【作者】 江晓东；

【导师】 李增嘉；

【作者基本信息】 山东农业大学 ， 作物学， 2007， 博士

【摘要】 本研究于2002²005年在山东省龙口市中村镇中村村进行,选用小麦品种烟农15、济麦20和玉米品种郑单958为试验材料,以大田试验为主,15N微区试验、辅以土壤水肥渗漏试验、结合室内生理生化分析,系统研究了施氮量和秸秆还田及秸秆还田条件下常规土壤耕作、旋耕、耙耕和免耕4种土壤耕作模式对土壤主要物理化学性状、小麦、玉米生长发育、以及对作物产量、籽粒品质的影响,主要结果如下:1秸秆还田与施氮量对土壤理化性状影响及小麦、玉米产量、品质1.1秸秆还田对小麦玉米产量、品质及土壤理化性状的影响与秸秆不还田处理相比,秸秆还田处理提高了0⁴0cm土层全氮、碱解氮、速效钾、速效磷以及有机质的含量,能将更多的硝态氮截留在0⁶0cm层次,有利于作物的吸收,减少氮肥淋失。在高产条件下（0²0cm土层土壤有机质含量为1.712%、碱解氮含量88.73 mg·kg -1、速效磷含量43.27 mg·kg -1、速效钾含量88.33 mg·kg–1）,短期（2年）秸秆还田对小麦、玉米增产效果不显著,但可以提高小麦蛋白质含量和延长面团稳定时间。1.2秸秆还田条件下的适宜氮肥用量麦季240 kg·hm^-2 （N2）施氮量和减氮处理168 kg·hm-2（N1）对小麦的产量无显著影响,麦季氮肥后效对玉米季产量无显著影响。试验第一年N1、N2处理对作物籽粒品质无显著影响,试验第二年小麦籽粒湿面筋含量及淀粉含量N1处理显著高于N2处理,N2处理玉米籽粒的淀粉含量显著高于N1,改变了玉米籽粒直链淀粉/支链淀粉比例。综合比较认为在秸秆还田条件下,麦季氮肥用量采用168 kg·hm-2较适宜。2耕作模式对土壤理化性状的影响2.1耕作模式对耕层构造的影响0-10cm土层,旋耕、耙耕和常规土壤耕作模式土壤容重、孔隙度无显著差异。在10-20cm,旋耕和耙耕模式容重明显高于常规耕作模式。免耕模式土壤容重在0²0cm均逐渐增高,最终显著高于常规耕作模式。2.2耕作模式对土壤水分的影响0²0cm土层旋耕、耙耕和免耕模式土壤贮水量与同期降雨量显著正相关,相关系数皆大于常规耕作模式,耙耕相关系数为0.70**,达到极显著水平,土壤保水性好于常规耕作模式。在0⁶0cm土壤层次,旋耕、耙耕和免耕模式尤其是耙耕模式在0⁶0cm土壤表层,较常规耕作能够涵养更多的水分,减少水分的下渗与蒸发。在作物不同生育时期,尤其是作物开花期,旋耕、耙耕和免耕模式的土壤贮水量高于常规耕作处理,这说明这三种模式可抑制作物开花前土壤无效蒸发,有利于促进籽粒灌浆。模式之间比较,旋耕和耙耕模式土壤贮水量差异不显著,免耕模式小于旋耕和耙耕模式,表明在灌溉条件下,免耕模式由于地表秸秆覆盖加之土壤表层容重变大,不利于土壤水分的下渗。土壤耕作影响土壤水分的渗漏,50cm处土壤灌溉水渗漏量常规耕作>旋耕>耙耕>免耕,与土壤耕作深度成正比,这表明土壤耕作深度对灌溉水的渗漏有显著影响。2.3耕作模式对土壤0⁴0cm养分状况的影响随定位试验时间延长,0²0cm土层旋耕和耙耕模式土壤全氮含量和速效氮、磷、钾含量逐渐高于常规耕作模式,免耕模式速效氮、钾高于常规耕作模式,全氮和速效磷含量低于常规耕作模式,这与免耕模式的氮肥表施方式有关。土壤20⁴0cm层次,常规耕作处理土壤全氮含量和速效氮、磷、钾含量显著高于旋耕、耙耕和免耕模式。2.4对土壤有机物质及离子交换性能的影响三年试验后,0²0cm土壤旋耕、耙耕和免耕模式土壤表层土壤有机无机复合程度高,重组有机碳含量也明显高于常规耕作模式,其对土壤0²0cm层次的培肥能力显著高于常规耕作模式,耙耕模式在该层次的阳离子交换量最高,说明耙耕模式土壤表层供肥特性最好。在20⁴0cm土壤层次,土壤重组有机碳含量、土壤的复合量、阳离子交换量皆为常规耕作模式显著高于旋耕、耙耕和免耕模式,常规耕作模式土壤有机无机复合程度比少免耕模式的高,土壤肥力好。2.5对脲酶、蔗糖酶活性的影响0¹0cm土层土壤脲酶和蔗糖酶活性免耕、耙耕和旋耕模式显著高于常规耕作模式,免耕模式最高;10²0cm土层酶活性则相反。旋耕、耙耕和免耕模式两层次酶活性差异大,常规耕作模式两个层次之间酶活性差异较小,这说明常规耕作模式有利于保持0²0cm土壤肥力的均匀性,少免耕模式易造成土壤层次间肥力的显著差异,对作物生长发育不利。2.6对秸秆腐解及土壤呼吸的影响秸秆腐解一年后,常规耕作、旋耕和耙耕模式的秸秆腐解率差异不显著,免耕显著低于常规耕作、旋耕和耙耕模式。麦季旋耕、耙耕土壤呼吸速率与常规耕作模式无显著差异,免耕模式呼吸速率显著低于常规耕作模式,玉米大口期常规耕作土壤呼吸大于少免耕模式,玉米收获期少免耕模式土壤呼吸速率高于常规耕作。2.7耕作模式与施氮量对土壤硝态氮含量的影响2.7.1耕作模式对土壤硝态氮含量的影响旋耕、耙耕土壤硝态氮移动速度显著低于常规土壤耕作,在0⁶0cm土层硝态氮含量高,积累量高,而60cm以下土层含量较常规耕作低。免耕模式土壤硝态氮含量显著低于常规耕作模式、旋耕和耙耕模式。土壤耕作影响硝态氮的淋失,施肥后N1处理土壤50cm处渗漏水中硝态氮含量常规耕作模式>旋耕>耙耕>免耕,灌溉水氮肥合计表观淋失率常规耕作模式最高。免耕模式灌溉水氮肥表观淋失率低,其土壤硝态氮含量也低,肥料氮的挥发损失较其它耕作模式多。2.7.2施氮量对土壤硝态氮含量的影响麦季N2处理的硝态氮积累量在0⁶0cm根区、60¹00cm淋失危险区及100²00cm淋失发生区皆显著高于N1处理,N2处理100²00cm层次硝态氮积累量显著高于N1处理是其0²00cm土层硝态氮积累量比N1处理高的主要原因,这部分硝态氮几乎不能被作物利用,易发生淋失。