不同培肥措施对采煤塌陷区复垦土壤氮素矿化的影响

为揭示不同培肥措施对采煤塌陷区复垦土壤氮素矿化特征,采用间歇淋洗好气培养法,研究了不施肥(CK)、单施化肥(CF)、单施有机肥(M)、化肥配施有机肥(MCF)和化肥配施生物有机肥(MCFB)5种培肥措施对复垦4年和8年土壤矿质态氮和可溶性有机氮变化及氮素矿化特征的影响。结果表明:间歇淋洗好气培养过程中,复垦8年土壤累积NO_3~-—N产生量较4年增加2.63%~26.83%,NH_4~+—N累积产生量增加12.50%~32.14%,可溶性有机氮(SON)累积产生量在CF和M处理下减少31.59%~62.50%,其他处理增加3.44%~34.69%。同一复垦年限下NO_3~-—N、NH_4~+—N和SON累积产生量均以MCFB最高。从矿化参数来看,5种培肥措施土壤矿化势(N_0)均表现为复垦8年高于复垦4年土壤,增加幅度为MCFB(26.9%)CK(15.9%)CF(15.0%)M(12.7%)MCF(4.8%);CK和CF处理下潜在可矿化有机氮(N_0/N)随复垦年限增加而减少,减少率分别为9.4%和13.8%,其余3种培肥措施N_0/N呈增加趋势,增加率表现为MCF(13.2%)MCFB(7.5%)M(2.8%);MCF处理下矿化率(N_t/N)随复垦年限增加而增加,增加率为13.2%,其余4种培肥措施的矿化率(N_t/N)均表现为复垦8年低于复垦4年土壤,减少幅度为CF(12.1%)CK(9.4%)MCFB(7.5%)M(2.7%)。不同处理间N_0、N_0/N和N_t/N值则均以8年复垦土壤的MCFB处理最高。综合来看,经过连续8年复垦,化肥配施生物有机肥较其他培肥措施更大程度上提高了各项矿化参数值,但随着复垦年限的增加,以化肥配施有机肥处理的N_0、N_0/N的增加幅度最大,以化肥配施生物有机肥处理的N_t/N减少率最低,长期单施化肥有降低潜在可矿化有机氮量(N_0/N)的趋势。

Effects of Different Fertilization Measures on Nitrogen Mineralization in Reclaimed Soil of Coal Mining Subsidence Area

In order to reveal the characteristics of nitrogen mineralization in reclaimed soil of coal mining subsidence area with different fertilization measures, this experiment used the method of intermittent leaching and aerobic culture to study the effects of five kinds of fertilization measures, such as no fertilizer application (CK), single application of chemical fertilizer (CF), single application of organic fertilizer (M), chemical fertilizer combined with organic fertilizer (MCF), and chemical fertilizer combined with biological organic fertilizer (MCFB) on the changes of mineral nitrogen and soluble organic nitrogen in reclamation soil for 4 years and 8 years, and the characteristics of nitrogen mineralization were also studied. The result showed that:As the years of reclamation increases, the accumulated NO₃^--N production in 8 years of reclamation is 2.63%~26.83% higher than that of 4 years, the cumulative production of NH₄⁺-N increases 12.50%~32.14%, the accumulative production of soluble organic nitrogen (SON) reduced by 31.59%~62.50% under CF and M treatments, and the other treatments increased 3.44%~34.69%. Under the same reclamation years, the accumulative production of NO₃^--N, NH₄⁺-N, and SON were the highest in MCFB. According to the mineralization parameters, the mineralization potential of the five fertilization measures was higher in 8 years than that in 4 years, and the increase range were MCFB(26.9%) > CK(15.9%) > CF(15.0%) > M(12.7%) > MCF(4.8%); Under CK and CF treatments, the potential mineralizable organic nitrogen (N₀/N) decreased with the increase of reclamation years, with the decrease rates being 9.4% and 13.8%, while the other three fertilization measures (N₀/N) showed an increasing trend, with the increase rate of MCF(13.2%)>MCFB(7.5%)>M(2.8%). Under MCF treatment, the mineralization rate (N_t/N) increased with the increase of reclamation years, and the increase rate was 13.2%, the mineralization rate of the other four fertilization measures was lower in 8 years than that in 4 years, and decreased by CF (12.1%) > CK (9.4%) > MCFB (7.5%) > M (2.7%). The values of N₀, N₀/N, and N_t/N in different treatments were the highest in 8 years of reclaimed soil with MCFB treatment. On the whole, after 8 consecutive years of reclamation, the biomineralization parameters of chemical fertilizer combined with biological organic fertilizer were improved to a greater extent than those of other fertilization measures. However, with the increase of reclamation years, the increase of N₀, N₀/N treated with chemical fertilizer and organic fertilizer was the largest, the reduction rate of N_t/N was the lowest in the treatment of chemical fertilizer combined with biological organic fertilizer, and the potential mineralizable organic nitrogen content decreased by (N₀/N) in long term single application of chemical fertilizer.