The Forms, Transformation And Availability Of Phosphorus In Sheltered Cultivation Soil

Based on the investigation of types of facilities and circumstance of soil of the sheltered bases of Shandong province, the research chose the sheltered cultivation soil of five sites, including Shouguang, Jiyang, Feicheng, Guangrao and Laiyang, where have a large number of sheltered cultivation bases and well management, taking bio-availability as the appraisal target, to explore the forms, transformation and bio-availability of phosphorus in sheltered cultivation soil. The main results are as follows:1 Compared with open field soil, content of P forms increases obviously. The conten of Olsen-P increases most, the average increasing reaches 579.7%, and the conten of Olsen-P exceed the normal requirement of vegetable.2 Under the condition of sheltered cultivation, fertilizer that was executed into the soil mainly changed to be the forms of C_a2-P, C_a8-P and Al-P, and mainly accumulated in 0-20cm soil layer. Compared with 0-20cm soil layer, content of P forms in 20-40cm soil layer reduced at varying degree, and the reducing of Al-P was the least, reached 50.9%.3 Inorganic P is the primary component of phosphorus in sheltered cultivation soil. The percent of inorganic P in total P reaches 82.9%, and the percent of organic P in total P reaches 17.1% only. Compared with open field soil, the percent of inorganic P and organic P in total P content are similar.4 Ca-P is the primary component of inorganic P in sheltered cultivation soil. The percent of the content of Ca-P accounting for inorganic P reaches 70.6%, and is obviously larger than other component. The percent of the content of C_a2-P, Ca8-P, Al-P, Fe-P, O-P and C_a10-P accounting for inorganic P is 12.7%,...