INPUT OF DRY-MATTER AND NUTRIENTS TO THE SOIL FROM COVER PLANTS CULTIVATED BETWEEN ROWS OF PERENNIAL CROPS AND THEIR EFFECTS ON SOIL REACTION

The total input of dry matter, N, P, K, Ca, and Mg to the soil from co ver crops planted between rows of coffee and apple trees was measured in six separated field sites in the State of Parana, Brazil. The follo wing cover crops were evaluated: Avena strigosa, Stizolobium cinereum, Stizolobium deeringianum, Lollium multiflorum, Crotalaria mucronata C rotalaria spectabilis, Crotalaria breviflora Vigna unguiculata, Arachi s hypogaea. and Leucaena leucocephala. Annual cover crops were sown be tween tree rows and the shoots cut off at the flowering stage. For Leu caena, a perennial crop, three cuttings had been applied per year. The cutted plant materials were allowed to dry and decompose on the soil surface as mulch. The total input of above ground dry matter ranged fr om 2.0 Mg ha(-1)y(-1) (Crotalaria spectabilis) to 15.7 Mg ha(-1)y(-1) (Leucaena leucocephala). Estimated N, P, K, Ca, and Mg contents in the residues ranged from 31.0 to 400.2; 2.2 to 26.2, 22.0 to 223.6, 20.6 to 273.1, and 4.0 to 37.9 kg ha(-1)y(-1), respectively. Plant residues were found to decrease soil acidity. Cover crops are recommended as a n important management strategy for coffee and apple production becaus e they provide large quantities of dry mater and plant nutrients to im prove soil fertility of the degraded acid soils in Parana.