Aluminium and nitrogen on pH variation and cation-exchange capacity in Brachiaria decumbens
Brachiaria decumbens was grown in nutrient solution with nitrogen applied either as NO3; or as NH4. Al was added (to four - week old plants) at 0, 0.75, 3, and 6 ppm, pH was read daily, and adjusted to 4.2 each 48 hours. Plants under NO3 were able to raise the solution pH up to 5 at Al levels up to 1.5 ppm. Above this level, plants under NO3 showed higher accumulation of Al and a marked reduction in root cation - exchange capacity (CEC). Changes in pH NO3 - fed plants were related to the size of root system but not to imbalances in (N+ P) - (Ca + K) uptake. Plants under NH4 showed an uniform trend in pH change, and no effects of Al levels on root and shoot Al contents were detected. Effects of Al levels on root CEC were much less accentuated in plants under NH4 than under NO3. The mechanisms through which N-carriers can affect the responses of Brachiaria plants to Al stress is discussed.
| Main Authors: | , , |
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| Format: | Digital revista |
| Language: | por |
| Published: |
Pesquisa Agropecuaria Brasileira
2014
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| Online Access: | https://seer.sct.embrapa.br/index.php/pab/article/view/15417 |
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