02506nam a2200325 a 450000100080000000500110000800800410001910000160006024500620007626001420013852015850028065000160186565000160188165000210189765000220191865000100194065000130195065000150196365000210197865000240199965000150202365000120203865000270205065300200207765300100209765300150210765300150212270000270213770000160216416685772017-08-17       1999    bl uuuu     u00u1 u    #d1 aLEHMANN, J.  aLeguminous cover crops in tropical fruit tree production.  aIn: ISHS CONFERENCE ON FRUIT PRODUCTION IN THE TROPICS AND SUBTROPICS, 2., 1999, Bonn. Book of abstracts... Bonn: ISHS, 1999. p. 9.c1999  aStudies on the effects of pueraria (Pueraria phaseoloides on nutrient availability in fruit tree production (cupuacu, Theobroma grandiflorum, pupunha, Bactris gasipaes, and guarana, Paullinia cupana var. sorbilis) in the humid tropics. Above-ground nitrogen accumulation in pueraria was 8 and 14 times higher in intercropped cupuacu (juice production) and pupunha (palm of heart production), respectively. Biomass production of pueraria was even 18 and 10 times higher in cupuacu and pupunha, respectively. Even without accounting for production, above-ground recovery of applied 15N in pueraria was as high as in cupuacu and four times higher than in pupunha, and led to less leaching of applied 15N and higher 15N contents in the topsoil. Furthermore, the biological nitrogen fixation of pueraria reached values from 9% to 45% depending on the season. As a result, total soil nitrogen contents significantly increased and the light organic matter fraction of the soil was significantly enriched with nitrogen. The amount of transfer, however, was negligible and needs to be increased by appropriate management, e.g., closer tree spacing. For other nutrients than nitrogen which canot be supplied by pueraria from external sources like phosphorus, care has to be taken that the cover crop does not sequester nutrients. Thus, foliar phosphorus contents of guarana (Paullinia cupana; juice production) decreased by 13% if associated with pueraria. In conclusion, research needs are specified in terms of improving services of leguminous cover crops for better fruit tree nutrition.  acover crops  afruit trees  aBactris Gasipaes  aCobertura do Solo  aFruta  aGuaraná  aLeguminosa  aPaullinia Cupana  aPlanta de Cobertura  aProdução  aPupunha  aTheobroma Grandiflorum  aAvore frutifera  aFruit  aLeguminous  aProduction1 aSILVA JUNIOR, J. P. da1 aTRUJILO, L.