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草地退化严重影响着草原的生态环境[1],退化草地内土壤环境恶劣[2],土壤水分、养分保持能力丧失[3],退化草地比未退化地区土壤水分含量降低54.28%[4],速效氮、磷、钾低58.33%、62.2%、29.3%[5]。恶劣的土壤环境导致土表植物多样性降低,土表植被覆盖度不足40%[6]。快速修复退化草地,已经成为保护草原生态环境、保障草原生产的重点研究方向。
草场封育、人工补播草种是目前修复退化草地最常用的治理方法[7],播种高品质、抗逆性强的牧草可提高退化草地牧草产量86.7%[8]。但退化草地土壤环境恶劣,植被生长受阻,利用封育、补播的方法难以在短时间内取得成效[9]。为缩短治理周期,王东磊等人通过施用化肥促进植物生长,较围栏封育处理植被覆盖度增加46.3%[10],但化肥对重度退化草地的生物多样性会有负面影响[11]。为避免化肥的负面影响,王小燕等人[12]利用微生物肥结合氮肥混合施用提升了28.83%的碱解氮含量。王雨等人[13]研究指出在干旱条件下利用微生物肥可增加11.3%植株高度和56.6%叶绿素含量。任卓然[14]等人利用微生物肥治理退化草地,地上生物量一年后增幅达到126%,但对土壤水分保持方面作用甚微。高吸水材料可有效改善土壤颗粒结构[15]、控制土壤侵蚀等功能[16]。程登喜等人研究指出,沙土混合高分子材料可提高33.9%土壤含水量[17]。马丙尧[18]等人发现保水剂与尿素凝胶混施后蔗糖酶、多酚氧化酶和脲酶活性较对照组可提高80.34%、62.71%和27.21%。但过量使用高分子材料会破坏土壤结构,导致土壤板结,对植物生长起到反作用[19]。宋双双等人也指出随着保水剂用量增加,会导致土壤微生物数量减少[20]。廖文菊等人[21]指出退化草地治理的关键是改善土壤环境,再通过牧草种植逐渐恢复草地生态。
由高吸水竹纤维与竹纤维共生菌组成的竹菌共生体系,具有提高土壤水分、促进根际微生物繁殖双重功能,其对缺水、根系生长不好的退化草地根际微生态环境改良是否具有促进作用?通过将共生体系应用于退化草场,探讨以下3个方面的内容:1)竹菌共生体系对沙地土壤水分的影响;2)竹菌共生体系对土壤微生物的影响;3)竹菌共生体系对菊苣-将军生长的影响。
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由表1可知随着季节变化,7—11月试验区土温逐渐降低,试验组7~11月土壤平均温度(10.85℃)均低于对照组(11.295℃)3.4%但差异并不显著(P=0.106),试验组和对照组月平均气温最高为8月,分别为15.49℃和16.18℃,试验组比对照组土温低4.26%;11月温度最低,试验组较对照组平均气温低15.54%,差异不显著。7—11月试验区内土壤水分含量逐渐降低,试验组7月土壤水分含量最高(64.61%)10月水分含量最低(39.57%),对照组10月土壤水分含量最高(54.01%),11月水分含量最低(28.72%);试验组月均土壤水分含量较对照组提升24.74%,这表明试验处理能够显著提升退化草地土壤水分含量。
时间time 试验组/℃ 对照组/℃ 较对照组±% 试验组/% 对照组/% 较对照组±% 7月 15.47±0.22a 15.72±0.26a −1.59 64.61±1.75b 51.13±2.17a 26.36 8月 15.49±0.36a 16.18±0.4a −4.26 58.35±1.34b 54.01±1.95a 8.35 9月 12.78±0.28a 13.29±0.34a −3.84 54.47±1.35b 41.11±1.96a 32.50 10月 8.37±0.67a 8.78±0.70a −4.67 39.57±1.61b 36.09±1.41a 9.64 11月 2.12±0.32a 2.51±0.31a −15.54 46.27±1.77b 28.72±1.73a 61.11 平均值 10.85±2.53 11.29±2.56 −3.40 52.65±4.42 42.12±4.68 24.74 注:字母不同表示差异显著(P<0.05)
Note: Different letters indicate significant differences (P<0.05).Table 1. Results of soil moisture and soil temperature in sandy land
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统计发现试验组细菌、真菌、放线菌数量均高于对照组,试验组0—10 cm细菌数量高对照组22.74%,但不显著P=0.078;10—20 cm和20—30 cm土层细菌数量显著高于对照组,分别高出22.34%、41.92%。10—20 cm土层真菌数量最高(113×106CFU/g),高对照组192.21%,20—30 cm土层真菌数量差异最大,试验组高对照组225.14%。试验组0—10 cm土层放线菌含量最高(123.27×106CFU/g),比对照组同土层放线菌数量(69.12×106CFU/g)高78.34%。数量差异最明显的为20—30 cm土层放线菌含量,试验组放线菌数量高对照组419.77%,差异最小的为10—20 cm土层细菌数量,处理组高对照组22.34%。证明竹菌共生体系能够有效提升土壤微生物数量。
