Long-term effects of cropping system on red clover proportion and crude protein concentration in mixed leys
Red clover is an important crop in Sweden, being the most cultivated forage legume in the country. It has a high crude protein concentration and fast establishment, which makes it a welcome addition to a ley mixture. However, red clover is not persistent and generally little remains in the third h...
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| Formato: | Second cycle, A2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2021
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/17423/ |
| Sumario: | Red clover is an important crop in Sweden, being the most cultivated forage legume in the country.
It has a high crude protein concentration and fast establishment, which makes it a welcome addition
to a ley mixture. However, red clover is not persistent and generally little remains in the third harvest
year. This is caused by a combination of several different factors such as management practices and
diseases. To determine how these factors affect red clover persistence, literature on the subject was
analysed and correlated with the results of an analysis of data from the long-term field experiment
R8-71. R8-71 includes six-year crop rotations with different proportions of timothy-red clover ley
in each rotation.
Diseases and pests are the most common causes of red clover decline, and without their presence,
red clover cultivars can persist for more than eight years. The analysis of R8-71 revealed typical
signs of both clover rot and root rot. There was a sharp decrease in red clover proportion in the third
harvest year, which is typical when plants are affected by root rot. Over time there was a decrease
of clover proportion in the first harvest year in the crop rotation with the most frequent use of
timothy-red clover ley, a typical sign of clover rot.
It is known that the clover proportion of a ley and crude protein of the forage increases between
the first and second harvest, and this was confirmed in this thesis. Having a three-year or five-year
ley did not influence the persistence of clover within a crop rotation cycle.
The clover proportion in the first and second harvest of the first production year declined with
each crop rotation cycle. The crop rotation with a five-harvest year ley was the only rotation where
the decline of clover proportion in the first production year was significant, but it was only
significantly different from the change in clover proportion of the two-harvest year cropping system.
In conclusion, red clover and crude protein concentration in the produced forage increased
between the first and second harvest. Red clover persistence was not significantly affected by the
proportion of ley within a rotation, but the proportion of red clover decreased over crop rotation
cycles when the gap between leys with clover was less than two years. |
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