Productivity and Water Source of Intercropped Wheat and Rice in a Direct-sown Sequential Cropping System: The Effects of No-tillage and Drought

Effects of Subsoiling to the Non-tilled Field of Wheat-Soybean Rotation on the Root System Development, Water Uptake, and Yield

“…3). By analyzing the deuterium concentration in xylem sap water, the source of water absorbed by the field grown crop species can be estimated (Iijima et al, 2005;Iijima et al, 2007). In wheat, water uptake trend in no-tillage indicated significantly higher dependence on recently supplied surface water, which agrees with our former findings (Iijima et al, 2007).…”

“…The heavy water application was regarded as the recent rainfall or recently irrigated water. About 15 hr after the application of the deuterated water, xylem sap was collected from the labeled plants and analyzed following the method of Iijima et al (2005Iijima et al ( , 2007.…”

Water Competition of Intercropped Pearl Millet with Cowpeaunder Drought and Soil Compaction Stresses

“…The compacted soil layer shows higher penetration resistance, causing mechanical stress to root elongation . No-tillage practice also often causes an increase in mechanical stress in the top soil (Iijima et al, 2003;Izumi et al, 2004a and b;Iijima et al, 2005). Besides the negative effect on root elongation in the deep soil layer (Araki and Iijima, 1998, soil compaction hinders water movement and distribution in the soil, limiting the availability of water and nutrients to plants (Rosolem et al, 2002).…”

“…Variations in the relative abundance of deuterium in plant xylem sap have been used as an indicator of water uptake from a simulated rainfall event (recently irrigated water) and existing soil water Dawson, 1993;Zegada-Lizarazu and Iijima, 2004;Araki and Iijima, 2005;Iijima et al, 2005). Water is the only source of hydrogen for plants, and no isotopic fractionation occurs during the movement of water from the roots to the shoot base.…”

Establishment rate of direct-seeded rice in the relay-intercropping system in Kanto region of Japan

“…Hamana and Kobayashi (1978) emphasized that SER in DSRI, which were seeded near the row of winter cereals, was low. Iijima, Asai, Zegada-Lizarazu, Nakajima, and Hamada (2005) suggested that rice seedlings and wheat might compete for water in a sequential double-cropping system with no-tillage seeding of wheat. Therefore, appropriate soil-water conditions are needed to ensure the stability of SER in DSRI.…”