Error message

Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in content_access_get_settings() (line 225 of modules\contrib\content_access\content_access.module).
content_access_get_settings('per_node', 'resource') (Line: 26)
Drupal\content_access\Access\ContentAccessNodePageAccessCheck->access(Object, Object)
call_user_func_array(Array, Array) (Line: 160)
Drupal\Core\Access\AccessManager->performCheck('access_check.content_access_node_page_access', Object) (Line: 136)
Drupal\Core\Access\AccessManager->check(Object, Object, NULL, 1) (Line: 93)
Drupal\Core\Access\AccessManager->checkNamedRoute('entity.node.content_access', Array, Object, 1) (Line: 327)
Drupal\Core\Menu\LocalTaskManager->getTasksBuild('entity.node.canonical', Object) (Line: 358)
Drupal\Core\Menu\LocalTaskManager->getLocalTasks('entity.node.canonical', 0) (Line: 95)
Drupal\Core\Menu\Plugin\Block\LocalTasksBlock->build() (Line: 171)
Drupal\block\BlockViewBuilder::preRender(Array)
call_user_func_array(Array, Array) (Line: 101)
Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_render callbacks must be methods of a class that implements \Drupal\Core\Security\TrustedCallbackInterface or be an anonymous function. The callback was %s. See https://www.drupal.org/node/2966725', 'exception', 'Drupal\Core\Render\Element\RenderCallbackInterface') (Line: 772)
Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array) (Line: 363)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 435)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 201)
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Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 186)
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Drupal\Core\Theme\ThemeManager->render('page', Array) (Line: 422)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 201)
Drupal\Core\Render\Renderer->render(Array) (Line: 479)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 97)
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twig_render_template('themes/custom/agrodep/templates/layout/html.html.twig', Array) (Line: 384)
Drupal\Core\Theme\ThemeManager->render('html', Array) (Line: 422)
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Drupal\Core\Render\Renderer->render(Array) (Line: 162)
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call_user_func(Array, Object, 'kernel.view', Object) (Line: 142)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 174)
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Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191)
Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128)
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Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 709)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Why has Africa become a Net Food Importer? Explaining Africa Agricultural and Food Trade Deficits

Authors
Manitra A. Rakotoarisoa, Massimo Iafrate, and Marianna Paschali
Publisher
Food and Agricultural Organization of the United Nations

High-income countries in Africa had high net food imports per capita, but they did not have problems paying for their large food imports because they had ample sources of foreign currencies. [...] Conversely, low-income countries imported less food per capita, but their agricultural export revenues, or even sometimes, their total merchandise export revenues, could not cover their relatively small food import bills.

Publication date
Last version on
Location
http://www.fao.org/fileadmin/templates/est/PUBLICATIONS/Books/AFRICA_STUDY_BOOK_REVISED_low_res.pdf