【作者】 王静；

【导师】 张永春；

【作者基本信息】 南京农业大学 ， 植物营养学， 2021， 硕士

【摘要】 磷是植物生长所必需的大量营养元素之一,但是植物从土壤中直接吸收的磷有效性较低。本文以石灰性潮土和弱酸性黄棕壤为研究对象,选取小麦-甘薯轮作的长期定位试验中甘薯季土壤为试验样本,选取施肥处理为:CK,不施肥;NK,不施磷肥;NPK,单施化肥;NPKM,施有机无机肥。探究长期施肥对土壤磷组分含量、土壤生物化学性状的影响以及磷转化微生物（含pho D和pqqc基因的微生物）群落多样性和组成。明确土壤关键磷组分对产量的相对贡献,阐明微生物在无机磷活化和有机磷转化过程的调控作用及其影响因素。结果表明:（1）黄棕壤中,NK、NPK和NPKM处理之间的甘薯产量和地上部生物量无显著差异。与CK处理比较,NK、NPK和NPKM处理的有效磷含量分别提高1.6、8.1和4.3倍,Ca-P含量降幅分别为67.0%、12.7%和17.2%。Ca-P、有效磷和活性有机磷是影响产量重要的磷组分,土壤有效磷含量与铝、铁结合磷显著正相关。潮土中,与CK处理比较,NK、NPK和NPKM处理的产量分别增加44.5%、147%和168%,有效磷含量分别是CK处理的1.1、1.8和25.3倍。与CK和NK处理比较,NPKM处理有机磷含量显著提高34.7%和30.6%;土壤有机磷和有效磷含量是影响产量的重要磷组分,Ca₂-P、Ca₈-P和高稳定有机磷与有效磷相关性最高。（2）黄棕壤中,与CK处理比较,NK、NPK和NPKM的土壤p H降幅为1.63、1.66和1.15;NK和NPK处理的微生物量碳、氮、磷含量和蔗糖酶、脲酶、碱性磷酸酶活性均有所下降,NPKM处理能缓解生物性状的下降。此外,土壤植酸酶活性分别提高10.0%、44.3%和75.6%。土壤p H和植酸酶活性影响产量和土壤磷组分变化,土壤p H与微生物量和酶活性显著正相关。在潮土中,施肥显著提高土壤微生物生物量和酶活性,其在有机肥处理下最高。有机碳水平是驱动土壤微生物量、酶活性和磷组分变化的主要因素,有机碳调控铁结合磷、Ca₂-P、碱性磷酸酶、植酸酶和活性有机磷组分含量的变化,进而影响作物产量和土壤磷素有效性。（3）黄棕壤中,施磷肥显著影响pho D微生物的多样性。门水平上,放线菌门和变形菌门为pho D微生物中相对丰度最高的类群,而对于pqqc微生物,变形菌门为相对丰度最高的类群,土壤p H是驱动微生物群落组成的主要因素。潮土中,pho D微生物和pqqc微生物群落组成主要受碳源和土壤养分含量调控,有机碳是影响pho D微生物群落组成最关键的因素,全氮和有效磷水平是驱动pqqc微生物群落组成的主要因素。综上所述,与施磷年限较长的潮土比较,十年不施磷肥的黄棕壤并未因土壤磷限制而影响甘薯产量,但长期单施化肥引起的土壤酸化进而影响了土壤微生物量及微生物功能。不同土壤类型下,影响土壤无机磷和有机磷组分分布和驱动磷转化生物过程的因素不同。因此,本研究为不同的植薯土壤合理施用磷肥优化施肥措施提供理论依据。更多还原

【Abstract】 Phosphorus is one of the essential nutrients for plant growth,however,the availability of phosphorus is generally low from soil to plants.We studied the calcareous fluvo-aquic soils and weakly acidic yellow brown soils following the long-term fertilization experiments of wheat-sweet potato rotation system.The soil samples were selected from sweet potato season to explore the effect of long-term fertilization on soil phosphorus fractions and soil biochemical properties.We aimed to study the contribution of key P fractions to yields and to investigate the roles of microorganisms in inorganic phosphorus activation and organic phosphorus transformation.The results show that as follows:（1）In yellow-brown soils,there was no significant effect on sweet potato yield and above-ground biomass under NK,NPK and NPKM treatments.Compared to CK treatment,the available P contents were 1.6,8.1 and 4.3 times in NK,NPK and NPKM treatments,respectively.Soil Ca-P contents were significantly increased by 67.0%,12.7%and 17.2%for NK,NPK and NPKM treatments,respectively.Ca-P,available P and LOP are the important P fractions for yields.The available P was significantly and positively correlated with Al-P and Fe-P.In fluvo-aquic soils,compared with CK treatment,the yields under NK,NPK and NPKM treatments were significantly increased by 44.5%,147%and 168%.The available P contents were 1.1,1.8 and 25.3 times in NK,NPK and NPKM treatments,respectively.Soil organic P and available P were more important for the yields.While Ca₂-P,Ca₈-P and highly resistant organic phosphorus had the higher correlation with available P.（2）In yellow brown soils,compared to CK treatment,the soil p H were decreased1.63,1.66 and 1.15 in NK,NPK and NPKM treatments,respectively.Soil microbial biomass carbon,nitrogen,phosphorus contents and soil invertase,urease,alkaline phosphatase activities were decreased under chemical fertilization（NK,NPK）.And organic fertilization had an alleviative role in decreasing of soil microbial traits.In addition,soil phytase activity were increased by 10.0%,44.3%and 75.6%.Yield and soil P contents were mainly regulated p H and phytase.The soil microbial biomass and enzyme activities were siginificantly and positively correlation with p H.In fluvo-aquic soils,fertilization significantly improved the microbial biomass and enzyme activity,which was the highest under organic fertilization treatment.The organic carbon was the main factor driving the soil enzyme activity and phosphorus fractions,and soil organic carbon regulates Fe-P,Ca₂-P,LOP contents and alkaline phosphatase,phytase.（3）In yellow brown soils,P fertilization significantly affected the diversity of pho D microorganisms.At the phylum level for harboring-pho D microorganisms,actinomycetes and proteobacteria had the highest abundance,while proteobacteria had higher relative abundance for harboring-pqqc microorganisms.Soil p H was the most important factor that drives pho D and pqqc microbial community composition.In fluvo-aquic soils,the composition of harboring-pho D and-pqqc microbial communities was mainly regulated by soil carbon and nutrients（total nitrogen,available phosphorus,available potassium）.Soil organic carbon was the most critical factor driving the composition of pho D microbial communities.Total nitrogen and available phosphorus were the most critical factors for driving pqqc microrganisms community compositon.In conclusion:compared with the fluvo-aquic soils following long-term P fertilization,the yellow brown soil without P fertilization for ten years does not affect the yield due to soil phosphorus limitation.But the long-term fertization causes soil acidification and influences the soil microbial biomass and microbial function.In different soil types,the biotic and abiotic factors affect the distribution of soil inorganic and organic phosphorus fractions.Therefore,this study provides a theoretical basis for rational application of P fertilization and optimizing the fertilization measures in different soil types for planting sweet potato.更多还原