Effects of different types of mulches and legumes for the restoration of urban abandoned land in semi-arid northern China

Abstract

Abandoned land is a type of resource wasteland that significantly damages the ecological environment and affects city construction. The northwestern Chinese ecological environment of the semi-arid field is fragile and susceptible to temperature variability. It is difficult to transform such abandoned land into sustainable urban land. However, vegetation restoration on urban abandoned land can ameliorate the soil conditions but received less attention. In the ecological restoration of such abandoned land, the use of certain types of mulch and legume is efficient and effective. In this research, three mulching methods, including a straw blanket (SB), bark plot (BP) and wood shavings (WS), and a control plot (CP) were evaluated over separate growing seasons to determine their effects on the vegetation biomass and the soil physicochemical properties, including soil temperature and soil moisture. The results indicated that mulching had multiple benefits, including improved vegetation growth by decreasing soil evaporation and regulating the soil temperature. SB and BP were the preferred materials because they were more effective. The wood shavings method did not favor the establishment of vegetation and resulted in vegetation similar to that of the control plot. In addition, the legumes Amorpha fruticosa, Lespedeza bicolor and Medicago sativa significantly enhanced the soil physicochemical properties. Thus, the straw blanket, bark plot mulch are recommended for a beneficial water retention effect on topsoil and vegetation growth of abandoned land. This ecological restoration technology for urban abandoned land also exhibits environmental friendliness and sustainability.