Those engaged in agriculture are not employed in the strict sense of terms as we think about employment in factories, firms, government departments, etc. In agriculture, higher incomes accrue to the landholders through higher output prices and higher productivity. Farm labour also benefits as the demand for their services also rises and poverty declines in rural areas too.
Part of this income finds its way into demand for consumer goods. Manufacturers seeing this upsurge respond by first increasing utilization of existing capacity and then expanding capacity through new investment. That is why we have seen double digit growth in investment, manufacturing production and sales and high overall growth rate of GDP.