were: soil with scarification and soil without scarification. Deep tillage decreased soil density and increased macroporosity, microporosity, and total porosity. Rice cultivation decreased macroporosity and increased microporosity. Soil scarification management had no influence on operational parameters in rice sowing. Soil with scarification required 5.3% more water for rice irrigation than soil without deep tillage. In conclusion, soildeep tillage before the cultivation of soybean crop has effects on rice in thefollowing crop season, maintaining greater soil porosity in relation to the non-deep tillage area and increasing the amount of water needed for irrigation of rice cultivated in the sequence. Deep tillage did not affect sowing operational parameters and rice grain yield.

RESUMO: A descompactação do solo é uma alternativa para o cultivo da soja em áreas de arroz, mas pode afetar o desenvolvimento do arroz irrigado em rotação. O objetivo do estudo foi avaliar o efeito remanescente da escarificação do solo realizada antes do cultivo da soja, sobre o uso da água de irrigação, o rendimento de grãos e parâmetros operacionais da semeadura do arroz, realizada na safra seguinte. A escarificação do solo foi feita no mês de setembro de 2017, anteriormente à soja na safra 2017/18 e o experimento de arroz foi conduzido na safra 2018/19. Os tratamentos foram:escarificação e não escarificação do solo. A escarificação aumentou a macroporosidade, a microporosidade e a porosidade total e diminuiu a densidade do solo. O cultivo do arroz reduziu a macroporosidade e aumentou a microporosidade. Não se observou influência do manejo de escarificação do solo sobre os parâmetros operacionais na semeadura do arroz. O solo escarificado necessitou 5,3 % a mais de água para irrigação do arroz, em relação ao solo não escarificado. Conclui-se que a escarificação do solo antes do cultivo da cultura da soja tem efeito remanescente em arroz na safra seguinte, mantendo maior porosidade do solo em relação à área não escarificada e elevando a quantidade de água necessária para irrigação do arroz cultivado na sequência. Não se verificou interferência da escarificação em parâmetros operacionais da semeadura e sobre o rendimento de grãos do arroz.

Soil deep tillage performed before soybean cultivation on the rice cultivation in the following harvest / Efeito remanescente da escarificação do solo realizada antes do cultivo da soja, sobre o cultivo de arroz na safra seguinte

Soil decompaction is an alternative for soybean cultivation in rice areas, but it can affect the growth of irrigated rice in rotation. The objective of the study was to evaluate the effects of soil deep tillage performed before soybean cultivation on rice irrigation water, grain yield, and operational parameters of rice sowing carried out in the following crop season. Soil scarification was implemented in September 2017, prior to soybean crop season in the 2017/18 crop, and the rice experiment was conducted in the 2018/19 season. Treatments were: soil with scarification and soil without scarification. Deep tillage decreased soil density and increased macroporosity, microporosity, and total porosity. Rice cultivation decreased macroporosity and increased microporosity. Soil scarification management had no influence on operational parameters in rice sowing. Soil with scarification required 5.3% more water for rice irrigation than soil without deep tillage. In conclusion, soildeep tillage before the cultivation of soybean crop has effects on rice in thefollowing crop season, maintaining greater soil porosity in relation to the non-deep tillage area and increasing the amount of water needed for irrigation of rice cultivated in the sequence. Deep tillage did not affect sowing operational parameters and rice grain yield.

A descompactação do solo é uma alternativa para o cultivo da soja em áreas de arroz, mas pode afetar o desenvolvimento do arroz irrigado em rotação. O objetivo do estudo foi avaliar o efeito remanescente da escarificação do solo realizada antes do cultivo da soja, sobre o uso da água de irrigação, o rendimento de grãos e parâmetros operacionais da semeadura do arroz, realizada na safra seguinte. A escarificação do solo foi feita no mês de setembro de 2017, anteriormente à soja na safra 2017/18 e o experimento de arroz foi conduzido na safra 2018/19. Os tratamentos foram:escarificação e não escarificação do solo. A escarificação aumentou a macroporosidade, a microporosidade e a porosidade total e diminuiu a densidade do solo. O cultivo do arroz reduziu a macroporosidade e aumentou a microporosidade. Não se observou influência do manejo de escarificação do solo sobre os parâmetros operacionais na semeadura do arroz. O solo escarificado necessitou 5,3 % a mais de água para irrigação do arroz, em relação ao solo não escarificado. Conclui-se que a escarificação do solo antes do cultivo da cultura da soja tem efeito remanescente em arroz na safra seguinte, mantendo maior porosidade do solo em relação à área não escarificada e elevando a quantidade de água necessária para irrigação do arroz cultivado na sequência. Não se verificou interferência da escarificação em parâmetros operacionais da semeadura e sobre o rendimento de grãos do arroz.

Soil spiders (Arachnida: Araneae) in native and reforested Araucaria forests

Spiders are part of the soil biodiversity, considered fundamental to the food chain hierarchy, directly and indirectly influencing several services in agricultural and forest ecosystems. The present study aimed to evaluate the biodiversity of soil spider families and identify which soil properties influence their presence, as well as proposing families as potential bioindicators. Native forest (NF) and reforested sites (RF) with Araucaria angustifolia (Bertol.) Kuntze were evaluated in three regions of the state São Paulo, both in the winter and summer. Fifteen soil samples were collected from each forest to evaluate the biological (spiders and microbiological), chemical and physical soil properties, in addition to properties of the litter (dry matter and C, N and S contents). For soil spiders, two sampling methods were used: pitfall traps and soil monoliths. In total, 591 individuals were collected, and distributed in 30 families, of which 306 individuals (22 families) came from pitfall traps and 285 individuals (26 families) from monoliths. Only samples obtained by the monolith method revealed seasonal differences in the mean density and richness of spiders between NF and RF. Canonical discriminant analysis showed the separation of these forests of Araucaria. Principal Component Analysis demonstrated the correlation of a number of spider families with certain soil properties (organic carbon, basal respiration, metabolic quotient, litter carbon, total porosity, bulk density and soil moisture). We identified 10 families (Anapidae, Corinnidae, Dipluridae, Hahniidae, Linyphiidae, Lycosidae, Nemesiidae, Palpimanidae, Salticidae, Scytodidae) that contributed most to separating native forest from the replanted forest, indicating the possibility of the spiders being used as bioindicators.

