Adapting Root Distribution and Improving Water Use Efficiency via Drip Irrigation in a Jujube (Zizyphus jujube Mill.) Orchard after Long-Term Flood Irrigation

Abstract

Jujube tree yields in dryland saline soils are restricted by water shortages and soil salinity. Converting traditional flood irrigation to drip irrigation would solve water deficit and salt stress. The root distribution reacts primarily to the availability of water and nutrients. However, there is little information about the response of jujube roots to the change from flood irrigation to drip irrigation. In this context, a two–year experiment was carried out to reveal the effects of the change from long–term flood irrigation to drip irrigation on soil water, root distribution, fruit yield, and water use efficiency (WUE) of jujube trees. In this study, drip irrigation amounts were designed with three levels, i.e., 880 mm (W1), 660 mm (W2), 440 mm (W3), and the flood irrigation of 1100 mm was designed as the control (CK). The results showed that replacing flood irrigation with drip irrigation significantly altered soil water distribution and increased soil moisture in the topsoil (0–40 cm). In the drip irrigation treatments with high levels, soil water storage in the 0–60 cm soil layer at the flowering and fruit setting, and fruit swelling stages of jujube trees increased significantly compared with the flood irrigation. After two consecutive years of drip irrigation, the treatments with higher irrigation levels increased root length density (RLD) in 0–60 cm soil depth but decreased that in the 60–100 cm depth. In the horizontal direction, higher irrigation levels increased RLD in the distance of 0–50 cm, while reducing RLD in the distance of 50–100 cm. However, the opposite conclusion was obtained in W3 treatment. Additionally, in the second year of drip irrigation, W2 treatment (660 mm) significantly improved yield and WUE, with an increasing of 7.6% for yield and 60.3% for WUE compared to the flood irrigation. In summary, converting flood irrigation to drip irrigation is useful in regulating root distribution and improving WUE, which would be a promising method in jujube cultivation in arid regions.

Modeling of soil moisture movement and wetting behavior under point-source trickle irrigation

“…Significant changes in water content at different soil depths with changes in flow rate and duration were associated with proper distribution and longer water opportunity times. This conclusion is similar to that of Sun et al 14 and Li et al 97 . Soil vertical wetting circle expanded to more than 20 cm in 120 min of water flow.…”

Soil Moisture, Nutrients, Root Distribution, and Crop Combination Benefits at Different Water and Fertilizer Levels during the Crop Replacement Period in an Apple Intercropping System

“…After crop replacement, the comprehensive benefits of drip irrigation treatments were higher than those of flood irrigation treatments. The reason for the observation could be that drip irrigation can effectively improve water and nutrient utilization efficiency when compared to flood irrigation [43], which enhances the growth and development of crops, as well as ADMQ accumulation, and increases crop yield, thereby resulting in higher RLDs under drip irrigation treatments than those observed under flood irrigation treatments. Maize RLD did not contribute significantly toward PC1 in 2020, although all nine indicators contributed significantly toward PC1 in 2021.…”

Effects of water volume of drip irrigation on soil bacterial communities and its association with soil properties in jujube cultivation

“…One previous study reported that DI aided during the cell expansion period of jujube fruit growth to conserve water while ensuring that the fruit receives adequate moisture (Wang et al, 2021). Another study revealed that DI could reconstruct the root distribution of jujube trees and improve water use efficiency (Li et al, 2021). Moreover, one study has been performed on appropriate water and fertilizer scheduling that can significantly improve the yield of jujube trees after flood irrigation changed to DI (Wang et al, 2018).…”