The nitrate content of lettuce in nutrient solution. 2. Nitrogen level and ammonium:nitrate ratio; replacement before harvest by a solution with a higher proportion of ammonium
Steenhuizen, J.W.; Boon, J. van der
Rapport, Instituut voor Bodemvruchtbaarheid, Netherlands (1-85): 85
1985
Accession: 001712632
In further NFT trials to reduce the nitrate content of lettuces (cultivars Panvit, Myranda and Ravel) at harvest, plants were grown in winter or spring in circulating solutions with 2.5 or 10 meq N/litre as NO3, or with 20% of the total amount of N as NH4 and the remainder as NO3. Towards the end of the growing period (5-21 days before harvest) some of the solutions were replaced by one with equal proportions of ammonium-N and nitrate-N at 2.5 or 10 meq total N/litre.