微生物类型 土层深度 试验组 对照组 较CK±% 细菌Bacteria(106CFU·g−1) 0—10 cm 111.67±20.87aA 91.00±7.64bA 22.71 10—20 cm 93.33±14.95aB 75.67±10.74abA 22.34 20—30 cm 73.33±5.49bB 51.67±9.82aA 41.92 真菌Fungus(106CFU·g−1) 0—10 cm 103.00±22.54aB 77.33±4.98bA 33.20 10—20 cm 113.00±11.85aB 38.67±6.00aA 192.21 20—30 cm 78.33±1.76bB 25.67±4.37aA 225.14 放线菌Actinomycetes(106CFU·g−1) 0—10 cm 123.27±4.58aB 69.12±3.61cA 78.34 10—20 cm 117.67±7.31aB 31.00±2.51bA 279.58 20—30 cm 105.67±10.53aB 20.33±2.40aA 419.77 注:小写为相同处理不同土层对比,大写字母为不同处理同土层对比,字母不同表示差异显著(P<0.05)
Note: The lowercase letters indicate the comparison of different soil layers with the same treatment, and the uppercase letters indicate the comparison of different treatments with the same soil layer. Different letters indicate significant differences (P<0.05).Table 2. Results of soil microorganisms
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由表3可知,试验组土壤速效养分含量均高于对照组。试验组铵态氮(182.95 mg/kg)、有效磷(28.76 mg/kg)和有机质(71.77 g/kg)含量高对照组60.06%、41.05%和10.47%,达到显著水平P<0.05,试验组速效钾含量高对照组8.14%但未达到显著水平。试验结果表明竹菌共生体系能够有效改良退化草场土壤环境,提升土壤速效养分含量。
土样 试验组 对照组 较CK±% 铵态氮 Ammonium nitrogen (mg·kg−1) 182.95±10.09a 114.3±9.48b 60.06 有效磷 Available phosphorus (mg·kg−1) 28.76±0.73a 20.39±1.13b 41.05 速效钾 Quick-acting potassium (mg·kg−1) 243.08±7.38a 224.77±1.99a 8.14 有机质 Organic matter (g·kg−1) 71.77±1.78a 64.97±1.55b 10.47 注:字母不同表示差异显著(P<0.05)
Note: Different letters indicate significant differences (P<0.05).Table 3. Soil nutrients result
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由表4可知,三种微生物数量呈正相关,细菌和真菌相关性显著(P<0.05),真菌与放线菌相关性极显著(P<0.01)。细菌、真菌、放线菌与土壤养分指标均呈正相关,真菌与土壤有效磷呈显著正相关,相关系数为0.851,表明土壤内真菌数量高低会显著影响到土壤有效磷含量。放线菌与铵态氮呈显著正相关,与有效磷呈极显著正相关,相关系数分别为0.831和0.925,证明土壤铵态氮、有效磷的含量高低与放线菌数量有直接联系。
微生物 细菌Bacteria 真菌Fungus 放线菌
Actinomycetes铵态氮
Ammonium nitrogen有效磷
Available phosphorus速效钾
Quick-acting potassium有机质
Organic matter细菌Bacteria 1 0.841* 0.764 0.511 0.579 0.768 0.679 真菌Fungus 0.841* 1 0.958** 0.717 0.851* 0.773 0.780 放线菌Actinomycetes 0.764 0.958** 1 0.831* 0.925** 0.808 0.914* 注:P<0.05 相关性显著。**. 在P<0.01 相关性极显著。
Note: * indicates significant correlation under the condition of P<0.05. * * means extremely significant correlation under the condition of P<0.01.Table 4. Correlation analysis between soil microorganisms and nutrients
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从表5菊苣-将军的生长生理指标调查结果可知,与对照相比较,试验组叶绿素含量、叶片长、宽、营养成分含量均高于对照组,增加幅度最大的是叶片宽度,显著高出对照组69.00%,叶绿素SPDA值含量增长最低为10.79%,试验组叶片厚度(5.89 mm)和全氮(16.33 g/kg)含量分别高于对照组18.27%、12.78%,但未达到显著水平。试验组叶长、叶宽、全磷、全钾含量显著高于对照组,分别高出15.8%、69%、31.46%和33.99%。
