Effects Of Liming On Soil And Tree Nutrients In Peach Orchard On Brown-Red Soil Of South Hubei Province

It is a serious issue that acid soil is widely distributed in the world. Liming is a traditional and effective method to amend acid soil. Previous studies mostly focused on annual crops, but rarely on the perennial fruit trees. In this paper, we used the 4-year-old peach (Amygdalus persica'Jingchun') trees in the orchard on brown-red soil of south HuBei province as experimental materials. The nutrient conditions of soil and trees in the peach orchard were studied, in which the different proportions of lime (Ca(OH)2) incorporated into the soil. Then path analysis was used to investigate the relationships between soil enzyme activities and soil fertility, foliar nutrient contents and chlorophyll content under the condition of liming. The major results are as follows:1. Soil acidity was greatest decreased in the incorporated lime treatment. Whether in 0-20 cm soil layer or 20～40 cm, the contents of exchangeable acid and Al in soil were significantly reduced with increasing lime consumption, and the pH value was significantly raised with increasing lime consumption.2. The incorporated lime treatment can significantly improve the content of soil organic matter, available N, Ca and Mg in both layers (0～20 cm,20～40 cm). The enhancement of soil nitrification increased the proportion of NO3--N in soil available N with the application of lime, and affected the effectiveness of soil P,Fe,Mn,Cu,Zn in the two layers. The contents of soil available Fe,Mn,Cu,Zn were significantly decreased with increasing lime consumption in 0-20 cm layer soil, but the Cu content of soil available in 20～40 cm layer didn't change. The effectiveness of soil K in 0-20 cm layer was decreased in the incorporated lime treatment, but the content of it was improved in 20～40 cm layer during the initial stage.3. In general, the incorporated treatment improved the activities of catalase, urease and acid phosphatase in both soil layers, but had significant inhibition effect on the activity of soil sucrase, particularly in 0-20 cm soil layer. Path analysis showed that the increased activities of catalase, urease, and acid phosphatase in soil mostly due to the increasing pH value, available Ca and organic matter, available Mg and organic matter, respectively, and the significant inhibition effect on the activity of soil sucrase dependent on the increased contents of available Ca and Mg.4. The incorporated lime treatment can improve the content of foliar total Ca and reduce the content of foliar total P and Zn during the initial stage. During the growing seasons of leaves, the content of total Mn was significantly reduced in the incorporated lime treatment, but there was no change for total N,Mg,Cu content. The contents of foliar total K,Fe were increased in low lime consumption treatment and decreased in high lime consumption treatment. 5. In April and August, the content of leaves chlorophyll was increased in the incorporated lime treatment, but with low peak at the middle growth stage of leaves. Path analysis indicated that we should both control the content of foliar P, and improve the content of foliar Zn and N to increase the content of leaves chlorophyll under the condition of liming.