Environment, Griffith University, Queensland Brisbane, Qld 4111) Seasonal dynamics and impact factors of soil soluble organic nitrogen in different subtropical fruit plantations

Authors Zhou Biqing; Chen Chengrong; Zhang Liming; Yang Wenhao; Mao Yanling; Xing Shihe

Journal Journal of Agro-Environment Science , 2016,9:35

Abstract To discuss the seasonal dynamics and its impact factors of soil soluble organic nitrogen(SON)in different subtropical fruit plantations, the plots sampling at fixing time and position were set in two adjacent different fruit plantations(Dimocarpus Longan Lour. and Eriobotrya Japonica Lindl.)with the same topography, parent material, soil type and planting time in south subtropics of Fujian. The concentrations of soil SON and relative properties at different seasons and depths of both fruit plantations were analyzed by TOC -TN analyzer, Quickchen Automateic Ion Analyzer and Gas Chromatography and the main impact factors of soil SON dynamics in the fruit plantation were discussed by grey correlation analysis. The results showed that the mean contents of soil SON accounted for 68.8% and 71.1% of total soluble nitrogen(TSN)in upper(0~20 cm)and lower(20~40 cm)layers of Dimocarpus Longan Lour. plantation, and 63.7% and 70.2% of TSN in upper(0~20 cm)and lower(20~40 cm)layers of Eriobotrya Japonica Lindl. plantation, respectively, and the SON contents in Dimocarpus Longan Lour. plantation at different seasons and depths were significantly higher than those in Eriobotrya Japonica Lindl. plantation, which indicated that SON was main component of soil soluble nitrogen in the fruit plantations and was significantly different between various types of fruit plantation in subtropics. Soil SON contents in Summer and Winter were significantly higher than those in Spring and Autumn in both fruit plantations, while the SON contents in upper and lower layers of Dimocarpus Longan Lour. plantation were highest in Winter, and those in both layers of Eriobotrya Japonica Lindl. plantation were highest in Summer. The grey correlation coefficients between SON content and possible impact factor in the fruit plantations showed following order:organic matter content, bacteria and fungi biomass>protease activity,soil temperature and pH>Asparaginase activity and soil moisture. The results indicated that the seasonal dynamics of soil SON in the subtropical fruit plantations were mainly affected not only by the differences of organic matter content, bacteria and fungi biomass, but also by the differences of protease activity, soil temperature and pH in different seasons.

Species covered 枇杷 Eriobotrya japonica 龙眼(变种) Dimocarpus longan