These people had advanced knowledge of astronomy and a highly developed agricultural system.

Better management of agricultural systems could provide enough food for the expected global population of 9 billion by 2050, according to a new study.

Its economy became based on the local tobacco-livestock agricultural system.

Those private plots are the most productive sector of their agricultural system.

Hell, it's the only part of the damned agricultural system that works.

These reforms were efforts to resolve perceived problems in military, economic, agricultural, financial and religious systems.

The region was rich in commerce and had a very productive agricultural system.

Having looked at the agricultural system the book turns to an examination of the systems historical development.

They were a very efficient agricultural system and could provide up to seven crops a year.

This is the result of a drought, a war, or some other drastic change to the agricultural system.