Soil spiders (Arachnida: Araneae) in native and reforested Araucaria forests

Spiders are part of the soil biodiversity, considered fundamental to the food chain hierarchy, directly and indirectly influencing several services in agricultural and forest ecosystems. The present study aimed to evaluate the biodiversity of soil spider families and identify which soil properties influence their presence, as well as proposing families as potential bioindicators. Native forest (NF) and reforested sites (RF) with Araucaria angustifolia (Bertol.) Kuntze were evaluated in three regions of the state São Paulo, both in the winter and summer. Fifteen soil samples were collected from each forest to evaluate the biological (spiders and microbiological), chemical and physical soil properties, in addition to properties of the litter (dry matter and C, N and S contents). For soil spiders, two sampling methods were used: pitfall traps and soil monoliths. In total, 591 individuals were collected, and distributed in 30 families, of which 306 individuals (22 families) came from pitfall traps and 285 individuals (26 families) from monoliths. Only samples obtained by the monolith method revealed seasonal differences in the mean density and richness of spiders between NF and RF. Canonical discriminant analysis showed the separation of these forests of Araucaria. Principal Component Analysis demonstrated the correlation of a number of spider families with certain soil properties (organic carbon, basal respiration, metabolic quotient, litter carbon, total porosity, bulk density and soil moisture). We identified 10 families (Anapidae, Corinnidae, Dipluridae, Hahniidae, Linyphiidae, Lycosidae, Nemesiidae, Palpimanidae, Salticidae, Scytodidae) that contributed most to separating native forest from the replanted forest, indicating the possibility of the spiders being used as bioindicators.(AU)

O cultivo do milheto com água salobra e adubação orgânica altera as características do solo / Pearl millet cultivation with brackish water and organic fertilizer alters soil properties

Regiões semiáridas são caracterizadas pela elevada evapotranspiração e baixa precipitação pluvial, favorecendo o acúmulo de sais quando irrigado com água salobra. Objetivou se avaliar o efeito do cultivo de milheto com níveis de água salobra e fertilização orgânica nas propriedades químicas e físicas do solo. Adotou-se o delineamento de blocos ao acaso, com arranjo fatorial, em parcelas subdivididas, com três repetições. As parcelas foram constituídas por quatro lâminas de irrigação (25, 50, 75 e 100% da evapotranspiração da cultura) e as subparcelas foram compostas por quatro níveis de fertilização orgânica (0; 15; 30 e 45 Mg ha-1). No final do ciclo de produção do milheto, o solo foi coletado nas camadas de 0-0.20 e 0.20-0.40 m, para aspectos físicos (densidade do solo, densidade de partículas e porosidade) e químicos (CE, pH, K, Na, Ca, Mg, H + Al, SB, CTC, V). Não houve interação entre a água salobra e a fertilização orgânica nas propriedades químicas do solo. A água salobra reduziu o potássio na camada de 0,20-0,.40 m. Observou-se efeito linear negativo para densidade na camada 0,20 - 0,40 m sob níveis de fertilização orgânica. Níveis de água salobra e fertilizante orgânico no cultivo do milheto não altera as propriedades químicas e físicas do solo na camada de 0-0,20 m. Porém, o uso de água salobra reduz a concentração de potássio no solo e a aplicação de fertilização orgânica reduz a densidade do solo na camada de 0.20-0,40 m.

Semi-arid regions are characterized by high evapotranspiration and low rainfall, favoring the accumulation of salts when irrigated with brackish water. The aim of this study was to evaluate the effect of pearl millet cultivation with brackish water levels and fertilized with organic fertilizer on the chemical and physical properties of the soil. A split plot randomized block design was adopted, in a factorial arrangement, with three repetitions. Plots consisted of four irrigation levels (25, 50, 75 and 100% crop evapotranspiration) and subplots consisted of four levels of organic fertilizer (0; 15; 30 and 45 Mg ha-¹). At the end of the pearl millet production cycle, soil was collected from layers 0-0.20 m and 0.20-0.40 m, for physical (soil bulk density, particle density and porosity) and chemical (EC, pH, K, Na, Ca, Mg, H + Al, SB, CEC, V) properties. There was no effect of interaction of brackish water levels and organic fertilizer levels on soil chemical properties. Brackish water reduced potassium on layer 0.20-0.40 m. A negative linear effect was found for density in the 0.20-0.40 m layer under different levels of organic fertilizer. Brackish water levels and organic fertilizer levels in the cultivation of pearl millet does not alter soil chemical and physical properties at the 0-0.20 m layer. However, the use of brackish water reduces the concentration of potassium in the soil and the application of organic fertilizer reduces soil density at the 0.20-0.40 m layer.

