Analysis Of The Influence Of The Different Planting Year Of Tea For The Soil Aggregate Water Stability In Mingshan County

To study the effect of different factors on water stability of soil aggregates and the effects of tea planting years,select the old alluvial yellow soil on the4th terrace paddy and the different years of tea garden soil changed from paddy field, in Baizhang town of Mingshan county, as the main study object. To evaluate of the corresponding aggregate water stability of soil sample and test the original soil physicochemical properties and the particle size of aggregate (>2mm,1-2mm,0.5-1mm,0.25-0.5mm,<0.25mm) and its effect on the aggregate water stability. The results are as follows:(1) With the decrease of the particle size of aggregate, content increased gradually. With the increase of soil the CK ness, the water stability for tea garden0a and the tea garden5a declines after rising first. Compared to the stability of aggregate of40-60cm in paddy field soil, the aggregate stability in the20-40cm of paddy field is drastic decline. However, the overall change in tea garden is small. Both20-40cm soil aggregate stability of water is best. The water stability of soil for garden10a shows a trend of decline after the first rise,0-20cm aggregate has best water stability. The water stability changing trend for team garden15a soil is not obvious. Sorting for water stability:40-60cm>0-20cm>20-40cm. The soil aggregate stability has significant differences in the same soil layer. In the soil layer of0-20cm and20-40cm, soil aggregate stability water is sorted as CK> tea garden5a> tea garden10a> tea garden15a; In the soil layer of40-60cm, the stability of paddy field is significant changed, its water stability sorted as tea garden5a> tea garden10a>CK> tea garden15a.Paddy planting tea help coordinate the overall stability of the soil, but it is not necessarily beneficial to the improvement of the soil aggregate stability. With the years of planting tea increasing, soil aggregate stability is on the decline.(2) With the increasing of depth of soil, the organic matter in different duration of tea garden soil is decreased. The highest organic matter content is in0-20cm of the tea garden5a. The HA/FA value is highest in0-20cm of the tea garden10a. Except rice free ferric oxide content increased with the increase of soil depth, the rest of the measured soil samples of free iron oxide with organic matter and CEC change trend is consistent. Soil phosphorus and potassium in soil profile is on the decline, especially in tea garden Oa and tea garden5a, Soil available potassium content in topsoil is twice subsoil. Available phosphorus content declines effective in CK. PH in Paddy soil is neutral and weak acid, paddy soil becomes acidification after planting tea, which makes serious acidification in topsoil. In20-40cm and40-60cm, acidification tend is increased with the increasing of planting tea years. Average moisture content decreased after paddy fields was changed to plant tea, along with the increasing year of planting tea; Soil bulk density and soil total porosity and>0.25mm aggregate content was significantly correlated.(3)>0.25mm water content, soil bulk density and total porosity are the most remarkable influencing factors for the water stability aggregate in the different fixed number of years soil in tea garden after planting tea. In terms of measured nutrients, the influence factor for water stability of tea garden0a is organic matter; the influence factors of tea garden5a are organic matter and cation exchange capacity (CEC); the influence factors of tea garden10a are organic matter, CEC and effective phosphorus content; and the influence factor of tea garden15a is the content of CEC.On the particle size CK level up to0.5-1mm, tea garden5a each particle levels were significantly higher (>0.984), tea garden10a and tea garden15a significant level of the highest particle size0.25-0.5mm and<0.25mm.