稻麦轮作体系下种养废弃物还田对土壤有机碳和酶活性的影响

发布时间：2018-04-09 09:01

本文选题：种养废弃物还田　切入点：有机碳　出处：《四川农业大学》2015年硕士论文

【摘要】：本研究在现阶段大量未循环利用有机肥及秸秆焚烧状况频繁的基础上,通过在成都平原田进行大田试验,研究成都平原稻麦轮作体系下不同种养废弃物配比还田对土壤有机碳及酶活性的影响,探讨不同土壤有机碳的变化机制,找出最佳种养废弃物还田配比,为该地区更高效的农业废弃物循环利用提供理论依据。小区试验共设不施肥(CK)、常规无机化肥(NKP)、猪粪25%+化肥(NKM1)、猪粪50%(NKM2)、猪粪100%(M3)、猪粪150%(M4)、常规化肥+秸秆全量(NPKS)、猪粪50%+化肥+秸秆全量(NKM2S)、猪粪100%+秸秆全量(M3S)、猪粪150%+秸秆全量(M4S)10个处理。分别在水稻和小麦的不同生育期采集0-20 cm和20-40 cm土层样品,研究不同处理对土壤有机碳(TOC)、水溶性有机碳(WSOC)、溶解性有机碳(DOC)、易氧化有机碳(ROC)和土壤酶活性的影响及土壤有机碳在生育期的动态变化,得出以下结果：1)水稻和小麦季试验结果表明：猪粪和秸秆还田能显著提高土壤总有机碳及其活性有机碳含量。0-20 cm土层TOC、WSOC、DOC和ROC含量均随猪粪还田量的增大而升高,秸秆覆盖处理有机碳及其组分含量均大于对应无秸秆覆盖处理,高量猪粪和秸秆配施对土壤有机碳及其组分影响最为明显,水稻季和小麦季TOC、WSOC、DOC和ROC含量均在M4S处理下达到最大值,分别为19.32和20.11 g/kg、94.00和97.96 mg/kg、55.70和74.75 mg/kg、2.81和2.40 g/kg。20-40 cm土层土壤有机碳及其组分含量显著低于表层土壤,也在150%猪粪加全量秸秆处理下达到最大值,不同处理之间变化幅度小于表层土壤。通过对比分析发现,3种活性有机碳之间极显著相关,且与总有机碳之间极显著正相关。2) 猪粪和秸秆还田对土壤酶活性影响显著,在水稻和小麦季中,除NKM1处理外,其余处理与CK处理相比,均显著提高表层土壤脲酶活性,猪粪还田量上的变化和秸秆覆盖对土壤脲酶活性影响不显著,土壤脲酶活性在M4S上达到最大值,比CK处理提高了76.69%和62.5%；表层土壤中性磷酸酶和蔗糖酶活性在猪粪还田量达到50%后达到最大值,之后随猪粪用量增加而降低。秸秆还田处理土壤中性磷酸酶和蔗糖酶活性显著高于对应无秸秆处理,土壤中性磷酸酶和蔗糖酶活性在NKM2S处理下达到最大值,分别为3.22和3.15mg g-1 h-1.20-40 cm土层土壤酶活性远小于表层土壤,且不同处理之间差异不显著。相关分析表明土壤酶活性与土壤有机碳呈极显著正相关。3)不同生育期对土壤有机碳及其组分含量的变化影响极显著(P0.01)。水稻季不同处理表层TOC、WSOC、DOC和ROC含量均随着生育期的推移呈现出先升高,在拔节期达到最大值,之后再降低的趋势；20-40 cm土层TOC和ROC在不同生育期的变化趋势与表层不同,土壤有机碳和易氧化有机碳含量随生育期推移缓慢增加,且变化幅度也小于表层。小麦季表层TOC含量随作物生育期的推移而呈增加的趋势；土壤WSOC和DOC含量在拔节期达到最大值,随后下降；土壤易氧化有机碳在分蘖期达到最大值,之后下降并趋于稳定。小麦季20-40 cm土层土壤有机碳随生育期推进变化不明显,WSOC、DOC和易ROC变化趋势与表层土壤类似,但变化幅度远小于0-20 cm土层土壤。
[Abstract]:The study in the present stage a large cycle based organic fertilizer and straw burning condition frequently, through the field experiment in Chengdu plain field, effects of waste ratio returning on organic carbon and enzyme activities in soil of different planting of rice wheat rotation in Chengdu plain system, discuss the mechanism of changes of soil organic carbon, find out the best the ratio of planting residues in the region, more efficient agricultural waste recycling area. Provide a theoretical basis for the test consists of no fertilizer (CK), conventional inorganic fertilizer (NKP), 25%+ (NKM1), chemical fertilizer manure, pig manure, pig manure and 50% (NKM2) 100% (M3), 150% (M4), pig manure and conventional fertilizer + straw (NPKS), chemical fertilizer + straw manure 50%+ (NKM2S) 100%+, pig manure straw, pig manure (M3S) 150%+ straw (M4S) 10. Respectively in rice and wheat in different growth stages of acquisition of 0-20 cm and 20-40 cm soil samples, research Different treatments of soil organic carbon (TOC), water soluble organic carbon (WSOC), dissolved organic carbon (DOC), easily oxidized organic carbon (ROC) and the effect of soil enzyme activity and soil organic carbon dynamics in the growth period, and obtained the following results: 1) test results showed that the rice and wheat season pig manure and straw could increase the.0-20 soil total organic carbon and labile organic carbon content in soil layer of CM TOC, WSOC, DOC and ROC decreased with the increasing of pig manure returning amount increased, straw