LAUSR

Three pineapple ( Ananas comosus L.) cultivation soils of the south-east Mexico were analyzed in relation to the amendment effect of two agro-industrial wastes: sugar mill filter cake (SC) and paper mill sludge (CR) jointly added by weight. The plot P50 was cultivated with only chemical fertilizer, P51 was lying fallow with only wastes added, and P52 was cultivated and fertilized by both ways. After 14 months the soils were analyzed again. The plots texture was found to be sandy loam whose organic matter widely increased, and the pH shifted from acidic to rather neutral. Low concentrations of N, P, and K were found in CR, although its content of Ca 2+ and Mg 2+ was high, while the SC contained P, N, and K in higher amounts than CR. Initially, the plots showed a low level of N, P, and K, in the specific case of P51 values clearly increased up to 522%, 190%, and 204%, respectively, due to the synergy effect of CR and SC combined as soil amendment. The cation exchange capacity (CEC) changed only in P51, increased 11.8%, but in the other two plots CEC did not change significantly.