造林整地对栗钙土钙积层化学性质干扰的研究

采用对比分析方法，对不同年龄杨树人工林地整地与未整地土壤化学性质进行了研究．结果表明，经犁沟整地破除钙积层后，土壤化学性质约在１０７年恢复到整地前状态，随后土壤养分迅速减小，以至低于整地前水平．２０年后随着林地有机物质的积累，养分开始回升，最终林地养分高于整地前水平．土壤养分恢复的先后顺序为有机质、ＣａＣＯ３、有效Ｎ、全Ｐ、全Ｎ、速效Ｋ和有效Ｐ，恢复周期分别为６、７、７５、９、１０、１７、１７５年．钙积层部位恢复周期为１１４年，恢复先后顺序为有效Ｎ、全Ｐ、有机质、速效Ｋ、ＣａＣＯ３、全Ｎ和有效Ｐ，恢复周期为５５、６、６、８５、９５、１０、３４年．

Disturbance of site preparation on chemical properties of calcic horizon in chestnut soil

This study comparatively analyzed the soil chemical properties of different aged poplar ( Populus spp.) plantations with and without site preparation. After its calcic horizon was broken by ditch ploughing, the soil took about 10.7 yr for its chemical properties recovering to the state of no site preparation. After that, soil nutrients decreased rapidly, and even below to the level of no site preparation. Twenty years later, with the accumulation of organic matter,soil nutrients increased again, and ultimately higher than before site preparation. The successive order of soil nutrient recovery was organic matter, CaCO 3, available N, total P, total N, rapidly available K, and available P, with the recovery cycle of 6,7,7.5,9,10,17 and 17.5 yr, respectively; while the recovery cycle of soil nutrients in calcic horizon was 11.4 yr, and the successive order was available N, total P, organic matter, rapidly available K, CaCO 3,total N, and available P, with the recovery cycle of 5.5, 6, 6,8.5, 9.5, 10 and 34 yr, respectively.