Effects of initial watering on nodulation of lupins

Abstract

The need for free water movement through the soil after sowing to obtain good nodulation of yellow lupins (Lupinus luteus) was verified in a glasshouse experiment. Withholding overhead watering after sowing reduced the number of plants nodulated by approximately 30% when compared with surface watering at either one or 3 days after sowing. The amount of nodule tissue of nodulated plants was also lowered. Lime pelleting or a higher rate of inoculation increased the number of plants nodulated, but did not increase the amount of nodule tissue on nodulated plants. With watering 3 days after sowing, fewer plants nodulated and they had less nodule tissue than with watering after one day, unless lime-pelleted seed was used or (in the case of number of plants nodulated) a higher rate of inoculum was used.