The effect of soil compaction on growth, yield and nitrogen use efficiency of maize in black soil

【Objective】 Black soil is widely distributed in northeastern China and other countries. Machinery operations in agricultural production in these regions has resulted in soil compaction. In this paper, we investigated the impact of soil compaction on growth, yield, and nitrogen use efficiency of maize in the black soil. 【Method】 The field experiment compared three soil compactions: low compaction (C1), moderate compaction (C2) and high compaction (C3). For each compaction, there were two fertilization treatments: nitrogen fertilization (F) and no fertilization (F0). In each treatment, we measured the growth, yield and nitrogen use efficiency of the maize. 【Result】 Increasing soil compaction significantly reduced leaf area index (LAI) and plant height of the maize. Nitrogen fertilization affected plant height significantly but did not impact LAI at significant levels. Soil compaction also impacted grain yield significantly, with the high and moderate soil compaction reducing grain yield by 24% and 10%, respectively, compared to the light compaction. Soil compaction and nitrogen fertilization combined to impact nitrate in the soil. Elaborated soil compaction inhibited maize growth, reduced nitrogen absorption, leading to an increase in residual nitrate nitrogen in soil as a result. Soil compaction also influenced nitrogen uptake and its subsequent translocation in the above-ground part of the maize. Nitrogen fertilization increased nitrogen absorption by the crop significantly, but reduced nitrogen use efficiency, especially in the high compaction treatment. 【Conclusion】 Elaborated compaction of the black soil due to machinery operations severely inhibited growth, absorption and use of nitrogen of the maize, thereby leading to an increase in residual nitrate nitrogen in the soil and reducing grain yield as a result.