EFFECT OF SOIL DEPTH ON WATER MANAGEMENT OF ROMAINE LETTUCE (LACTUCA SATIVA L.) CULTIVATED IN A MUCK SOIL

L. Plamondon, L. Gaudreau, A. Gosselin, J. Caron, S. Jenni, D. Van Winden
In Canada, field lettuce growers have difficulties to irrigate properly without causing nutrient leaching in muck soils. Thus, it is important to make an optimal use of water and fertilizers for these soils. A greenhouse study was conducted to determine the optimal soil water matric potential required for initiating lettuce irrigation. Romaine lettuce transplants (‘Sunbelt’) were seeded and grown in sphagnum peat cubic blocks for 14 days. Lettuce transplants were then transplanted into 84 and 250-L plastic containers 30 and 100-cm deep respectively. The containers were previously filled with large muck soil blocks by keeping the stratification to reduce soil disturbance and placed in greenhouse. High pressure (HPS) sodium lamps supplied a supplemental PPF of 500 µmol m-2 s-1 for a photoperiod of 16 h approximately. HPS lamps were turned off at a PPF of 500 µmol m-2 s-1. Temperatures were maintained at 21°C during the day and at 17°C during the night. Transplants were hand-irrigated whenever 4 different soil water matric potentials were reached (-10, -20, -30 or -50 kPa), as measured with tensiometers. Plant fresh weight, leaf number, as well as photosynthesis rate were measured forty-five days after transplanting. Soil water was depleted at 30 and 60-cm depth, 15 and 30 days after transplantation respectively. No decrease in yields resulted from irrigation of low soil matric potential (-30 and -50 kPa) in the 100-cm deep container. These results imply that growers could gradually supply more water less frequently, as root can explore deeper soil horizons with time.
Plamondon, L., Gaudreau, L., Gosselin, A., Caron, J., Jenni, S. and Van Winden, D. (2011). EFFECT OF SOIL DEPTH ON WATER MANAGEMENT OF ROMAINE LETTUCE (LACTUCA SATIVA L.) CULTIVATED IN A MUCK SOIL . Acta Hortic. 889, 453-458
DOI: 10.17660/ActaHortic.2011.889.57
https://doi.org/10.17660/ActaHortic.2011.889.57
lettuce, irrigation, soil matric potential, greenhouse, muck soil, yields
English

Acta Horticulturae