©2021 Scienceweb Publishing Coffee-banana systems in transition: Resource allocation and crop interactions in smallholder farms of Burundi Anaclet Nibasumba 1 * • Laurence Jassogne 2 • Piet VanAsten 2 • Gilbert Nduwayo 1 • Claudette Nkurunziza 1 • Charles Bielders 3 • Bruno Delvaux 3 1 Institut des Sciences Agronomiques du Burundi (ISABU), P.O. Box 795 Bujumbura, Burundi. 2 International Institute of Tropical Agriculture (IITA), P.O. Box 7878, Kampala, Uganda. 3 Earth and Life Institute, Université catholique de Louvain, Croix du Sud, Louvain-la-Neuve, 1348, Belgium. *Corresponding author E-mail: anaclet.nibasumba@hotmail.fr Accepted 8 th November, 2021. Abstract. This study aimed to analyse interactions between coffee and banana plants in adjunct banana and coffee plots. A diagnostic survey was conducted in 60 farms with adjunct banana and coffee plots selected in a humid plateau ecological zone. Banana plots were divided into two sub-plots, a sub-plot near coffee (NC) and a sub-plot far from coffee (FC). Coffee plots were divided into two sub-plots, sub-plot near banana (NB) and sub-plot far from banana (FB). Results showed that banana yield was higher in sub-plots NC (28.6 Mg ha -1 cycle -1 ) than subplots FC (10.4 Mg ha -1 cycle -1 ). The coffee yield was not significantly different among sub-plots. The weight of 100 cherries was significantly higher NB. Soils under coffee were significantly richer near banana and banana nutrient leaf content higher NC. Limiting factors in banana sub-plots FC were, in descending order, K > Mg > Corg > P > pH. In banana sub-plots NC, limiting factors were K / (Ca + Mg) > pH > Zn > P and N. In coffee sub-plots NB, limiting factors were Corg > Mulch > Zn > P > K. In sub-plots FB, limiting factors were Zn > N > P > Mulch. The presence of bananas did not affect coffee growth and coffee yield NB while increasing soil characteristics NB. The presence of coffee has significantly increased the yield and growth of banana NC. Keywords: Banana-coffee, growth-characteristics, nutrient-deficiency, limiting-factor. INTRODUCTION In Burundi, it has long been recommended to conduct coffee monocropping without shade trees and annual food crops (Gaie and Flémal, 1988; Ndihokubwayo et al., 2021). This practice was recommended because trees used for shade or intercropped crops should compete with coffee trees. However, several benefits of shade in coffee trees have been reported (Perdoná et al., 2020). Tree shade: (i) allows moderate temperature variations (Gomes et al., 2020), (ii) reduce soil water loss through evaporation by soil moisture conservation (Lin, 2010), (iii) improve soil fertility by providing nutrients, and (iv) limit erosion (Beer, 1987). In some cases, coffee yield is not affected by shade (Rigal, 2020). On the other hand, coffee intercropping with crops other than shade trees ensures optimal land use, increases income and food availability (Daryanto et al., 2020). Under demographic pressure effect, association with some annual crops such as beans is tolerated in Burundi during the first years of young coffee plantation establishment (Gaie and Flémal, 1988). But, special restrictions exist on coffee intercropping with bananas. The reason given was linked to the high potential of competition between the two crops because they have, both banana and coffee, and high demand for N and K, and a superficial root system (Muliele, 2020; Partelli et al., 2020). To avoid any competition between banana and coffee, a buffer distance of a minimum of 3m was required between banana plots and coffee plots (discussions with coffee growers before data collection). However, in the Burundian cropping system, banana and coffee crops are Journal of Agricultural and Crop Research Vol. 9(11), pp. 250-263, November 2021 doi: 10.33495/jacr_v9i11.21.167 ISSN: 2384-731X Research Paper