Efeito da compostagem sobre a solubilização e a eficiência agronômica de diferentes fontes de fósforo
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Data
2005-03-21
Autores
Cézar, Vicente Rodolfo Santos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Com o intuito de avaliar o efeito do processo de compostagem sobre a solubilização e a eficiência agronômica de diferentes fontes de fertilizantes fosfatados, foram desenvolvidos dois experimentos. O primeiro constou da produção de compostos orgânicos enriquecidos ou não com superfosfato triplo (ST) ou fosfato natural de Arad (FN). Foi realizado o acompanhamento da temperatura da pilha e do pH do material orgânico durante o processo, além de uma análise química do composto ao final do processo de compostagem. No experimento II, conduzido em vasos com plantas de alface, em casa de vegetação, os compostos orgânicos gerados foram aplicados ao solo para avaliar, através da planta, a Eficiência Agronômica (IEA) do fósforo. Para ambas as fontes, as quantidades de P adicionadas nos vasos foram de 200 mg de P L-1 de terra. Os tratamentos foram: testemunha, fosfato natural de Arad (FN), superfosfato triplo (ST), composto orgânico + ST (COST) com 1,5; 3,0; 4,5 e 6,0% de P, composto orgânico com FN (COFN) com 1,5; 3,0; 4,5 e 6,0% de P adicionada antes da compostagem, COSTF e COFNF com adição das mesmas quantidades de P (ST ou FN) no composto orgânico após o processo de compostagem. Utilizou-se o delineamento estatístico inteiramente casualizado para os dois experimentos. Não se observou no experimento I, efeito favorável do enriquecimento com diferentes porcentagens de superfosfato triplo na compostagem sobre os parâmetros avaliados. Já para adição de diferentes porcentagens de fosfato natural de Arad, observou-se aumento sobre os valores de temperatura, pH, redução da massa da pilha e diminuiu à solubilidade do P solúvel em água, o que sugere que o processo biológico não promoveu a solubilização do fósforo. Para o experimento II os resultados do IEA, baseado na matéria seca e na quantidade de fósforo extraído pela parte aérea...
To evaluate the composting process on the solubility and agronomic efficiency of different phosphate sources, two experiments were developed. The first consisted of producing organic composts enriched with different levels of triple superphosphate (TS) or natural Arad phosphate (NP). Compost heap temperature and organic material pH were monitored throughout the process; compost chemical analysis was performed at the end of the composting process. In the second experiment, the organic composts were applied to the soil in potted lettuce plants under greenhouse conditions and agronomic phosphate efficiency (APE) was evaluated analysing the plants. For both compost sources, the quantity of additional phosphate was 200mg/L soil. Treatments were: control, NP, TS, organic compost + TS (OCTS) with 1.5, 3.0, 4.5, and 6.0% P, organic compost + NP (OCNP) with 1.5, 3.0, 4.5, and 6.0% P added before composting, OCTSP and OCNPP adding the same quantities of P (NP or TS) after the composting process. A completely randomized experimental design was used for both experiments. No favourable enrichment effects were seen in Experiment I from the different TS levels. However, increase in NP increased temperature and pH, and reduced heap mass and soluble P solubility; this suggests that the biological process did not promote phosphate solubility. APE results from Experiment II, based on dry material and quantity of phosphorous extracted from the above soil part of the lettuce plants, showed that the pre-enrichment composts were inferior to the post-enrichment composts in both crops, indicating that there was no favourable effect in adding TS and NP to the composting process in the evaluated period.
To evaluate the composting process on the solubility and agronomic efficiency of different phosphate sources, two experiments were developed. The first consisted of producing organic composts enriched with different levels of triple superphosphate (TS) or natural Arad phosphate (NP). Compost heap temperature and organic material pH were monitored throughout the process; compost chemical analysis was performed at the end of the composting process. In the second experiment, the organic composts were applied to the soil in potted lettuce plants under greenhouse conditions and agronomic phosphate efficiency (APE) was evaluated analysing the plants. For both compost sources, the quantity of additional phosphate was 200mg/L soil. Treatments were: control, NP, TS, organic compost + TS (OCTS) with 1.5, 3.0, 4.5, and 6.0% P, organic compost + NP (OCNP) with 1.5, 3.0, 4.5, and 6.0% P added before composting, OCTSP and OCNPP adding the same quantities of P (NP or TS) after the composting process. A completely randomized experimental design was used for both experiments. No favourable enrichment effects were seen in Experiment I from the different TS levels. However, increase in NP increased temperature and pH, and reduced heap mass and soluble P solubility; this suggests that the biological process did not promote phosphate solubility. APE results from Experiment II, based on dry material and quantity of phosphorous extracted from the above soil part of the lettuce plants, showed that the pre-enrichment composts were inferior to the post-enrichment composts in both crops, indicating that there was no favourable effect in adding TS and NP to the composting process in the evaluated period.
Descrição
Palavras-chave
Compostos organicos, Fosfatos, Alface, Natural phosphate, Triple superphosphate, Organic material, Lactuca sativa L
Como citar
CÉZAR, Vicente Rodolfo Santos. Efeito da compostagem sobre a solubilização e a eficiência agronômica de diferentes fontes de fósforo. 2005. x, 66 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, 2005.