麦季土壤残留硝态氮含量尤其是0⁶0cm层次硝态氮积累量对玉米季0²00cm土壤硝态氮的积累影响显著,麦季该层次硝态氮积累量多,则玉米季土壤0²00cm土壤积累量多。3耕作模式与施氮量对小麦、玉米生长发育及产量的影响3.1耕作模式与施氮量对小麦生长发育的影响在试验第二年,旋耕和耙耕模式在旗叶光合速率、旗叶衰老特性和光合产物转移量和转移率,以及干物质积累量上与常规耕作模式无显著差异。在试验第三年,旋耕和耙耕模式光合产物转移、植株干物质积累量都明显低于常规耕作模式。免耕模式在生育后期具有较高的光合特性和生理活性,而旗叶光合产物转移量和转移率显著低于其它模式,说明在本试验条件下,免耕模式栽培的小麦贪青晚熟,进而抑制了植株营养器官中的碳水化合物向籽粒中转移,其干物质积累量也显著低于其它模式。N1和N2处理在试验第二年对小麦旗叶光合、衰老特性和光合产物转移情况没有显著影响,在试验第三年,旗叶光合产物转移量和转移率N2显著高于N1。3.2耕作模式与施氮量对作物产量的影响短期（2年）土壤旋耕和耙耕,小麦产量与常规耕作无显著差异,第三年产量显著低于常规耕作模式,免耕模式三年产量皆显著低于常规耕作、旋耕和耙耕模式。试验前两年N1、N2处理对小麦产量无显著影响,第三年N1产量低于N2,在N2处理下,常规耕作显著高于旋耕耙耕和免耕模式,在N1处理下,耙耕显著高于常规耕作,旋耕与常规耕作无显著差异。麦季氮肥后效对玉米产量有显著影响,N2>N1,试验第二、第三年差异达到显著水平。在N2处理下,旋耕和耙耕模式高于常规耕作模式,N1处理下,旋耕和耙耕模式产量不如常规耕作模式。免耕模式两氮肥处理下皆低于常规耕作模式。麦季氮肥用量对全年产量有显著影响,N2>N1,差异显著。在N2处理下,旋耕和耙耕模式尤其是旋耕模式产量高于常规耕作模式,在N1处理下,旋耕和耙耕模式产量相当,免耕模式在两个氮肥处理下均显著低于常规耕作模式。4耕作模式与施氮量对小麦、玉米品质的影响4.1耕作模式对小麦、玉米品质的影响耕作模式对小麦蛋白质含量、湿面筋含量和面筋指数无显著影响,蛋白质组分中球蛋白受耕作模式影响最显著,清蛋白次之。耙耕和旋耕模式的沉降值含量、面团稳定时间大于常规耕作模。小麦籽粒直链淀粉受耕作因素的影响比支链淀粉敏感,旋耕模式小麦籽粒淀粉含量的高于常规耕作,免耕和耙耕模式淀粉含量低于常规模式,免耕模式的淀粉含量最低。玉米籽粒淀粉和蛋白质含量,旋耕和耙耕式与常规耕作无显著差异。免耕模式玉米籽粒淀粉含量年度间变化幅度大,蛋白质含量随试验时间延长逐渐较常规耕作模式变少。4.2氮肥用量对小麦、玉米品质的影响小麦籽粒蛋白质含量N2、N1处理之间差异不显著。免耕在试验第二、第三年度,耙耕在试验第三年度,蛋白质含量N1处理显著低于N2处理。蛋白质组分中,球蛋白受氮肥用量影响最显著,清蛋白次之。小麦籽粒沉降值N2>N1,N1、N2处理对湿面筋含量、面筋指数和粉质仪参数无显著影响,说明N1、N2处理对小麦蛋白质品质无显著影响。籽粒直链淀粉和支链淀粉N1、N2处理含量不同,总淀粉含量N1>N2。麦季氮肥后效对玉米籽粒淀粉含量和蛋白质含量影响不显著。说明在本试验条件下,和N2相比N1处理对作物品质无显著影响。5长期耕作和施氮量对小麦、玉米氮素吸收利用的影响2005年15N测定结果表明,耙耕模式小麦的氮肥利用率最高,免耕模式氮肥利用率最低,但其显著提高了对土壤来源氮素的吸收。耙耕模式还显著提高小麦氮肥表观利用率和氮肥生产效率。N1处理下旋耕、耙耕和免耕模式氮素生理效率、氮肥生产效率表观氮肥利用率处理显著高于N2处理,常规耕作模式氮素生理利用率、氮素生产效率N2显著大于N1,这说明旋耕、耙耕和免耕模式种植的冬小麦比常规耕作模式种植的冬小麦更能有效的利用氮肥,以耙耕模式最佳。麦季氮肥对玉米季的氮肥利用效率有显著影响,旋耕和耙耕模式的氮肥利用率高于免耕模式和常规耕作模式。全年氮肥利用效率,耙耕模式优于其它三种耕作模式,常规耕作模式最差。两种氮肥处理,常规耕作和旋耕氮肥利用效率N2>N1,耙耕和免耕模式N1>N2处理。6耕作模式的适应性及合理氮肥用量初步认为在旋耕和耙耕模式可以在高产及有灌溉条件下短期（1²年）应用,免耕模式不适宜。麦季氮肥用量在168kg·hm-2可保证小麦高产优质。更多还原

【Abstract】 The field experiment was carried out in Zhongcun villages, Longkou City, Shandong Province China, in order to study the effects of nitrogen applied amount, straw returning and four soil tillage systems (including the conventional tillage (C), rotary tillage (R), serrated disk harrow tillage (H), zero-tillage (Z)) on soil physical and chemical characters, crop yield and kernel quality from 2002 to 2005. In this experiment two wheat cultivars Yangnong15, Jimai20 and maize cultivars Zhengdan958 were used. Meanwhile, 15N isotope tracing was adopted. soil fertilizer & water leakage test were the aided experiment, and physiological & biochemical was also studied. The results were as follows:1 Effects of straw returning and nitrogen applied amount on soil physical and chemical characters, yield and quality of wheat and maize1.1 Effects of straw returning on soil physical and chemical characters, yield and quality of wheat and maizeCompared with no straw returning treatment, straw returning treatment improved soil total nitrogen content, alkali-hydrolysable nitrogen content, available potassium content, available phosphorus and organic matter content in 0-40cm soil layer, also it could keep more nitrate in 0-60cm soil layer, reduce its leaching.In high-yield farmland (organic matter content, 1.712%; alkali-hydrolysable nitrogen content, 88.73mg·kg-1; available phosphorus content , 43.27 mg·kg -1; available potassium content, 88.33 mg·kg–1;in 0~20cm soil layer), short-term (2 years) straw returning had no significant effect on crop yield, but it could increase wheat protein content and dough stability time.1.2 Suitable nitrogen applied amount under straw returning conditionIn wheat season, nitrogen applied amount of 240 kg·hm-2 (N2) and 168 kg·hm-2 had no notable effect on wheat yield and maize yield. Meanwhile in the first year N1 and N2 had no significant impact on kernel quality. In the second year, wheat kernel wet gluten content and starch content under N1 treatment were significantly higher than that of N2 treatment, but maize kernel starch content under N2 treatment was noticeably higher than that of N1 treatment, and N2 treatment also changed the ratio of amylase content to amylopectin of maize. So in this experiment, the result showed that under straw returning conditions, 168 kg·hm-2 of nitrogen applied was more suitable.2 Effects of tillage systems on soil physical and chemical characters2.1 Effects of tillage systems on structure of tilthThere was no significant difference in soil bulk density and porosity among R, H and C treatments in 0~10cm soil layer. But in 10~20cm layer, soil bulk density of R and H treatment were noticeably higher than that of C treatment. Soil bulk density of Z treatment was gradually increased in three years, which was significantly higher than that of C treatment in 0~20cm soil layer.2.2 Effects of tillage systems on soil moisture contentThere was significantly positive correlation between soil pondage and rainfall of the same period in R, H and Z treatments, and the correlation