Boron deficiency in white clover ( Trifolium repens L.) seedlings grown in an organic soil

In a pot trial using Rukuhia peat, white clover ( Trifolium repens L.) seedlings grown without added boron developed distinctive deficiency symptoms. The addition of borax at 20 lb per acre increased the dry matter yield five‐fold at the first harvest. This response diminished in subsequent harvests, and after three harvests there was no response in dry matter yield. Boron application increased the boron content of the plants at all harvests but it affected the nitrogen content of the plants in the same way as it did dry matter yield. It is concluded that the effect of boron was an indirect one and that it operated through an effect on the nitrogen nutrition of the clovers. A considerable amount of the added boron was rendered insoluble in hot water during the period of the trial.