Abstract:To investigate the effects of different fertilizerair coupling treatments on crop growth characteristics, photosynthetic characteristics and yield under cycle aerated subsurface drip irrigation, tomato (Jinglu 6335) was taken as the research object, and the recycling aeration device was used to supply water, fertilizer and gas. Four aeration quantities (O1 was high aeration, O2 was medium aeration, O3 was low aeration, S was no aeration, aeration ratio was 16.25%, 14.58%, 11.79% and 0, respectively), three fertilizer quantities (F1 was high fertilizer, F2 was medium fertilizer, F3 was low fertilizer) were set, and a two-factor randomized block experimental design was adopted, with a total of 12 treatments. The effects of different fertilizer-air couplings on plant growth characteristics, chlorophyll content, photosynthesis, plant dry matter accumulation and yield of greenhouse tomato were studied. The results showed that cycle aerated subsurface drip irrigation could significantly increase plant height, stem diameter, leaf chlorophyll content and stomatal conductance, enhance photosynthesis, and increase dry matter accumulation and yield of greenhouse tomato. The plant height and stem diameter were increased with the increase of aeration. The maximum increase of plant height and stem diameter was 22.57% and 7.25% respectively in aerated irrigation treatment compared with nonaerated irrigation treatment. At the same fertilization levels, compared with non-aerated irrigation, the net photosynthetic rate, stomatal conductance and transpiration rate of high aeration irrigation treatment were increased by 52.46%, 60.64% and 36.88% respectively, the contents of chlorophyll a and chlorophyll b were increased by 33.17% and 48.71%, respectively. The plant dry matter accumulation and fruit dry matter accumulation under high aeration irrigation at medium fertilizer level were increased by 31.66% and 36.95% on average, and the yield of single plant and the weight of single fruit were increased by 12.80% and 19.51% compared with that of nonaerated irrigation. At the same aeration level, plant height, stem diameter, net photosynthetic rate, chlorophyll a, chlorophyll b and plant dry matter accumulation of tomatoes under medium fertilizer treatments were significantly increased compared with those under high and low fertilizer treatments. The yield of tomato single plant was significantly positively correlated with plant height, stem diameter and net photosynthetic rate (P<0.01), and the correlation coefficient between yield and plant height, stem diameter and net photosynthetic rate of tomato under medium fertilizer treatment in high aeration irrigation was higher than that of other treatments. Therefore, considering the effects of various treatments on the growth characteristics, photosynthetic characteristics, plant dry matter accumulation and yield, the medium fertilization level in high aeration irrigation was the preferable irrigation and fertilization mode for greenhouse tomato.