Kaul


Die Bodenkultur - Journal for Land Management, Food and Environment

H.-P. Kaul:

Pre-crop effects of grain legumes and linseed on soil mineral N and productivity of subsequent winter rape and winter wheat crops

Summary

Pre-crops can have yield effects on subsequent crops due to their nitrogen (N) residues and for other agronomical reasons.

The present study evaluates for pre-crops with substantially different crop residues whether fertilized subsequent crops show any yield effects. For that purpose, in a field experiment on the experimental station Ihinger Hof of Hohenheim University (49° N, 9° E, avg. temperature 8.0 °C, precipitation 690 mm year-1, 480 m a. s. l.) the grain legumes pea, faba bean and white lupin, and linseed were planted with two cultivars, respectively, in 1995 and 1996. After precrop harvest, winter rape or winter wheat were sown and fertilized with mineral N (in total 150 kg N ha-1) to enable high yields and eventually compensate pre-crop effects.

Pea and faba bean produced high yields, while linseed yields were only on a moderate level and white lupins did not attain their yield potential. Total N residues ranged between 48 and 110 kg N ha-1. The soil mineral N before winter rest and in late winter was in both years highest after pea > faba bean > white lupin and linseed. Subsequent winter rape plant density in spring was highest after pea, while rape crops after faba bean in both years and after white lupin in 1997 showed the lowest densities. The differences between pre-crops in yield of rape were comparatively small.

However, winter rape crops after pea had in both years the highest grain yield. Pre-crops did not affect wheat density and grain yield was similar after all pre-crops, but wheat N uptake was enhanced by pre-crops of pea and faba bean.

In conclusion, fertilization can substantially reduce although not completely balance yield effects of different precrops.

Key words: Pre-crop effects, nitrogen, grain legumes, linseed, winter wheat, winter rape.