coefficient was higher than C, especially the H treatment, its correlation coefficient was 0.70**, which reached a highly significant level, and its soil water retention was better than C. In 0~60cm soil layer, R, H and Z treatments could conserve more water than C and reduce water infiltration and evaporation, especially the H treatment. In different growth stage, the soil pondage of R, H and Z treatments was larger than C, especially in anthesis stage, which indicated that R, H and Z could inhibit the useless evaporation of soil water before anthesis and promote grain filling. Different tillage systems had different Effects on soil pondage. In this experiment, there was no significant difference between R and H treatment. The soil pondage of Z treatment was less than that of R and H, which indicated that Z treatment was disadvantageous to soil water infiltration under irrigation conditions because Z was covered by straw and had high density.The results also showed that soil tillage could affect soil water leakage. Irrigation water leakage volume in 50cm soil layer showed that C>R>H>Z. And the leakage was in the direct ratio to the depth of plowing, which showed the depth of plowing had noticeable Effects on irrigation water leakage.2.3 Effects of tillage systems on nutrient status in 0-40cm soil layerWith the extend of location experiment time, alkali-hydrolysable nitrogen content, available P and available K content of R and H treatments were gradually higher than those of C, total nitrogen content and available P of Z treatment was lower than that of C in 0-20cm soil layer. That was because of topdressing nitrogen fertilizer in Z treatment. But in 20~40cm soil layer, total nitrogen content, alkali-hydrolysable nitrogen content, available P and available K content of C treatment were the highest among all treatments.2.4 Effects of tillage systems on soil organic matter properties and cation exchange capacity (CEC)After three years, the compound degree of soil organo-mineral and the organic carbon in heavy fraction of R, H, Z treatments were higher than those of C treatment in 0-20cm soil layer. Meanwhile, R, H, and Z treatments significantly improved the soil fertility. CEC of H is the highest in 0~20cm soil layer, which indicated that H had the best effects on supplying fertility. But in 20-40cm layer, the results were reversed. So the C treatment had better soil fertility.2.5 