临安雷竹林施肥现状及问题的分析

The Status and Problem Analysis of Fertilization in the Bamboo Forest in Lin'an

为探究临安雷竹林土壤理化性状的变化,以临安雷竹林种植区进行施肥调查和土壤样品采集,对临安雷竹林土壤进行研究。研究结果表明,雷竹林表层土壤（0~20 cm）酸化严重,最低的p H 3.2,酸化且有明显深层化趋势;表土有机质和速效磷积聚,含量分别高达57.6 g/kg和765.0 mg/kg。据分析,雷竹林过量施用化肥,特别是氮肥和磷肥造成土壤养分失衡,导致雷竹林土壤p H下降。表土（0~20 cm）酸化严重,p H最低值达3.2,远低于雷竹适宜生长的p H 5.5~7.0,同时,土壤有效磷和速效钾含量大幅上升,最高分别达693.0、507.0 mg/kg。结合当地生产实践分析,雷竹种植过程中过量施用化肥、覆盖大量有机物分解产生的酸性物质以及雷竹林自身分泌有机酸共同作用导致竹园土壤有明显的酸化趋势。

To ascertain the change of soil physical and chemical properties in the bamboo forest in Lin＇ an, an investigation was made on the status of fertilization and soil samples were gathered in the main bamboo- planting area in Lin＇ an. The results showed the grave acidification of the topsoil （0-20 cm）, with the lowest pH value of 3.2 and a trend of declining in pH value with the depth of the soil, and the accumulation of organic matter and available phosphorus in the topsoil, with the contents of 57.6 g/kg and 765.0 mg/kg respectively. By analysis, the long-term over-application of chemical fertilizers, especially nitrogen and phosphorus fertilizers, has caused the imbalance of soil nutrients in the bamboo forest, leading to a fall in soil pH and the grave acidification of the topsoil （0-20 cm）, with the lowest value of soil pH of 3.2, well below the suitable soil pH value of 5.5-7.0 for the growth of the bamboo, along with a significant increase in available phosphorus and potassium, with the highest contents of 693.0 and 507.0 mg/kg respectively. In the conventional practice of bamboo planting, a combination of over-application of chemical fertilizers, acid matter released by a large amount of organic materials covering the topsoil and organic acid excreted by the bamboo plant contributed to the significant acidification of the bamboo forest.