Is polyhouse farming worth it for a small farmer with one acre?

Honestly, a polyhouse can work for a small farmer but only under specific conditions, and it is not a guaranteed path. It suits you if you have assured irrigation, can arrange the upfront capital even with subsidy support, are willing to learn intensive crop management, and have access to a premium market in a nearby city. A small unit of 500 to 1000 sq m is the usual starting size and the family doing the labour itself improves the economics a lot. It does not suit you if you need passive income, cannot give daily attention, or have no buyer beyond the local mandi. The capital and skill demands are real and the failure rate among casual entrants is high. A safer route for many small farmers is to start with a lower cost shade net or net house for one crop, learn the management, and scale up only after proving you can sell the produce. Talk to your district horticulture officer and a working small grower before deciding.