Improving spring maize yield while mitigating nitrogen losses under film mulching system by right fertilization and planting placement

Abstract

Efficient agronomic management strategies, such as “4 R” fertilization techniques combined with rational agronomic practices, are crucial options to overcome the challenge of increasing yields while mitigating environmental hazards. A three-year (2019–2021) field trial was carried out to screen for the right fertilization and planting placement that is suitable for labor-saving and mechanical cultivation practices. Fertilization placement [nitrogen (N) fertilizer was deep applied under the film-mulched band (FM) and in the un-mulched zone (FuM)] and planting placement [seeds were sowed in the film-mulched band (PM) and un-mulched zone (PuM)] were assigned as the main plots and split plots, separately, in a split-plot design. So, there were four treatments (FM-PM, FM-PuM, FuM-PM, and FuM-PuM). The yield, carbon and N accumulation and translocation, root traits and their spatial distribution with soil mineral N, soil N loss, etc., were examined. Results showed that the grain yield of FM and PuM was significantly higher by 10.7 % and 8.8 % than that of FuM and PM, respectively. Root traits and dry matter and N accumulation in maize at the silking stage in FM were higher than those in FuM due to the synergistic root and mineral N spatial distribution in soil profiles. The PuM had higher post-anthesis dry matter and N accumulation than PM, which was attributed to the more root distribution in the un-mulched zone and deep soil (40–100 cm), higher leaf area index and chlorophyll relative content at the milk stage. Compared with FuM, FM cut down the ammonia volatilization loss by 17.6 % and prevented nitrate leaching. The PuM cut down the ammonia volatilization loss by 41.2 % compared with PM. Although there was no significant difference in the yield of FM-PuM, FM-PM and FuM-PuM, lower ammonia loss and smaller deep nitrate leaching in the rooting zone were observed under FM-PuM treatment. The band and deep applied N fertilizer under the film-mulched zone combined with planting in the un-mulched zone (FM-PuM) could be recommended as an effective agronomic practice for rainfed spring maize production with banded film mulching. • The N placement under film-mulched band cut down NH 3 loss and nitrate leaching. • Seeding at un-mulched zone increased post-anthesis dry matter and N accumulation. • The N and planting placement manipulated root and soil mineral N distribution. • Right N and planting placement enhanced maize yield and lowed N loss.