Effect of subsurface drip irrigation on root growth and water utilization of maize in Xiliao River Plain

Abstract

【Objective】 Subsurface drip irrigation is a water-saving technique that involves burying emitters in the soil. Its efficacy depends on irrigation amount. This paper investigates the impact of irrigation amount in subsurface drip irrigation on root growth and water use efficiency of maize cultivated in the Xiliao River Plain, Northeastern China. 【Method】 The experiment was conducted in a maize field in the Keerqin District of Tongliao City, comprising six treatments with its associated irrigation amount being 220 mm (CK), 195 mm (W1), 170 mm (W2), 145 mm (W3), 120 mm (W4), and 95 mm (W5), respectively. For each treatment, we measured root distribution and water use efficiency. 【Result】 The spatial distribution patterns of root dry matter, root length, root surface area, and root diameter in the 0-40 cm soil layer at the maturity stage were similar across all treatments. As the irrigation amount decreased, these root characteristics initially increased and then decreased. The total water consumption of the maize during its growing season decreased with reduced irrigation amount, while the relationship between kernel yield and irrigation amount followed a quadratic pattern. With increasing irrigation amount, water use efficiency initially increased and then declined, with W2 achieving the highest water use efficiency at 2.46 kg/m3. Grain yield showed significant positive correlations with root weight density, root length density, and root surface area density in the 0-20 cm soil layer, and root diameter in the 30-40 cm soil layer. Net benefit increased with reduced irrigation among initially and then declined, with the highest net benefit of 20 098 Yuan/hm2 achieved when the irrigation amount was 170 mm. 【Conclusion】 Subsurface drip irrigation is a water-saving technology, applicable for maize production in Xiliao River Plain in the northeastern China. The optimal irrigation amount was 170 mm.

Keywords

• shallow buried drip irrigation
• maize
• root traits
• water use efficiency
• irrigation regime