Soil Nutrient Content Distribution in Gully in Loess Hilly Region

Abstract

In order to find out the distribution of soil organic matter, total nitrogen and total phosphorus contents in gully in loess hilly region and the difference between gully and slope, 29 and 58 samples were taken from gully and slope in Yuanzegou small watershed respectively. The results showed that the contents of total nitrogen, total phosphorus and organic matter in the 0-60cm soil layer ranged 0.091~0.628g/kg, 0.402~1.388g/kg, and 0.826~6.550g/kg respectively. According to the results of the second national soil census, the total nitrogen and organic matter content in the gully are at the lower level of grade 6, the total phosphorus content is at the higher level of grade 2, and the variation coefficient ranges from 21.6% to 33.4%, which is moderate. Pearson correlation analysis shows that soil total nitrogen, total phosphorus and organic matter contents are positively correlated with slope direction and elevation, negatively correlated with slope, and weakly correlated with soil moisture content, clay content and silt content, and negatively correlated with sand content. 0-20cm, the organic matter contents in the gully was higher than that slope 7.19%; 20-40cm and 40-60cm, the organic matter content in the gully was lower than that slope 4.66% and 12.67% respectively, but there was no significant difference. 0-20cm, 20-40cm, 40-60cm, the content of total nitrogen and total phosphorus in gully were higher than that slope, and the total nitrogen content was higher 24.31%, 13.04% and 8.70% respectively, with significant difference only in 0-20cm (p<0.05); The total phosphorus content was higher 15.68%, 13.56% and 15.11% respectively, with significant differences (p<0.05).