Available phosphorus status and critical threshold for leaching in greenhouse soils influenced by different fertilizer sources

In this paper, laboratory soil incubation experiment was conducted to investigate soil available P (Olsen-P) and calcium chloride extracts P (CaCl2-P) contents influenced by manure and inorganic P sources at different rates in three soils with different planting years in Raoyang County, Hebei Province.The three soils included soil next to the greenhouse without planting vegetables (control), plastic greenhouse soil with 30 years of planting vegetables (plastic greenhouse soil) and solar greenhouse soil with 4 years of planting vegetables (solar greenhouse soil). The main purpose was to study the effects on available P content in greenhouse soils and determine the threshold of P leaching under manure and inorganic fertilizers application by mathematical stimulation.