A disponibilidade do potássio da "leucita de Poços de Caldas", estudada por meio do arroz

Catani, R. A.; Gallo, J. R.

doi:10.1590/S0071-12761960000100004

Resumo

In order to know potassium availability in "leucita de Poços de Caldas" from Poços de Caldas, Minas Gerais, a Mitscherlich pot experiment was set up. The pots were filled with 6 kilograms of sieved (4 mm) "Terra Roxa Misturada" soil. Rice (Oryza sativa, L.), Dourado Agulha variety was the testing plant. Doses of potassium referred to are 1,5 g (as K(2)0) from both KCl and "leucita de Poços de Caldas". There were 6 treatments, with 3 repetitions, as follows: 1) Control; 2) NP + 1 dose K (KCl); 3) NP + 2 doses K (KCl)); 4) NP + 3 doses K (KCl); 5) NP + 1 dose K (leucita); 6) NP + 2 doses K (leucita) and 7) NP + 3 doses K (leucita). Each pot received 50 seeds. Five days after germination the seedlings were thinned to 35. Harvesting took place 4 months after germination. Potassium (as KCl) promoted an increase in yield of both stalk and grain as compared with control. Potassium content in the leaves was also higher in all treatment in which KCl was supplied. Potassium, as "leucita de Poços de Caldas» did not show any favorable effect on both stalk and grain yield and on its content in the leaves.

^IEscola Superior de Agricultura «Luiz de Queiroz»

^IIInstituto Agronômico do Estado de S. Paulo

SUMMARY

In order to know potassium availability in "leucita de Poços de Caldas" from Poços de Caldas, Minas Gerais, a Mitscherlich pot experiment was set up. The pots were filled with 6 kilograms of sieved (4 mm) "Terra Roxa Misturada" soil. Rice (Oryza sativa, L.), Dourado Agulha variety was the testing plant. Doses of potassium referred to are 1,5 g (as K₂0) from both KCl and "leucita de Poços de Caldas". There were 6 treatments, with 3 repetitions, as follows: 1) Control; 2) NP + 1 dose K (KCl); 3) NP + 2 doses K (KCl)); 4) NP + 3 doses K (KCl); 5) NP + 1 dose K (leucita); 6) NP + 2 doses K (leucita) and 7) NP + 3 doses K (leucita).

Each pot received 50 seeds. Five days after germination the seedlings were thinned to 35. Harvesting took place 4 months after germination.

Potassium (as KCl) promoted an increase in yield of both stalk and grain as compared with control. Potassium content in the leaves was also higher in all treatment in which KCl was supplied.

Potassium, as "leucita de Poços de Caldas» did not show any favorable effect on both stalk and grain yield and on its content in the leaves.

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LITERATURA CITADA

Recebido para publicação em 29 de abril de 1960.

CATANI, R.A., 1954 - A determinação do potássio pelos métodos do cobaltihexanitrito e de fotometria de chama; sua aplicação no estudo do potássio nos solos do Estado de S. Paulo. Tese. 145 pp.
FRAYA, R., 1952 - Rochas potássicas. Em Ericksen, A.I., Relatório da Diretoria (1950). Boletim n⁹ 93 - Departamento da Produção Mineral - pp 107-113.