Journal article
Effects of shade-tree species and spacing on soil and leaf nutrient concentrations in cocoa plantations at 8 years after establishment
Agriculture, Ecosystems and Environment, Vol.246, pp.134-143
2017
Abstract
Intercropping in agroforestry systems improves ecosystem services. Appropriate species compositions and spacing regimes are critical to achieve ecosystem benefits and improve yields of all the component crops. Cocoa (Theobroma cacao) is an important cash crop globally but it requires shade for survival and growth. However, the effects of shade-tree species composition and spacing regime on nutrient cycling in cocoa plantations are not well understood. This study investigated the effects of shade tree species and spacing regimes on soil and plant nutrient availability at 8 years after plantation establishment in Papua New Guinea. Three cocoa intercropping systems were established in which T. cacao was planted with either a non-legume timber tree, Canarium indicum, or a legume non-timber tree, Gliricidia sepium. The shade-tree spacing regimes included either 8 m × 16 m or 8 m × 8 m in the Theobroma + Canarium plantations. There was an ongoing thinning regime in the Theobroma + Gliricidia plantation, with a final shade-tree spacing of 12 m × 12 m. Soil total carbon (TC) and total nitrogen (TN) were significantly higher in the Theobroma + Gliricidia plantation with 12 m × 12 m spacing and the Theobroma + Canarium plantation with 8 m × 16 m spacing than in the Theobroma + Canarium plantation with 8 m × 8 m spacing. Foliar TN and P were correlated with soil TN and P, respectively, whereas no correlation was detected between soil and leaf K concentrations. Foliar TN, P and K were under ideal concentrations for T. cacao in all of the plantations. The Theobroma + Gliricidia plantation had higher soil water extractable phosphorus (P) than the two Theobroma + Canarium plantations, probably due to frequent pruning of the G. sepium trees. Foliar C isotope composition (δ13C) of T. cacao suggested that T. cacao close to G. sepium or close to C. indicum with spacing of 8 m × 16 m and 8 m × 8 m had similar light interception. However, increased C. indicum spacing increased the light interception of T. cacao trees that were not planted next to C. indicum. This study indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T.cacao. However, our study indicated all three plantations required fertilisation and better nutrient management.
Details
- Title
- Effects of shade-tree species and spacing on soil and leaf nutrient concentrations in cocoa plantations at 8 years after establishment
- Authors
- Shahla Hosseini Bai (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and EngineeringStephen J Trueman (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and EngineeringTio Nevenimo (Author) - National Agricultural Research Institute, Papua New GuineaGodfrey Hannet (Author) - National Agricultural Research Institute, Papua New GuineaPeter Bapiwai (Author) - Papua New Guinea Cocoa Coconut Institute, Papua New GuineaMathew Poienou (Author) - National Agricultural Research Institute, Papua New GuineaHelen M Wallace (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and Engineering
- Publication details
- Agriculture, Ecosystems and Environment, Vol.246, pp.134-143
- Publisher
- Elsevier BV
- Date published
- 2017
- DOI
- 10.1016/j.agee.2017.06.003
- ISSN
- 0167-8809
- Organisation Unit
- School of Science and Engineering - Legacy; University of the Sunshine Coast, Queensland; GeneCology Research Centre - Legacy
- Language
- English
- Record Identifier
- 99450685702621
- Output Type
- Journal article
Metrics
4 File views/ downloads
805 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- International collaboration
- Web Of Science research areas
- Agriculture, Multidisciplinary
- Ecology
- Environmental Sciences
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites