树冠位置对砂质果园土壤养分空间异质化的影响

对浙江衢州96 m²橘园土壤中速效N(NH₄-N,NO₃-N)及有效P,Cu,Zn等成分进行分析,结果表明在长期集约化经营条件下,成年砂质果园土壤养分在空间上呈明显的非均质性。果树树冠以下土壤速效养分和电导率等明显高于其他区域,这可能与树冠对雨水的拦载作用减弱了对树下土壤的淋洗作用及喷施在果树上的微量元素随雨水降落在树冠以下土壤有关。在进行田间采集土样和测土施肥时应该考虑这方面的变异性。

Effects of canopy position on spatial variations of nutrients in sandy soils in citrus garden

To evaluate effects of canopy on accumulation of N, P, Cu and Zn in sandy agricultural soils, the horizontal variations of soil available N, P, Cu and Zn in a 96 m² plot within a citrus garden in Quzhou City of Zhejiang Province were examined. The spatial distribution of soil nutrients in mature sandy orchard showed obvious heterogeneity. The differences in labile nutrients spatial distributions in the soils were related to the interception of canopy to rainfall, which reduced leaching intensity of the soils under the canopies. The results suggested that it was necessary to consider the variation of available nutrients in citrus garden, when soil samples for chemical analysis were collected and amount of applied fertilizers was recommended.