title: Is the inherent potential of maize roots efficient for soil phosphorus acquisition?
abstract: Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1), and the threshold indicating a significant environmental risk was about 15 mg kg(-1), which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1), indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Keru
authors.initials: K
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wan
authors.initials: W
authors.lastname: Teng
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resource, Yangling, China.
authors.forename: Ai
authors.initials: A
authors.lastname: Zhan
authors.affiliation: State Key Laboratory for Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Tong
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Gu
authors.initials: G
authors.lastname: Feng
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Fusuo
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
authors.forename: Xinping
authors.initials: X
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D010758:Phosphorus / Q000032:analysis*; D018517:Plant Roots / Q000502:physiology*; D016133:Polymerase Chain Reaction; D012987:Soil / Q000737:chemistry*; D003313:Zea mays / Q000502:physiology*
chemical_list: D017931:DNA Primers; D012987:Soil; D010758:Phosphorus