@article {688, title = {The influence of karit{\'e} (Vitellaria paradoxa) and n{\'e}r{\'e} (Parkia biglobosa) trees on sorghum production in Burkina Faso}, journal = {Agroforestry Systems}, volume = {17}, year = {1992}, month = {February 1992}, pages = {97-118}, abstract = {

Sorghum grain yields under the karit{\'e} and the n{\'e}r{\'e} are reduced by an average of 50\% and 70\% respectively, in comparison with yields in the open field. Soil fertility, limiting primary production in the region, is at least as favorable under the tree canopies as in the open field. Reduced light intensity, to a minimum of 20\% under the n{\'e}r{\'e} canopy, is probably largely responsible for low sorghum production under the tree canopies. Benefits from the tree products are more valuable than losses in cereal yields, explaining why trees are maintained on the agricultural fields.

Pruning of tree branches, selection of (shade-) crops and tree selection could reduce crop yield losses but cannot be expected to increase tree- and crop production.

}, keywords = {agriculture, forestry, Parkia biglobosa, parkland, savanna, shade influence, tree management, tree-crop relations, Vitellaria paradoxa, West Africa}, doi = {10.1007/BF00053116}, url = {https://doi.org/10.1007/BF00053116}, author = {J. J. Kessler} } @article {601, title = {Karit{\'e} (Vitellaria paradoxa) and n{\'e}r{\'e} (Parkia biglobosa) associated with crops in South Mali}, journal = {Agroforestry Systems}, volume = {18}, year = {1992}, month = {May 1992}, pages = {89-105}, abstract = {

The effect of two tree species, karit{\'e} (Vitellaria paradoxa) and n{\'e}r{\'e} (Parkia biglobosa) on soil condition, development and production of cotton, sorghum and pearl millet, main crops in South Mali, has been investigated.

The soil under the trees is slightly richer (organic matter content and several cations) compared to adjacent tree-less sites. Also tree-specific effects exist.

Soil enrichment, however, is mainly a matter of redistribution of locally available nutrient resources.

Of the six associations studied, only karit{\'e}-cotton shows no tree-induced reduction in crop production. All other associations suffer greatly from reduced crop outputs caused by the trees, usually in the order of 60\%.

There are at least two reasons that explain tree-induced yield reduction. Because of increased humidity in the immediate surroundings of trees, in both soil and air, lower numbers of crop plants survive up to maturity, presumably because plants are attacked by fungi. Secondly, crop plants that mature show reduced output because of inter-specific competition for light and nutrients.

In case of n{\'e}r{\'e}, in order to minimize the trees\&$\#$39; negative influence lopping is advised. Such practice, however, is less suitable in case of karit{\'e}, because of its assumed lower potential to regenerate, as compared to n{\'e}r{\'e}.

}, keywords = {agriculture, Butyrospermum paradoxum, cotton, forestry, Mali, Parkia biglobosa, pearl millet, sorghum, tree/crop interface, Vitellaria paradoxa, West Africa}, doi = {10.1007/BF00115407}, url = {https://doi.org/10.1007/BF00115407}, author = {L. J. M. Kater and S. Kante and Arnoud Budelman} }