Increased nitrogen supply promoted the growth of non-N-fixing woody legume species but not the growth of N-fixing Robinia pseudoacacia

Abstract

Nitrogen (N) is an essential macronutrient for plant development and growth, and the deposition of N has increased in recent decades. Legumes that fix N can also provide N for nearby species. However, N in soil inhibits N fixation. We tested the effects of N fertilisation on one N-fixing (Robinia pseudoacacia) and two non-N-fixing (Sophora japonica and Senna surattensis) woody legume species, which were subjected to five different N levels (0, 1.5, 2.9, 5.9 and 11.4 mg N per plant day−1) under greenhouse conditions. The growth of the two non-N-fixing species was promoted by N supply, while that of R. pseudoacacia was unaffected. Among the three species, R. pseudoacacia had the largest specific leaf area and chlorophyll concentration, S. japonica had the largest root-to-shoot ratio and main root-to-lateral root ratio, and S. surattensis had the largest leaf N and phosphorus concentrations. The N-fixing species was mostly unaffected by N supply. The growth, leaf chlorophyll concentration, and leaf number in the non-N-fixing species were promoted by N supply. The N-fixing species showed better growth in low-N environments, while under increased N deposition, its growth was similar to that of the non-N-fixing species.

Soil prokaryotic community shows no response to 2 years of simulated nitrogen deposition in an arid ecosystem in northwestern China

“…With the increase in N addition rate, the N‐fixing activity of L. potaninii might be disrupted (Regus et al ., 2017), and the advantage of S. collina (C 4 herb) in water‐use efficiency and growth rate (Luo et al ., 2018) may counteract the competitive advantage of L. potaninii in N‐fixing in the desert steppe. The growth of another dominant legume plant, A. propinquus , showed no noticeable shift under increased N addition (Tables S5), indicating the weak N‐fixing capacity of the species (Wang et al ., 2018). Given that N‐fixing capacity varies among the species of Leguminosae (Ament et al ., 2018) and is sensitive to drought stress (Torabian et al ., 2019), the results of the present study might suggest that L. potaninii is probably one of the most critical N‐fixing plants in the desert steppe.…”

“…The effects were accompanied by evident shifts in soil microbial community structures and functions (Fierer et al ., 2012; Wei et al ., 2013; Li et al ., 2016; Zeng et al ., 2016). In different ecosystems, the α‐diversity of soil microbial communities decreases (Zeng et al ., 2016; Wang et al ., 2018) or does not change (Fierer et al ., 2012; Yuan et al ., 2017) under increased N deposition. These patterns of soil microbial community response to N deposition have been proved to correlate with the variations in soil abiotic conditions (Zhang et al ., 2008; Wei et al ., 2013; Zeng et al ., 2016) and nutrient availability (Bardgett et al ., 1999).…”

Neighbors, Drought, and Nitrogen Application Affect the Root Morphological Plasticity of Dalbergia odorifera

“…Previous studies on root responses to competition for resources have focused on either non-leguminous species in a forest ecosystem (Wang et al, 2018a) or leguminous herbaceous crops in an agroforestry ecosystem (Hauggaard-Nielsen et al, 2001;Wang et al, 2017). Leguminous woody species also play a key role in measuring the impact of external conditions on the dynamics of forestry systems (Wang et al, 2018b), especially in the context of climate change. Water and N as main inducers of competition for belowground resources directly affect outcomes of competition.…”

“…Water and N as main inducers of competition for belowground resources directly affect outcomes of competition. The majority of leguminous species retain homeostasis after the addition of N because of the N absorbed from the soil and that from biological N fixation (Markham and Zekveld, 2007;Guo et al, 2017;Wang et al, 2018b). Conversely, some leguminous species are sensitive to N (Hansen et al, 1992) or water deficits (Sadras et al, 2016).…”

Effects of Fertilization Management under WSPI on Soil Nitrogen Distribution and Nitrogen Absorption in Apple Orchard in Loess Plateau

“…However, there are few studies on the low soil fertility that is another limiting factor of agricultural production in the Loess Plateau of North China. As we know, nitrogen is an important nutrient element and an important index of soil fertility [17,18]. Optimizing fertilization management can improve soil fertility and promote plant growth and yield [19], and reduce the risk of environment pollution [20], such as reducing excess greenhouse gas emissions and groundwater pollution due to fertilizer leaching [21,22].…”