Abstract:

To investigate the evolution and distribution of soil nutrients in tobacco-growing areas, 450 soil samples were collected in Luliang County. The classical statistical methods were used in combination with geostatistical and geographic information technology to analyze the abundance and deficiency and spatial-temporal variation of soil nutrients. The results showed that the average values of soil pH, organic matter, alkali-hydrolyzable nitrogen, available phosphorus and available potassium of tobacco-planting soil in Luliang County were pH 6.01, 2.64%, 108.47 mg/kg, 41.69 mg/kg and 200.93 mg/kg, respectively. Except for the medium variation of pH, other nutrients were belonged to strong variation. The contents of pH, organic matter and alkali-hydrolyzable nitrogen were appropriate, but the proportions of soil pH, soil organic matter and nitrogen fertilizer needed increasing were 37.42%, 27.62% and 37.64%, respectively. At the same time, the contents of available phosphorus and available potassium were rich, and the proportion of rich and suitable ranges reached 89.09% and 83.07% respectively. There were no significant differences in pH and organic matter among years, but they showed decreasing trends. There was significant difference in alkali-hydrolyzed nitrogen and showed a trend of first increasing and then decreasing. There were significant differences in available phosphorus and available potassium and showed tendency to decrease and later increase. The spatial distribution pattern of pH value showed a transition from low in the west to suitable in east, then slightly higher in the north and the south. Organic matter gradually increased from the west to the central and then to the east. The area of alkali-hydrolyzable nitrogen in the range of 90-120 mg/kg and the available phosphorus in the high and very high range were the largest, respectively. The available potassium gradually increased from the west to the east. The spatial variation of pH, available phosphorus and available potassium were mainly caused by human factors.

Key words: Luliang County, soil nutrient, abundance and deficiency assessment, spatial-temporal variability