长期施肥下灰漠土易氧化有机碳的变化特征研究

A Study on Changes of Readily oxidation Carbon in Grey Desert Soil under a Long-Term Fertilization Regime

以长期定位施肥下灰漠土易氧化有机碳变化特征为研究对象,于2013年采集不同施肥处理的对照(CK)、单施氮肥(N)、化肥平衡配施(NPK)、化肥配施有机肥(NPKM)、化肥配施秸秆(NPKS)、撂荒(CK0)的土样,分析测定土壤易氧化有机碳及总有机碳含量。结果表明,24 a后,化肥配施有机肥(NPKM)处理土壤有机碳含量达到17.42 g/kg,比1990年的基础值增加了80%;对照(CK)处理土壤有机碳含量最低,仅为6.46 g/kg左右,比1990年下降了48%;单施氮肥(N)、化肥平衡配施(NPK)的土壤有机碳下降了30%;化肥配秸秆(NPKS)的土壤有机碳下降了10%;撂荒(CK0)处理的土壤有机碳增加了11%。配施有机肥(NPKM)处理土壤易氧化有机碳含量显著增加了188%;除化肥平衡配施(NPK)处理以外,CK、N、NPKM、NPKS、CK0处理的易氧化有机碳含量均有所增加,但与基础值差异不显著(P>0.05),NPK处理比基础值下降了28%。各处理的活度、碳库管理指数和活度指数都较基础土壤值高(除NPK处理),NPKM处理明显提高了土壤碳库管理指数。易氧化有机碳与土壤有机碳的相关性达极显著水平(P<0.01),与作物产量的相关性达显著水平(P<0.05)。长期化肥配施有机肥有利于土壤有机碳的积累。土壤易氧化有机碳是反映土壤碳素动态变化灵敏而有效的指标,该指标为培肥地力、增加土壤活性有机质含量提供了量化依据。

Compared with the samples as CK,N,NPK,NPKM,NPKS and CK0 in 2013,readily oxidation carbon and total organic carbon content were analyzed.The results showed that soil organic carbon content treated with NPKM reached 17.42 g/kg,which increased by 80%,compared with that in 1990;The soil orG ganic content treated with CK were about 6.46 g/kg,which reduced by 48%,compared with that in 1990;The soil organic carbon of N,NPK reduced by 30%;The soil organic carbon of NPKS reduced by 10%;The soil organic carbon treated with CK0 increased by 1 1%.The combined application of fertilizer treated with soil readily oxidation carbon content significantly increased by 188%;Except for treatment of equilibrium combined application of chemical fertilizer （NPK）,the organic carbon content of other treatments CK,N, NPKM,MPKS and CK0 were increased.But there were no significant differences,compared with basic valG ue.NPK treatment reduced by 28%,compared with basic value.The activities,carbon administration indeG xes of carbon sink and activities indexes of different treatments all were higher than those of basic soil valG ue （Except for NPK treatment）,thus it can be seen that the soil carbon sink administration indexes were significantly increased by NPKM treatment.The relativity of readily oxidation carbon and soil organic carG bon and crop yield had significant level （P 〈 0.01）.The chemical fertilizer applied with organic fertilizer were advantageous to accumulation of soil organic carbon.The soil readily oxidation carbon reflected sensiG tive change and effective indexes of soil carbon dynamic state,whose indexes provided an important basis for culturing soil fertility,organic content of increasing soil activities.