Effects of short-term nitrogen and phosphorus addition on root biomass and morphological characteristics of ligustrum lucidum ait in new reclamation coastal field

Abstract

Root system plays an important role in plant’s nutrient acquisition and ecosystem carbon cycle. Nitrogen (N) and phosphorus (P) work significantly in promoting root system growth. To reveal the influence of N and P application on landscaping plants’ root morphology characteristics, Ingrowth soil core fertilization method was applied in the coastal reclaimed soil (196.25 cm3) where Ligustrum lucidum ait grew from June to August in 2018. We set 11 processing gradients, including 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 20 g, and explored the influence of different N and P addition types on Ligustrum lucidum ait root morphology, biomass and other indicators. The results showed that compared with the control group, 3 g N application increased length of root by 62.39%, surface area by 120.87%, volume by 169.97%, biomass by 102.75%, root length density by 59.19% and root surface area density by 106.99%. 3 g P application increased those indexes by 77.37%, 111.15%, 147.50%, 98.05%, 73.87%, and 97.88%. The study indicated that compared with the control group, the application of 3 g N and P into 196.25 cm3 soil made significant differences on total length, diameter, surface area, volume, biomass, root length density, and root surface area density (P < 0.05).