长期不同耕作措施下陇中黄土高原旱作农田土壤磷的组分特征

摘要

[Objective]To study the effect of organic phosphorus components in different soils under different tillage measures,in order to reduce the destruction of agricultural production on the environment through better understanding the phosphate use efficiency in rain-fed agricultural system,and then,reduc-ing excessive consumption of phosphorus.[Method]The traditional tillage (T),no-tillage with straw mulching (NTS),no-tillage (NT)and traditional tillage with straw returning (TS)were designed to deter-mine the characteristics of organic phosphorus composition in 0~5 cm,5~10 cm,10~20 cm and 20~40 cm soil layers after 1 5 years.[Result]There was no significant difference between no-tillage and traditional tillage in 4 soil layers,and no-tillage treatment was significantly higher than that of traditional tillage under straw mulching condition.Compared with 4 soil layers,TS was higher than NT,and straw mulching treat-ment was higher than that of no-tillage treatment.The weighted average of 0~40 cm soil layer was NTS>TS>T>NT.The content of active organic phosphorus in 0~5 cm soil layer in NTS treatment was signifi-cantly higher than those of NT,TS and T treatments by 11.21%,19.62% and 30.75% (PT>T>T.This indicated that no-tillage plus straw mulching was beneficial for the accu-mulation and improvement of total organic phosphorus.%[目的]探究黄绵土有机磷各组分在不同耕作措施下的效应关系,了解雨养农业区农业系统磷素利用效率,降低过多的磷素投入,进而减少农业生产对环境的破坏.[方法]本研究通过设置在陇中黄土高原半干旱区的保护性耕作长期定位试验,应用Bowman-Cole法,测定了传统耕作(T)、免耕秸秆覆盖(NTS)、免耕不覆盖(NT)、传统耕作秸秆还田(TS)四种耕作措施实施 15 年后,0~5,5~10,10~20,20~40 cm土层的有机磷组分特征.[结果]4个土层免耕与传统耕作差异不大,在秸秆覆盖方式下免耕处理显著高于传统耕作,并且从 NT处理与 TS处理下 4个土层相比较,TS处理均高于NT处理,秸秆覆盖处理高于免耕处理;同时,0~40 cm土层加权平均值表现为NTS>TS>T>NT.活性有机磷在各处理间差异显著,0~5 cm土层 NTS处理下活性有机磷含量显著高于 NT、TS、T处理,分别高出 11.21%,19.62%,30.75%;0~5 cm中等活性有机磷在处理 NTS 下含量最高,分别较 NT、TS、T处理高4.63%,6.71%,8.69%.有机磷各组分含量以中等活性有机磷为主体含量最大;各处理有机磷组分含量都随土层深度的增加而减小.[结论]通过研究不同处理下有机磷各组分含量来看,总体均表现为 NTS>TS>NT>T,说明免耕的基础上进行秸秆覆盖,有利于总有机磷的积累与提高,免耕加秸秆覆盖对本地区的土壤有机磷组分提高明显,增加了土壤磷库的储存量.