不同林龄板栗叶片矿质营养的季节变化及差异分析

以河北省迁西县不同林龄(8,12,20,30年生)板栗品种‘燕山早丰’Castanea mollissima‘Zaofeng’为试材,通过测定不同物候期结果枝叶片主要矿质元素的质量分数并进行差异分析,研究了不同林龄板栗需肥规律及树体营养差异,旨为不同林龄‘燕山早丰’的营养诊断和科学施肥提供参考。结果表明:①不同林龄板栗对养分的需求规律一致,其中开花授粉期对氮、磷、钾、钙和硼与果实膨大期对氮、磷、钾、钙需求量较大;果实发育期间板栗对铁和锰的需求有持续增加的趋势;不同物候期板栗对铜和锰的需求量变化较小。②与8年生和12年生板栗相比,20年生、30年生板栗由于长期养分大量输出导致树体营养镁亏损,对此,生产上应适当增加镁肥(硫酸镁)施用量,及时补充板栗养分,以延长‘燕山早丰’的盛果期。③不同林龄‘燕山早丰’叶片主要矿质元素质量分数在幼果期(7月10日-8月10日)相对稳定,是采用叶分析法进行营养诊断的最佳采样期。图2表1参28

Seasonal changes of mineral nutrients and difference analysis with chestnut leaves for different-age plantations

 To provide reference for nutritional diagnoses and balanced fertilization, the seasonal changes and difference analysis of mineral nutrient contents in leaves during different phonological periods were analyzed, with Castanea mollissima ‘Zaofeng’ plantations at different ages（8 a，12 a，20 a，30 a）planted in Qianxi County of Hebei Province as experimental materials, aim to research the fertilizer demand regularity and nutritional differences of chestnut plantations at different ages. The results showed that（1）C. mollissima ‘Zaofeng’ plantations at different ages had the similar nutrition requirement regularity. Elements N，P，K，Ca，and B were in greater demand during pollination；N，P，K，and Ca demands were greater during the fruit expansion period；and Fe and Mn demand increased during fruit growth. However，Cu and Mg demand decreased in different phenological periods.（2）The difference analysis revealed lower Mg in the 20-and 30-year-old chestnut plantations than the 8?- and 12-year-old plantations.（3）For 8-，12-，20-，and 30-year-old chestnut plantations，content of the main mineral nutrients in leaves changed the least from the middle of July to the middle of August. Since Mg decreased over time，the rate of Mg fertilizer application should be increased with time to keep chestnut trees at full productivity，and for optimal leaf nutrient analysis，sampling should be taken from the middle of July to the middle of August. ［Ch，2 fig. 1 tab. 28 ref.］