半干旱雨养区不同覆盖方式对马铃薯土壤氮含量及分布的影响

Effects of different mulching methods on soil nitrogen content and distribution of potato in semi-arid rain-fed areas

【目的】探讨西北半干旱雨养区不同覆盖方式对马铃薯地土壤氮素含量及分布的影响。【方法】设玉米整秸秆带状覆盖(T_(秸秆))、黑色地膜覆盖(T_(地膜))和露地平作(T_(露地))3个处理。测定分析了2019年和2020年马铃薯开花期和成熟期的秸秆种植带株行间(T_(秸秆-带上))、秸秆覆盖带下(T_(秸秆-带下))、地膜下(T_(地膜))和露地对照(T_(露地))在0~120 cm土层的土壤全氮、铵态氮、硝态氮、微生物量氮和碳氮比的变化。【结果】地膜覆盖较对照显著提高了0~20cm土层的土壤速效氮含量,2 a平均提高了22.73%,降低了0~40 cm土层土壤微生物量氮含量,降低了10.01%。秸秆带状覆盖较露地能够显著提高土壤0~20 cm土层土壤全氮和速效氮含量,全氮两年平均提高了17.32%,速效氮提高了9.41%;能够显著提高0~90 cm土层土壤微生物量氮含量,平均提高了45.01%;较地膜覆盖处理显著提高了0~20 cm土层的全氮含量和0~40 cm土层微生物量氮含量,分别提高了20.98%和83.83%。【结论】秸秆带状覆盖能够有效提高土壤氮素含量,是促进农业农田可持续利用与发展,提高土壤生产潜力的有效方法。

【Objective】This study aimed to investigate the effects of different mulching methods on soil nitrogen content and the distribution of potato in the semiarid rain-fed area of Northwest China.【Method】In the study,three treatments were set,i.e.,the mulching with the whole corn straw(T_(straw)),mulching with black plastic film (T_(plastic film)) and open field (T_(open field)). The soil in potato planting zone(T_(straw-strip)),strawmulching zone (T_(straw-strip)),mulching film (T_(mulching film)) and control plot (T_(dew field)) was sampled from the soillayer of 0~120 cm at the flowering and maturity stages in 2019 and 2020;and then,the changes of soil totalnitrogen,ammonium nitrogen,nitrate nitrogen,microbial nitrogen and C/N ratio were measured and analyzed.【Result】 Our results showed that under the treatment of Tplastic film,the soil available nitrogen contentin 0~20 cm soil layer was significantly increased by 22. 73% in two years,and the soil microbial nitrogencontent in 0~40 cm soil layer was decreased by 10. 01% when compared with the control. The straw stripmulching treatment could significantly increase the contents of both total nitrogen and available nitrogen in0~20 cm soil layer when compared with the open field treatment,which was on average increased by17. 32%,and 9. 41% in two years,respectively. Meanwhile,the soil microbial biomass nitrogen content in0~90 cm soil layer was significantly increased by 45. 01% on average. However,when compared with thefilm mulching treatment,the total nitrogen content in 0~20 cm soil layer and microbial nitrogen content in0~40 cm soil layer were significantly increased by 20. 98% and 83. 83%,respectively.【Conclusion】 Our results suggested that the straw strip mulching could effectively increase the content of soil nitrogen,and thusit might serve as effective methods of promoting the sustainable utilization of agricultural farmland and ofimproving the potential of soil production.