Soil nitrate N as influenced by annually undersown cover crops in spring cereals
| Autor: | H. KÄNKÄNEN, C. ERIKSSON, M. RÄKKÖLÄINEN |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Agricultural and Food Science, Vol 12, Iss 3-4 (2008) |
| Druh dokumentu: | article |
| ISSN: | 1459-6067 1795-1895 |
| Popis: | Cover crops can reduce leaching and erosion, introduce variability into crop rotations and fix nitrogen (N) for use by the main crops. In Finland, undersowing is a suitable method for establishing cover crops in cereals. The effect of annual undersowing on soil nitrate N was studied at two sites. Red clover (Trifolium pratense L.), white clover (Trifolium repens L.), a mixture of red clover and meadow fescue (Festuca pratensis Huds.), and westerwold ryegrass (Lolium multiflorum Lam. var. westerwoldicum) were undersown in spring cereals during six successive seasons, and a pure stand of cereal was grown in two years after that. In all years, the soil nitrate N was measured in late autumn, and in addition in different times of the season in last four years. The effect of undersowing on soil NO3-N content was generally low, but in one season when conditions favoured high N leaching, westerwold ryegrass decreased soil NO3-N. The negligible increase of N leaching risk in connection with undersowing clovers, associated with late autumn ploughing, supports the use of clovers to increase the cereal grain yield. The highest levels of soil NO3-N were recorded at sowing in spring irrespective of whether a crop was undersown or not. NO3-N contents were higher in sandy soil than in silt. Undersowing can be done annually in cereal cultivation either to fix or catch N. No cumulative effects on soil nitrate N were associated with undersowing after six years.; |
| Databáze: | Directory of Open Access Journals |
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