{"id":3054,"date":"2017-09-21T15:13:16","date_gmt":"2017-09-21T13:13:16","guid":{"rendered":"http:\/\/www.supagro.fr\/wordpress\/modeleco\/?page_id=3054"},"modified":"2019-06-27T14:48:20","modified_gmt":"2019-06-27T12:48:20","slug":"activite-28-b-determiner-une-rotation-dun-modele-recursif","status":"publish","type":"page","link":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/auto-formation\/sequence3\/cours-3-2-les-modeles-dynamiques\/lecon-28-les-modeles-recursifs\/activite-28-b-determiner-une-rotation-dun-modele-recursif\/","title":{"rendered":"Activity 28 A : \u00ab Centre-Val de Loire \u00bb model \u2013 Interpreting an output file \u2013 Crop succession over time"},"content":{"rendered":"

Length : around 30 minutes<\/u><\/h4>\n

The modelEco_dynamique.gms<\/a> model written in lesson 28 covers a period of 20 years.<\/p>\n

Observe the lst. file. What rotations are carried out by the farmer ? What impact does the initial cropping pattern have ?\u00a0 What can you say about the \u201cEPS\u201d that appear in the marginal values of variables ? How can the dual value of the ROT constraint be interpreted ?<\/p>\n

\u00ab\u00a0An arable crop farmer that grows special crops (INOSYS Syst\u00e8me GC 131 data) in the Centre-Val de Loire region has 110 ha of land. Irrigation and the economic environment of his farm offer him a large range of productions options : soft wheat, durum wheat, spring barley, potato for human consumption, sugar beet and rapeseed. Five of these crop types are irrigated in order to ensure high quality regular production. The farmer has 60 000 m3 of water.<\/p>\n

Irrigation needs and economic data are shown in the table below :<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Irrigation water needs<\/td>\n<\/tr>\n
Crops<\/td>\nVol in m3\/ha<\/td>\n<\/tr>\n
Soft wheat<\/td>\n175<\/td>\n<\/tr>\n
Durum wheat<\/td>\n350<\/td>\n<\/tr>\n
Spring barley<\/td>\n700<\/td>\n<\/tr>\n
Potato for human consumption<\/td>\n1800<\/td>\n<\/tr>\n
Sugar beet<\/td>\n1750<\/td>\n<\/tr>\n
Other technico-economic data<\/td>\n<\/tr>\n
Crops<\/td>\nYields (qx\/ha)<\/td>\nPrices\/qx (\u20ac)<\/td>\nTotal costs (\u20ac\/ha)<\/td>\n<\/tr>\n
Soft wheat<\/td>\n85<\/td>\n16<\/td>\n460<\/td>\n<\/tr>\n
Durum wheat<\/td>\n71<\/td>\n28<\/td>\n565<\/td>\n<\/tr>\n
Spring barley<\/td>\n70<\/td>\n17.5<\/td>\n470<\/td>\n<\/tr>\n
Potato for human consumption<\/td>\n495<\/td>\n14<\/td>\n4210<\/td>\n<\/tr>\n
Sugar beet<\/td>\n950<\/td>\n2.6<\/td>\n1082<\/td>\n<\/tr>\n
Rapeseed<\/td>\n40<\/td>\n38<\/td>\n490<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Source\u00a0: from the Syst\u00e8me GC 131 of the INOSYS network of agricultural chambers in the Centre Val de Loire region. 2016<\/strong><\/em><\/p>\n

Crop yields depend on previous crops (a zero means that it is not possible to cultivate a given crop with that previous crop) :<\/p>\n\n\n\n\n\n\n\n\n\n\n
Crops<\/td>\nPrevious crops<\/td>\n<\/tr>\n
Soft wheat<\/td>\nDurum wheat<\/td>\nSugar beet<\/td>\nRapeseed<\/td>\nPotato for human consumption<\/td>\nBarley<\/td>\n<\/tr>\n
Soft wheat<\/td>\n0<\/td>\n80<\/td>\n85<\/td>\n85<\/td>\n85<\/td>\n80<\/td>\n<\/tr>\n
Durum wheat<\/td>\n65<\/td>\n0<\/td>\n70<\/td>\n70<\/td>\n70<\/td>\n65<\/td>\n<\/tr>\n
Sugar beet<\/td>\n950<\/td>\n950<\/td>\n0<\/td>\n0<\/td>\n0<\/td>\n950<\/td>\n<\/tr>\n
Rapeseed<\/td>\n40<\/td>\n40<\/td>\n0<\/td>\n0<\/td>\n0<\/td>\n40<\/td>\n<\/tr>\n
Potato for human consumption<\/td>\n495<\/td>\n4954<\/td>\n0<\/td>\n0<\/td>\n0<\/td>\n495<\/td>\n<\/tr>\n
Barley<\/td>\n70<\/td>\n60<\/td>\n70<\/td>\n70<\/td>\n70<\/td>\n0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The initial cropping pattern is as follows : 10 ha of soft wheat, 20 ha of durum wheat, 30 ha of sugar beet, 0 ha of rapeseed, 40 ha of potato and 10 ha of barley.<\/p>\n

The farmer maximizes his profit every year.\u00a0\u00bb<\/p>\n

Then check the solution :\u00a0\"solution\"<\/a><\/strong><\/p>\n

\n

\"\"<\/a><\/strong><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Length : around 30 minutes The modelEco_dynamique.gms model written in lesson 28 covers a period of 20 years. Observe the lst. file. What rotations are carried out by the farmer ? What impact does the initial cropping pattern have ?\u00a0 Continue reading Activity 28 A : \u00ab Centre-Val de Loire \u00bb model \u2013 Interpreting an output file \u2013 Crop succession over time<\/span>→<\/span><\/a><\/p>\n","protected":false},"author":92,"featured_media":0,"parent":3005,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3054","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/pages\/3054","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/users\/92"}],"replies":[{"embeddable":true,"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/comments?post=3054"}],"version-history":[{"count":21,"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/pages\/3054\/revisions"}],"predecessor-version":[{"id":4642,"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/pages\/3054\/revisions\/4642"}],"up":[{"embeddable":true,"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/pages\/3005"}],"wp:attachment":[{"href":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/wp-json\/wp\/v2\/media?parent=3054"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}