Author
FERREIRA, C - UNIV. FEDERAL DO PARANA | |
DOS SANTOS, N - UNIV. FEDERAL DO PARANA | |
VALASKI, J - UNIV. FEDERAL DO PARANA | |
Prior, Stephen - Steve | |
MOTTA, A - UNIV. FEDERAL DO PARANA | |
FERREIRA, N - UNIV. FEDERAL DO PARANA | |
GABARDO, J - UNIV. FEDERAL DO PARANA |
Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 8/5/2007 Publication Date: 8/5/2007 Citation: Ferreira, C.F., Dos Santos, N.Z., Valaski, J.C., Prior, S., Motta, A.C.V., Ferreira Neto, A., and Gabardo, J. 2007. Disponibilidade de nutrientes na fitomassa produzida por cultivares de milho (Zea mays L.) de diferentes niveis tecnologicos. In XXXI Congresso Brasileiro De Ciencia Do Solo: Conquistas & Desafios Da Ciencia Do Solo Brasileira. August 5-10, 2007, Gramado, Brazil. p. 5. Interpretive Summary: Corn genetic selection can influence nutrient uptake and the quantity and quality of residues returned to the soil and subsequent residue decomposition processes. Ten corn varieties divided into pairs representing one of five technological levels used in Brazil were selected: single-cross hybrid, double-cross hybrid, triple-cross hybrid, developed varieties, and regional varieties. The triple-cross hybrid DKB 566 obtained the highest grain yield of 3,204 kg ha-1, differing from regional variety named Palotina with 221 kg ha-1 and GI045 with 702 kg ha-1 as well as developed varieties named BR 106 with 1668 kg ha-1. The low yields were a consequence of adverse climatic conditions. Stalk residue presented the highest C/N and C/P ratio for single-cross hybrid (AG9010 and DKB950); these varieties also exhibited the highest ratio for leaf residue. These ratios suggest the occurrence of N and P immobilization processes during decomposition. However, the smaller ratio for grain indicated the potential of mineralization in cases of grain loss to soil. Findings indicated that residue quality can be altered among different technological corn levels. Technical Abstract: Macronutrient uptake, accumulation, and exportation can be affected by corn genetic selection. The objectives of this study were to quantify macronutrient extraction and to evaluate C/P and C/N ratio. The experiment was established at Rolândia County, Paraná State. Ten corn varieties divided into pairs representing one of five technological levels were used: single-cross hybrid, double-cross hybrid, triple-cross hybrid, developed varieties, and regional varieties. Samples of leaf, stalk, and grain were evaluated for C, N, P, K, Ca, and Mg. The results indicated that triple-cross hybrid DKB 566 obtained the highest grain yield of 3,204 kg ha-1, differing from regional variety named Palotina with 221 kg ha-1 and GI045 with 702 kg ha-1 as well as developed varieties named BR 106 with 1668 kg ha-1. The low yields were a consequence of adverse climatic conditions for the crop. Stalk biomass presented the highest C/N and C/P ratio for single-cross hybrid (AG9010 and DKB950) with 44, 1120, 40, and 1089, respectively. For leaf, the highest ratio was observed for single-cross hybrids (AG9010 and DKB950). All varieties presented ratios suggesting the occurrence of N and P immobilization processes during decomposition. However, the smaller ratio for grain indicated the potential of mineralization in cases of grain loss to soil. The experimental results indicated that macronutrient availability can be altered among different technological corn levels. |