Zinc Sources and Methods of Application for Rice1
- P. M. Giordano and
- J. J. Mortvedt2
Because of the relatively recent diagnosis of Zn deficiency in rice (Oryza sativa L.), the most effective sources of Zn and methods of application for flooded soils have not been established. In a greenhouse experiment, growth of rice on flooded Nolichucky sandy clay loam limed to pH 7.5 was similar with soil applications of ZnO, ZnSO4, and ZnEDTA. Uptake of Zn by immature plants was in the order: ZnO > ZnSO4 > ZnEDTA. Application of ZnSO4 to the flood water, the rice seed, or the soil resulted in comparable increases in dry matter production and Zn uptake.
The adherence of Zn to rice roots dipped in Zn suspensions and the subsequent availability to the plant was studied in the laboratory and the greenhouse. Suspensions containing ZnO were more effective in supplying Zn than those prepared with ZnS. The presence of attapulgite clay in the suspensions increased adherence to roots but decreased Zn availability to the plant. Suspensions containing more than 5% Zn were not practical because of excessive viscosity. Response, however, to Zn adhering to seedling dipped in suspensions containing 1 and 5% Zn as ZnO was similar to that where ZnO was mixed with the soil to supply 4 ppm of Zn.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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