|YAN, ZHENGJAUN - Sichuan University|
|Collins, Harold - Hal|
|MACHADO, STEPHEN - Oregon State University|
Submitted to: Nutrient Cycling in Agroecosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2021
Publication Date: 4/20/2021
Citation: Yan, Z., Collins, H.P., Machado, S., Long, D.S. 2021. Residue management changes soil phosphorus availability in a long-term wheat-fallow rotation in the Pacific Northwest. Nutrient Cycling in Agroecosystems. 120(1):69-81. https://doi.org/10.1007/s10705-021-10136-7.
Interpretive Summary: Crop residue management strategies have exhibited significant effects on crop growth and soil properties, which in turn influence soil phosphorus transformation and availability. The long-term field experiment (1931-present) at the Columbia Basin Agricultural Research Center, Pendleton, OR provided a unique resource to investigate the long-term influences of residue management on soil P transformations. The effect of crop residue management on soil phosphorus availability and storage capacity were investigated relative to straw incorporated in a wheat-fallow rotation in the Pacific Northwest. Residue burning and nitrogen application significantly decreased soil available phosphorus where manure application increased soil P accumulation. Nitrogen and manure applications, and residue burning had significant effects on crop growth, soil nutrient balance, soil physical, chemical and biological properties in the wheat-fallow regions of the Pacific Northwest.
Technical Abstract: Crop residue management strategies have exhibited significant effects on crop growth and soil properties, which in turn may influence the soil phosphorus (P) transformation and availability. In this study, the effect of long-term crop residue management treatments (N1 and N2, straw plus 45 and 90 kg N ha-1, respectively; FB and SB, straw burning in fall and spring, respectively; M, straw plus manure) on soil P availability and storage capacity in surface (0-30 cm) and subsurface (30-60 cm) were investigated relative to straw incorporated into soil (control) in a wheat-fallow rotation in the Pacific Northwest. Compared to the control, N application significantly decreased soil available P by 20-50%, measured as Olsen-P, due to the higher P removal by grain. The significant decrease in NaOH-extractable inorganic P (Pi) and Oxalate-extractable Fe suggests N application induced Fe associated-Pi release to supply crop growth. Straw burning moderately increased soil P balance, but decreased available P, which can be attributed to the transformation of labile Pi and/or moderately labile Pi to stable Pi due to the increased soil pH. FB increased labile organic P fractions in surface soil and SB increased the potential of P downward transport, indicated by the decreased soil P storage capacity (SPSC). Manure application significantly increased soil P accumulation and availability while resulted in a negative SPSC in surface soil (-103 mg P kg-1 in 2014) and high potential of P downward transport due to long-term positive P surplus together with the increase in soil pH.