【作者】 黎阳燕；

【导师】 黄建国；

【作者基本信息】 西南大学 ， 植物营养学， 2009， 硕士

【摘要】 根系是植物吸收养分和水分的器官,根际营养的研究是近年来国内外研究的重要领域。我国肥料利用率较低,氮肥的利用率一般在30%左右、磷肥不足25%、钾肥低于40%。根际营养研究可以为提高化肥利用效率提供有益的信息。为此,试验利用根箱培养技术,设置不施肥,纯施化肥和猪粪化肥配施等处理,培养小麦幼苗,通过测定植株和根际土壤中的养分含量,研究了化肥猪粪配施对小麦根际微区养分的空间效应。主要结果如下:1.在小麦生长前期,对照和各种施肥处理的小麦根长、株高和生物量无显著差异。但是,随着培养时间的延长,处理之间的差异逐渐明显。在48天时,化肥猪粪配施处理的小麦根长、株高和生物显著高于不施肥和纯施化肥的处理;配施处理之间的根长和株高无显著差异。2.纯施化肥的小麦地上部和地下部的氮、磷、钾含量与对照相似,显著低于猪粪化肥配施的各个处理。在猪粪化肥配施的处理之间,植株含钾量无差异,氮、磷含量化₂粪₂最高。说明有机无机适量配施可以改善小麦营养状况。3.猪粪化肥配施处理的小麦氮、磷、钾的吸收量最高,纯施用化肥的次之,不施肥最低。在猪粪化肥配施的处理中,化₃粪₁的氮、磷、钾的吸收量最高,化₂粪₂次之,化₁粪₃最差。说明猪粪化肥配施有利于养分吸收。在小麦施肥过程中,应提倡有机无机适量配合。4.在根际土壤中,猪粪化肥配施处理的有机质含量显著高于不施肥和纯施化肥的处理。在根系周围（＜2mm）的有机质积累可能与根系分泌有机物质有关;随着离根表距离的增加（2mm～8mm）,有机质含量显著降低;当＞8mm,土壤有机质含量增加。在猪粪化肥配施的处理中,2mm～8mm的根际土壤有机质的亏缺现象显著大于不施肥和纯施化肥的处理。估计猪粪化肥配施对土壤微生物活性有较强的促进作用,造成有机质分解,有益于土壤无效态养分释放,提高土壤养分的有效性。5.根际土壤中的碱解氮因施肥而显著提高。在根系周围（＜6mm）,碱解氮含量最低,随着距离的增加而提高。说明小麦根系可以有效利用碱解氮,施肥可以提高根际土壤氮的供应强度。根际硝态氮、铵态氮含量各施肥处理均高于CK,说明配施提高了硝态氮和氨态氮的含量。6.在根系周围（＜6mm）,有效磷、钾含量最低,但随着距离的增加而提高。在猪粪化肥配施的处理中,有效磷、钾含量的亏缺区大于纯施用化肥和不施肥的处理。说明猪粪化肥配施提高了有效磷、钾的有效空间,提高了有效磷钾的供应容量。此外,猪粪配施处理的根际土壤有效磷、钾含量含量显著高于纯化肥的处理,纯化肥又显著高于不施肥。7.在小麦根系周围（0mm～4mm）,氨化和硝化细菌数量最多,随着距离的增加氨化和硝化细菌数量减少。说明施肥促进了氨化和硝化细菌的繁殖,有益于土壤有机氮转化为氨态氮。8.不施肥和纯化肥的根际pH显著高于猪粪化肥配施的处理。在猪粪化肥配施的处理中,pH值的变化趋势为化₁粪₃＞化₂粪₂＞化₃粪₁。在根际不同部位,pH值的著异不大。更多还原

