Data/hora: 01/06/2024 02:35:17

Biblioteca(s): | Embrapa Cerrados; Embrapa Gado de Corte; Embrapa Mandioca e Fruticultura; Embrapa Soja; Embrapa Solos; Embrapa Trigo.
Data corrente: | 18/12/1995
Data da última atualização: | 10/05/1996
Autoria: | LOPES, A. S.
Título: | A survey of the fertility status of soils under cerrado vegetation in Brazil.
Ano de publicação: | 1975
Fonte/Imprenta: | Raleigh: North Carolina State University, 1975.
Páginas: | 138p.
Idioma: | Inglês
Notas: | Tese Mestrado.
Conteúdo: | Soil under natural "cerrado" vegetation were surveyed for their fertility status. A total of 518 toposoil samples were collected from a 600,000-square kilometer  area in central Brazil. The samples were characterized for soil pH, Al, nutrient (including micronutrient),  and organic matter levels, effective cation exchange capacity (CEC), texture, and color (hue, value, and chroma). The range, median, and relative frequency distribution were calculated for each soil property. The soils typically have a pH of 4.8 to 5.2 and an organic matter level of 1.5 to 3.0%. They have extremely low values of effective CEC and extractable calcium, magnesium, phosphorus, zinc, and probably copper. The degree of aluminum saturation in the samples, however, was high, as ere the levels of extractable iron and manganese. there was a  broad range in the textura of these soils.  The natural  vegetation was also classified at the site  each soil sample  was taken, and this was used to estimate productivity. Correlation and regression procedures were conducted to determine the relation between vegetation and  the various soil properties. The correlation procedure indicated a positive relation between the amount of vegetation and  the following (in order of degree of importance); zinc, magnesium,  effective CEC, clacium, pH, phosphorus, potassium, copper, chrom, and organic matter level. There was a negative relation between the amount of vegetation and hue, value, percent aluminum saturation, silt/clay ratio, silt, and iron level. Multiple regression analyses were conducted to further elucidate the relation between amount of vegetation and soil properties. The  results indicated that groups of variables were important. They were (1) chemical variables (phosphorus, zinc, and magnesium), (2) texture variables (silt/clay ratio and sand), (3) color variables (hue and chroma). The amount of vegetation was positively related to  each of these properties except silt/clay ratio. Additional insight regarding each important chemical variable was obtained by relating the phosphorus, sinc, and magnesium levels to other soil properties. Numerous variables and interactions among variables appeared related to the native phosphorus status of these soils. Manganese level, color variables, and their interactions seemed somwhat more important than other variables, and their interactions seemed somwhat more important than other variables in this case. The zinc status of  these soils was largely related to cation exchange capacity and factors associated with it, such as organic matter and soil pH. Zinc level was also generally higher if the manganese level in the soil was high. This may be an indication of differences in parent material. The magnesium status of these soils was found to be very closely related to the cation exchange capacity, calcium level, and percent aluminum saturation
Palavras-Chave: | Tese.
Thesagro: | Cerrado; Fertilidade do Solo; Solo.
Thesaurus Nal: | Brazil.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)

Exemplares:

CNPGC - (6947-1) - ADD - TS - PP - T170/75 -  - T170/75 - DIS
CNPS - (4504-1) - ADD - TS - -- - 79029 - LOP/75 - 1997.02018 - DIS
CNPSO - (22167-1) - ADD - TS - -- - 31/75 -  - 31/75 - DIS
CPAC - (8720-1) - ADD - TS - -- - CRI719 -  - CRI719 - DIS
CNPMF - (20081-1) - ADD - TS - -- - T14/75 -  - T14/75 - DIS
CNPT - (29784-1) - ADD - TS - -- - TS-0204 -  - 0204 - DIS