【作者】 岳亚鹏；

【导师】 郭世伟；

【作者基本信息】 南京农业大学 ， 植物营养学， 2008， 硕士

【摘要】 本研究采用长期定位实验土壤(水作水稻、覆膜旱作和覆草旱作和裸露旱作四种不同水稻栽培方式下的土壤),通过2005-2007年两年的盆栽模拟田间条件试验,研究了不同覆盖方式对水稻和大麦土壤速效养分、作物生长、养分吸收和利用效率的影响;同时研究了在旱作条件下不同氮素形态对水稻生长和养分吸收的影响。旨在阐明不同水稻覆盖方式对水稻和大麦的土壤肥力特征、作物生长的影响以及不同供氮形态对旱作水稻生长和养分吸收的影响,为提高氮肥利用效率和改善土壤肥力状况提供解决方法,并为水稻旱作的进一步推广提供理论依据。1.对不同覆盖方式下土壤速效养分含量和形态的研究结果表明:(1)覆盖方式对水稻季土壤氮素形态具有显著影响,水作处理的土壤铵态氮含量在各个时期都显著高于旱作处理;(2)不同覆盖方式对后作大麦土壤铵态氮的含量影响不大;在大麦的整个生育期,水作处理后茬大麦土壤硝态氮含量均最低,其中分蘖期裸露、覆膜和盖草处理的硝态氮含量分别比水作的高5.26%、4.23%和18.04%;(3)水稻土壤速效P的含量在各个采样时期均以水作处理最高,处理间没有明显的差异;(4)在水稻-大麦的整个生育期,盖草处理的土壤速效K的含量均最高,水作处理的最低。2.水作处理有利用水稻的生长,2006年和2007年水稻的产量比旱作处理分别高26～47%和7～31%;且产量构成因素优于旱作处理,具有较高的每穗粒数,结实率和千粒重,旱作方式中盖草旱作水稻能够基本达到水作处理的产量;水稻旱作均较水作有利于后茬大麦的生长,2005年和2006年大麦产量分别比WB高5～17%和12～29%;其产量构成也均优于水稻水作后茬大麦;在不同水稻旱作方式中,水稻盖草旱作后茬大麦的冬前分蘖发生早,每穗实粒数和千粒重均略高于其他旱作处理。3.水作水稻氮、磷、钾的累积量在各个时期均最高,其中氮累积量在收获期分别比盖草处理、覆膜处理和裸露处理的高22.59%、18.79%和42.48%;大麦整个生育期SMB的地上部氮累积量均最高,磷累积量是生育前期最高,钾累积量则是生育后期最高。水稻生育后期各部位的氮累积量和氮素转移量均是水作处理最高,氮转移率则是盖草处理最高;大麦的氮转移量和转移率均是SMB最高,WB最低。水稻的氮肥生产效率(NPE)、氮素吸收效率(NUPE)和氮素利用效率(NUTE)均以水作处理最高,氮素收获指数(NHI)则是盖草处理最高;大麦的NPE、NUPE和NHI均是SMB处理最高,WB处理最低。4.为研究不同形态氮素营养对旱作水稻生长和养分吸收的影响,采用土培试验覆盖旱作水稻,研究铵态氮(A),硝态氮(N)和铵态氮加硝化抑制剂(A+DCD)对旱作水稻分蘖期、孕穗期生长和养分吸收的影响。结果表明:(1)在分蘖期和孕穗期,铵态氮和铵态氮加硝化抑制剂处理的水稻各部位生物量、分蘖数及新完全展开叶的叶面积均较硝态氮处理的水稻高;(2)铵态氮加硝化抑制剂处理的水稻叶片的净光合速率最高,硝态氮处理的水稻叶片的光合速率最低;(3)铵态氮和铵态氮加硝化抑制剂处理的水稻体内的钾向叶片中分配比例较高,硝态氮处理的水稻向茎秆中分配的比例较高。综上所述,水稻旱作在一定程度上改变了土壤速效养分存在的形态和含量,从而提高后茬作物产量,提高养分的吸收和利用;旱作条件下铵态氮处理提高了水稻的生物量、光合速率以及改变了钾的分配,有利于水稻的生长。更多还原

