Root Lodging Resistance in Maize (Zea mays L.) Under Conservative Strip-Till Cultivation System

Abstract

Root lodging significantly affects maize yield and is influenced by both genotypes and soil characteristics. Strip-till (ST) is a conservative cultivation method that disturbs only the planting strip, leaving the remaining soil undisturbed and covered with maize residues. Less is known about the effect of ST on root lodging. Here, a field experiment was conducted in Northeast China in 2020 and 2021 with 20 maize genotypes to study the relationship between root lodging and soil environment and root system architecture (RSA) under ST. Compared with conventional-till (CT), in which the maize residues were cleared and the soil was cultivated using a rotary tiller, ST led to a smaller and narrower RSA, with crown root length reduced by 9.5% and crown root biomass reduced by 9.3%. Additionally, inter-row root expansion angle and width were smaller by 5.3% and 17.3%, respectively. Despite these reductions, the root lodging rate in ST plants was significantly lower than in CT plants, with an absolute decrease of 25.5%. This enhanced resistance is attributed to the increased soil strength in the inter-row, where the soil bulk density was 10.3% higher and the soil porosity was 10.2% lower in the 0–10 cm layer. Notably, certain maize genotypes, such as ZD958, developed a greater number of fine roots in the compacted inter-row soil, showing a 66.4% increase compared to XY335 in the 0–12 cm soil layer. This trait contributed to improved resistance to root lodging. In conclusion, ST enhances root lodging resistance and offers opportunities to increase maize yield through optimised management practices, including the selection of high-yielding cultivars with wide RSA.