重庆市石柱县烟田土壤肥力演变与施肥区划

分析2017年重庆市石柱县230份土壤样品的pH和养分指标，并与2002、2012年数据对比，了解该县植烟土壤肥力状况及其演变趋势，提出针对性施肥策略。结果表明，2017年该县植烟土壤pH均值为5.52，其中pH<5.5的酸性土壤占49.1%；土壤有机质平均含量为30.67 g/kg，其中>20 g/kg的比例占92.6%。土壤碱解氮、有效磷和速效钾平均含量分别为156.35、108.40、436.25 mg/kg，其含量过高的比例分别占21.35%、88.2%、98.0%。比较2002、2012和2017年数据，植烟土壤pH先下降后上升，土壤有机质含量稳步上升，土壤碱解氮、有效磷、速效钾含量显著增长。综上所述，该县土壤酸化问题仍较严重，养分含量过于丰富，整体土壤肥力较低且呈下降趋势，因此，可按照“区域大配方，地块小调整”的原则，运用施肥区划图和烤烟配方施肥建议卡，对该县不同种植单元烟田提出具体的施肥方案，实现该县优质烤烟生产。

Evolution and Fertilization Zoning of Tobacco-growing Soil Fertility of Shizhu County, Chongqing City

This paper analyzed pH and nutrients of 230 typical tobacco-growing soil samples from Shizhu County of Chongqing City in 2017 and compared the corresponding data of 2002 and 2017 in order to understand the condition and evolution of tobacco-growing soil fertility for the rational targeted fertilization strategies. The results showed that the average pH was 5.52 in 2017, soil samples with pH < 5.5 accounted for 49.1% of the total samples. The average SOM content was 30.67 g/kg in 2017, soil samples with SOM>20 g/kg accounted for 92.6% of the total samples. The average contents of soil alkali-hydrolyzed nitrogen, available phosphorus and available potassium were 156.35, 108.40 and 436.25 mg/kg respectively, with the proportions of soil samples at the high grades of 21.35%, 88.2% and 98.0% respectively. Compared with the data in 2002, 2012 and 2017, soil pH was decreased at first and then increased, SOM increased steadily, soil alkali-hydrolyzable nitrogen, available phosphorus and available potassium significantly increased. To sum up, soil acidification was serious and nutrients were exceedingly abundant. The integrated soil fertility was poor and declining. Hence, according to macro-strategy in huge restrict and small-adjustment in the field, through using fertilization zoning map and flue-cured tobacco formula fertilization card, specific fertilization program was put forward aiming at tobacco fields with different planting units to accomplish high-quality flue-cured tobacco production.