不同移栽日期烟草对土壤养分的利用特征

以云烟97为试验材料，在陕西省汉中市南郑县小南海镇烟草基地进行随机区组试验，分别测定5个移栽日期处理移栽前和收获后土壤基础养分含量，分析不同移栽期烟草对土壤养分的吸收特征。结果表明，不同移栽期烟草对土壤氮、磷、钾养分利用率的最大值均出现在5月15日或5月20日，最小值出现在5月5日或5月10日，对速效养分利用率最小值则出现在5月20日，对土壤有机质的利用率在各个移栽日期较为一致。烟草对土壤有机质利用量随移栽期推迟基本呈减少趋势， 5月20日移栽的烟草利用量最少，为5.59 g·kg^-1，对土壤全氮、全磷、全钾、速效氮、速效磷、速效钾的利用量均随移栽期的推迟呈先增加后减少趋势；烟草对有机质的利用率与全氮、全钾利用量呈显著负相关性，与全氮与全钾利用量呈显著正相关，不同移栽期相关性均呈现极显著正相关。综合分析，本烟区5月15日或5月20日移栽较合适。

Study on Soil Nutrient Utilization at Different Transplanting Date of Tobacco

A randomized block experiment was conducted in a tobacco field of Xiaonanhai town of Nanzheng county in Hanzhong city of Shaanxi province with Yunyan 97 variety to find the suitable transplanting date from five treatments (May 5, May 10, May 15, May 20, May 25) on the basis of soil nutrient utilization, soil samples were collected and analyzed before transplanting and after harvest.The results showed that: (i) the maximum utilization rates of soil nitrogen, phosphorus and potassium all occurred on May 15 or May 20 while the minimum ones appeared on May 5 or May 10 for the total nutrient utilization and on May 20 for the available nutrient; the utilization rates of soil organic matter were similar at different transplanting date.(ii) As the transplanting time were postponed, the utilization capacity of soil organic matter gradually decreased and the minimum appeared on May 20 while the utilization capacity of soil total nitrogen, phosphorus, potassium, available N, P and K increased firstly and then decreased the peaks all appeared on May 15 or May 20.(iii) The utilization rates of organic matter showed significantly negative correlation with those of total nitrogen and total potassium, different transplanting date all showed significantly positive correlations.(iiii) Generally, May 15 or May 20 were the suitable transplanting stage for the study region based on tobacco utilization of soil nutrients.