The supermarket chain's 20 by 20 Sustainability Plan, launched last week, also included an expectation that its suppliers will be "leaders in meeting or exceeding our social and environmental standards".
Own-brand suppliers will also have to work towards a 50 per cent cut in carbon emissions.
Welcoming the commitment, NFU president Peter Kendall said: "This additional demand will send a really positive signal to the industry at a time when farmers are facing massive investment pressures."
Sainsbury's sources more than £4bn worth of produce annually from UK suppliers and last week reported strong crop yield of British-grown brassicas and onions this season. It is also taking delivery of late strawberries and the first batch of Beni Shogun Fuji apples from growers in Suffolk and Kent.
Horticulture manager Jo Hipperson said: "Our growers have overcome the challenges of the warm spring and wet summer by carefully monitoring fluctuations in soil moisture. As a result, we are now seeing fantastic yields in British produce."
The supermarket has also claimed to be the largest retailer of UK apples and pears for the third consecutive year. During the current season, it will offer 51 British apple and nine pear varieties.
British branding - Growers' profile raised
The Co-operative has introduced packaging for seasonal British-grown fruit and vegetables to reinforce customer perceptions of their provenance.
Set against a Union Jack, the designs include pictures and comments from the produce's growers, including four from its own farms.
In addition, a quick response code on some lines will link to a website with more details on the product, its growers and sample recipes.
The company's new packaging is due to be rolled out across the nearly 3,000-strong chain over the next 12 months, in line with the British season for each crop.
The Co-operative manages 15 farms across the UK, consisting of 20,000ha of field crops.
Co-operative Farms managing director Christine Tacon said: "Research told us that our customers trust British farmers to deliver great quality produce and they value our support of UK farming."
She continued: "This bold new packaging will enable our customers to support these growers and also get the freshest and highest-quality products when they are at their best."