Pearl millet cultivation with brackish water and organic fertilizer alters soil properties / O cultivo do milheto com água salobra e adubação orgânica altera as características do solo

Semi-arid regions are characterized by high evapotranspiration and low rainfall, favoring the accumulation of salts when irrigated with brackish water. The aim of this study was to evaluate the effect of pearl millet cultivation with brackish water levels and fertilized with organic fertilizer on the chemical and physical properties of the soil. A split plot randomized block design was adopted, in a factorial arrangement, with three repetitions. Plots consisted of four irrigation levels (25, 50, 75 and 100% crop evapotranspiration) and subplots consisted of four levels of organic fertilizer (0; 15; 30 and 45 Mg ha-1). At the end of the pearl millet production cycle, soil was collected from layers 0-0.20 m and 0.20-0.40 m, for physical (soil bulk density, particle density and porosity) and chemical (EC, pH, K, Na, Ca, Mg, H + Al, SB, CEC, V) properties. There was no effect of interaction of brackish water levels and organic fertilizer levels on soil chemical properties. Brackish water reduced potassium on layer 0.20-0.40 m. A negative linear effect was found for density in the 0.20-0.40 m layer under different levels of organic fertilizer. Brackish water levels and organic fertilizer levels in the cultivation of pearl millet does not alter soil chemical and physical properties at the 0-0.20 m layer. However, the use of brackish water reduces the concentration of potassium in the soil and the application of organic fertilizer reduces soil density at the 0.20-0.40 m layer.

Regiões semiáridas são caracterizadas pela elevada evapotranspiração e baixa precipitação pluvial, favorecendo o acúmulo de sais quando irrigado com água salobra. Objetivouse avaliar o efeito do cultivo de milheto com níveis de água salobra e fertilização orgânica nas propriedades químicas e físicas do solo. Adotou-se o delineamento de blocos ao acaso, com arranjo fatorial, em parcelas subdivididas, com três repetições. As parcelas foram constituídas por quatro lâminas de irrigação (25, 50, 75 e 100% da evapotranspiração da cultura) e as subparcelas foram compostas por quatro níveis de fertilização orgânica (0; 15; 30 e 45 Mg ha-1). No final do ciclo de produção do milheto, o solo foi coletado nas camadas de 0-0.20 e 0.20-0.40 m, para aspectos físicos (densidade do solo, densidade de partículas e porosidade) e químicos (CE, pH, K, Na, Ca, Mg, H + Al, SB, CTC, V). Não houve interação entre a água salobra e a fertilização orgânica nas propriedades químicas do solo. A água salobra reduziu o potássio na camada de 0,20-0,.40 m. Observou-se efeito linear negativo para densidade na camada 0,20 - 0,40 m sob níveis de fertilização orgânica. Níveis de água salobra e fertilizante orgânico no cultivo do milheto não altera as propriedades químicas e físicas do solo na camada de 0-0,20 m. Porém, o uso de água salobra reduz a concentração de potássio no solo e a aplicação de fertilização orgânica reduz a densidade do solo na camada de 0.20-0,40 m.

Least limiting water range, S-index and compressibility of a Udalf under different management systems

Agricultural areas in the region of Turuçu, on the Southeast Hillside in the state of Rio Grande do Sul (RS), Brazil present many examples of soil physical degradation. Accordingly, strategies aimed at evaluating and ameliorating the structural quality of soils should be developed to ensure the sustainable use of these areas. This study aimed to evaluate the least limiting water range (LLWR), S-index, compressibility parameters, organic carbon and the organic matter granulometric fractions of a Udalf under different agricultural uses. Soil samples with disturbed and non-disturbed structure from the 0.00 to 0.10 m layer were collected on farms in the Southeast Hillside, Turuçu region, RS, for analyzing soil under: i) conventional system of corn after tobacco crop, (CT); ii) conventional system of corn after native field (CNF), iii) native field (NF) and iv) native area (NA). Both the CT and the CNF systems had a negative influence on the values of bulk density, soil porosity, least limiting water range, compressibility parameters and total organic carbon, coarse fraction carbon and carbon associated with minerals.

Least limiting water range, S-index and compressibility of a Udalf under different management systems

Agricultural areas in the region of Turuçu, on the Southeast Hillside in the state of Rio Grande do Sul (RS), Brazil present many examples of soil physical degradation. Accordingly, strategies aimed at evaluating and ameliorating the structural quality of soils should be developed to ensure the sustainable use of these areas. This study aimed to evaluate the least limiting water range (LLWR), S-index, compressibility parameters, organic carbon and the organic matter granulometric fractions of a Udalf under different agricultural uses. Soil samples with disturbed and non-disturbed structure from the 0.00 to 0.10 m layer were collected on farms in the Southeast Hillside, Turuçu region, RS, for analyzing soil under: i) conventional system of corn after tobacco crop, (CT); ii) conventional system of corn after native field (CNF), iii) native field (NF) and iv) native area (NA). Both the CT and the CNF systems had a negative influence on the values of bulk density, soil porosity, least limiting water range, compressibility parameters and total organic carbon, coarse fraction carbon and carbon associated with minerals.(AU)

Soil retraction and relationship with the physical properties and organic matter of Latossolos and Nitossolos of the South of Brazil / Retração do solo e relação com as propriedades físicas e matéria orgânica de Latossolos e Nitossolos do Sul do Brasil

Recent studies have shown that the main origin factor of the retractable character observed in Latossolos and Nitossolos is not mineralogy. Thus, it was hypothesized that soil shrinkage in Latossolos and Nitossolos originates from soil structural factors, so they can be investigated indirectly through the physical properties of soil structure. Thus, the objective of this work was to relate the shrinkage with physical properties and the organic matter of the soil, indirectly investigating the process of soil shrinkage. Six profiles collected in the states of Santa Catarina and Rio Grande do Sul were selected, which have a retractable character and one Vertissolo Ebânico in Rio Grande do Sul. The following were evaluated: particle size, consistency limits, soil and particle density, total porosity, micropores. and macropores, specific surface area, shrinkage index, soil organic matter and soil water retention. The relationship between the properties was performed through principal component analysis (PCA). Additionally, to analyze the effect of structure and organic matter on shrinkage index, samples were collected on the A, AB, BA, Bt1, Bt2, Bt3 horizons of the Nitossolo Bruno of Painel, which has a natural gradient of matter decrease organic in profile. In this, the retention curve and shrinkage index determinations were performed with preserved and altered structure samples

