EFFECTS OF NITROGEN AND THREE SOIL TYPES ON MAIZE (ZEA MAYS L.) GRAIN YIELD IN NORTHEAST CHINA

The study aimed to understand the effects of nitrogen (N) and soil types on maize (Zea mays L.). Grain yield (GY) is essential for identifying optimal N fertilizer management practices and agricultural policies. In this study, we report results from an on-farm experiment carried out from 2009 to 2012 with five N levels and three soil types in Northeast China Results revealed that the GY was affected significantly by soil types, with loam soil having an average GY of 10225 kg ha(-1), followed by clay soil (9218 kg ha(-1)) and sandy soil (6434 kg ha(-1)). The optimal N rates required to achieve maximum GY were on average 182, 173, and 160 kg ha(-1), and the corresponding maximum GYs were 10872, 9999, and 7266 kg ha(-1) for loam, clay, and sandy soils, respectively. The optimum N treatment (168 kg N ha(-1)) reduced residual nitrate N content and N losses by 97 and 451 kg N ha(-1), respectively, and improved N recovery efficiency (REN) by 17%. In conclusion, within-field soil management zones based on soil textural classes could be used to guide soil sampling and establish soil-specific N fertilizer recommendations to achieve high GY with high REN in Northeast China.