Effect of Row Space on Photosynthetic Index and Seed Yield of Elymus sibiricus L.

In this study, with Elymus sibiricus L. being experimental material, a randomized block design was utilized with five row gradients (30cm, 45cm, 60cm, 75cm, 90cm) . In the third year, the photosynthetic parameters (photosynthetic rate, transpiration rate, stomatal conductance, etc.) and production index were measured and analyzed. The results showed that: with the increasing of row space, the photosynthetic rate was strengthened. The photosynthetic rate in the row space of 30cm was highly significant lower than that of other row space. When row space increased, the trend of intercellular CO2 concentration and photosynthetic rate was reverse. Yet when row space was lower than 75cm, the transpiration rate, stomatal conductance and vapor pressure deficit was consistent with the photosynthetic rate. The photosynthetic rate was significantly negatively correlated with grass production because of the significantly negative correlation between the photosynthetic rate and the vegetative branches and total tiller. But the photosynthetic rate was significantly positively correlated with seed yield because of the significantly positively correlation between the photosynthetic rate and seeds and florets per fertile tiller. Therefore, under the appropriate row space condition, irrigating timely, because of changing transpiration rate and photosynthetic rate, would increase seed production.