Spatial and temporal variability of the chemical and microbiological soil attributes in the strawberry crop production sytems in the Turuçu-RS county, Brazil.

Strawberry crop is an important option for small properties, being of great relevance for people fixation at countryside and generation and maintenance of rural jobs. Studies related to soil attributes monitoring, which can be used as soil quality indicators, are important to evaluate the sustainability of agricultural practices and to point to sound environment management, aiming to its conservation. This work intended to analyze the spatial and temporal variability of the chemical and microbiological soil attributes during the strawberry crop cycle in fourteen rural properties affiliated to the Association of Strawberry Producers of Turuçu-RS, to identify and evaluate the potential impacts of irrigation water on these attributes and to propose actions to minimize these impacts if needed. In this way, deformed soil samples were collected in four different periods at depth 0-0.20 m, to determine their chemical attributes (organic matter, active and potential acidity, CEC and at pH 7.0, base saturation and aluminum saturation), microbiological (carbon and nitrogen of microbial biomass, basal respiration and metabolic quotient) and about fertility (total nitrogen, phosphorus, potassium, copper and zinc). In order to evaluate the mean values of all attributes along the time in each property was applied the LSD mean comparison test with significance to 5%. The spatial and temporal variability of all attributes were evaluataded by means of box plots. Results indicated that between the soil chemical indicators, the mean values of potential acidity presented the major significant variation along the time, while the mean values of aluminum saturation presented the minor variation. Between the soil microbiological indicators, the mean basal respiration presented the major significant variation along the time, while the mean values of nitrogen of microbial biomass presented the minor variation. Between soil fertility indicators the mean values of copper presented the major significant variation along the time, while the mean values of zinc presented the minor variation. With regard to the spatial and temporal variability of the chemical indicators it was found that organic matter presented the greatest amplitude and the aluminum saturation the lowest. Regarding to the spatial and temporal variability of the microbiological indicators it was found that carbon of microbial biomass presented the greatest amplitude while the metabolic quotient presented the lowest. Regarding to the spatial and temporal variability of the soil fertility indicators it was found that copper presented the greatest amplitude while zinc presented the lowest. The concentrations of phosphorus, potassium, copper and zinc presented high levels in all strawberry crops. The organic matter levels were classified as low in most strawberry crops. It was not possible to identify the impact of irrigation water over the chemical and soil fertility indicators, meanwhile, there was a possible impact over the microbiological indicators, specially over the carbon and nitrogen of microbial biomass and metabolic quotient.A cultura do morango é uma importante alternativa para pequenas propriedades, sendo de grande importância para a fixação do homem no campo e para a geração e manutenção de emprego na área rural. Estudos relativos ao monitoramento dos atributos do solo, que podem ser utilizados como indicadores de qualidade do solo, são importantes para avaliar a sustentabilidade das práticas agrícolas, além de sinalizar o manejo adequado do ambiente visando à sua conservação. Em virtude disto, este trabalho teve como objetivos estudar a variabilidade espacial e temporal dos atributos químicos e microbiológicos do solo ao longo do ciclo de produção da cultura do morango em quatorze propriedades pertencentes a Associação de Produtores de Morango do município de Turuçu/RS, identificar e avaliar os possíveis impactos da água de irrigação sobre estes atributos e propor ações para minimizar estes impactos caso existirem. Para tal, foram coletadas, em quatro diferentes épocas e na profundidade de 0-0,20 m, amostras deformadas de solo em cada uma das propriedades, determinando seus atributos químicos (matéria orgânica, acidez ativa e potencial, CTC efetiva e pH 7,0, saturação por alumínio e saturação por bases), microbiológicos (carbono microbiano, nitrogênio microbiano, respiração basal e quociente metabólico) e de fertilidade (nitrogênio total, fósforo, potássio, cobre e zinco). Para verificar o comportamento dos valores médios de todos os atributos ao longo do tempo e em cada propriedade foi aplicado o teste de comparação de médias DMS, a nível de 5% de significância, enquanto que para avaliar a distribuição temporal e espacial de todos os atributos foram construídos gráficos em caixa. Os resultados indicaram que dentre os indicadores químicos do solo, os valores médios de acidez potencial foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de saturação por alumínio foram os que menos diferiram; dentre os indicadores microbiológicos do solo, os valores médios de respiração basal foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de nitrogênio microbiano foram os que menos diferiram ao longo do tempo; dentre os indicadores de fertilidade do solo, os valores médios de cobre foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de zinco foram os que menos diferiram; quanto a variabilidade espacial e temporal dos indicadores químicos, foi constatado que a matéria orgânica apresentou a maior amplitude e a saturação por alumínio a menor; quanto a variabilidade espacial e temporal dos indicadores microbiológicos, foi constatado que o indicador carbono microbiano apresentou a maior amplitude e o quociente metabólico a menor; quanto a variabilidade espacial e temporal dos indicadores de fertilidade, foi constatado que o cobre apresentou a maior amplitude e o zinco a menor; as concentrações dos elementos fósforo, potássio, cobre e zinco encontram-se com elevados teores em todas as lavouras de morango; os teores de matéria orgânica foram classificados como baixos na maioria das lavouras de morango envolvidas neste estudo; não foi possível identificar o impacto da adição da água de irrigação sobre os indicadores químicos e de fertilidade do solo, entretanto, houve um possível impacto sobre os indicadores microbiológicos, principalmente, verificado sobre o carbono microbiano, nitrogênio microbiano e o quociente metabólico

