保水剂和微生物菌肥配施对旱作燕麦土壤微生物生物量碳、氮含量及酶活性的影响

为探讨保水剂和微生物菌肥配施后旱作燕麦土壤微生物生物量碳、氮含量及酶活性的影响,在内蒙古黄土高原旱作农田设置不施用保水剂和微生物菌肥(CK)、保水剂和微生物菌肥配施(A)、单施微生物菌肥(B)和单施保水剂(C)4个处理,分析燕麦全生育期内0—10,10—20,20—40 cm土壤微生物生物量碳、氮含量及酶活性时空动态变化和产量变化。结果表明:(1)全生育期,土壤微生物量碳含量呈"双峰"曲线变化,峰值均出现在孕穗期和灌浆期;氮含量呈先降低后升高再降低趋势,苗期含量最高;过氧化氢酶、蔗糖酶、脲酶活性均呈"单峰"曲线变化,过氧化氢酶、土壤蔗糖酶峰值在孕穗期,土壤脲酶则在抽穗期。(2)除CK外,土壤微生物量碳、氮含量及过氧化氢酶、蔗糖酶和脲酶活性表现为0—10 cm10—20 cm20—40 cm,其中配施(A)对0—10,10—20 cm影响均显著(p0.05),单施(B、C)仅对10—20 cm土层影响显著(p0.05)。(3)10—20 cm土层,配施(A)与其他3个处理间差异均显著(p0.05),提高微生物量碳含量4.82%～40.28%、微生物生物量氮含量8.44%～68.66%、过氧化氢酶活性13.32%～60.16%、蔗糖酶活性10.45%～39.14%、脲酶活性12.40%～55.62%。(4)配施(A)能同时显著(p0.05)提高燕麦籽粒产量和生物产量,提高幅度分别为8.40%～20.12%和10.80%～25.09%。因此,保水剂和微生物菌肥配施在黄土高原旱作区具有较好改善土壤微生物活性效果,提高旱作燕麦产量。

Effects of Combination of Super Absorbent Polymer and Microbial Fertilizer on Soil Microbial Biomass Carbon, Nitrogen and Enzymes Activities of Oat Farmland in Dry Area

In order to study the effects of combination of super absorbent polymer and microbial fertilizer on soil microbial biomass carbon, nitrogen and enzymes activities, four treatments, including no application of super absorbent polymer and microbial fertilizer (CK), combination of super absorbent polymer and microbial fertilizer (A), single application of microbial fertilizer (B) and single application of super absorbent polymer (C) were set up in the dryland area of the Loess Plateau. The spatial and temporal dynamics of soil microbial biomass carbon, nitrogen and enzymes activities of 0-10, 10-20, 20-40 cm soil layers during oat growth was analysed. The results showed that: (1) During the whole growth period, soil microbial biomass carbon showed a double-peak curve, the peaks appeared at the booting and filling stages. The soil microbial biomass nitrogen showed the trend of first decreasing, next increasing and then decreasing, with the highest content at the seeding stage. All the soil catalase, invertase and urease activities showed a single-peak curve, with the peak activities of soil catalase and invertase at the booting stage, and the peak of soil urease at heading stage. (2) Except CK, all the soil microbial biomass carbon, nitrogen, soil catalase, invertase and urease activities showed 0-20 cm > 0-10 cm > 20-40 cm. The combination treatment (A) had significant effects on 0-10, 10-20 cm soil layer (p<0.05), the single treatments (B, C) had significant effects only on 10-20 cm soil layers (p<0.05). (3) In 10-20 cm soil layer, compared with other three treatments, the combination treatment (A) all had the significant effects (p<0.05). Soil microbial biomass carbon was improved by 4.82%~40.28%, soil microbial biomass nitrogen improved by 8.44%~68.66%, soil catalase activity improved by 13.32%~60.16%, invertase activity improved by 10.45%~39.14% and urease activity improved by 12.40%~55.62%. (4) Combination treatment (A) had significant effects both on grain and biological yield (p<0.05), the increasing range was 8.40%~20.12% and 10.80%~25.09%. So the combination of super absorbent polymer and microbial fertilizer had best effects on improving soil microbial activity and oat yield in the dry farmland of Inner Mongolia Loess Plateau.