Effects of arbuscular mycorrhizal fungi on phosphorus and potassium absorption at grain filling stage under different nitrogen fertilizer input in maize

Understanding the effects of arbuscular mycorrhizal fungi（AMF） on maize grain phosphorus（P） and potassium（K）absorption at grain filling stage with nitrogen（N） fertilizer input could provide a theoretical basis for the rational application of biological fertilizers in farmland and the improvement of nutrient uptake and utilization in farmland. Two factorial pot experiments were established during maize growth periods in Zhengzhou and Shangqiu. The two factors were N fertilizer rates(N1: 180kg N hm–2; N2: 270 kg N hm–2), and mycorrhizae treatments（M0: no AMF inoculation; M1: AMF inoculation）. Maize grain weight, plant biomass, root characteristics, plant P and K content and their accumulation were measured. Both N fertilizer rates and mycorrhizae significantly affected maize 100-kernel weight, grain-filling rate, root characteristics, plant P and K content, and their accumulation in Zhengzhou and Shangqiu, respectively. Grain P accumulation increased gradually at grain filling stage,while grain K accumulation i