Estudos recentes apontaram que o principal fator de origem do caráter retrátil, observado em Latossolos e Nitossolos, não é a mineralogia. Com isso formulou-se a hipótese de que a retração do solo em Latossolos e Nitossolos tem origem em fatores estruturais do solo, portanto podem ser investigados indiretamente através das propriedades físicas da estrutura do solo. Sendo assim o objetivo deste trabalho foi relacionar a retração com propriedades físicas e a matéria orgânica do solo, investigando de maneira indireta o processo de retração do solo. Foram selecionados seis perfis coletados nos Estados de Santa Catarina e no Rio Grande do Sul que apresentam caráter retrátil e um Vertissolo Ebânico no Rio Grande do Sul. Foram avaliados: granulometria, limites de consistência, densidade do solo e de partículas, porosidade total, microporos e macroporos, área superficial específica, índice de retração, matéria orgânica do solo e retenção de água no solo. A relação entre as propriedades foi realizada através de análise de componentes principais (ACP). Adicionalmente, para analisar o efeito da estrutura e da matéria orgânica no índice de retração, e amostras foram coletadas nos horizontes A, AB, BA, Bt1, Bt2, Bt3 do Nitossolo Bruno de Painel, o qual possui um gradiente natural de decréscimo de matéria orgânica no perfil. Neste, as determinações da curva de retenção e índice de retração

Soil retraction and relationship with the physical properties and organic matter of Latossolos and Nitossolos of the South of Brazil / Retração do solo e relação com as propriedades físicas e matéria orgânica de Latossolos e Nitossolos do Sul do Brasil

Recent studies have shown that the main origin factor of the retractable character observed in Latossolos and Nitossolos is not mineralogy. Thus, it was hypothesized that soil shrinkage in Latossolos and Nitossolos originates from soil structural factors, so they can be investigated indirectly through the physical properties of soil structure. Thus, the objective of this work was to relate the shrinkage with physical properties and the organic matter of the soil, indirectly investigating the process of soil shrinkage. Six profiles collected in the states of Santa Catarina and Rio Grande do Sul were selected, which have a retractable character and one Vertissolo Ebânico in Rio Grande do Sul. The following were evaluated: particle size, consistency limits, soil and particle density, total porosity, micropores. and macropores, specific surface area, shrinkage index, soil organic matter and soil water retention. The relationship between the properties was performed through principal component analysis (PCA). Additionally, to analyze the effect of structure and organic matter on shrinkage index, samples were collected on the A, AB, BA, Bt1, Bt2, Bt3 horizons of the Nitossolo Bruno of Painel, which has a natural gradient of matter decrease organic in profile. In this, the retention curve and shrinkage index determinations were performed with preserved and altered structure samples(AU)

Estudos recentes apontaram que o principal fator de origem do caráter retrátil, observado em Latossolos e Nitossolos, não é a mineralogia. Com isso formulou-se a hipótese de que a retração do solo em Latossolos e Nitossolos tem origem em fatores estruturais do solo, portanto podem ser investigados indiretamente através das propriedades físicas da estrutura do solo. Sendo assim o objetivo deste trabalho foi relacionar a retração com propriedades físicas e a matéria orgânica do solo, investigando de maneira indireta o processo de retração do solo. Foram selecionados seis perfis coletados nos Estados de Santa Catarina e no Rio Grande do Sul que apresentam caráter retrátil e um Vertissolo Ebânico no Rio Grande do Sul. Foram avaliados: granulometria, limites de consistência, densidade do solo e de partículas, porosidade total, microporos e macroporos, área superficial específica, índice de retração, matéria orgânica do solo e retenção de água no solo. A relação entre as propriedades foi realizada através de análise de componentes principais (ACP). Adicionalmente, para analisar o efeito da estrutura e da matéria orgânica no índice de retração, e amostras foram coletadas nos horizontes A, AB, BA, Bt1, Bt2, Bt3 do Nitossolo Bruno de Painel, o qual possui um gradiente natural de decréscimo de matéria orgânica no perfil. Neste, as determinações da curva de retenção e índice de retração(AU)

Changes in soil chemical and physical properties in pasture fertilised with liquid swine manure

Chemical and physical properties of soil can be altered with the successive application of liquid swine manure (LSM), also known as slurry. Therefore, monitoring the impact of LSM is essential to an assessment of the potential agronomic and environmental benefits and risks associated with management practices. The aim of this study was to evaluate the effects of LSM on the chemical and physical attributes of soil under pasture (Cynodon spp.), located in southern Brazil. Four areas were sampled: three areas cultivated with Cynodon spp. pasture with successive applications of 200 m3 ha1 y1 of LSM for three, eight and 15 years; and untreated native forest as a reference. The soil attributes evaluated were: organic carbon (OC), active (pH water) and potential acidity (H + Al+ 3), nutrient availability (i.e., P, K, Ca, Mg, Cu and Zn), soil bulk density, macro, micro and total porosity. Successive applications of LSM on pasture reduced soil active acidity, and increased the soil organic C and plant-available N, P, Ca, Mg, Cu and Zn contents. These effects were more intense with time and in the shallowest layers, i.e. 0-10 cm. Excessive increases in P, Cu and Zn in the soil should be carefully monitored to minimize the contamination risks to soil, ground and surface waters. Soil physical attribute changes were more associated with land use (pasture versus native forest) than LSM use, and LSM applications induced slight improvements in the soil structural quality over time.

