00714cam a22002057a 4500008004100000020001500041100001700056245014900073260006500222300001900287650001900306650001600325650002000341650003000361650002800391700002100419700002200440700002100462050002500483020620s2000    ne ab    b    000 0 eng d  a9068321285  aTOON, Defoer00aManaging soil fertility in the tropics :bBuilding common knowledge :participatory learning and action research /cToon Defoer, Arnoud Budelman,  a[Amsterdam, Netherlands :bRoyal Tropical Institute,cc2000]  a207 p.bill.,  0aSoil fertility 0aFertilizers 0aSoil management 0aSoil fertilityxResearch. 0aSustainable agriculture1 aBUDELMAN, Arnoud1 aTOULMIN,  Camilla1 aCARTER, Simon E.00aS633.5.T76bM35 2000