The effect of rate of water addition on the response of wheat roots to added nitrogen in a leaching environment

Abstract

Wheat was grown under a range of leaching regimes in columns of a loamy sand soil to which nitrogen had been added as calcium nitrate. Rates of water addition up to depths of 4.5 cm per week were found to have little effect on the amount of nitrogen taken up at 6 weeks after seeding, but higher rates of water addition progressively reduced uptake. Distributions of root length in the soil profiles varied markedly with leaching intensity, and were found to be related to the distributions of mineral nitrogen that had existed in the soil as the roots were growing.