Resumo
Cotton (variety I. A. C. 11) was grown on a sandy soil under two treatments, namely: (1) NPK + lime and (2) no fertilizers. Three weeks after planting a systematic sampling of entire plants was done every other week. In the laboratory determinations of dry weight were made and afterwards the various plant partes were submitted to chemical analyses, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) being determined. The aim of this work was to obtain information on the periods in which the absorption of the several macronutrients was more intense, this providing a clue for time of application of certain mineral fertilizers. Data obtained hereby allowed for the following main conclusions. The initial rate of growth of the cotton plant, judged by the determinations of dry weight, is rather slow. Seven weeks after planting and again five weeks two distinct periods of rapid growth take place. The uptake of macronutrients is rather small until the first flowers show up. From there on the absorption of minerals is intensified. From the time in which fruits are being formed to full maturity, the crop draws from the soil nearly 75 percent of the total amount of elements required to complet life cycle. This seams to point out the need for late dressings of fertilizers, particularly of those containing N and K. The following amounts of element in Kg/ha were absorbed by the fertilized plants: N - 83.2 P - 8.1 K - 65.5 Ca - 61.7 Mg - 12.8 and S - 33.2. The three major macronutrients, namely, N. P and K are exported as seed cotton in the following proportions with respect to the total amounts taken up by the entire crop: N - 1/3, P - 1/2 and K - 1/3.
Estudo sobre a Alimentação Mineral do algodoeiro I. Marcha da absorpção do macronutrientes (Nota prévia)* * Com a ajuda da Fundação Rockefeller (N. York) e da Fundação de Amparo à Pesquisa no Estado de S. Paulo.
J. R. SarrugeI; L. GomesII; H. P. HaagI; E. MalavoltaI
ICadeira de Química Orgânica e Biológica Escola Superior de Agricultura «Luiz de Queiroz»
IIEstagiária da SUDENE
SUMMARY
Cotton (variety I. A. C. 11) was grown on a sandy soil under two treatments, namely: (1) NPK + lime and (2) no fertilizers. Three weeks after planting a systematic sampling of entire plants was done every other week. In the laboratory determinations of dry weight were made and afterwards the various plant partes were submitted to chemical analyses, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) being determined. The aim of this work was to obtain information on the periods in which the absorption of the several macronutrients was more intense, this providing a clue for time of application of certain mineral fertilizers.
Data obtained hereby allowed for the following main conclusions.
The initial rate of growth of the cotton plant, judged by the determinations of dry weight, is rather slow. Seven weeks after planting and again five weeks two distinct periods of rapid growth take place.
The uptake of macronutrients is rather small until the first flowers show up. From there on the absorption of minerals is intensified. From the time in which fruits are being formed to full maturity, the crop draws from the soil nearly 75 percent of the total amount of elements required to complet life cycle. This seams to point out the need for late dressings of fertilizers, particularly of those containing N and K.
The following amounts of element in Kg/ha were absorbed by the fertilized plants:
N - 83.2
P - 8.1
K - 65.5
Ca - 61.7
Mg - 12.8 and
S - 33.2.
The three major macronutrients, namely, N. P and K are exported as seed cotton in the following proportions with respect to the total amounts taken up by the entire crop: N - 1/3, P - 1/2 and K - 1/3.
Texto completo disponível apenas em PDF.
Full text available only in PDF format.
LITERATURA CITADA
- 1 - CATANI, R. A. & J. R. GALLO, 1955 - Avaliação da exigência em calcário dos solos do Estado de S. Paulo, mediante correlação entre o pH e a porcentagem de saturação em bases. Rev. de Agricultura 30:49-60.
- 2 - FRANCO, C. M. & H. P. MEDINA, 1960 - Arrastamento de potássio e fósforo pela água de infiltração do solo. Bragantia 19: LXXII-LXXVI.
- 3 - MALAVOLTA, E., F. PIMENTEL GOMES, 1958 - Estudos sobre a alimentação mineral do cafeeiro. I. Resultados preliminares E.S.A. «Luiz de Queiroz», Bol. 14.
- 4 - MENDES, H. C., 1960 - Nutrição do algodoeiro. II. Absorção mineral por plantas cultivadas em soluções nutritivas. Bragantia 19: 435-458.
- 5 - RANZANI, G., 1956 - Levantamento da carta de solos da Secção Técnica «Química Agrícola» da Esc. Super. de Agr. «Luiz de Queiroz», Tese de Livre Docência, 36 págs. mais Tabelas e diagramas.
Datas de Publicação
-
Publicação nesta coleção
06 Set 2012 -
Data do Fascículo
1963
