Studies on Changes of Soil Carbon and Nitrogen Dynamics under Long-Term Fertilizer in the Black Soil Based on DSSAT Model

Abstract

Long-term experiment of Gongzhuling base for the study through three treatments(1)NPK: NPK fertilizer; (2)N165M: Manure and NPK fertilizer; (3)1.5M+NPK: 1.5Manure and NPK fertilizer, used DSSAT-Century soil model to study the long-term effects of different fertilizer treatments on soil organic carbon, total nitrogen content and the laws of growth and decline. The results show that: long-term application of nitrogen fertilizer can significantly improve crop yields compare with NPK.. Corn production is also affected by climatic conditions, especially in drought years with less precipitation. Larger impact of organic manure on soil organic carbon (SOC)and total nitrogen, SOC content obtained in descending order of 1.5M + N165> N165> N0 by Century model simulation. Soil organic carbon content and nitrogen content has a certain relevance, and the trend is consistent. Organic manure and inorganic fertilizer can significantly reduce soil inorganic nitrogen content and reduce the risk of nitrogen leaching. Through model simulations C / N ratio could be explained: C / N increases indicated an increase of organic carbon faster than organic nitrogen in soil, and changes of soil chronic library SOM2 determined organic carbon content. Therefore we should pay attention to organic manure carbon return level, vigorously promote the use of farmyard manure to improve soil nutrient content.