Effects of early soil water distribution on the dry matter partition between roots and shoots of winter wheat

This research was aimed at testing the influence of Various soil water profiles on root biomass distribution in winter wheat (Triticum aestivum L.), and the relationship of dry matter partitioning between roots and shoots. Wheat plants were grown in boxes with length 30 cm x width 7 cm and 200 cm deep. The boxes were divided into two soil layers at half the column. Three treatments were employed: (a) both soil layers were wet close to field water capacity (WW), (b) both the layers were dry (DD), (c) the bottom soil layer was wet and the top soil layer was dry (DW). Water treatments started on 3 March. Plants were harvested at 15 days after anthesis for measurements. The results showed that treatment DW maintained the highest soil water content, plant water content, and had a larger root system. Root dry matter in the bottom soil layer, flag leaves, spikes and yield potential were also highest for this treatment. Water use efficiency decreased in the sequence DD > DW > WW. Drought-stressed plants had higher water use efficiency than well-watered plants. (C) 2001 Elsevier Science B.V. All rights reserved.