The objective of this work was to evaluate the chemical characteristics of the whole plant and the leaf and stem fractions of signal grass in different sowing arrangements to determine the productive performance of the corn/signal grass intercrop. The production of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) per area was evaluated, as well as the concentration of CP, digestible crude protein (CPD), neutral detergent insoluble crude protein (NDICP), neutral detergent fiber (NDF), lignin (LIG) non-fiber carbohydrate (NFC) and TDN in DM and the leaf:stem ratio (L:S) at different sowing arrangements and culture age. The sowing arrangements tested were: two lines of signal grass in the corn inter-lines, hand-sowed signal grass in the corn inter-lines, one line of signal grass in the same line of corn, one line of signal grass in the corn inter-lines, exclusive signal grass and exclusive corn culture. The culture age effect was evaluated by sampling plants at 128, 141, 174 and 199 days after sowing. The largest production of DM, CPD and TDN was obtained for signal grass in exclusive culture. During the period when the corn culture shadowed the signal grass, the leaf:stem ratio of intercropped signal grass was lower than the signal grass in exclusive culture. Forages from arrangements with higher shadowing (hand-sowed signal grass and one line of signal grass at the same line of corn) were less productive and presented higher CP concentration in the DM. In general, higher concentrations of CP and lower of NDF and LIG were found in the leaf fraction in relation to the stem fraction, regardless the sowing arrangements. The intercrop did not affect the LIG, NFC and TDN concentration in the DM of the signal grass, but the age had an effect on these variables. The corn production was not affected by the intercrop or by the different arrangements.
agriculture; cattle; chemical composition; intercrop; recovery of degraded pastures
