INFLUENCE OF N SPLIT APPLICATION ON NH3 VOLATILIZATION LOSSES AND N RECOVERY EFFICIENCY FROM PLASTIC MULCHING MAIZE IN LOESS PLATEAU, CHINA

Wang, S. J. , Luo, S. S. , Gao, Q. , Li, S. Q.

2019 APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 2019   17(卷), 4(期), (9215-9227页)

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Ammonia (NH3) volatilization is one of the main reasons of applied-N loss from agricultural cropping systems. Adjusting the application timing of N fertilizer to improve temporal synchronicity between crop-N demand and soil-N availability could result in higher nitrogen (N) recovery efficiency (NRE) and lower N losses. A two-year experiment was conducted to investigate the effect of split fertilizer N application on NH3 volatilization, grain yield, and NRE. Four treatments were included according to the N application ratio: (i) a single application of total N fertilizer at sowing (N1), (ii) N applied with two splits at a ratio of 4:6 (N2), (iii) N applied with three splits at a ratio of 4:3:3 (N3), and (iv) no N applied as a control (N0). The results show that NH3 fluxes peaked at 3-5 days after fertilization and then dropped sharply within the next week. NH3 fluxes increased significantly with N application rate and were significantly and positively correlated with soil NH4+-N content. Slight precipitation (< 10 mm) promoted NH3 volatilization, while heavy precipitation (> 10 mm) restrained it. Applying N with two or three splits significantly increased the grain yield, total N uptake, and NRE of maize and significantly reduced NH3 volatilization losses.