Application of Soil Analyzer to Analyze the Spatial Distribution of Soil Nutrients in Taihu Lake Area

The spatial variability of soil nutrients, which is one of the important properties of soil, is known. This is a result of factors such as soil type, topography, parent material, land use patterns, and human-farming management. Taihu Lake Region is one of the major rice producing areas in China. Soil nutrients have a decisive role in grain yield. Understanding the influencing factors of soil nutrient variation in the Taihu Lake area is of great significance to improving the utilization efficiency of farmland water and fertilizer and improving field management measures. The analysis of soil nutrients was carried out using a soil analyzer. This method has certain advantages in accuracy and convenience.

Different types of soil, because of their different soil forming conditions and dominant factors, can also cause great differences in soil nutrients. In the Taihu Lake area, paddy soil, fluvo-aquic soil, and red soil are the main soil types, accounting for about 90% of the total area, of which paddy soil area is nearly 66% (discussed in sub-categories). Using the soil analyzer, it was found that the soil nutrients in different soil types had extremely significant differences, indicating that the soil types could reflect the different characteristics of soil nutrients. The content of total N in limestone soil, marsh-type paddy soil, and paddy-type paddy soil was relatively high, ranging from 1.60 to 1.85 g/kg. The contents of other soil types were lower than the mean value, while the total P was highest in the infiltration type paddy soil. 1.27g/kg, the lowest content of red soil, only 0.39g/kg; the total K content is not changed, mostly between 14.08~24.97g/kg; the range of available P is 2.71~20.63mg/kg; the highest available K content is Coastal saline soil reached 198.73 mg/kg, and the lowest was side-seeded paddy soil with a value of 61.44 mg/kg.

From the data of soil nutrient measurements in the Taihu Lake soil analyzer, it can be seen that the spatial differentiation is very obvious. The contents of total N, total P, total K, and available P in the plain area are all abundant; while in the low hilly area, all P, The content of available P and available K were all in the low value range, which was attributed to lack of P and K deficiency. The effect of soil type on soil N and available K space differentiation is greater than that of parent material and topography. Different types of soil should be treated differently during fertilization to avoid excess fertility or deficiency of fertilization caused by average fertilization; topographic effects of full P and available P The spatial variation is more obvious than that of the parent material and the soil type, and the parent material is the dominant factor affecting the total K, and the spatial variation is more significant than the soil type and topography. At the same time, soil parent materials, soil types, and topography all have extremely significant effects on soil nutrients, which also confirms that it is reasonable to set sampling points according to the parent material, soil type, or terrain during soil survey sampling.