Soil quality and yield of Pinus taeda in the Planalto Catarinense region

Abstract

Em \ue1reas florestais, o uso cont\uednuo do solo altera seus atributos f\uedsicos e geralmente deteriora sua qualidade, em decorr\ueancia do tr\ue1fego de m\ue1quinas nas opera\ue7\uf5es florestais, com redu\ue7\ue3o da produtividade das culturas. Diante disso, avaliou-se a rela\ue7\ue3o entre a qualidade do solo em diferentes s\uedtios com a produ\ue7\ue3o de Pinus taeda , em solos do Planalto Catarinense. Foram utilizadas quatro fazendas, com dois s\uedtios em cada uma delas, escolhidos pelo tipo de solo e produtividade da floresta (alta e baixa produtividade). Foi descrita a morfologia e amostras de solo foram coletadas em cada horizonte pedogen\ue9tico para an\ue1lises f\uedsicas e qu\uedmicas. Existe grande varia\ue7\ue3o nas caracter\uedsticas f\uedsicas dos perfis, especialmente na sequ\ueancia e espessura dos horizontes. Foi constatada compacta\ue7\ue3o na camada superficial dos perfis mais rasos, evidenciada pela maior densidade e/ou, resist\ueancia \ue0 penetra\ue7\ue3o do solo, nos quais, a produtividade foi reduzida entre 14 a 36 %, comparados aos perfis mais profundos e com menor grau de compacta\ue7\ue3o.In forest areas, the continual use of the soil alters its physical attributes and deteriorates its quality, in consequence of the traffic of machines used in forest operations, resulting in lower yields of crops. The relationship between soil quality at different sites and the production of Pinus taeda was evaluated in soils of the Planalto Catarinense region. Four farms were used, with two sites on each farm, chosen for the soil type and yield of the forest. The soil morphology was described and samples were collected in each pedogenetic horizon for physical and chemical analyses. Great variation exists in the physical attributes of the profiles, especially in the sequence and thickness of the horizons. Compaction was verified in the surface layer of the shallow profiles, evidenced by the higher bulk density and, or, soil resistance to penetration. In these profiles, the yield was reduced by between 14 and 36%, compared to the deeper profiles with a smaller degree of compaction