Long-term Fertilization Effects On Temporal And Spatial Variation Of Soil Sulfur

Nitrogen, phosphorus and potassium elements have been considered as essential nutrients for plant growth and elemental sulfur is nitrogen, phosphorus and potassium elements is one of the important elements. But in recent years,because of the improper fertilization and tillage system, leads to the lack of sulfur land area continued to increase. This paper under long-term fertilization conditions, brown corn corn soybean rotation system in soil sulfur contents of all forms, transformation and the main influence factors research, reasonable crop rotation and fertilization and fertility provide scientific basis. The results were as follows:(1) The sulfur content of the soil in the soil showed a decreasing trend under long term fertilization or only application of urea; while the long-term application of phosphorus, potassium can increase the sulfur content in soil of different forms (except the acid soluble sulfur content).Long term application of organic fertilizer or organic fertilizer and chemical fertilizer combined application can improve the content of topsoil in addition to effective sulfur and other forms of sulfur and with the organic fertilizer of the increase of the amount of fertilizers increased effect more obvious; and for effective sulfur, although the long-term increasing application of organic fertilizer or mixed with nitrogen, phosphorus and potassium application can also increase the content of soil available sulfur, but due to the absorption of crops, available sulfur accumulation content of deficit, resulting in organic manure group in all treatment soil except M1N1PK and MiNP effective sulfur accumulation showed a decreasing trend.(2)Long term application of organic fertilizer is beneficial to the accumulation of various forms of sulfur in the soil, and the effect of high amount of organic fertilizer is greater than the low amount of organic fertilizer; with the deepening of the soil layer, the content of different forms of sulfur(except for the effective sulfur and acid soluble sulfur)showed a gradual downward trend; in addition to N2, N1 and CK, available sulfur content in 40～80 cm appear obvious accumulation, increasing application of organic fertilizer can reduce the amplitude of its downward leaching, increase tilth soil available sulfur in soil in the proportion increased, to improve the effectiveness of surface soil.(3)The application of organic fertilizer to the growth of corn and soybean is helpful to increase the proportion of residual sulfur in total sulfur, namely high content organic fertilizer area; for each component of the inorganic sulfur, the proportion of the total sulfur is decreased with the increase of the amount of organic fertilizer; in the year of planting maize, the percentage of total sulfur in the soil of different fertilization treatments was higher than that of soybean, and the percentage of residual sulfur was less than that of soybean; the other two kinds of organic sulfur components(C-bonded S and ester-S)are not too much to do with the variety of cultivated crops, whether the application of organic fertilizer.(4)Studies have shown that acid soluble state sulfur and soil pH were positively correlated, effective sulfur,water soluble state total sulfur and pH was negatively correlated, which correlation between available sulfur and pH reached extremely significant level. The content of total sulfur, water soluble sulfur, adsorbed sulfur, ester bond sulfur, carbon bond sulfur and organic carbon were positively correlated, which soil total sulfur, between ester sulfur and carbon bonded sulfur and organic carbon reached extremely significant level.