The Comparison Of Soil Characters In Apple Orchards Of Different Cultivation Years

Loess Plateau region in Northwest China is an excellent area suitable for apple's growth, as well as one of the main apple producing areas of China. The Loess Plateau locates in China's arid and semi-arid regions, the climate is dry. Because of planting crops of long time, physical and chemical properties et al. have changed, and affecting crop growth and development. The changes in water content, nutrients, microbes and enzymes of rhizosphere soil and non-rhizosphere soil were studied between farmland and apple orchards with 5, 10, 15, 20 planting years. The results showed that, 1, the variation trend of soil water content in open space was similar with the various plantations orchards. Water content in the topsoil (0-1m) changed markedly, water content in the soil between 1 to 2 m presented a strong regularity, which declined along with the increase of planting cultivation years; otherwise, water content in the soil between 2-8m presented a gentle decreasing trend along with the planting cultivation years of apple orchards, which increased significantly. Water content in the soil between 8-10 m presented an increasing trend. Water content in the soil between 10-15m declined along with the increase of plant life. 2, with the increasing in apple orchard cultivation age, the content of total P and total K and and was significantly increased, the content of total nitrogen was decreased. The content of total N, total P and total K in rhizosphere soil was significantly higher than the content of non-rhizosphere soil, but the rhizosphere effect increased with increasing planting years without obvious regularity. In different cultivation ages of apple orchards, the content of total N, total P and total K was lower than open space soil. 3, available hydrolysable nitrogen, available P, available K content were on the rise with increasing planting years, the content of available nutrition in rhizosphere soil was significantly higher than the content of non-rhizosphere soil, and the rhizosphere effect of available K was the highest, but the rhizosphere effect increased with increasing planting years without obvious regularity. 4, with the increasing in apple orchard cultivation age, Soil pH values and organic matter of orchards were decline; with different cultivation age was lower than open space in the soil without changes in the law. 5, in different cultivation age of apple orchards, the amount of bacteria was the largest, actinomyces the second, and fungi the least. An augment in the microbial content of bacteria and fungi, with the increasing years of apple cultivation, and a decrease in actinomytes counts were found in the rhizosphere soil. 6, soil enzyme activity was declined with the increasing in apple orchard cultivation age. There was no significant difference between rhizosphere soil and non-rhizosphere soil.