The inventory of geological heritage of the state of São Paulo, Brazil: Methodological basis, results and perspectives

An inventory of geological sites based on solid and clear criteria is a first step for any geoconservation strategy. This paper describes the method used in the geoheritage inventory of the State of São Paulo, Brazil, and presents its main results. This inventory developed by the geoscientific community aimed to identify geosites with scientific value in the whole state, using a systematic approach. All 142 geosites representative of 11 geological frameworks were characterised and quantitatively evaluated according to their scientific value and risk of degradation, in order to establish priorities for their future management. An online database of the inventory is under construction, which will be available to be easily consulted and updated by the geoscientific community. All data were made available to the State Geological Institute as the backbone for the implementation of a future state geoconservation strategy.The authors acknowledge the Science Without Borders Programme, Process 075/2012, which supported this study and the São Paulo Research Foundation (FAPESP), Process 2011/17261-6. We also thanks C. Mazoca for his help with maps and figures.info:eu-repo/semantics/acceptedVersio

Release, plant nutrition and potassium leaching from coated fertilizer

O aumento do consumo de alimentos e a limitação de área para exploração agrícola requer maior eficiência dos insumos aplicados na nutrição vegetal. Os fertilizantes de liberação lenta ou controlada são uma alternativa para sincronizar a disponibilidade do nutriente com a demanda das plantas e reduzir as perdas para o ambiente. O objetivo do presente estudo foi avaliar a eficácia de um fertilizante potássico revestido com polímeros em comparação ao cloreto de potássio (KCl) convencional sob três aspectos: tempo necessário para liberação do nutriente, redução de perdas por lixiviação e nutrição de plantas. Os produtos foram incubados no solo em condições controladas de temperatura (25 °C) e umidade (0,2 g g-1). O cultivo de plantas de milho em casa-devegetação foi realizado em vasos com solo de textura franco arenosa ou argilosa. O teor inicial de K nos solos era 13 mg dm-3 e 85 mg dm-3, respectivamente. As doses de K aplicadas nos tratamentos foram 0, 18, 36 e 54 mg dm-3. Os vasos foram irrigados com o equivalente a 210 mm de chuva ao longo de 34 dias. O líquido percolado dos vasos foi coletado para determinação do K lixiviado. As plantas foram cortadas após 30 dias da semeadura para quantificar a massa de matéria seca (MS) e o seu teor de K. No estudo de incubação a liberação de K do fertilizante revestido foi de 32 % e 42 % nos períodos de 72 e 154 dias de incubação, respectivamente. Os dados foram ajustados por uma função linear que estimou o prazo de 315 dias necessários para liberação de 75 % do nutriente. No estudo em casa de vegetação a tecnologia de revestimento foi eficaz em preservar o K da perda por lixiviação em solos de textura franco arenosa, no entanto, somente a dose de 54 mg dm-3 promoveu produção de MS equivalente ao KCl convencional. O uso de fertilizante potássico revestido pode não atender a necessidade de K na fase inicial de desenvolvimento da cultura do milho e, por isso, comprometer o rendimento final.The increase in food consumption and area limitation for farm requires improved efficiency of inputs applied to the plant nutrition. The slow or controlled release fertilizers are an alternative to synchronize the nutrient availability with demand of plants and reduce losses to the environment. The aim of this study was to evaluate the efficacy of a potassium fertilizer coated with polymers compared to conventional potassium chloride (KCl) in three aspects: time taken to release the nutrient, reducing losses by leaching and plant nutrition. The products were incubated in soil under controlled conditions of temperature (25 °C) and humidity (0.2 g g-1). A greenhouse experiment was carried out with corn plants in pots under a loamy sand or clay texture soil type. The initial concentration of K in soil was 13 mg dm-3 and 85 mg dm-3, respectively. K rates used in the treatments were 0, 18, 36 and 54 mg dm-3. The pots were irrigated with the equivalent to 210 mm of rain over 34 days. The percolated liquid from pots was collected to determine the K lost by leaching. The plants were harvested 30 days after sowing to quantify dry matter (DM) mass and its K content. In the study of incubation K release of the coated fertilizer was 32% and 42% for periods of 72 and 154 days, respectively. The data were fit by a linear function that estimates the period of 315 days required to release 75% of the nutrient. In the greenhouse’ study the coating technology was effective in preserving the K loss by leaching in sandy loam textured soils, however, only the dose of 54 mg dm-3 promoted DM production equivalent to conventional KCl. It is possible that the need for K in the early stages of corn development is not met by a coated potassium fertilizer and thus compromising the final yield

