剑麻麻茎腐解及养分释放特征研究

摘要

应用网袋法研究剑麻茎秆在大田条件下的腐解及养分释放特征.结果表明:麻茎在覆土还田后的300 d内,鲜茎、干叶基、鲜叶基的腐解率分别达82.7%、57.9%、34.5%,氮素释放率分别为89.2%、81.3%、34.0%,磷素释放率分别达84.6%、53.8%、32.1%,钾素释放率分别为94.9%、86.5%、34.5%.麻茎还田300 d内,每667 m2麻茎约释放氮(纯N)、磷(纯P)、钾(纯K)量分别为24.3、6.3、15.2 kg,相当于剑麻年平均施肥量所施入的化学氮、磷、钾肥养分量.麻茎完全腐解约需4年半,麻茎腐解和养分释放速率均表现为前期(30 d)快速而后期缓慢,不同部位顺序为鲜茎>干叶基>鲜叶基.通过麻茎还田,可以有效降低运输成本,减少肥料用量.%Net bags were employed to analyze characteristics of decomposing and nutrients releasing of sisal stalk under field conditions.The results showed that the decomposing rates of fresh stalks,dry leaf base and fresh leaf base were 82.7%,57.9% and 34.5% respectively,and the nitrogen release rates of them were 89.2%,81.3% and 34.0%;the phosphorus release rates of them were 84.6%, 53.8% and 32.1%,and the potassium release rates of them were 94.9%,86.5% and 34.5%.During 300 days since the sisal stalk returning field,the quantity of N,P and K of sisal stalk released were a-bout 24.3 kg,6.3 kg and 15.2 kg in every 667 m2 field,which are equivalent to the N,P and K fertil-izer averagely applied a year per 667 m2 field.It was about four and a half years for a sisal stalk to be de-composed completely.All of the decomposition rates of the sisal stalks and the nutrient release rates were high in early days (30 d)but low in the latter period.The order of decomposition rates of different parts were fresh stalks,dry leaf base and fresh leaf base from more to less.The transportation costs were re-duced and the dosage of fertilizer decreased through the method of sisal stalk returning.