The expansion of agricultural land on the largest scale took place during the Gupta age.

During the Gupta period, which lasted from the 4th to the 6th century CE, there was a significant increase in agricultural activities and land cultivation. This period is often referred to as the "Golden Age of India" as it witnessed advancements in various fields, including agriculture.

The Gupta rulers implemented several measures to promote agriculture and increase agricultural output. These measures played a crucial role in expanding agricultural land and boosting agricultural productivity.

Here are the key factors that contributed to the expansion of agricultural land during the Gupta age:

1. Land Grants: The Gupta rulers were known for granting land to agricultural communities and farmers. These land grants aimed to encourage cultivation and settlement in new areas, thus leading to the expansion of agricultural land.

2. Irrigation Systems: The Gupta rulers also focused on the development of irrigation systems. They constructed canals, reservoirs, and tanks to ensure the availability of water for agriculture. The establishment of efficient irrigation systems allowed farmers to cultivate larger areas of land.

3. Agricultural Technology: The Gupta age witnessed advancements in agricultural technology. Farmers started using improved tools such as iron plows, sickles, and harrows, which made cultivation easier and more productive. The introduction of new agricultural techniques, such as crop rotation and multiple cropping, also contributed to increased agricultural land expansion.

4. Trade and Commerce: The Gupta period saw significant growth in trade and commerce. The expansion of trade routes and the flourishing trade network facilitated the exchange of agricultural products. This led to increased demand for agricultural produce and encouraged farmers to cultivate more land to meet the market demands.

5. Population Growth: The Gupta age witnessed a growth in population, which created a demand for more food. To meet this demand, farmers expanded their agricultural activities and cultivated more land.

The combination of these factors during the Gupta age resulted in the largest scale expansion of agricultural land in ancient India. This expansion played a crucial role in supporting the growing population, promoting economic prosperity, and establishing the Gupta empire as a powerful and prosperous kingdom.