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Effects Of Organic Fertilizer And DMPP On N2O Emission And Ammonia-oxidizing Microorganisms

Posted on:2018-10-16Degree:MasterType:Thesis
Country:ChinaCandidate:X LanFull Text:PDF
GTID:2323330515987499Subject:Plant Nutrition
Abstract/Summary:PDF Full Text Request
The vegetable ecosystem is an agricultural system with high chemical fertilizer application rate and multiple cropping index.Excessive usage of chemical fertilizer in vegetable production system is a serious problem in China,and unreasonable chemical nitrogen fertilizer application is the most severe,which not only cause the waste of fertilizer,but also result in environment pollution.The undisturbed soil core lysimeter experiment and lab incubation experiment were conducted to study the effects of application of organic and chemical fertilizer or combined with DMPP?3,4-dimethylpyrazole phosphate?on vegetable yield and quality,soil nitrogen content,N2 O emission and activity of ammoniaoxidizing microorganisms,contributing to provide a basic theory for vegetable production and N2 O emission decreasing in fields.The tested soil was Alfisols?yellowbrown soil?and sampled from Wuhan suburb.Four vegetable crops?Chinese cabbage?Brassica Chinensis L.?,swamp cabbage?Ipomoea aquatic Forsk.?,amaranth?Amaranthus mangostanus L.?and radish?Raphanus sativus L.??were grown sequentially.There were seven different treatments?no nitrogen fertilizer?CK?;chemical nitrogen fertilizer?CF?;chemical nitrogen fertilizer with organic fertilizer?CF+OM?;70% chemical nitrogen fertilizer with organic fertilizer?70%CF+OM?;chemical nitrogen fertilizer with DMPP?CF+DMPP?;chemical nitrogen fertilizer with organic fertilizer and DMPP?CF+OM+DMPP?;70% chemical nitrogen fertilizer with organic fertilizer and DMPP?70%CF+OM+DMPP??were set in experiments.The main results were as follows:1.Undisturbed soil core lysimeter experiment was carried out to study effects of application of organic and chemical fertilizer or combined with DMPP on vegetable yield,nitrate content and nitrogen accumulation amount.The results showed that: vegetable yield,nitrate content and nitrogen accumulation were significantly increased by nitrogen fertilizer application;addition of organic fertilizer increased or observably increased yield and nitrogen accumulation of Chinese cabbage and radish,but decreased or significantly decreased nitrate content of swamp cabbage and amaranth;organic fertilizer partial substituting chemical nitrogen fertilizer decreased or significantly decreased vegetable yields,nitrate content and nitrogen accumulation;addition of DMPP increased or significantly increased the yield of Chinese cabbage and swamp cabbage,but didn't affect vegetable nitrate content and nitrogen accumulation.2.Undisturbed soil core lysimeter experiment was conducted to study effects of application of organic and chemical fertilizer or combined with DMPP on physicalchemical properties of soil.The results showed that: nitrogen fertilizer application significantly increased soil organic matter content in amaranth and radish seasons and soil nitrogen content?available-N,NH+4-N,NO3--N?in all vegetable seasons,but lower the p H of soil;organic fertilizer application elevated organic matter and p H of soil,significantly increased soil available nitrogen in radish season and NH+4-N content?swamp cabbage season expected?,but decreased or remarkably decreased soil NO3--N content in Chinese cabbage and amaranth seasons;organic fertilizer replaced part of chemical fertilizer could increase soil organic matter content and p H,but can't affect soil nitrogen content;adding DMPP increased or remarkably increased soil organic matter content in amaranth and radish seasons,relieved soil p H decrease and reduced soil NO3--N content,but increased soil NH+4-N content.3.Lab incubation experiment was conducted to study effects of application of organic and chemical fertilizer or combined with DMPP on physical-chemical properties of soil.Nitrogen fertilizer application decreased soil p H,NH+4-N and NO3--N content rose first and then decrease,NH+4-N content reached the maximum value at the 3rd day,and reduced to the same level as unfertilized treatment,NO3--N content reached peak value at the 80 th day;adding organic fertilizer did not influence the soil p H and NH+4-N content,but increased NO3--N content and organic matter;part of chemical fertilizer replaced by organic fertilizer result in the increase of soil p H and organic matter during late period of experiment,but decrease of soil NH+4-N and NO3--N content;DMPP inhibited soil nitrification progress,so that increased NH+4-N residence time and soil p H,addition of DMPP reduced soil NO3--N content in early period of experiment,but increased in late period.4.In undisturbed soil core lysimeter experiment,nitrogen fertilizer promoted N2 O emission rate and increased cumulative soil N2 O emission,applying organic fertilizer and organic fertilizer partial replacing chemical fertilizer can not affect N2 O emission,DMPP inhibited soil N2 O emission and significantly reduced cumulative soil N2 O emission of organic fertilizer treatment and organic fertilizer alternative chemical fertilizer treatment.There was no difference in N2 O emission seasonal variation among different treatments.5.In lab incubation experiment,nitrogen application observably increased soil N2 O emission during early period?50d?and N2 O emission amount;applying organic fertilizer and organic fertilizer partial replacing chemical fertilizer decreased N2 O emission rate and significantly reduced soil N2 O cumulative emissions.DMPP addition inhibited N2O emission rate during early period?1-28d?,but promoted N2 O emission during late period?28-120d?,soil N2 O cumulative emission decreased before the 68 th day and increased after 68 th day because of DMPP,and significantly increased N2 O cumulative emission of the whole experiment period.In treatments with DMPP,soil NH+4-N content has a bigger influences in N2 O emission rate than NO3--N content,and opposite in treatments without DMPP.6.In lab incubation experiment,nitrogen fertilizer application inhibited soil ammonium-oxidizing archaea?AOA?activity,but promoted ammonium-oxidizing bacteria?AOB?activity in eraly period;organic addition did not affect activity of AOA and AOB,organic fertilizer partial replacing chemical fertilizer increase AOA amo A gene abundance during the whole experiment period and AOB amo A gene abundance in late period;adding DMPP significantly inhibited AOB amo A gene abundance,but remarkable increased AOA amo A gene abundance during early period,and did not affect ammonia-oxidizing microorganisms anymore when incubation finished.
Keywords/Search Tags:Vegetable, Organic fertilizer, DMPP, N2O emission, Ammonia-oxidizing microorganisms
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