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A two-year field experiment was conducted to elucidate the adaptive growth mechanism of maize under strip-till (ST) compared with conventional-till (CT). The biomass accumulation of ST plants was significantly lower than CT until V14 (14th leaf), but restored thereafter with one below-ear-node leaf reduced. At silking, the accumulation of nitrogen (N) was reduced by 8.3–10.7% compared to CT. During post-silking, vegetative-N remobilization was reduced by 20.4%, post-silking N uptake increased by 33.9% in ST compared to CT. Leaf senescence was delayed and more green leaf area at physiological maturity in ST. It is concluded that ST plants have the mechanism of ‘Recovery Growth Adaptation’ to get the similar yield as in CT plants: (1) facilitating growth rate at around V14 when the soil temperature was greatly improved to stabilize ear growth and grain number; (2) getting to silking the same time as in CT plants, so as to ensure the duration of grain filling; (3) increasing post-silking N uptake to fulfill the demand of grain development and reduce leaf N remobilization, so as to maintain leaf function and increase thousand-grain weight, which compensate for the loss of grain number per ear.

The effects of 13 plant growth–promoting rhizobacteria (PGPR) from the maize rhizosphere and a model PGPR strain Azospirillum brasilense Az39 on maize growth were monitored in a 3-year field inoculation experiment (from 2018 to 2020) with low-nitrogen (N) (N input reduced by 50%) and low-phosphorus (P) (no P supply) soils in Northeast China. The effects of four efficient PGPR that stably promoted maize plant growth and affected on the composition and function of the rhizobacterial community were further investigated in 2019 and 2020. On average, Sinorhizobium sp. A15, Bacillus sp. A28, Sphingomonas sp. A55, and Enterobacter sp. P24 stably increased grain yield by 8.1–17.8% and 11.0–20.1% in low-N and low-P soil, respectively. Inoculation of these four strains increased the abundance and species richness of rhizobacteria, enriched special beneficial bacteria such as Chloroflexia_KD4-96 and Bacilli, and decreased bacterial functions related to soil-N loss. We conclude that some PGPR can N- and P-use efficiency and maize yield through reshaping the rhizobacterial community.