组名 T CK 较对照增加% 叶绿素含量 Chlorophyll(SPDA) 30.08±7.37a 27.15±2.3a 10.79 叶长Leaf length(cm) 30.19±1.39a 26.07±1.02b 15.80 叶宽Leaf width(mm) 52.07±3.44a 30.81±1.31b 69.00 10片叶片厚度 Thickness of 10 blades(mm) 5.89±0.91a 4.98±0.3a 18.27 全氮Total nitrogen(g·kg−1) 16.33±0.95a 14.48±0.45a 12.78 全磷Total phosphorus(g·kg−1) 4.22±0.32a 3.21±0.44b 31.46 全钾Total potassium(g·kg−1) 43.52±2.19a 32.48±3.01b 33.99 注:字母不同表示差异显著(P<0.05)
Note: Different letters indicate significant differences (P<0.05).Table 5. Growth physiological indexes of Chicory-General
Effects of bamboo symbiotic microorganism system on severely degraded grassland in Hongyuan County
doi: 10.12172/202304060002
- Received Date: 2022-12-27
- Available Online: 2023-10-24
- Publish Date: 2024-02-25
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Key words:
- super absorbent bamboo fiber /
- bacteria /
- degraded grassland
Abstract: Grassland degradation had a serious impact on local ecological and economic development. In order to alleviate the influence of degraded grassland on vegetation growth and improve the soil environment of degraded grassland, a bamboo fungus symbiotic system composed of high water absorbing bamboo fibers and bamboo fiber symbiotic bacteria was used to treat severely degraded grassland (the total coverage decreased by more than 30% and the total grass yield decreased by more than 50%). The effects of the system were as follows: (1) Compared with the control group, the monthly average soil moisture in the test group was 24.74% higher, and the monthly average temperature was 3.4% lower. The soil moisture from July to November was significantly higher than that in the control group. (2) The number of bacteria, fungi and actinomycetes in the test group was higher than that in the control group, which were 27.48%, 107.76% and 187.76% respectively. (3) The contents of ammonium nitrogen, available phosphorus and organic matter in soil were higher than those in control group, which were 60.06%, 41.05% and 10.47% respectively. (4) The number of soil microorganisms was positively correlated with soil nutrient content, fungi was significantly positively correlated with available phosphorus, and actinomycetes was extremely significantly positively correlated with available phosphorus. (5) The leaf length, width, total phosphorus and total potassium contents of chicory general leaves in the test group were significantly higher than those in the control group.