【Abstract】 Pot experiments were conducted by with the soil from a long-term different aerobic rice cultivation experimental station to study soil available nutrient,crop growth,nutrient absorption and nutrient use efficiency under different cultivation conditions in rice-barley rotation system from 2005 to 2007.In order to provide a theoretical basis for further popularization of rice aerobic cultivation,the effects of different N forms on rice growth, nutrient absorption,nitrogen use efficiency,and soil fertility status under non-flooded cultivation were studied as well.1.According to mensurating soil available nutrient content,the results showed that:（1） different rice cultivation modes significantly affected soil nitrogen form in rice season,soil NH₄⁺ content in waterlogged cultivation treatment（W） was higher than in aerobic cultivation at all rice growth stages;（2） in barley reason,different cultivation modes had no effects on NH₄⁺ content in soil;NO₃^--N content in WB（barley cultivated after water-logged rice） was the lowest during the whole growth stage,and NO₃^--N content in BB（barley cultivated after rice bare）,PFB（Barley cultivated after rice covered with plastic film） and SMB（Barley cultivated after rice covered with straw mulching） was 5.26%,4.23%and 18.04%higher than that in WB, respectively,at the tillering stage;（3） in rice season,soil available P content in W treatment was the highest during the whole growth stage.There were no significant differences among all four treatments;（4） at the whole rice-barley stage,soil available K content was the highest in SMB treatment and the lowest in WB treatment.2.Waterlogged cultivation（W） was beneficial to rice growth,and its yields were 26-47% and 7-31%higher than aerobic cultivation treatment in 2006 and 2007,respectively.The yield composition factors of waterlogged cultivation（W） were better than those of aerobic cultivation,with higher grains per spike,seed bearing rate and thousand seed weight.There were no significant differences in rice yield between SM and W treatment.Aerobic rice cultivations were beneficial to the aftercrop barley growth,and its barley yields were 5～17% and 12～29%higher than W treatment in 2005 and 2006,respectively;The yield composition factors of barley cultivated after rice cultivated in aerobic soil were better than those of waterlogged cultivation（WB）.In all aerobic rice cultivation treatments,tiUering occurred before winter in SMB treatment earlier than others,with higher grains per spike and thousand seed weight.3.N,P and K accumulation in W were the highest at whole rice growth stage,and N accumulation at maturing stage were 22.59%,18.79%and 42.48%higher than in aerobic cultivation rice straw mulching covered（SM）,aerobic cultivation with plast film mulching covered（PF） and aerobic cultivation with without any mulching（B）,respectively.Compared to other treatments,above-ground N accumulation in SMB was the highest at the whole growth stage,and P and K accumulation at tillering stage.In rice growth season,N accumulation and NT in W were the highest at later stage,while NTE was the highest occurred in SM;In barley season,NT and NTE were the highest in SMB,and the lowest in WB;（4） NPE,NUPE and NUTE in rice season were the highest occured in W,but NHI was the highest occured in SMB; NPE,NUPE and NHI in barley season were the highest occured in SMB,and the lowest occured in WB.4.In order to study the effects of different N forms（ammonium,as A;nitrate,as N; ammonium and nitrification inhibitor,as A+DCD） on growth and nutrient absorption of rice plants under non-flooded cultivation at tillering and booting stage,a pot experiment with different form N fertilization was conducted in green house.The results showed that:（1） At tillering and booting stage,biomass,number of tillers and area of newly expanded leaves of rice plants under A and A+DCD treatments were higher than that under N treatment;（2） The highest net photosynthetic rate occurred in rice plants under A+DCD treatment,and the lowest net photosynthetic rate occurred in rice plants under N treatment;（3） Proportion of potassium distributing in leaves of rice plants under A and A+DCD treatments was higher than that under N treatment,while proportion of potassium distributing in stems of rice plants under N treatments was higher.更多还原