Influência da disponibilidade hídrica e do preparo do solo no crescimento de Pinus elliottii Engelm. cultivado em neossolo quartzarênico

Abstract

The establishment of forest stands on degraded sandy soils environments presents challenges related to low fertility and drought. The objective of this study was to evaluate the growth of young plants of Pinus elliottii Engelm. in sandy soil with the use of chemicals and organic fertilizer under different levels of water availability. The cultivation of plants lasted 13 months in a greenhouse in pots of 7 liters were kept at 20, 40, 60 and 80% of maximum water holding capacity of the container. The treatments consisted of combinations of soil preparation (NPK and / or partially decomposed pine needles and control) with the level of water availability, resulting in 16 treatments in factorial quali-quantitative distribution completely random distribution with four replications. The height and diameter of te stem base at the end of the experiment, analysis of monthly growth, dry matter yield, water use efficiency and water use in the assimilation of dry mass were observed. The results showed that the use of chemical fertilizer negatively influenced the survival of the plants, especially at lower water availability in the soil. The final height and its growth were influenced by soil water availability, the diameter of the stem base and its increment was influenced by the availability of water and its interaction with soil preparation. The growth in height over time was attributed to soil prepare, also the diameter growth period of the diameter was extended by the low water saturation in the soil. The water consumption rose as increased water availability, however, the efficiency of water use increases with the lower water quantity in soil, and in the presence of chemical fertilizer.