Use of rice husk ash as a soil corrective and conditioner

Deriving from rice processing, rice husk is a high calorific and low cost waste that has been replacing the wood used as energy source in rice industries. Rice husk ash is the product resulting from the burning of rice husk. Although high amounts of rice husk ash have been produced by rice processing in the south region of Rio Grande do Sul, few studies have been done on the use of these residues as a soil corrective and conditioner. Therefore, this investigation aimed to evaluate the potential of rice husk ash as a soil acidity corrective, fertilizer and conditioner. Thus, a field experiment was conducted with twelve treatments: ten rice husk ash dosages (0, 10, 20, 30, 40, 60, 80, 100, 120 and 140 t ha-1) and two references (an absolute control and a recommended soil lime plus fertilizer). For chemical analysis, soil samples were collected at two times: 15 and 180 days after rice husk ash incorporation in the 0.00-0.10 m and 0.10-0.20 m soil layers. The following chemical properties were determined: soil pH (pH), base saturation (V %), relative power of total neutralization (PRNT), neutralization power (PN), exchangeable cation values (Ca, Mg, K, Na), H + Al, C, N, Si and P and cation exchange capacity (CEC) at pH 7.0. The soil samples for physical analysis were collected 180 days after rice husk ash incorporation in the 0.00-0.10 m and 0.10-0.20 m soil layers. The treatments 0, 40, 80 and 120 t ha-1 of rice husk ash and absolute control were considered for the following physical atributes were determined: soil bulk density, total porosity, macroporosity, microporosity, water stable aggregate size distribution, mean weight diameter of aggregates, available soil water, S parameter and soil compressibility. Results showed that rice husk ash acts as a soil acidity corrective, reacting faster than conventional limestone, even with its low PRNT (around 3 %). The use of rice husk ash increased the levels of Mg, K, Na, Si and P in the soil. As a soil conditioner, the rice husk ash caused a reduction of soil bulk density and increased total porosity and 10 macroporosity in the 0.00 to 0.10 m soil layer. The S parameter, the pre-consolidation pressure and the compression index values converges with the improvements of soil porous space.Do processo de beneficiamento de arroz, tem-se como resíduo a casca de arroz, que devido ao seu alto poder calorífico e custo praticamente nulo, vêm substituindo a lenha empregada como fonte de energia nas indústrias de beneficiamento de arroz. Como resultado da queima da casca de arroz é produzido a cinza de casca de arroz (CCA). Apesar das altas quantidades de CCA geradas no processo de beneficiamento do arroz na região sul do Rio Grande do Sul (RS), observa-se poucos trabalhos de pesquisa utilizando estes resíduos como corretivo e condicionador do solo. Em virtude disto, este trabalho teve como objetivo avaliar o potencial da cinza da casca de arroz como corretivo da acidez, fertilizante e condicionador do solo. Para tal, foi realizado um experimento de campo constituído por doze tratamentos: dez dosagens de cinza de casca de arroz 0, 10, 20, 30, 40, 60, 80, 100, 120 e 140 t ha-1; e duas referências: uma testemunha absoluta e outra com calagem e adubação recomendada. Para as análises químicas foram realizadas duas amostragens de solo, aos 15 e 180 dias após a incorporação da CCA, nas camadas de 0,00-0,10 m e 0,10-0,20 m, determinando-se seus atributos químicos: pH em água (pH), saturação por bases (V %), poder relativo de neutralização total (PRNT), poder de neutralização (PN), teores de cátions trocáveis (Ca, Mg, K, Na), de H + Al, C, N, P e Si e da CTC a pH 7,0). As amostras de solo para análises físicas foram coletadas 180 dias após a incorporação da CCA nas camadas de 0,00-0,10 m e 0,10-0,20 m. Os tratamentos: 0, 40, 80 e 120 t ha-1 e a testemunha absoluta foram considerados para os seguintes atributos físicos do solo: densidade do solo (DS), porosidade total (PT), macroporosidade (Ma), microporosidade (Mi), agregados estáveis em água, diâmetro médio ponderado (DMP), capacidade de água disponível (CAD), parâmetro S e compressibilidade. Os resultados indicaram que a cinza de casca de arroz atuou como corretivo de acidez de solo reagindo mais rápido que um calcário dolomítico convencional, apesar de ter o PRNT baixo, na ordem de 3 %. O uso da cinza de casca de arroz elevou os teores de Mg e K, Na, Si 8 e P no solo. Como condicionador do solo, a cinza de casca de arroz promoveu diminuição da densidade do solo e aumento da porosidade total e da macroporosidade na camada de 0,00-0,10 m. Os valores do parâmetro S, da pressão de pré-consolidação e do índice de compressão convergem com as melhorias do espaço poroso do solo

