A dynamic model for determining the optimum cutting schedule of Italian ryegrass
A quantitative approach to the determination of the optimum cutting schedule of Italian ryegrass (Lolium multiflorum Lam.) was presented. Optimization was based on a dynamic growth model which included the concepts crop growth rate, development rate and proper growth rate. The proper growth rate mea...
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Scientific Agricultural Society of Finland
1975
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ftdoajarticles:oai:doaj.org/article:90689656121d4b39925018fe07fe61b9 2023-05-15T15:09:21+02:00 A dynamic model for determining the optimum cutting schedule of Italian ryegrass Veli Pohjonen 1975-03-01T00:00:00Z https://doaj.org/article/90689656121d4b39925018fe07fe61b9 EN eng Scientific Agricultural Society of Finland https://journal.fi/afs/article/view/71842 https://doaj.org/toc/1459-6067 https://doaj.org/toc/1795-1895 1459-6067 1795-1895 https://doaj.org/article/90689656121d4b39925018fe07fe61b9 Agricultural and Food Science, Vol 47, Iss 2 (1975) Agriculture S Agriculture (General) S1-972 article 1975 ftdoajarticles 2022-12-30T22:19:34Z A quantitative approach to the determination of the optimum cutting schedule of Italian ryegrass (Lolium multiflorum Lam.) was presented. Optimization was based on a dynamic growth model which included the concepts crop growth rate, development rate and proper growth rate. The proper growth rate measured the growth potential associated with the stages of development in the sward. The crop growth rate of Italian ryegrass was studied at the Arctic Circle Experiment Station during 1973 and 1974. The proper growth rate was determined from primary observations as the derivative of an ordinary logistic curve which passes through origin. The maximum theoretical daily growth of Italian ryegrass was calculated as approx. 300 kg • ha-1• day-1. The optimum cutting schedules using gradient method were sought for Italian ryegrass sward. First, the maximum total dry-matter yield was looked for. Then the maximization was extended to the case, when the yield was weighted with the digestibility of the dry-matter. The maximum yield was obtained when the sward was cut three times, and when the cuttings were concentrated into the latter half of the growing season. The yield of the optimum cutting schedule was not sensitive to small changes in the cutting dates. In the conditions of Finnish Lapland the optimum cutting schedule of Italian ryegrass was: first cut at the end of July, second cut at the end of August and the third cut at the end of September. Article in Journal/Newspaper Arctic Lapland Directory of Open Access Journals: DOAJ Articles Arctic |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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English |
topic |
Agriculture S Agriculture (General) S1-972 |
spellingShingle |
Agriculture S Agriculture (General) S1-972 Veli Pohjonen A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
topic_facet |
Agriculture S Agriculture (General) S1-972 |
description |
A quantitative approach to the determination of the optimum cutting schedule of Italian ryegrass (Lolium multiflorum Lam.) was presented. Optimization was based on a dynamic growth model which included the concepts crop growth rate, development rate and proper growth rate. The proper growth rate measured the growth potential associated with the stages of development in the sward. The crop growth rate of Italian ryegrass was studied at the Arctic Circle Experiment Station during 1973 and 1974. The proper growth rate was determined from primary observations as the derivative of an ordinary logistic curve which passes through origin. The maximum theoretical daily growth of Italian ryegrass was calculated as approx. 300 kg • ha-1• day-1. The optimum cutting schedules using gradient method were sought for Italian ryegrass sward. First, the maximum total dry-matter yield was looked for. Then the maximization was extended to the case, when the yield was weighted with the digestibility of the dry-matter. The maximum yield was obtained when the sward was cut three times, and when the cuttings were concentrated into the latter half of the growing season. The yield of the optimum cutting schedule was not sensitive to small changes in the cutting dates. In the conditions of Finnish Lapland the optimum cutting schedule of Italian ryegrass was: first cut at the end of July, second cut at the end of August and the third cut at the end of September. |
format |
Article in Journal/Newspaper |
author |
Veli Pohjonen |
author_facet |
Veli Pohjonen |
author_sort |
Veli Pohjonen |
title |
A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
title_short |
A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
title_full |
A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
title_fullStr |
A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
title_full_unstemmed |
A dynamic model for determining the optimum cutting schedule of Italian ryegrass |
title_sort |
dynamic model for determining the optimum cutting schedule of italian ryegrass |
publisher |
Scientific Agricultural Society of Finland |
publishDate |
1975 |
url |
https://doaj.org/article/90689656121d4b39925018fe07fe61b9 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Lapland |
genre_facet |
Arctic Lapland |
op_source |
Agricultural and Food Science, Vol 47, Iss 2 (1975) |
op_relation |
https://journal.fi/afs/article/view/71842 https://doaj.org/toc/1459-6067 https://doaj.org/toc/1795-1895 1459-6067 1795-1895 https://doaj.org/article/90689656121d4b39925018fe07fe61b9 |
_version_ |
1766340560712368128 |