Changes in soil chemical and physical properties in pasture fertilised with liquid swine manure

Chemical and physical properties of soil can be altered with the successive application of liquid swine manure (LSM), also known as slurry. Therefore, monitoring the impact of LSM is essential to an assessment of the potential agronomic and environmental benefits and risks associated with management practices. The aim of this study was to evaluate the effects of LSM on the chemical and physical attributes of soil under pasture (Cynodon spp.), located in southern Brazil. Four areas were sampled: three areas cultivated with Cynodon spp. pasture with successive applications of 200 m3 ha1 y1 of LSM for three, eight and 15 years; and untreated native forest as a reference. The soil attributes evaluated were: organic carbon (OC), active (pH water) and potential acidity (H + Al+ 3), nutrient availability (i.e., P, K, Ca, Mg, Cu and Zn), soil bulk density, macro, micro and total porosity. Successive applications of LSM on pasture reduced soil active acidity, and increased the soil organic C and plant-available N, P, Ca, Mg, Cu and Zn contents. These effects were more intense with time and in the shallowest layers, i.e. 0-10 cm. Excessive increases in P, Cu and Zn in the soil should be carefully monitored to minimize the contamination risks to soil, ground and surface waters. Soil physical attribute changes were more associated with land use (pasture versus native forest) than LSM use, and LSM applications induced slight improvements in the soil structural quality over time.(AU)

Water retention and penetration resistance equations for the least limiting water range

he least limiting water range is a soil physical quality indicator, which is useful to predict the optimum water range for plant growth in a given soil and to study the effects of soil use and management over this optimum water range by integrating the effects of available water, penetration resistance and air filled porosity. This study tested six equations to fit water retention and penetration resistance surface responses used to determine the least limiting water range and present a simple algorithm written in the open source software R for fitting, calculation and visualization of the least limiting water range. Five soils from Brazil and Canada, under different use and management conditions were used to test the functions. The results show that the three water retention surface responses had good statistical properties for fitting water retention and that two of the penetration resistance surface responses were adequate to fit the data, while one failed to achieve convergence in two instances. The open source code performed as well as the commercial statistical package SAS for fitting the penetration resistance and water retention equations.

Water retention and penetration resistance equations for the least limiting water range

he least limiting water range is a soil physical quality indicator, which is useful to predict the optimum water range for plant growth in a given soil and to study the effects of soil use and management over this optimum water range by integrating the effects of available water, penetration resistance and air filled porosity. This study tested six equations to fit water retention and penetration resistance surface responses used to determine the least limiting water range and present a simple algorithm written in the open source software R for fitting, calculation and visualization of the least limiting water range. Five soils from Brazil and Canada, under different use and management conditions were used to test the functions. The results show that the three water retention surface responses had good statistical properties for fitting water retention and that two of the penetration resistance surface responses were adequate to fit the data, while one failed to achieve convergence in two instances. The open source code performed as well as the commercial statistical package SAS for fitting the penetration resistance and water retention equations.(AU)

Distribuição do tamanho de poros em um Latossolo Vermelho em sistema integrado de produção agropecuária / Distribution of size of pores in a Oxisolin an integrated system of agricultural production

Os sistemas integrados de produção agropecuária visam a sustentabilidade, procurando explorar o máximo da área, além de diminuir os impactos sobre as propriedades do solo. O presente trabalho teve objetivo estudar a distribuição do tamanho de poros de um Latossolo Vermelho em um sistema integrado de produção agropecuária após três anos de implantação do sistema. O experimento foi realizado na Fazenda pertencente ao grupo Facholi, no município de Caiuá/SP. O delineamento experimental utilizado foi em blocos casualizados, com três repetições e compostos por 7 tratamentos: 1 - Soja–Milho + B. ruziziensis (pastejo); 2 - Soja – Milho + Piatã (pastejo); 3 - Soja – Milho + Paiaguás (pastejo); 4 - Soja - Piatã (pastejo 2 anos) – Soja - Piatã (pastejo); 5 - Soja - Paiaguás (pastejo 2 anos) – Soja - Paiaguás (pastejo); 6 -Soja – milho (Plantio direto); 7 - Soja – milho (Preparo convencional). Foram realizadas as avaliações dos seguintes atributos do solo: macroporosidade, microporosidade, porosidade total e densidade do solo, em duas camadas do solo; 0,00-0,10 e 0,10-0,20 m de profundidade, em três épocas de coleta, utilizando o teste Tukey a 5% de probabilidade para a comparação de médias. Os resultados mostram que a macroporosidade aumentou com o tempo (3 anos de avaliação), e houve uma diminuição da densidade do solo, mostrando que os sistemas avaliados influenciaram positivamente os atributos do solo estudados. De forma geral, todos ao tratamentos aumentaram a macroporosidade em relação a caracterização inicial, com destaque para os tratamentos soja+piatã e soja+milho+piatã, camada de 0-0,10m que obtiveram valores médios superiores aos demais.

Integrated agricultural production systems aim at sustainability, seeking to exploit the maximum of the area, as well as reducing impacts on soil properties. The objective of this work was to study the distribution of pore size of an Oxisol in an integrated agricultural production system after three years of system implantation. The experiment was carried out at Fazenda belonging to the Facholi group, in the municipality of Caiuá / SP. The experimental design was a randomized complete block with three replicates and composed of 7 treatments: 1 - Soya - Maize + B. ruziziensis (grazing); 2 - Soybean - Maize + Piatã (grazing); 3 -Soya - Maize + Paiaguás (grazing); 4 - Soya - Piatã (grazing 2 years) - Soya - Piatã (grazing); 5 - Soybean - Paiaguás (grazing 2 years) - Soybean - Paiaguás (grazing); 6 - Soybean - maize (Direct planting); 7 - Soybean - corn (Conventional preparation). The following soil attributes were evaluated: macroporosity, microporosity, total porosity and soil density in two depths of soil; 0.00-0.10 and 0.10-0.20 m depth, in three sampling periods, using the Tukey test at 5% probability for the comparison of means. The results show that the macroporosity increased with time(3 years of evaluation), and there was a decrease in soil density, showing that the evaluated systems positively influenced the soil attributes studied. In general, all treatments increased the macroporosity in relation to the initial characterization, especially the soybean + piatan and soy + maize + piatã treatments, 0-0.10 m depth, which obtained higher, average values than the others.

