Effects of varied water regimes on root development and its relations with soil water under wheat/maize intercropping system.

Background and Aims: Understanding the characteristics of root system is important for optimization of intercropping systems and increased utilization efficiency of limited resources. However, few studies have examined root development and water uptake in wheat/maize intercropping system under different water conditions. Methods: A two-year field experiment of sole wheat, sole maize, and intercropped wheat/maize was carried out under rainfed conditions and supplementary irrigation. Roots of wheat and maize were sampled seven times over the two growing seasons (2014–2015 and 2015–2016) using auger and monolith methods. Results: Root growth and distribution were promoted in intercropped wheat, while in intercropped maize roots both were suppressed. The maximum lateral extension distance of intercropped wheat under rainfed conditions varied from 40 to 50 cm during the co-growth period, which was significantly (p < 0.05) greater than that under supplementary irrigation conditions (25–30 cm), allowing intercropped wheat to access soil water in the area between the wheat and maize strips. Meanwhile, after wheat harvest, intercropped maize roots grown under supplementary irrigation showed growth recovery mainly in a horizontal direction with maximum lateral distance of 50 cm. Conclusions: Intercropping boosted the capacity of wheat roots but suppressed root growth in maize, and rainfed conditions encouraged the lateral distribution of intercropped wheat roots. [ABSTRACT FROM AUTHOR]