Abstract:

To screen out the optimal forage planting pattern and provide theoretical and technical support for the improvement of degraded farmland and sustainable land use, taking Medicago sativa CV. Aohan and Elymus sibiricus L. as materials, we set 3 different planting patterns: single-seeding Medicago sativa CV. Aohan (Ms), single-seeding Elymus sibiricus L. (Es) and intercropping of these two forage (In), with fallow treatment as the control (CK). The results showed that: with the increase of planting years, the soil available phosphorus content first decreased and then increased; organic matter, available potassium, total nitrogen, total potassium content increased; compared with CK, in the first year, the contents of soil organic matter, available potassium, alkali-hydrolyzed nitrogen and total nitrogen increased under different planting patterns; and the contents of soil total phosphorus and total potassium increased under Ms and In groups; in the second year, the alkali-hydrolyzed nitrogen content of Ms, Es and In decreased by 20.91%-40.05% in 10-20 cm soil layer, and the available phosphorus content decreased by 32.19%-39.65% in 20-40 cm soil layer; the contents of soil organic matter and total potassium increased overall, while the contents of available phosphorus and available potassium decreased; the total phosphorus content decreased significantly in the 20-40 cm soil layer.

Key words: forage, single-seeding, intercropping, degraded farmland, nutrients, planting years