土壤酸度的调节对烤烟养分吸收、干物质积累的影响

适当提高酸性土壤 ｐ Ｈ 值，能显著增加土壤细菌、放线菌、好气性纤维素分解菌的数量，促进结构简单的有机物矿化，提高土壤供 Ｎ 能力，土壤 ｐ Ｈ 值调节至 ５．６～６．６，土壤磷酸酶活性提高，增加土壤 Ｐ 的有效性，且有利于烤烟对 Ｎ、 Ｐ、 Ｋ 元素的吸收，提高 Ｎ、 Ｐ、 Ｋ 肥料的利用率，随土壤ｐ Ｈ 值的升高，土壤中 Ｍｇ 和 Ｂ、 Ｚｎ 等微量元素有效性下降，不利于烤烟的吸收．因此，酸性土壤施石灰不宜将土壤ｐ Ｈ 值调节过高，且要注意增施 Ｋ 肥、配施适量的 Ｍ ｇ 肥和微肥，酸性土壤 ｐ Ｈ 值从 ５．０ 调节至 ５．６～６．６，有利于烟叶干物质积累，烟叶各成分含量较适宜，且各成分间较协调，烟叶内的质量较高

Effects of soil acidity adjustment on nutrient absorption and dry matter accumulation in tobacco

The acid soil pH could be properly raised to increase bacteria,actionmyces and aerobic cellulose decomposing bacteria and to promote mineralization of simple structured organisms,thus nitrogen supply of the soil was increased.When soil pH was 5.6 6.6,phosphatase activity and phosphorus availability were enhanced,which was favourable for tobacco to absorb nitrogen,phosphorus and potassium.The utilizaton ratio of N,P,K fertilizer would increased.Along with the raise of soil pH,the availability of magnesium and some micro ele ments such as boron and zinc was declined,which inhibited the absorption of tobacco.Therefore,when lime was applied to acid soi,pH should not be too high and potassium should be added,combined with appropriate amount of magnesium and micro elements.The adjustment of pH in acid soil from 5.0 to 5.6 6.6 was helpful to dry matter accumulation and optimal proportion of components in tobacco,so as to keep high quality.