Abstract:

In order to explore the rapid and scientific improvement model of soil fertility in newly cultivated land,it took the maize wheat rotation system of newly cultivated land as the research object,and conducted different fertilization treatment experiments (including no fertilization control (CK),organic fertilizer 15 t/ha(OF15),chemical fertilizer (MIN),organic fertilizer 7.5 t/ha+fertilizer (OF7.5+MIN),organic fertilizer 15 t/ha+fertilizer (OF15+MIN),and organic fertilizer 30 t/ha+fertilizer (OF30+MIN)).Based on the basic data of soil physical and chemical properties such as total nitrogen,alkaline nitrogen,available phosphorus,available potassium,and organic matter,the integrated fertility index (IFI) of soil nutrients was used to quantitatively and comprehensively evaluate the soil fertility of different fertilizers.The results showed that:on the basis of applying chemical fertilizers to newly cultivated land, organic fertilizers were added to improve soil available nutrients, increasing soil total nitrogen by 108.6%-149.0%, soil alkali hydrolyzed nitrogen by 253.6%-311.0%, soil available phosphorus by 78.8%-171.6%, soil available potassium by 35.6%-80.5%, soil organic matter content by 5.8%-41.9%, soil capacity by 1.0%-8.3%, soil pH value by 3.4%-7.3%, soil fertility comprehensive index by 21.6%-27.7%, and annual yield of corn and wheat by 33.2%-127.1%. The available nutrients, organic matter, soil fertility level, and annual yield of corn and wheat in newly cultivated land all showed an increasing trend with the increase of organic fertilizer application, among which 30 t/ha of organic fertilizer had the best effect. Compared with the application of organic fertilizer alone, the combination of organic fertilizer and chemical fertilizer effectively increased soil organic matter and soil comprehensive fertility index by 12.3% and 22.0%, respectively. In summary, under the conditions of this experiment, the combination of organic fertilizer and chemical fertilizer resulted in higher soil comprehensive fertility and annual crop yield compared to single application of chemical fertilizer or single application of organic fertilizer. The treatment with 30 t/ha of organic fertilizer and 2+chemical fertilizer significantly improved the soil fertility and crop yield of newly reclaimed farmland.

Key words: Corn, Wheat, Newly cultivated land, Organic fertilizer, Annual production, Soil comprehensive fertility index