Crescimento de mudas de Ipê Rosa e Cedro submetidas à calagem e omissão de nutrientes

Abstract

The predatory exploitation of forest resources in the Amazon region has contributed to the reduction of the genetic basis of their species, causing some are listed as endangered and having their exploitation prohibited by law. This problem is exacerbated because many of these species has not silvicultural behavior elucidated, complicating the management of them. The aim of this study was to investigate the effects of the use of liming and chemical fertilizers on the growth of seedlings of pink ipe and cedar grown in Yellow Latosol. The experiment was conducted in a greenhouse at the University Federal of Amazonas in Manaus/AM. The treatments were carried out in randomized block design with four replications with 10 treatments: T1: complete; T2: complete - liming; T3: complete - N; T4: complete - P; T5: complete - K; T6: complete - Ca; T7: complete - Mg; T8: complete - S; T9: complete - micronutrients and T10: control (natural soil). After 110 days were evaluated the growth characteristics and biomass, quality of seedlings and the nutrient content in the dry matter of shoots. We also determined the chlorophyll content in pink ipe seedlings.The pink ipe seedling growth were not affected by the omission of variables S, while for the biomass variables the omission S only affect the root and shoot ratio. Have the cedar seedlings showed no requirements for N. These species were demanding the other nutrients, especially the P. Based on Dickson quality index of both species under the omission of P, were equivalent to the control treatment. The absorption of nutrients by pink ipe seedlings was higher when it omitted the S. The largest accumulation of nutrients, except for Cu, in cedar seedlings was found when was omitted N. Regarding the chlorophyll content, the pink ipe seedlings showed differences only for chlorophyll a, and the lowest levels were found in the treatment with omission of N, P and Mg. The chlorophyll content index (CCI) also showed lower values for omission of N, P and Mg. There was no correlation between the two methods for the determination of assessed chlorophyll. The results showed that both the pink ipe as to Cedar P deficiency in the soil makes the nutrient that most limits the growth of the species. The decreasing order of limiting nutrients based on the relative production of total dry matter for the pink ipe: P> micronutrients> Mg> Liming> K> Ca> N> S, and the cedar: P> S> micronutrients> Mg> K > Ca> Liming> N.