Journal Article

PreJuSER-20783

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Complementarity in Root Architecture for Nutrient Uptake in Ancient Maize/Bean and Maize/Bean/Squash Polycultures

Postma, J. A.FZJ* ; Lynch, J. P.

2012
Oxford University Press Oxford

This record in other databases:      

Please use a persistent id in citations: doi:10.1093/aob/mcs082

Abstract: During their domestication, maize, bean and squash evolved in polycultures grown by small-scale farmers in the Americas. Polycultures often overyield on low-fertility soils, which are a primary production constraint in low-input agriculture. We hypothesized that root architectural differences among these crops causes niche complementarity and thereby greater nutrient acquisition than corresponding monocultures.A functional-structural plant model, SimRoot, was used to simulate the first 40 d of growth of these crops in monoculture and polyculture and to determine the effects of root competition on nutrient uptake and biomass production of each plant on low-nitrogen, -phosphorus and -potassium soils.Squash, the earliest domesticated crop, was most sensitive to low soil fertility, while bean, the most recently domesticated crop, was least sensitive to low soil fertility. Nitrate uptake and biomass production were up to 7 % greater in the polycultures than in the monocultures, but only when root architecture was taken into account. Enhanced nitrogen capture in polycultures was independent of nitrogen fixation by bean. Root competition had negligible effects on phosphorus or potassium uptake or biomass production.We conclude that spatial niche differentiation caused by differences in root architecture allows polycultures to overyield when plants are competing for mobile soil resources. However, direct competition for immobile resources might be negligible in agricultural systems. Interspecies root spacing may also be too large to allow maize to benefit from root exudates of bean or squash. Above-ground competition for light, however, may have strong feedbacks on root foraging for immobile nutrients, which may increase cereal growth more than it will decrease the growth of the other crops. We note that the order of domestication of crops correlates with increasing nutrient efficiency, rather than production potential.

Keyword(s): J ; oThree sisters' (auto) ; polyculture (auto) ; root architecture (auto) ; SimRoot (auto) ; functionalstructural model (auto) ; nutrient deficiency (auto) ; maize (auto) ; bean (auto) ; squash (auto) ; niche complementarity (auto) ; root competition (auto)

Note: Record converted from VDB: 12.11.2012

---

Contributing Institute(s):

1. Pflanzenwissenschaften (IBG-2)

Research Program(s):

1. Terrestrische Umwelt (P24)

Appears in the scientific report 2012

---

Database coverage:
; Allianz-Lizenz / DFG ; BIOSIS Previews ; Current Contents - Agriculture, Biology and Environmental Sciences ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---