【Abstract】 Root is an important organ of plant to obtain nutrients and water from soils.Rhizospheric nutrition is an important field in recent years.Low fertilizer utilization efficiencies are now found in Chian.Usually,nitrogen fertilizer efficiency is about 30%,phosphorus less than 25%and potassium lower than 40%.Research on rhisosheric nutrition could provide us benefial information for increase in fertilizer utilization efficiencies.Therefore,present experiment was carried out to study the spatial nutrient effects produced by combination fertilization of pig manure with chemical fertilizer fertilizer in the rhizosphere of wheat by us root culture chamber.In the study,nutrients in the seedlings and the rhizosphere were measured and following are the main results:1.There were no different in root length,plant height and biomass among fertilization treatments in initial growth period.As the culture prolonged,however,variations were observed amoung the fertilization treatments.When the wheat seedlings were grown for 48 days,lowest root length,plant height and biomass were found in blank and chemical fertilization treatment.In the fertilization of pig manure mixed with chemical fertilizer,they were higher than blank and chemical fertilization treatment but no difference among the orgainic-inorganic fertilization for root leang and plant height.2.The concentrations of nitrogen,phosphorus and potassium in upper parts and roots were similar in balnk and chemical fertilization,which was greatly lower than combination fertilization of chemical fertilizaer and pig manure.There were also no difference in the content of potassium amount combination fertilization of chemical fertilizaer and pig manure.The contents of nitrogen and phosphorus,however,were highest in C₂P₂,suggesting the possible improvement of nutrition by appropriate combination of organic and inorganic fertilizer.3.The absorptions of nitrogen,phosphorus and potassium by wheat seedlings were highest in combination fertilization of chemical fertilizaer and pig manure,followed by pure application of fertilizer,and the lowest was blank fertilization.Amoung combination fertilizations,the absorptionm was highest in C₃P₁,followed by C₂P₂,and lowest in C₁P₃.It suggests that combination fertilization was beneficial to nutrient absorption.In wheat fertilization,it is necessary advocate appropriate combination of organic and inorganic fertilizer.4.In the rhizospheric soil,the organic matter contents with manure fertilizer supplies were significantly higher than pure fertilizer or chemical fertilizer treatments.The organic matters around the root（＜2mm） were accumulated due to oganic matter secretion by roots.As the distance from root surface increased（2mm～8mm）,the contents of organic matter significantly reduced, appearing deficit phenomenons in this areas,then they increased（＞8 mm）.In chemical and manure fertilizer treatment,the depression of organic matter in rhizosphere was significantly greater than the blank and the pure fertilizer treatments.Combination fertilization could promote the activity of soil microbial,resulting in decomposition of organic matter,benefit the release of unavailable nutrients in soils,and improve effectively soil nutrient supplies.5.In the rhizosphere soil,the contents of nitrogen dissociated by alkali improved significantly due to fertilizer.The content of nitrogen was the lowest around the root（＜6mm）,as the distance increased,the content was higher.It illuminate that wheat roots could make the effective utilization of nitrogen alkaline hydrolysis,and fertilization could increase the strength of nitrogen supplyment in rhizosphere soil.Rhizosphere nitrate,ammonium nitrogen fertilizer to deal with the handling of high,while the lowest CK that increased fertilizer and ammonium nitrate content.6.It had the lowest contents of available phosphorus and potassium around root（＜6mm）, however,as the distance increased,contents of phosphorus and potassium was higher.In the handling of combination fertilizationof chemical fertilizaer and pig manure,the lacking zone of available phosphorus and potassium was bigger than that handled by blank and pure fertilizer.That showed the effective space effectively was increased and the supplement of available phosphorus and potassium was improved by fertilizing combination ones.In addition,the combination handled ones had higher contents of available phosphorus and potassium than the pure ones in rhizosphere soil,and the pure ones was higher than the blank ones.7.Overall,around the root of wheat（0mm～4mm）,it had the largest number of ammonification and nitrification bacteria,as the distance increased,the number droped.That illumimated fertilizition promoting the breeding of ammonification and nitrification bacteria,increasing the number in the rhizosphere,and benefited organic nitrogen transferring into ammonia nitrogen,ammonia nitrogen into nitrate-N in the soil,to improve the bioavailability of nitrogen.8.The rhizosphere pH was significantly higher in blank and pure fertilizer than that of combination fertilization of chemical fertilizaer and pig manure.In the handling of combination fertilization,pH changes in trends was C₃P₁＞C₂P₂＞C₁P₃.And it had no notability differences during different parts of the rhizosphere.更多还原