Distribuição do tamanho de poros em um Latossolo Vermelho em sistema integrado de produção agropecuária / Distribution of size of pores in a Oxisolin an integrated system of agricultural production

Os sistemas integrados de produção agropecuária visam a sustentabilidade, procurando explorar o máximo da área, além de diminuir os impactos sobre as propriedades do solo. O presente trabalho teve objetivo estudar a distribuição do tamanho de poros de um Latossolo Vermelho em um sistema integrado de produção agropecuária após três anos de implantação do sistema. O experimento foi realizado na Fazenda pertencente ao grupo Facholi, no município de Caiuá/SP. O delineamento experimental utilizado foi em blocos casualizados, com três repetições e compostos por 7 tratamentos: 1 - Soja–Milho + B. ruziziensis (pastejo); 2 - Soja Milho + Piatã (pastejo); 3 - Soja Milho + Paiaguás (pastejo); 4 - Soja - Piatã (pastejo 2 anos) Soja - Piatã (pastejo); 5 - Soja - Paiaguás (pastejo 2 anos) Soja - Paiaguás (pastejo); 6 -Soja milho (Plantio direto); 7 - Soja milho (Preparo convencional). Foram realizadas as avaliações dos seguintes atributos do solo: macroporosidade, microporosidade, porosidade total e densidade do solo, em duas camadas do solo; 0,00-0,10 e 0,10-0,20 m de profundidade, em três épocas de coleta, utilizando o teste Tukey a 5% de probabilidade para a comparação de médias. Os resultados mostram que a macroporosidade aumentou com o tempo (3 anos de avaliação), e houve uma diminuição da densidade do solo, mostrando que os sistemas avaliados influenciaram positivamente os atributos do solo estudados. De forma geral, todos ao tratamentos aumentaram a macroporosidade em relação a caracterização inicial, com destaque para os tratamentos soja+piatã e soja+milho+piatã, camada de 0-0,10m que obtiveram valores médios superiores aos demais.(AU)

Integrated agricultural production systems aim at sustainability, seeking to exploit the maximum of the area, as well as reducing impacts on soil properties. The objective of this work was to study the distribution of pore size of an Oxisol in an integrated agricultural production system after three years of system implantation. The experiment was carried out at Fazenda belonging to the Facholi group, in the municipality of Caiuá / SP. The experimental design was a randomized complete block with three replicates and composed of 7 treatments: 1 - Soya - Maize + B. ruziziensis (grazing); 2 - Soybean - Maize + Piatã (grazing); 3 -Soya - Maize + Paiaguás (grazing); 4 - Soya - Piatã (grazing 2 years) - Soya - Piatã (grazing); 5 - Soybean - Paiaguás (grazing 2 years) - Soybean - Paiaguás (grazing); 6 - Soybean - maize (Direct planting); 7 - Soybean - corn (Conventional preparation). The following soil attributes were evaluated: macroporosity, microporosity, total porosity and soil density in two depths of soil; 0.00-0.10 and 0.10-0.20 m depth, in three sampling periods, using the Tukey test at 5% probability for the comparison of means. The results show that the macroporosity increased with time(3 years of evaluation), and there was a decrease in soil density, showing that the evaluated systems positively influenced the soil attributes studied. In general, all treatments increased the macroporosity in relation to the initial characterization, especially the soybean + piatan and soy + maize + piatã treatments, 0-0.10 m depth, which obtained higher, average values than the others.(AU)

Water erosion in a Haplic Dystrudept soil after application of swine slurry / Erosão hídrica em um Cambissolo Háplico após aplicação de dejeto líquido de suínos

Water (WL), soil (SL), phosphorus (P) and potassium (K) losses by water erosion and subsurface flow are influenced by soil management and by soil fertilization with swine slurry (SS). The study was conducted between 09/2014 and 11/2015, in a Haplic Dystrudept, to evaluate the 0 (zero), 50, 100 and 200 m³ ha-1 SS doses applied to millet (Pennisetum americanum), black oats (Avena strigosa) and crotalaria (Crotalaria ochroleuca), compared with a soil without cultivation and without SS. The soil total porosity (Tp) and macroporosity (Ma), the P and K concentration in the soil, in the runoff, and in the subsurface flow, the dry mass of the aerial part (DM) of crops, and the WL and SL were determined. The main results show the application of SS in the soil results in an increase in Tp and Ma, as well as in the concentration of P and K in the soil and the DM of the plants, in relation to the absence of SS. Water erosion decreases with an increased dose of SS applied to the soil in the interval between 50 and 200 m3 ha-1. The increase in the dose of SS increases the concentration and total losses of P and K in the runoff and decreases the concentration of these nutrients in the subsurface flow in the interval between 50 and 200 m3 ha-1. The increase of DM of the plants, in the interval between 13.75 and 22.82 t ha-1, decreases SL at an average rate of 2.90 t ha-1. The concentration of K in the subsurface flow water was negatively related to the concentration of the element in the subsurface flow.

