Abstract:

The paper aims to select high efficient ecology and economic plants suitable for planting in the coastal saline-alkali land of the Yellow River Delta, establish their reasonable planting years and provide technological support for biological management of saline-alkali land. NyPa forage was planted in the heavy saline-alkali wasteland of the Yellow River Delta Horse Farm Base in Hekou District of Dongying City, and the saline-alkali wasteland was taken as the control to explore the soil improvement effect of plants with different planting years. The results showed that: (1) compared with the wasteland of the same period, the soil physicochemical properties of NyPa forage planted for three, six and nine years were greatly improved, which were manifested by the obvious decrease of soil density, salinity and pH value, and significant increase of soil total porosity, organic matter content, available nitrogen content and available phosphorus content, and these seven soil factors were significantly different from those of the same period of the wasteland (P<0.05); while the available potassium content was on the contrary, the content of potassium ions in NyPa grassland was always lower than that in wasteland at the same period, which did not increase the content of potassium ions in soil.(2) with the increase of planting years, the soil physicochemical indexes (soil density, salinity, pH value, total porosity, organic matter content, available nitrogen content and available phosphorus content) of NyPa forage showed a continuous improvement trend, the results of variance analysis also showed that the above soil physicochemical indexes were significantly different in the three time periods of three, six and nine years after planting NyPa forage compared with those before planting (P<0.05), and there were also significant differences between three years’ planting and six and nine years’ planting, but there was no significant difference between six years’ planting and nine years’ planting. Therefore, planting NyPa forage could not only accelerate the process of improving the environmental condition of saline-alkali land, but also have obvious effect from the economic and ecological point of view, the suitable planting period is 5-6 years.

Key words: NyPa forage, native plant, saline-alkali land, soil improvement, effect