title: Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns.
abstract: The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P balance.
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/ National Engineering Laboratory for Improving Quality of Arable Land, Beijing, 100081, P. R. China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhan
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/ National Engineering Laboratory for Improving Quality of Arable Land, Beijing, 100081, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Soil and Fertilizer Institute, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang 150086, P. R. China.
authors.forename: Baoku
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Center of Agricultural Environment and Resources, Jilin Academy of Agricultural Sciences, Gongzhuling, Jilin 136100, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/ National Engineering Laboratory for Improving Quality of Arable Land, Beijing, 100081, P. R. China.
authors.forename: Shuxiang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/ National Engineering Laboratory for Improving Quality of Arable Land, Beijing, 100081, P. R. China.
authors.forename: Minggang
authors.initials: M
authors.lastname: Xu
mesh_terms: D000383:Agriculture; D005308:Fertilizers / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008372:Manure / Q000032:analysis; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D010758:Phosphorus / Q000737:chemistry* / Q000378:metabolism; D010944:Plants / Q000378:metabolism; D011188:Potassium / Q000737:chemistry / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005308:Fertilizers; D008372:Manure; D012987:Soil; D010758:Phosphorus; D009584:Nitrogen; D011188:Potassium