As perdas de água, solo, fósforo (P) e potássio (K) por erosão hídrica e escoamento subsuperficial são influenciadas pelo manejo e fertilização do solo com dejeto líquido de suínos (DLS). A pesquisa foi conduzida em 09/2014 e 11/2015, em um Cambissolo Háplico, para avaliar as doses 0 (zero), 50, 100 e 200 m³ ha-1 de DLS aplicado no milheto (Pennisetum americanum), aveia preta (Avena strigosa) e crotalária (Crotalaria ochroleuca), em comparação ao solo sem cultivo e sem DLS. A porosidade total (PT) e macroporosidade (Ma) do solo, as concentrações de P e K no solo, na enxurrada e no escoamento subsuperficial, a massa seca da parte aérea das culturas (MS), e as PA e PS pela foram determinadas. Os principais resultados mostram que a aplicação de DLS no solo resulta em aumento da PT e Ma e da concentração de P e K no solo, além da MS das plantas, em relação à ausência de dejeto. A erosão hídrica diminui com o aumento da dose de DLS, no intervalo entre 50 e 200 m3 ha-1 do dejeto aplicado no solo em relação à dose de 50. O aumento da dose de DLS faz aumentar a concentração e as perdas totais de P e K no escoamento superficial e diminuir a concentração desses nutrientes no fluxo subsuperficial, no intervalo entre 50 e 200 m3 ha-1 de dejeto. O aumento de MS das plantas, no intervalo entre 13,75 e 22,82 t ha-1, faz diminuir as PS a uma taxa média de 2,90 t ha-1. A concentração de K na água do fluxo subsuperficial se relaciona negativamente com a concentração do elemento no escoamento superficial.

Water erosion in a Haplic Dystrudept soil after application of swine slurry / Erosão hídrica em um Cambissolo Háplico após aplicação de dejeto líquido de suínos

Water (WL), soil (SL), phosphorus (P) and potassium (K) losses by water erosion and subsurface flow are influenced by soil management and by soil fertilization with swine slurry (SS). The study was conducted between 09/2014 and 11/2015, in a Haplic Dystrudept, to evaluate the 0 (zero), 50, 100 and 200 m³ ha-1 SS doses applied to millet (Pennisetum americanum), black oats (Avena strigosa) and crotalaria (Crotalaria ochroleuca), compared with a soil without cultivation and without SS. The soil total porosity (Tp) and macroporosity (Ma), the P and K concentration in the soil, in the runoff, and in the subsurface flow, the dry mass of the aerial part (DM) of crops, and the WL and SL were determined. The main results show the application of SS in the soil results in an increase in Tp and Ma, as well as in the concentration of P and K in the soil and the DM of the plants, in relation to the absence of SS. Water erosion decreases with an increased dose of SS applied to the soil in the interval between 50 and 200 m3 ha-1. The increase in the dose of SS increases the concentration and total losses of P and K in the runoff and decreases the concentration of these nutrients in the subsurface flow in the interval between 50 and 200 m3 ha-1. The increase of DM of the plants, in the interval between 13.75 and 22.82 t ha-1, decreases SL at an average rate of 2.90 t ha-1. The concentration of K in the subsurface flow water was negatively related to the concentration of the element in the subsurface flow.(AU)

As perdas de água, solo, fósforo (P) e potássio (K) por erosão hídrica e escoamento subsuperficial são influenciadas pelo manejo e fertilização do solo com dejeto líquido de suínos (DLS). A pesquisa foi conduzida em 09/2014 e 11/2015, em um Cambissolo Háplico, para avaliar as doses 0 (zero), 50, 100 e 200 m³ ha-1 de DLS aplicado no milheto (Pennisetum americanum), aveia preta (Avena strigosa) e crotalária (Crotalaria ochroleuca), em comparação ao solo sem cultivo e sem DLS. A porosidade total (PT) e macroporosidade (Ma) do solo, as concentrações de P e K no solo, na enxurrada e no escoamento subsuperficial, a massa seca da parte aérea das culturas (MS), e as PA e PS pela foram determinadas. Os principais resultados mostram que a aplicação de DLS no solo resulta em aumento da PT e Ma e da concentração de P e K no solo, além da MS das plantas, em relação à ausência de dejeto. A erosão hídrica diminui com o aumento da dose de DLS, no intervalo entre 50 e 200 m3 ha-1 do dejeto aplicado no solo em relação à dose de 50. O aumento da dose de DLS faz aumentar a concentração e as perdas totais de P e K no escoamento superficial e diminuir a concentração desses nutrientes no fluxo subsuperficial, no intervalo entre 50 e 200 m3 ha-1 de dejeto. O aumento de MS das plantas, no intervalo entre 13,75 e 22,82 t ha-1, faz diminuir as PS a uma taxa média de 2,90 t ha-1. A concentração de K na água do fluxo subsuperficial se relaciona negativamente com a concentração do elemento no escoamento superficial.(AU)

Atributos físicos de um latossolo após o uso de doses de cama de frango acrescidas à adubação mineral / Physical attributes of a latosolo after the use of doses with poultry litter added mineral fertilization