Release, plant nutrition and potassium leaching from coated fertilizer

O aumento do consumo de alimentos e a limitação de área para exploração agrícola requer maior eficiência dos insumos aplicados na nutrição vegetal. Os fertilizantes de liberação lenta ou controlada são uma alternativa para sincronizar a disponibilidade do nutriente com a demanda das plantas e reduzir as perdas para o ambiente. O objetivo do presente estudo foi avaliar a eficácia de um fertilizante potássico revestido com polímeros em comparação ao cloreto de potássio (KCl) convencional sob três aspectos: tempo necessário para liberação do nutriente, redução de perdas por lixiviação e nutrição de plantas. Os produtos foram incubados no solo em condições controladas de temperatura (25 °C) e umidade (0,2 g g-1). O cultivo de plantas de milho em casa-devegetação foi realizado em vasos com solo de textura franco arenosa ou argilosa. O teor inicial de K nos solos era 13 mg dm-3 e 85 mg dm-3, respectivamente. As doses de K aplicadas nos tratamentos foram 0, 18, 36 e 54 mg dm-3. Os vasos foram irrigados com o equivalente a 210 mm de chuva ao longo de 34 dias. O líquido percolado dos vasos foi coletado para determinação do K lixiviado. As plantas foram cortadas após 30 dias da semeadura para quantificar a massa de matéria seca (MS) e o seu teor de K. No estudo de incubação a liberação de K do fertilizante revestido foi de 32 % e 42 % nos períodos de 72 e 154 dias de incubação, respectivamente. Os dados foram ajustados por uma função linear que estimou o prazo de 315 dias necessários para liberação de 75 % do nutriente. No estudo em casa de vegetação a tecnologia de revestimento foi eficaz em preservar o K da perda por lixiviação em solos de textura franco arenosa, no entanto, somente a dose de 54 mg dm-3 promoveu produção de MS equivalente ao KCl convencional. O uso de fertilizante potássico revestido pode não atender a necessidade de K na fase inicial de desenvolvimento da cultura do milho e, por isso, comprometer o rendimento final.The increase in food consumption and area limitation for farm requires improved efficiency of inputs applied to the plant nutrition. The slow or controlled release fertilizers are an alternative to synchronize the nutrient availability with demand of plants and reduce losses to the environment. The aim of this study was to evaluate the efficacy of a potassium fertilizer coated with polymers compared to conventional potassium chloride (KCl) in three aspects: time taken to release the nutrient, reducing losses by leaching and plant nutrition. The products were incubated in soil under controlled conditions of temperature (25 °C) and humidity (0.2 g g-1). A greenhouse experiment was carried out with corn plants in pots under a loamy sand or clay texture soil type. The initial concentration of K in soil was 13 mg dm-3 and 85 mg dm-3, respectively. K rates used in the treatments were 0, 18, 36 and 54 mg dm-3. The pots were irrigated with the equivalent to 210 mm of rain over 34 days. The percolated liquid from pots was collected to determine the K lost by leaching. The plants were harvested 30 days after sowing to quantify dry matter (DM) mass and its K content. In the study of incubation K release of the coated fertilizer was 32% and 42% for periods of 72 and 154 days, respectively. The data were fit by a linear function that estimates the period of 315 days required to release 75% of the nutrient. In the greenhouse’ study the coating technology was effective in preserving the K loss by leaching in sandy loam textured soils, however, only the dose of 54 mg dm-3 promoted DM production equivalent to conventional KCl. It is possible that the need for K in the early stages of corn development is not met by a coated potassium fertilizer and thus compromising the final yield

Nutrient release, plant nutrition, and potassium leaching from polymer-coated fertilizer

The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots with loamy sand- or clay-textured soil types to evaluate plant nutrition and losses due to leaching. The K application rates were 0, 18, 36, and 54 mg dm-3. The pots were irrigated, and the percolated liquid was collected. The plants were harvested 30 days after sowing to quantify dry matter (DM) and its K content. In the incubation study, the K release from the coated fertilizer was found to be 42 % over 154 days. The data were fit to a linear function from which a period of 315 days was estimated as required for the release of 75 % of the nutrient. Meanwhile, conventional KCl releases 85 % of the K nutrient in the first 48h. In the cultivation of plants in pots, the coating reduced K losses due to leaching in the loamy sand soil; however, only the application rate of 54 mg dm-3 promoted DM production equivalent to conventional KCl. It is possible that the need for K in the early stages of corn development was not met by a coated KCl

Nutrient release, plant nutrition, and potassium leaching from polymer-coated fertilizer

The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots with loamy sand- or clay-textured soil types to evaluate plant nutrition and losses due to leaching. The K application rates were 0, 18, 36, and 54 mg dm-3. The pots were irrigated, and the percolated liquid was collected. The plants were harvested 30 days after sowing to quantify dry matter (DM) and its K content. In the incubation study, the K release from the coated fertilizer was found to be 42 % over 154 days. The data were fit to a linear function from which a period of 315 days was estimated as required for the release of 75 % of the nutrient. Meanwhile, conventional KCl releases 85 % of the K nutrient in the first 48h. In the cultivation of plants in pots, the coating reduced K losses due to leaching in the loamy sand soil; however, only the application rate of 54 mg dm-3 promoted DM production equivalent to conventional KCl. It is possible that the need for K in the early stages of corn development was not met by a coated KCl