Impact of Phosphorus Fertilization on Leaching, Accumulation, and Microbial Cycling in New Apple Orchards

• Published in: Agronomy (Basel) Vol. 15; no. 4; p. 952
• Main Authors: Shen, Yuwen, Lin, Haitao, Xue, Rui, Ma, Yanan, Song, Yan
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.04.2025
• Subjects: Accumulation; Acid phosphatase; Agricultural land; Agricultural practices; Agriculture; Alkaline soils; Aluminum; Bacterial leaching; Barren lands; Bioavailability; Calcium; Carbon content; Crops; Cycles; Efficiency; Electrical conductivity; Electrical resistivity; Environmental risk; Fertilization; Fertilizers; Field tests; Grasses; Intercropping; Irrigation; Leaching; Microorganisms; new apple orchard; Orchards; Organic carbon; Organic soils; Phosphatases; Phosphates; Phosphatic fertilizers; Phosphorus; Phosphorus content; phosphorus cycling genes; phosphorus fertilization; phosphorus fixation; Potassium; Runoff; Soil acidity; Soil amendments; Soil chemistry; Soil conditioners; Soil fertility; Soil pH; soil phosphorus leaching; Soils; United States; China; California
• DOI: 10.3390/agronomy15040952
• ISSN: 2073-4395

Field experiments spanning five years were conducted to convert barren mountainous land into apple orchards, testing five phosphorus (P) fertilization schemes: no inorganic P (NP0K), superphosphate (FP), water-soluble inorganic P (WSF), superphosphate with alkaline soil conditioner (SC), and superphosphate with grass interplanting (GC). Fertilizer solubility and soil pH were found to significantly impact P leaching and accumulation. Among the schemes, WSF exhibited the highest P leaching loss (3.65–3.87%), while SC (2.17–2.79%) and GC (2.79–3.25%) minimized such losses. As soil pH declined over time, aluminum P (Al-P) replaced calcium P (Ca-P) as the dominant inorganic P fraction, while occluded P (O-P) increased, resulting in reduced P bioavailability. Soil organic carbon (SOC) and acid phosphatase activity positively influenced inorganic P fractions, whereas prolonged orchard establishment decreased fixed inorganic P content. Microbial P cycling genes were less abundant and showed negative correlations with soil nitrate-N, electrical conductivity, available P (Olsen P), and SOC. These findings highlight that grass interplanting with superphosphate (GC) is an optimal strategy to minimize phosphorus leaching, enhance soil phosphorus bioavailability, and reduce environmental risks, making it a sustainable approach for orchard management.