Aufhammer


Die Bodenkultur - Journal for Land Management, Food and Environment

W. Aufhammer and E. Kühler:

Effects of row distance and undersowing on the yield of silage maize and the Nmin-residues after harvest

Summary

In a three years field experiment the effects of row distances (75 cm, 55/20 cm = double rows) and undersown grass mixtures on the dry matter yield and the N-uptake of silage maize (cv. Aviso) and the Nmin-residues in a post-harvest period were investigated. The experiments were conducted, using farmer's technical equipment and fields in large plots, with four replications. In interaction with years an early undersowing of grasses reduced dry matter yields and the N-uptake of maize. No further yield effects were significant. In interaction with sowing equipments and years planting densities varied, increasing plant numbers per m2 were accompanied by decreasing weights per plant without effects on the dry matter yields per ha and N-uptake. On a medium high N-fertilization level early undersown and well developed grasses limited in 1993 and 1994 the dry matter production and the N-uptake of maize stands.

Double rowed maize stands and early undersown grasses reduced under high N-mobilization rates in 1992 the Nmin levels at the harvesting date of maize significantly, but no treatment was able to fulfill a set soil-N-limit of 45 kg N/ha.

In 1993 mineralization rates were low and under all stands Nmin-levels remained below the set limited.

Key words: Row distances, undersowing, silage maize yield, Nmin-residues.