Effects of long-term nitrogen application on soil acidification and solution chemistry of a tea plantation in China

• Published in: Agriculture, ecosystems & environment Vol. 252; pp. 74 - 82
• Main Authors: Yang, Xiang-de, Ni, Kang, Shi, Yuan-zhi, Yi, Xiao-yun, Zhang, Qun-feng, Fang, Li, Ma, Li-feng, Ruan, Jianyun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2018; Elsevier BV
• Subjects: Acidic soils; Acidification; Anions; Calcium; Cations; Fertilization; Fertilizers; Hydrogen ions; Incubation; Magnesium; N fertilization; Nitrogen; Nutrient deficiency; Nutrients; Organic fertilizers; Organic soils; pH effects; Plantations; Soil acidification; Soil chemistry; Soil pH; Soil solution; Soil surfaces; Soils; Studies; Subsoils; Taxonomy; Tea; Tea plantation; Ultisol; China; Soil acidification; Soil solution; Ultisol; Tea plantation; N fertilization
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/j.agee.2017.10.004

•Soil acidification naturally decreased by 0.071 per year in a tea plantation.•Long-term heavy urea-N fertilization can accelerate the soil acidification process.•Subsoil was more vulnerable to acidification by heavy nitrogen fertilization.•High N input caused Al3+ accumulation and base-cations’ depletion in the soil. In tea (Camellia sinensis) plantation areas, soil acidification mainly results from excessive nitrogen fertilization. However, the proposed theoretical explanations for soil acidification due to nitrogen fertilization are still lacking empirical validation because most studies have used short-term incubation periods or pot experiments. Here, both soil and soil solution samples were taken from a tea plantation field (Ultisol in USDA taxonomy system, or Alisol in WRB taxonomy system) treated using different nitrogen application rates: 0 (N0), 119 (N119), 285 (N285), and 569 (N569)kgNha−1yr−1 for 8 years (2006–2013). Soil pH and the concentrations of the relevant cations and anions were also determined. With no nitrogen fertilization (N0), the surface soil pH decreased from 4.16 to 3.32 after 8 years in the tea plantation. Compared with no nitrogen fertilization (N0), high nitrogen fertilization (N569) significantly decreased the soil pH from 3.32 to 3.15 and 3.67 to 3.35 in the soil at depths of 0–40cm and 40–90cm, respectively. However, the low (N119) and moderate (N285) nitrogen treatments showed non-significant effects upon soil pH. Our results confirm the previous findings that a high nitrogen application rate can accelerate soil acidification in a tea plantation, and that the subsoil is particularly susceptible to acidification after heavy nitrogen fertilization. Soil acidification also significantly decreased the nutrient base cations Ca2+, Mg2+, and K+ in the soil. Our results suggest that heavy synthetic nitrogen fertilization should be partly replaced with compound or organic fertilizers to mitigate soil acidification and nutrient cation deficiency in tea plantation fields.