Seasonal changes in productivity and quality of temperate grasses and the fluctuations with years, 3: Changes of mineral content
1997
Watanabe, K. (Iwate Univ., Morioka (Japan). Faculty of Agriculture) | Nonaka, J. | Saiga, S.
Seasonal changes of mineral contents of 6 temperate grasses were compared and the relationship between mineral contents and meteorological elements was investigated. Lolium perenne, Dactylis glomerata, Festuca arundinacea, Agrostis alba, Festuca rubra and Poa pratensis were sown in 1984, and the mineral contents were determined from 1985 to 1989 under frequent cutting based on the pattern derived by an overlapping sequence of 3-weekly cuts. The grasses were received 200 kg N + 100 kg P3O5 + 175 kg K2O/ha/year with even amount of top-dressing after each cut and no irrigation. Seasonal changes of average air temperature and precipitation showed that less precipitation was around the middle of June and less precipitation combined with high air temperature was around the middle of August, especially for August of 1985 and 1989. The N content of grasses declined around May, and recovered gradually by autumn. P and K contents and K/(Ca+Mg) ratio declined in mid June and in mid August, especially for August of 1985 and 1989, and recovered gradually thereafter. P and Ca contents were high, especially during the summer, in Lolium perenne. K content was low in Poa pratensis and Mg content was high in Festuca arundinacea. In Dactylis glomerata, K/(Ca+Mg) ratio was high, especially during the spring in the first harvest year, and Ca content was low during the spring
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