Influence Of Warming And Nitrogen Application On Mineral Nutrition Elements Of Leymus Chinensis Leaves On The Songnen Grassland

Global warming and nitrogen application is the main two problems, temperature and nitrogen is the main limiting factors to plant growth. The change of the earth's surface temperature and nitrogen pattern will be had a profound impact on plant growth. This thesis focuses on Leymus chinesis Tzvel. grassland in Songnen plain. We simulated atmospheric warming and nitrogen application and discussed the change of mineral nutrition elements contents of Leymus chinensis leaves in order to provide theoretical basis for the response to global change.The result showed that the total trend changes of N, P, K content in Leymus chinensis leavess: the highest content is in the early growth, at this time, the contents of leaves should be the most throughout the growing season, and then the contents has gradually declined or ups and downs with the leaves maturing, the lowest contents showed in the end of growth. The content of magnesium ions were dynamic changed similarly with calcium ions. The maximum appears in August and lower appears in initial stage and the end. The content of Leymus chinesis leaves sodium ions showed slow droping during the periods from May to June, and showed slow increasing during the periods from June to July, and showed quick increasing during the periods from July to August, and appeared maximum in the August. After the content had sharply droping, and appeared minimum in the September. Warming treatments haven't significant differences for nitrogen, calcium and magnesium ions, but it was reduced phosphorus by 8.73%,potassium ion by 10.6% and sodium ions by 12.8%. Nitrogen application was increased N by 31.2%, P by 14.2%, sodium ions by 4.32%, calcium ions by 16.1%, magnesium ions by 5.25%,but it reduced potassium ion by 8.41%. Warming and Nitrogen application treatments was increased N by 3.17%,sodium by 9.63%,calcium by 9.83%,but it was reduced P by 13.2%, potassium ion by 9.98%,magnesium ions 6.4%.It is clear that warming reduced ions contents of the plant leaves; to a certain extent, exerting nitrogen was increased to nitrogen, phosphorus, sodium, calcium and magnesium absorption of the plant leaves, but nitrogen and potassium had a certain antagonist role; Warming and Nitrogen application treatment eased the curtailing the negative ion absorption inhibition because of adding N, but reduced P and magnesian ion content of the leaves.