Response of Maize Root Growth to Residue Management Strategies

Abstract

Core Ideas Efficient use of crop residues can improve circular economy in agro‐ecosystems.Amount of stover to the field explained the variation in root length density and root dry weight density in double cropping of winter wheat and summer maize.Returning stover increased the yield of summer maize.Root characteristics and the yield of summer maize improved by returning stover. A 5‐yr experiment was conducted to explore the effects of returning various amounts of stover to the field on root characteristics and yield in a wheat (Triticum aestivum L.) and maize (Zea mays L.) double‐cropping system. The experiment was designed as a randomized block design with three replications for three treatments: based on all stalks of winter wheat returned to the field (i) all summer maize stalks were mechanically pulverized and returned to the field (SR); (ii) half of the summer maize stalks were mechanically pulverized and returned to the field (1/2 SR); and (iii) all summer maize stalks were fully removed (CK). Results indicated that, in the SR treatment, root fresh weight (RFW) and root dry weight (RDW) were 19.4 and 18.5% higher, respectively, compared with the CK treatment. Root length density (RLD), root surface area density (RSAD) were 13.7 and 29.4% higher in the SR treatment, compared with the CK treatment. The yield of summer maize was 15.1 and 17.1% higher in the SR and 1/2 SR treatments, respectively, compared with the CK treatment. Furthermore, RLD, RSAD, root dry weight density (RDWD), and root length in the 1/2 SR treatment were significantly higher than those in the SR treatment. These results indicated that moderate amounts of straw returned to the field had the greatest effect on root growth and development of maize. This work provides a theoretical basis for optimizing crop yield and the use of straw resources.