不同水肥处理对夏玉米田土壤微生物特性的影响

Effects of irrigation and fertilization on soil microbial properties in summer maize field

以氮高效率型玉米品种（ZN99）为试验材料,研究了不同水肥处理对夏玉米田土壤微生物特性的影响.采用裂区设计,主区为灌水处理,设置了2个灌溉水平（玉米全生育期内灌水526和263 mm）;副区为施肥处理,设置了3种肥料类型（无机肥U、有机肥M、有机无机混施UM）和2个施氮水平（N 100和200 kg·hm^-2）.结果表明：灌水量影响了肥料对土壤微生物生物量（碳、氮）和微生物多样性的调控,施有机肥只有在充足灌水条件下才能显著提高土壤微生物生物量碳（14.3%-33.6%）、微生物生物量氮（1.8-2.3倍）和丰富度.适量灌水、增施有机肥或有机无机配施可增加土壤中具有固氮能力的厚壁菌、γ-变形菌或α-变形菌的种类和相对数量.同一施氮量下,有机肥与无机肥对产量的影响差异不显著.从可持续生产角度考虑,适量灌水条件下,增施有机肥更有利于土壤微生物生物量及多样性的提高,增强土壤水肥供应能力.

In order to investigate the effects of different irrigation and fertilization on soil microbial properties of summer maize field, we used ZN99 with high nitrogen use efficiency as the test materi- al. The experiment adopted the split plot design which included two irrigation levels （526 mm and 263 mm） as the main plots, three fertilizer types （U, M, UM） and two fertilizer levels （N 100 kg·hm^-2 and 200 kg·hm^-2） as the subplots. The results showed that the irrigation level affected the regulating effects of fertilizer on soil microbial biomass （carbon and nitrogen） and microbial di- versity. The organic fertilizer application must be under the sufficient irrigation level to increase the soil MBC （14.3%-33.6%）, MBN（ 1.8-2.3 times） and abundance significantly. A moderate rate of irrigation, higher rates of organic fertilizer application or organic manure combined with inorganic fertilizer could increase the nitrogen-fixation species and quantity of Firmicutes, γ-Proteobacteria and α-Proteobacteria in the soil. Under the same N level, there was no significant difference of grain yield between organic manure and inorganic fertilizer treatments. Considering sustainable pro- duction, proper organic manure application with moderate irrigation could increase the quantity of the soil microbial biomass and microbial diversity, and nutrients. and improve the capacity of soil to supply water