Location: Sustainable Perennial Crops LaboratoryTitle: Edaphic and physiographic attributes and their impact on death of cacao trees in drought years
|SOUZA, JOSE OLIMPIO - Universidade Estadual De Santa Cruz|
|SILVEIRA, FELIPE GOMES FR - Bahia State University|
|SILVA PEREIRA, BRUNO LAECIO - Bahia State University|
|MATEUS-RODRIGUEZ, JULIAN FERNANDO - University Of Reading|
|AHNERT, DARIO - University Of Santa Cruz - Brazil|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2022
Publication Date: 3/24/2022
Citation: Souza, J.J., Silveira, F.E., Silva Pereira, B., Mateus-Rodriguez, J., Ahnert, D., Baligar, V.C. 2022. Edaphic and physiographic attributes and their impact on death of cacao trees in drought years. Agronomy Journal. 115(3):1069-1084. https://doi.org/10.1002/agj2.21215.
Interpretive Summary: The increase frequency of drought in cacao production regions of the world has become a major production issue for small cacao producers and one of the main risk factors for crop survivability. Findings of this long-term field research shows that soil edaphic properties such as texture, porosity and density and mineralogy and physiographic features such as slope, terrain orientation in relation to the sun, and crop shading have great impact on cacao survivability in dry years. The lowest mortality was observed in Oxisols soil and on slopes facing south and east. With these results it is possible to establish planting recommends with the most suitable edaphic attributes to ensure a greater survival of cacao trees cultivated in regions susceptible to recurring drought. These findings can be used to guide farmers on how to mitigate the effects of drought on cacao production.
Technical Abstract: Occurrence of more frequent events of prolonged periods of low rainfall (drought) in the worldwide cocoa production zones has not only compromised productivity of small cacao farmers, but also crop survival. This study aimed to evaluate how and to what extent cacao trees mortality in dry years is associated with variations in soil edaphic and physiographic features. The rate of mortality of cacao trees cultivated under an agroforestry system was evaluated at three periods (1994 to 1995, 2009 to 2013 and 2015 to 2019) on 36 plots of a farm in Bahia, Brazil, which has a wide diversity of soils and is established in a region with a sub-humid to dry climate. Correlation analyses (single and multiple), cluster analysis and mean tests were performed. The variables studied were the attributes of two soil layers (physical, mineralogical, and chemical), the diagnostic horizon and the physiographic attributes (slope, terrain orientation in relation to the sun, and crop shading). The edaphic attributes most related to cacao trees mortality were physical (granulometry, porosity and density) and mineralogical (Ki), mainly in the subsurface layer. The lowest mortality was observed in Oxisols and on slopes facing south and east. It was possible to establish recommend limits of the most suitable edaphic attributes to ensure greater survival of cacao trees cultivated in a region subject to recurrent water deficit. These findings can be used to guide farmers on how to mitigate the effect of drought.