%A CHEN Xiao-Ying,LIU Peng,CHENG Yi,DONG Shu-Ting,ZHANG Ji-Wang,ZHAO Bin,REN Bai-Zhao,HAN Kun %T The root-layer regulation based on the depth of phosphate fertilizer application of summer maize improves soil nitrogen absorption and utilization %0 Journal Article %D 2020 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2020.93029 %P 238-248 %V 46 %N 02 %U {https://zwxb.chinacrops.org/CN/abstract/article_6826.shtml} %8 2020-02-12 %X

Favorable root phenotypes can promote crops to obtain soil nutrients efficiently. The root-layer regulation technology based on the depth of phosphate fertilizer application can optimize the spatial and temporal distribution of summer maize root system and promote its spatial matching with soil water and nutrients to supply, providing a theoretical and technical support for realizing fertilizer saving and efficiency improvement by tapping potential of maize root system. In the present study, there were five treatments including CK (no P applied), P5 (phosphorus placement depth of 5 cm), P10 (phosphorus placement depth of 10 cm), P15 (phosphorus placement depth of 15 cm), and P20 (phosphorus placement depth of 20 cm). The effect of phosphorus application depth on root distribution, plant growth and yield formation, as well as nitrogen uptake, accumulation and transport in summer maize was analyzed. The suitable application depths of phosphate fertilizer promoted the growth of summer maize roots and increased root dry weight, root length density, root surface area and root volume significantly totally showing a trend of P15 > P10 > P20 > P5 > CK. With the increase of phosphate fertilizer application depth, the deep corn roots increased significantly. The proportion of root dry weight in P15 and P20 treatments was 12.3% and 12.1% in the 20-40 cm soil layer, and 6.7% and 6.9% in the 40-60 cm soil layer, respectively. The increase of root distribution depth promoted the absorption of nitrogen in the soil, and the nitrogen content in each soil layer, especially below 20 cm, was reduced significantly by the deep application of phosphate fertilizer. The optimization of root distribution promoted the accumulation and transportation of nitrogen in plants. Compared with P5 treatment, the averaged nitrogen fertilizer absorption efficiency, accumulation amount, accumulation rate, partial factor productivity and the grain yield in two years of P15 treatment increased by 14.5 kg kg -1, 19.2%, 48.9%, 6.4 kg kg -1, and 16.4% respectively, showing that under the conditions of the present study, concentrated application of phosphate fertilizer in -15 cm treatment can significantly promote the growth of deep soil roots, expand the space of nutrient utilization for root system, increase the absorption of nitrogen in deep soil, promote the accumulation and transportation of plant nitrogen, improve the productivity and ultimately yield in summer maize.