Problemas sôbre rotação soja x algodão* * Trabalho apresentado oo VII Congresso Brasileiro de Ciência do Solo, realizado em Piracicaba, S. Paulo, de 20 a 30 de julho de 1959. Os autores agradecem oo Dr. Álvaro Santos Costa, pela leitura do texto.
Problems on soybean x cotton rotation
Shiro Miyasaka; J. Romano Gallo; J. Gomes da Silva
SUMMARY
Cotton yields obtained in rotation experiments with soybean have been lower than expected. This observation was confirmed by the results from a long-term rotation experiment corn x cotton x soybean, carried out at the Ribeirão Preto Agr. Exp. Sta.
Data from this experiment indicated that cotton yields from plots under rotation were lower than those from plots under continuous cropping. Also, the results from leaf analysis showed that cotton plants in rotation plots had lower levels of phosphorus and palassium than those in plots under continuous cropping.
Three explanations for the observed results are advanced: (1) the nutrient level ovoilable for the cotton planls in plots under rotation is lower than in those under continuous cropping, because the crops in rotation remove more soil nutrients than cotton; (2) the lower cotton yields under rotation could be explained on the basis of nematode attack; in this case soil infestation would be increased by the soybean crop and the lower nutrient levels in the leaves could result from root damage induced by the nematodes; (3) the possibility exists that the soybean plant leaves a substance in the soil that might be detrimental to the cotton plant.
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Full text available only in PDF format.
Recebido para publicação em 16 de outubro de 1959.
Datas de Publicação
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Publicação nesta coleção
14 Abr 2010 -
Data do Fascículo
1960
