Research Progress on the Physiological Mechanisms and Regulatory Effects of Subsoiling Depth on Spring Maize Yield Formation

As one of the world's three major grain crops, maize is a key crop for ensuring food security. However, problems such as compacted plow pan, insufficient soil water retention capacity, and relatively low resource use efficiency severely limit the yield potential of spring maize in China. Subsoiling, as a crucial tillage practice for improving soil structure, promoting crop root growth, and enhancing the efficiency of water and nutrient utilization, holds significant application value in spring maize production. The depth of subsoiling is a key parameter affecting its effectiveness. An appropriate subsoiling depth (35~40 cm) creates a water-and-nutrient synergistic environment by altering soil moisture, aeration, and nitrogen utilization processes. This promotes deeper root growth and optimized root morphology, thereby expanding the resource "pool" and providing sufficient photosynthetic "sources", which in turn affects the formation of ear number, kernel number per ear, and thousand-kernel weight to regulate spring maize yield. This paper reviews the physiological mechanisms and regulatory effects of subsoiling depth on spring maize yield formation. It conducts an in-depth analysis of research methods, water use, soil aeration, nitrogen transport efficiency, and other aspects, summarizes yield performance under different soil types and subsoiling depths, and looks forward to future research directions, aiming to provide a theoretical basis for high-yield and efficient cultivation of spring maize.