EFFECT OF CONTROLLED-RELEASE FERTILIZER ON MAIZE YIELD AND NUTRIENT UPTAKE UNDER A ONE-TIME FERTILIZER LAYERED SYSTEM

Currently, maize production in China suffers from many problems such as excessive fertilizer application, inefficient fertilizer use and insufficient agricultural labour. This research explores the efficient fertilization pattern of maize for fertilizer decrease and yield increase by studying the effect of one-time mechanical point-applied fertilization of controlled-release compound fertilizer in the root-zone, on yield and nutrient uptake. There were six treatments in the application program: 1) no fertilizer (CK); 2) a one-time banding fertilizer application (BDP) 5 cm off the seeds between rows and 10 cm deep; 3) one-time point-applied fertilization (RZF) 5 cm off seed in the row and 10 cm deep; 4) a layered banding application 5 cm off seed, 10 cm and 20 cm deep between rows at a rate of 3:7 (LBD); 5) a 5 cm off seed, 10 cm deep point-applied fertilization, and 20 cm banding application between rows at a rate of 3:7 (LRZ); 6) a fertilizer reduction of 10% between rows at a rate of LRZ (90% LRZ). The results showed that the one-time mechanical layered application of slow-release compound fertilizer (LRZ and LBD) in the root zone increased yields by 11.97% and 11.15%, respectively, compared to the non-layered application of slow-release compound fertilizer (BDP and RZF), and the differences were significant, indicating that mechanical layered application can replace the BDP mode and achieve increased crop yield. The average increase in agronomic efficiency and partial factor productivity of 25.95% and 11.15% for LBD over BDP and 26.10% and 11.97% for LRZ over RZF were significant, indicating that mechanized stratified fertilizer application can significantly improve fertilizer utilization and reduce fertilizer losses and surface source pollution.