Xie Jun-Yu, Bai Yu-Yan, Cao Han-Bing, Zhang Feng-Mao, Shi Xin-Ge, Liu Yi-Fan, Li Ting-Liang
College of Resources and Environment, Shanxi Agricultural University, Taigu 030801, China.
Huan Jing Ke Xue. 2024 Oct 8;45(10):6028-6037. doi: 10.13227/j.hjkx.202311136.
We studied the changes in various physical fractions within aggregates in the arid plateau of southern Shanxi Province, which has great significance for synergistically improving soil fertility and crop productivity in this region. Bulk soil samples were collected from 0-20 cm layers during a 7-year long-term experiment in Hongtong County, Shanxi Province. Wheat grain yields, SOC concentrations, proportions, and OC contents within soil aggregates were analyzed. OC contents included： unprotected coarse particulate organic carbon within macroaggregate （M-cPOC） and fine particulate organic carbon within macroaggregate （M-fPOC）, physically protected intra-aggregate particulate organic carbon within macroaggregate （M-iPOC）, chemically/biochemically protected mineral organic carbon within macroaggregate （M-MOC）, unprotected fine particulate organic carbon within microaggregate （m-fPOC）, physically protected intra-aggregate particulate organic carbon within microaggregate （m-iPOC）, and chemically/biochemically protected mineral organic carbon within microaggregate （m-MOC）. The treatments were ① farmer fertilization （FP）, ② nitrogen reduction monitoring and control fertilization （MF）, ③ nitrogen reduction monitoring and control fertilization plus ridge film and furrow sowing （RF）, and ④ nitrogen reduction monitoring and control fertilization plus flat film hole sowing （RF）. The results showed that compared with that in the FP treatment, MF reduced SOC concentration while maintaining wheat grain yield, RF and FH synergistically improved soil fertility and crop yield, especially for the FH with SOC concentration, and wheat grain yield increased by 8.44% and 48.86%, respectively. MF significantly reduced the content of M-cPOC, RF significantly increased the content of M-iPOC, and FH significantly increased the contents of M-fPOC, M-iPOC, M-MOC, and m-iPOC by 64.00%, 98.39%, 6.16%, and 17.48%, respectively. In addition, combined with redundancy analysis, we found that the M-iPOC fraction played a major role in increasing SOC concentration and wheat grain yield, with a contribution rate of 61.5%. Therefore, the contribution of macroaggregates to soil fertility and crop productivity was higher than that of microaggregates in the arid plateau area of southern Shanxi, and flat film hole sowing could increase the content of M-iPOC, thereby synergistically increasing SOC sequestration and wheat grain yield, which could promote this cultivation technology in the region and even in the country's arid agricultural areas.
我们研究了山西省南部干旱高原地区团聚体内各种物理组分的变化，这对于协同提高该地区土壤肥力和作物生产力具有重要意义。在山西省洪洞县进行的为期7年的长期试验中，采集了0-20厘米土层的原状土样。分析了小麦籽粒产量、土壤有机碳（SOC）浓度、比例以及土壤团聚体内的有机碳（OC）含量。OC含量包括：大团聚体内未受保护的粗颗粒有机碳（M-cPOC）、大团聚体内的细颗粒有机碳（M-fPOC）、大团聚体内物理保护的团聚体内颗粒有机碳（M-iPOC）、大团聚体内化学/生物化学保护的矿物有机碳（M-MOC）、微团聚体内未受保护的细颗粒有机碳（m-fPOC）、微团聚体内物理保护的团聚体内颗粒有机碳（m-iPOC）以及微团聚体内化学/生物化学保护的矿物有机碳（m-MOC）。处理方式包括：①农户施肥（FP）、②减氮监测控肥（MF）、③减氮监测控肥+垄膜沟播（RF）、④减氮监测控肥+平膜穴播（FH）。结果表明，与FP处理相比，MF降低了SOC浓度但维持了小麦籽粒产量，RF和FH协同提高了土壤肥力和作物产量，尤其是FH处理的SOC浓度和小麦籽粒产量分别提高了8.44%和48.86%。MF显著降低了M-cPOC的含量，RF显著增加了M-iPOC的含量，FH显著增加了M-fPOC, M-iPOC, M-MOC和m-iPOC的含量, 分别增加了64.00%、98.39%、6.16%和17.48%。此外，结合冗余分析，我们发现M-iPOC组分对增加SOC浓度和小麦籽粒产量起主要作用，贡献率为61.5%。因此，在山西省南部干旱高原地区，大团聚体对土壤肥力和作物生产力的贡献高于微团聚体，平膜穴播可以增加M-iPOC的含量，从而协同增加SOC固存和小麦籽粒产量，这可以在该地区乃至全国干旱农业区推广这种种植技术。
