飞播种子丸粒化技术应用对植被和土壤的影响

Effects of seed pelleting in aerial seeding on vegetation and soil

为阐明丸粒化技术应用对植被和土壤的影响,以阿拉善左旗腾格里沙漠飞播区为研究区,采用空间替代时间方法,对比分析了2017—2020年种子丸粒化和未丸粒化飞播区植被生长状况、土壤水分、养分和土壤微生物的变化情况。结果表明:(1)飞播种子丸粒化技术应用后,丸粒化播区植物盖度及地上、地下和总生物量分别以13.72%、395.88%、127.97%和526.16%的年增长率增加;未丸粒化播区各项指标增量明显低于丸粒化播区;(2)每个飞播年丸粒化和未丸粒化播区土壤含水量和养分之间差异性不明显;随着生长年限增加,土壤有机碳呈增加趋势,土壤全氮含量呈减少趋势,土壤全磷含量变化不大,不同飞播年限丸粒化和未丸粒化播区土壤全磷含量分别为208.67~222.5 mg·kg^(-1)和192.83~213.33 mg·kg^(-1);(3)对8个样地的土壤样本提取DNA进行微生物群落分析,其中仅采自2017年及2019年丸粒化播区的样本满足后续测序要求,相比于2019年丸粒化播区,2017年丸粒化播区土壤的Simpson指数出现了些许降低,而Sobs指数、Chao1指数和ACE指数均显著增加,分别提高了46.67%、43.73%和43.91%。总体上,飞播种子丸粒化对阿拉善左旗沙漠土壤环境具有一定的改善作用。

To illustrate the impact of seed pelleting technology on vegetation and soil,vegetation and soil samples were collected from 8 sampling sites in four aerial sowing years from 2017 to 2020,including 4 seed pelleted areas and 4 non-pelleted areas,and comparative analysis of vegetation growth,soil moisture,nutrients and soil microbial changes was conducted.Results show that:(1)The annual growth rates of plant coverage,aboveground biomass,underground biomass and total biomass were 13.72%,395.88%,127.97%and 526.16%,respectively.The increment of every index in the non-pelletized area was obviously lower than that in the pelletized area.(2)There was no significant difference in soil water content and soil nutrients between pelleted and non-pelleted sown areas in each year of aerial seeding,and soil organic carbon increased and soil total nitrogen decreased with the increase of growing years,the total phosphorus content of the soil varied between 208.67-222.5 and 192.83-213.33 mg·kg^(-1) in the pelletized and non-pelletized areas under different years of aerial sowing.(3)Soil DNA was extracted from 8 plots for microbial community analysis,and only the 2017 and 2019 samples from pelleted sown areas met the requirements for follow-up sequencing.Compared with 2019,the Simpson index of pelleted soil in 2017 decreased slightly,while Sobs Index,Chao1 Index and ACE index increased significantly by 46.67%,43.73%and 43.91%,respectively.In general,the pelleting of air-seeded seeds could improve the soil environment of the Alxa Left Banner Desert.