Rice husk ash as corrective of soil acidity

Rice husk ash (RHA) is a by-product from the burning of rice husk that can have favorable effects on the soil in terms of acidity correction. The objectives of this study were to determine the effective calcium carbonate equivalent (ECC) of RHA under field conditions, and establish technical criteria as a basis for estimating the overall ECC of RHA. The 12 treatments of the experiment consisted of 10 RHA dosages (0, 10, 20, 30, 40, 60, 80, 100, 120, and 140 Mg ha-1) and two references, one of which was an absolute control (AC) and the other a plot limed and fertilized according to official recommendations (recommended fertilization - RF). The soil was sampled twice (15 and 210 days after incorporating RHA), in the layers 0.00-0.10 and 0.10-0.20 m, to determine the pH(H2O) and base saturation (V%). The ECC and neutralizing value (NV) of RHA were also determined. The results showed that RHA neutralizes soil acidity, in a faster reaction than conventional limestone, despite a low ECC (around 3 %)

Reaction rate and residual effect of rice husk ash in soil acidity parameters

ABSTRACT The rice husk ash has been applied in agricultural land, with potential of replace limestone and, supply phosphorus and potassium. However, its residual effect in soil is still unknown. This investigation aimed to evaluate the reaction rate and residual effect of rice husk ash in soils acidity parameters. A field experiment was conducted with five treatments: four rice husk ash dosages 0, 30, 60 and 120 t ha-1 and one treatment with recommended soil lime and fertilizer (dolomitic limestone to reach pH 6, 150 kg ha-1 P2O5 as single superphosphate and 80 kg ha-1 K2O as potassium chloride) where five soil samples. Soil samples were collected in the layers 0.00 - 0.10 m and 0.10 - 0.20 m at 15, 211, 400, 517 and 804 days after ash incorporation. Chemical attributes were determined: soil pH (pH), soil base, exchangeable cation values (Ca, Mg, K and Na) and cation exchange capacity (CEC) at pH 7. Results showed that reaction rate of rice husk ash is faster when compared to liming. As greater was rice husk ash dosage applied in soil, higher is the residual effect in pH. As corrective of soil acidity, the residual effect of rice husk ash is just the required time to occur the natural process of reacidification and leaching of basic cations, about 33 months for soils and weather conditions similar to this work

Caracterização de lavouras de morango quanto aos atributos químicos do solo com o uso da análise de componentes principais

