不同改良措施对晋北盐碱土盐碱障碍和青贮玉米氮素吸收的调控

2019-2020年，本研究以晋北大同盆地的中度盐碱地为研究对象，分析不施肥（CK）、常规施肥下添加生物质炭和CaSO₄（L）、常规施肥下添加生物质炭和CaSO₄及种植2，3，4行（LC1，LC2，LC3）绿肥等5个处理对土壤pH、土壤盐分含量、钠吸附比（Sodium adsorption ratio，SAR）以及作物氮素吸收利用的影响。研究结果表明：与对照相比，经过2年的土壤改良，各改良措施对盐碱土0～20 cm土壤pH调控显著；各改良措施对0～20 cm土壤盐分调控作用明显，LC1，LC2和LC3处理的脱盐率分别达到了41.16%，39.18%和38.88%；4种改良措施均显著降低了土壤的SAR（P<0.05），其中，CL2处理SAR降幅最大。此外，各改良措施均明显提高了青贮玉米的生物产量和氮肥利用率，尤以CL1处理的效果显著。综合分析可知，各改良措施能有效促进盐渍土降盐脱碱，改善土壤结构，且CL1处理下生物产量高，可实现生态效益和经济效益的双赢。

Effects of Different Improvement Measures on the Mitigating Soil Salinity and N Uptake of Silage Corn in Salt-alkali Soil

To provide a scientific basis for the improvement and rational utilization of soda saline-alkali,the effects of different improvement measures on soil salinity-alkalinity and crop uptake and utilization of Nitrogen in the soil were revealed in Shanxi. The five treatments were as follows:non-fertilizing (CK),adding biomass charcoal under conventional fertilization and CaSO₄(L),adding biomass charcoal under conventional fertilization and CaSO₄, and planting green manure (LC1,LC2,LC3) with different row spacing. The results showed that:Compared to the control,after 2 years of soil improvement,each improvement measure significantly regulated the 0~20 cm soil pH. Soil salt showed seasonal changes,and the improvement measures regulated 0~20 cm better than 20~40 cm. The LC1,LC2,and LC3 desalination rates of 0~20 cm reached 41.16%,39.18%,and 38.88%,respectively. The improvement measures all significantly reduced the sodium adsorption ratio of the soil. Among them,the sodium adsorption ratio of CL2 treatment decreased by 45.45%. In addition,the improvement measures significantly improved the yield and nitrogen fertilizer utilization of silage corn,especially with the remarkable effect of CL1 treatment. The comprehensive analysis shows that the improvement measures can effectively promote the salt and alkali of salt soil,improve the soil structure,and have the highest economic benefits under CL1 treatment. This mode makes the ecological and economic benefits achieve a win-win situation,which is conducive to the sustainable development of the improvement model.