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为了探索不同形态及配比的氮肥对铁核桃(Juglans sigillata Dode.)根际生态因子的影响,为施肥提供科学依据,采用土壤盆栽试验方法,以铵态氮(NH4+-N)、硝态氮(NO3--N)和酰胺态氮[CO(NH2)2]为氮源,研究氮肥形态及配比对实生苗生长和根际土壤中低分子量有机酸含量、微生物数量及多种酶活性的影响。结果表明:混施等比例NH4+-N和NO3--N的实生苗株高、基径、植株的鲜质量及地上部和根系的鲜质量都最大(P<0.05),分别为58.03 cm、18.21 mm、238.19 g、147.68 g和90.51 g,根际土壤中有机酸总量和细菌、真菌、放线菌的数量及微生物多样性指数显著高于其它处理,分别为16.72μg·g-1 FW、592.00×105 CFU·g-1、34.33×104 CFU·g-1、19.33×105 CFU·g-1和0.1738;酸性磷酸酶、中性磷酸酶、碱性磷酸酶、蔗糖酶和淀粉酶的活性最强(P<0.05),分别为9.54、0.24、3.60、61.98和8.03 mg·g-1。单一施CO(NH2)2、NO3--N、NH4+-N会降低根际土壤中有机酸含量、微生物数量和微生物多样性指数。在混施NH4+-N和NO3--N的情况下增加NO3--N比例会明显降低根际土壤蛋白酶活性。根际土壤中细菌、真菌和放线菌的数量与中性磷酸酶、碱性磷酸酶、硝酸还原酶、蔗糖酶和淀粉酶活性呈显著或极显著正相关;细菌数量与酸性磷酸酶活性呈显著正相关;有机酸总量与脲酶、中性磷酸酶、碱性磷酸酶、硝酸还原酶、蔗糖酶和淀粉酶的活性及微生物数量呈显著或极显著正相关;微生物数量及有机酸总量与过氧化氢酶呈极显著负相关。混施等比例的NH4+-N和NO3--N能够改善铁核桃根际生态环境,促进实生苗的生长。
In order to explore the effect of different forms and proportions of nitrogenous fertilizer on rhizosphere ecological factors of Juglans sigillata Dode. To provide a scientific basis for fertilization, soil pot experiment was conducted to study the effects of nitrogenous fertilizer (NH4 + -N), nitrate nitrogen (NO3 - N) and amido nitrogen [CO (NH2) 2] were used as nitrogen source to study the effects of nitrogen forms and proportions on the growth of seedlings and the contents of low molecular weight organic acids, influences. The results showed that the fresh weight, base diameter, fresh weight of plant and fresh weight of shoots and roots were highest (P <0.05), which were 58.03 cm, 18.21 mm, 238.19 g, 147.68 g and 90.51 g. The total amount of organic acids and the numbers of bacteria, fungi and actinomycetes in the rhizosphere soil were significantly higher than those of the other treatments (16.72 μg · g-1 FW, 592.00 × 10 5 CFU · g -1, 34.33 × 10 4 CFU · g -1, 19.33 × 10 5 CFU · g -1 and 0.1738; the activities of acid phosphatase, neutral phosphatase, alkaline phosphatase, invertase and amylase The strongest (P <0.05), respectively 9.54,0.24,3.60,61.98 and 8.03 mg · g-1. Single application of CO (NH2) 2, NO3 - N and NH4 + -N reduced the contents of organic acids, microbial population and microbial diversity in rhizosphere soils. In the case of NH4 + -N and NO3 - N, increasing the ratio of NO3 - N could significantly reduce the rhizosphere soil protease activity. The numbers of bacteria, fungi and actinomycetes in rhizosphere soil were positively or significantly correlated with the activities of neutral phosphatase, alkaline phosphatase, nitrate reductase, invertase, and amylase. The numbers of bacteria and the activity of acid phosphatase The total amount of organic acids was significantly or very significantly positively correlated with the activity of urease, neutral phosphatase, alkaline phosphatase, nitrate reductase, invertase and amylase and the number of microorganisms; the number of microorganisms and total amount of organic acids There was a significant negative correlation with catalase. Mixing equal proportions of NH4 + -N and NO3 - N can improve the rhizosphere ecological environment and promote the growth of seedlings.