One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS) is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA). Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM), soil total nitrogen (N), available phosphorus (P) and potassium (K), exchangeable calcium (Ca) and magnesium (Mg), soil pH (pH), cation exchange capacity (CEC) at pH 7.0, soil base (V%) and soil aluminum saturation(m%). No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.Um dos locais que mais se produz morango no Estado do Rio Grande do Sul é o município de Turuçu. O sistema de produção de morango adotado pelos produtores desse município é similar aos sistemas adotados em outras regiões do Brasil e no mundo; entretanto, a principal diferença se encontra no manejo do solo utilizado, que pode alterar os seus atributos químicos durante o ciclo do morango. O objetivo deste trabalho foi avaliar a distribuição temporal e a espacial dos parâmetros de fertilidade do solo, usando a análise de componentes principais (PCA). Foram selecionadas 14 lavouras onde a amostragem de solo em cada uma foi com base na sua topografia, dividindo a área em três terços: superior, mediano e inferior. Em cada um desses terços, coletaram-se, de forma aleatória, cinco amostras simples de solo na camada de 0-0,20 m, formando uma amostra composta em cada terço. Foram realizadas quatro amostragens ao longo do ciclo da cultura do morango e determinados os seguintes atributos químicos: matéria orgânica (MO), nitrogênio total (N), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg), capacidade de troca de cátions (CTC) a pH 7,0, pH em água (pH), saturação por bases (V%) e saturação por alumínio (m%). Os resultados evidenciaram que nenhum dos parâmetros de fertilidade do solo estudados apresentou variação espacial dentro das lavouras e apenas o K apresentou variação temporal. Os teores de P e de K estiveram sempre altos ou muito altos desde o início do ciclo da cultura do morango, enquanto o pH variou de muito baixo até muito alto. A análise de componentes principais permitiu o agrupamento das lavouras de morango com base nas variáveis relacionadas à acidez do solo e matéria orgânica

Characterization of soil chemical properties of strawberry fields using principal component analysis

One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS) is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA). Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM), soil total nitrogen (N), available phosphorus (P) and potassium (K), exchangeable calcium (Ca) and magnesium (Mg), soil pH (pH), cation exchange capacity (CEC) at pH 7.0, soil base (V%) and soil aluminum saturation(m%). No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content

Hydro-Physical Properties of a Typic Hapludult under the Effect of Rice Husk Ash

ABSTRACT The combustion of rice husk generates a partially burnt mixture called rice husk ash (RHA) that can be used as a source of nutrients to crops and as a conditioner of soil physical properties. The objective of this study was to evaluate the effect of RHA levels on the hydro-physical properties of a Typic Hapludult. The experimental design was composed of random blocks with four replications, which comprised plots of 24 m2 and treatments with increasing RHA rates: 0, 40, 80 and 120 Mg ha-1. Undisturbed soil samples were collected in the soil layers of 0.00-0.10 and 0.10-0.20 m after nine months of RHA application, using steel cylinders (0.03 m of height and 0.047 m of diameter). These samples were used to determine soil bulk density (Bd), total soil porosity (TP), soil macroporosity (Ma), soil microporosity (Mi) and the available water capacity (AWC). Disturbed soil samples were collected to determine the stability of soil aggregates in water, mean weight diameter of water stable aggregates (MWD), and soil particle size distribution. The results show that, as the RHA rate increased in the soil, Bd values decreased and TP, Ma and MWD values increased. No effect of RHA was found on Mi and AWC values. The effects of RHA on the S parameter (Dexter, 2004), precompression stress and compression index (Dias Junior and Pierce, 1995) values are consistent those shown for density and total porosity. Rice husk ash was shown to be an efficient residue to improve soil physical properties, mainly at rates between 40 and 80 Mg ha-1. Rice husk ash reduces bulk density and increases total porosity, macroporosity and soil aggregation, but does not affect microporosity, field capacity, permanent wilting point, and available water capacity of the soil. The effect of rice husk ash on the S parameter, precompression stress and index compressibility coefficient values are consistent with those observed for the bulk density and total porosity

Reaction rate and residual effect of rice husk ash in soil acidity parameters

<div><p>ABSTRACT The rice husk ash has been applied in agricultural land, with potential of replace limestone and, supply phosphorus and potassium. However, its residual effect in soil is still unknown. This investigation aimed to evaluate the reaction rate and residual effect of rice husk ash in soils acidity parameters. A field experiment was conducted with five treatments: four rice husk ash dosages 0, 30, 60 and 120 t ha-1 and one treatment with recommended soil lime and fertilizer (dolomitic limestone to reach pH 6, 150 kg ha-1 P2O5 as single superphosphate and 80 kg ha-1 K2O as potassium chloride) where five soil samples. Soil samples were collected in the layers 0.00 - 0.10 m and 0.10 - 0.20 m at 15, 211, 400, 517 and 804 days after ash incorporation. Chemical attributes were determined: soil pH (pH), soil base, exchangeable cation values (Ca, Mg, K and Na) and cation exchange capacity (CEC) at pH 7. Results showed that reaction rate of rice husk ash is faster when compared to liming. As greater was rice husk ash dosage applied in soil, higher is the residual effect in pH. As corrective of soil acidity, the residual effect of rice husk ash is just the required time to occur the natural process of reacidification and leaching of basic cations, about 33 months for soils and weather conditions similar to this work.</p></div