mulch and organic carbon contents were greater than the corresponding no straw mulching, high amount of pig manure and straw fertilizer on soil organic carbon and its components influence is most obvious, the rice season and wheat season TOC, WSOC, DOC and ROC contents reached the maximum value in the treatment of M4S, were 19.32 and 20.11 g/kg, 94 mg/kg and 97.96, 55.70 and 74.75 mg/kg, 2.81 g/kg.20-40 and 2.40 cm soil layer soil Organic carbon and its components were significantly lower than the surface soil, also reached the maximum in 150% pig manure Treated Straw under different treatment between the change is smaller than the surface soil. By comparison, significant correlation between the 3 kinds of active organic carbon, and total organic carbon significantly correlated effects of pig manure and.2) straw on soil enzyme activity significantly in rice and wheat season, except for NKM1 treatment, other treatment compared with the CK treatment significantly increased soil urease activity on the surface of pig manure returning amount changes and straw mulching on soil urease activity were not significantly affected the soil urease activity reached the maximum at M4S, improve 76.69% and 62.5% than CK; soil neutral phosphatase and invertase activity of the surface reaches 50% in pig manure returning amount after reaching a maximum, then decreased with amount of pig manure. Straw returning soil neutral Phosphatase and invertase activity was significantly higher than the corresponding non straw treatments, neutral phosphatase and invertase activity reached the maximum value in the treatment of NKM2S, 3.22 and 3.15mg respectively g-1 h-1.20-40 cm soil enzyme activity is far less than the surface soil, and the difference between the treatments was not significant. Correlation analysis showed that soil enzyme activity and soil organic carbon was significant positive correlation.3) changes in different growth period on soil organic carbon content and the group had significant effect (P0.01). The rice season different surface TOC, WSOC, DOC and ROC content increased with the growth process is increased in the jointing stage reached the maximum value, then decreased; 20-40 cm layers of TOC and ROC are different in different growth stages and the change trend of surface soil organic carbon and labile organic carbon content with the growthperiod increased slowly, and the amplitude of variation is less than the surface wheat season. The content of TOC increased with the passage of the crop growth period; soil WSOC and DOC content at jointing stage reached the maximum value, then decreased; soil labile organic carbon in tillering stage reached the maximum value, then decreased and stabilized. Wheat season 20-40 cm soil organic carbon with the advance of the growth stage is not obvious change WSOC, DOC and ROC change trend of surface soil is similar, but the change rate is far less than the 0-20 cm soil layer.

【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141

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