Efeito da cobertura do terreno em laranjal sobre as temperaturas extremas do ar1 1 Apresentada durante o III Seminário Brasileiro de Herbicidas e Ervas Daninhas, realizado em julho de tpfío, em Campinas. Os autores agradecem ao Eng. Agr. Carlos Roessing, da Estação Experimental de Limeira, pela colaboração na montagem e leitura do instrumental meteorológico.
Influence of soil cover on the extreme temperatures of the air
A. Paes de Camargo; Altino A. Ortolani; Ody Rodriguez; H. Godoy
SUMMARY
Extremes of soil and air temperatures were measured on bare and straw covered soil in a citrus orchard soil cover experiment. Earth thermometers and air maximum and minimum thermometers were located at different depths in the soil and heights above the soil, in the center of half-acre plots of same treatment.
It was found that, in bright and dry weather condition, the daily range of extreme air temperatures was much wider above mulched soil than above bare soil. This is the reverse of what happens in the ground, where, as we know, the extreme temperatures arp much lower under the mulch cover.
The maximum air temperature at 5 cm above the ground was 6.6?C higher on mulched plot than on the bare one and the minimum temperature was 1.73c lower in the mulched soil. Similar air temperature behavior was still found at higher heights. At 170 cm height the maximum temperature in mulched treatment was 1.9'-*C higher than that observed on bare soil and the minimum temperature was 0.5?C lower. The effect of a mulch cover is to increase the extreme daily temperature variation on the air at the same time as it minimizes the temperature variation of the soil under the straw cover.
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Recebido para publicação em 8 de janeiro de 1961.
Datas de Publicação
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Publicação nesta coleção
09 Mar 2010 -
Data do Fascículo
1961
