Effects of weeding and fertilization on soil biology and biochemical processes and tree growth in a mixed stand of Dalbergia odorifera and Santalum album

Abstract

In southern China, the eucalyptus plantation industry has been severely restricted by government policy over concerns on negative environmental impacts. In its place, large-scale plantations of high-value tropical tree species such as nitrogen-fixing Dalbergia odorifera and hemiparasite Santalum album have been widely cultivated including in mixed-species plantations. However, despite their poor growth, little information is available on suitable silvicultural practices of these plantations. Therefore, we subjected an 8-year-old mixed stand of D. odorifera and S. album to weeding, fertilization, weeding + fertilization, or no (CK) treatments and measured soil microbial biomass, respiration, nutrients, nitrogen mineralization and leaching and tree growth and litter production. Weeding and fertilization decreased microbial biomass but increased soil respiration, inhibited mineralization, had not effect on leaching of soil nitrogen, and improved the nutrient status of plantation soil. All practices improved the growth of D. odorifera. In the mixed plantation, fertilization increased litter production and nutrient content, but weeding and weeding + fertilization decreased growth of S. album and litter production in mixed plantation because weeding decreased the number of S. album haustoria in underground plant roots. In conclusion, fertilization is recommended; however, weeding-related practices are inappropriate for D. odorifera and S. album mixed plantations. These conclusions have important implications for managing other parasite or mixed-species plantations.

Differential responses and mechanistic controls of soil phosphorus transformation in Eucalyptus plantations with N fertilization and introduced N2‐fixing tree species

“…Here, we conducted a field experiment including a pure plantation of E. urophylla × E. grandis without nitrogen fertilization (Pure) or with N‐fertilization (Fert N), and a mixed plantation of E. urophylla × E. grandis by introducing an N 2 ‐fixing tree of Dalbergia odorifera T. Chen without fertilization (N‐fixer). The great N 2 fixation efficiency and interspecific N transfer of D. odorifera have been reported in many previous studies (Lu et al ., 2013; Yao et al ., 2019), which has been widely considered as one of the effective measures for improving Eucalyptus plantations in China (Yao et al ., 2021; Zhang et al ., 2021). The main aim of this study was to explore how N fertilization or introduced N 2 ‐fixing tree species to impact soil P transformation in Eucalyptus plantations.…”

Early Field Performance and Genetic Variation of Dalbergia tonkinensis, a Valuable Rosewood in Vietnam

“…No research on tree selection, sylviculture or field performance has been undertaken. In contrast, there has been considerable effort in genetic improvement, plantation sylviculture and heartwood induction for D. odorifera in China [22][23][24].…”