How did technology spur a second agricultural revolution in medieval times?

Answer 1

A leading cause for new agricultural technology in the Middle Ages was the exposure of Europeans to crops, equipment, and methods that were brought to them by Arabs, particularly in Spain.

There were other causes of change in agriculture. Among them were the inventions of such things as the horse collar, the horseshoe, and the heavy plow, all of which seem to have been European in origin.

Answer 2

Agricultural output was very much increased in the Early Middle Ages because of the introduction of new technology. The important hardware included the horse collar, horse shoes, and the heavy plow. These made it possible for a single farmer with a horse to plow much more land in a day without getting any more tired.

The three field system of crop rotation increased the amount of tillage.

There were a number of other things that were imported from Islamic lands or developed within Europe. There is a link below to a related question dealing with them.