Resíduos oriundos da atividade agroindustrial têm sido comumente utilizados na agropecuária, isolados ou mesmo associados a fertilizantes minerais, podendo alterar as propriedades físicas do solo. O presente trabalho objetivou avaliar os efeitos da utilização de fertilizantes minerais e combinados com cama de frango (CF) nos atributos físicos de um Latossolo. O experimento foi realizado em delineamento em blocos ao acaso, com 4 tratamentos e 5 repetições. Os tratamentos foram os seguintes: AM – Adubação mineral com 220 kg de 00-32-00 + 150 kg de KCl ha-¹; AM + 2 Mg ha-1 CF ; AM + 4 Mg CF; AM + 6 Mg CF. Após o quarto ano de utilização de cama de frango associada a fertilizantes minerais, coletou-se amostras para determinação de atributos físicos do solo nas profundidades de 0 - 0,05 m, 0,05 - 0,10 m e 0,10 - 0,20 m. A associação de cama de frango, com adubação mineral, nas maiores doses, tende a elevar o volume total de poros de 0,45 m³ m-³no tratamento AM, atingindo 0,53 m³ m-³no AM + 4 Mg ha-¹ CF. A microporosidade obteve comportamento semelhante ao VTP, saindo de 0,32 m³ m-³ no AM, atingindo 0,40 m³ m-³ no AM + 4 Mg ha-¹ CF. Contudo o diâmetro médio ponderado de agregados, foram reduzidos de 2,95 mm no AM, para 2,43 mm no AM + 6 Mg ha-¹ CF. A porcentagem de macroagregados foram reduzidas com a adição de maiores doses de cama de frango ao fertilizante mineral.

Wastes from agroindustrial activity have been commonly used in agriculture, isolated or even associated with mineral fertilizers, and can alter the physical properties of the soil. This study aimed to evaluate the effects of the use of mineral and combined fertilizers with poultry litter (CF) on the physical attributes of a Cerrado Latosol. The experiment was conducted in a randomized block design with four treatments and five replicates. The treatments were as follows: AM - Mineral fertilization with 220 kg of 00-32-00 + 150 kg of KCl ha-¹; AM + 2 Mg ha-¹ CF; AM + 4 Mg CF; AM + 6 Mg CF. After the fourth year of chicken litter use associated with mineral fertilizers, samples were collected to determine soil physical attributes at depths of 0 - 0.05 m, 0.05 - 0.10 m and 0.10 -0.20 m. The association of chicken litter, with mineral fertilization, at the highest doses tends to increase the total pore volume of 0.45 m³ m-³ in the AM treatment, reaching 0.53 m³ m-³ in the AM + 4 Mg ha-¹ CF. The microporosity obtained a similar behavior to VTP, going out 0.32 m³ m-³ in AM reaching 0.40 m³ m-³ in AM + 4 Mg ha-¹ CF. However the weighted average diameter of aggregates were reduced from 2.95 mm in AM to 2.43 mm in AM + 6 Mg ha-¹ CF. The percentage of macroaggregates was reduced with the addition of higher doses the poultry litter to mineral fertilizer.

Atributos físicos de um latossolo após o uso de doses de cama de frango acrescidas à adubação mineral / Physical attributes of a latosolo after the use of doses with poultry litter added mineral fertilization

Resíduos oriundos da atividade agroindustrial têm sido comumente utilizados na agropecuária, isolados ou mesmo associados a fertilizantes minerais, podendo alterar as propriedades físicas do solo. O presente trabalho objetivou avaliar os efeitos da utilização de fertilizantes minerais e combinados com cama de frango (CF) nos atributos físicos de um Latossolo. O experimento foi realizado em delineamento em blocos ao acaso, com 4 tratamentos e 5 repetições. Os tratamentos foram os seguintes: AM Adubação mineral com 220 kg de 00-32-00 + 150 kg de KCl ha-¹; AM + 2 Mg ha-1 CF ; AM + 4 Mg CF; AM + 6 Mg CF. Após o quarto ano de utilização de cama de frango associada a fertilizantes minerais, coletou-se amostras para determinação de atributos físicos do solo nas profundidades de 0 - 0,05 m, 0,05 - 0,10 m e 0,10 - 0,20 m. A associação de cama de frango, com adubação mineral, nas maiores doses, tende a elevar o volume total de poros de 0,45 m³ m-³no tratamento AM, atingindo 0,53 m³ m-³no AM + 4 Mg ha-¹ CF. A microporosidade obteve comportamento semelhante ao VTP, saindo de 0,32 m³ m-³ no AM, atingindo 0,40 m³ m-³ no AM + 4 Mg ha-¹ CF. Contudo o diâmetro médio ponderado de agregados, foram reduzidos de 2,95 mm no AM, para 2,43 mm no AM + 6 Mg ha-¹ CF. A porcentagem de macroagregados foram reduzidas com a adição de maiores doses de cama de frango ao fertilizante mineral.(AU)

Wastes from agroindustrial activity have been commonly used in agriculture, isolated or even associated with mineral fertilizers, and can alter the physical properties of the soil. This study aimed to evaluate the effects of the use of mineral and combined fertilizers with poultry litter (CF) on the physical attributes of a Cerrado Latosol. The experiment was conducted in a randomized block design with four treatments and five replicates. The treatments were as follows: AM - Mineral fertilization with 220 kg of 00-32-00 + 150 kg of KCl ha-¹; AM + 2 Mg ha-¹ CF; AM + 4 Mg CF; AM + 6 Mg CF. After the fourth year of chicken litter use associated with mineral fertilizers, samples were collected to determine soil physical attributes at depths of 0 - 0.05 m, 0.05 - 0.10 m and 0.10 -0.20 m. The association of chicken litter, with mineral fertilization, at the highest doses tends to increase the total pore volume of 0.45 m³ m-³ in the AM treatment, reaching 0.53 m³ m-³ in the AM + 4 Mg ha-¹ CF. The microporosity obtained a similar behavior to VTP, going out 0.32 m³ m-³ in AM reaching 0.40 m³ m-³ in AM + 4 Mg ha-¹ CF. However the weighted average diameter of aggregates were reduced from 2.95 mm in AM to 2.43 mm in AM + 6 Mg ha-¹ CF. The percentage of macroaggregates was reduced with the addition of higher doses the poultry litter to mineral fertilizer.(AU)