Effects of tillage systems on activity of urease and sucraseThe activity of urease and sucrose of Z, H and R were significant higher than C in 0-10cm soil layer, and Z was the highest. But in 10-20cm soil layer, the result showed the reverse trend. The activity of enzymes under R, H and Z treatments had great difference in different layer, but the difference of C was little. That showed C treatment was conducive to maintain the uniformity of soil fertility in 0-20cm soil layer, but Z was unfavorable to crop growth.2.6 Effects of tillage systems on straw decomposition and soil respirationAfter a crop year, straw decomposition of C was remarkably lower than that of R, H and Z treatments, but there was no difference among three treatments. In wheat season, there was no significant difference of soil respiration rate among R, H and C treatments, but the soil respiration rate of Z was lower than that of C. In maize season, the soil respiration rate of C was higher than that of R, H, Z at maize pre-tasselling stage, but at maize maturity stage, the soil respiration rate of C was the lowest.2.7 Effects of tillage systems and nitrogen applied amount on nitrate content in soil2.7.1 Effects of tillage systems and nitrogen amount on content of nitrate in soilThe nitrate movement of H and R was significantly lower than C treatment. The results also showed soil nitrate content of R and H treatments was higher than that of C treatment in conglomeration zone of the root system (0-60cm), while under 60cm soil layer, C was higher than other treatments. Soil nitrate content of Z treatment was the lowest among all treatments.Soil tillage systems had effect on nitrate leaching. After applying fertilizer, soil nitrate content of water leakage under N1 treatment, C was the highest, R was the next, and Z was the last. Apparent nitrogen leaching rate of C was the highest, while that of Z was the lowest. Soil nitrate content of Z was lower than other treatments, and the loss of fertilizer nitrogen volatilization was more than other treatments.2.7.2 Effects of fertilizer application on soil nitrate contentIn wheat season, the nitrate accumulation of N2 was significantly higher than that of N1 in 0-60cm layer (root zone), in 60-100cm layer (danger zone in which leaching always easily occurred) and in 100-200cm layer(the zone leaching easily occurred). Nitrate accumulation of N2 treatment was notably higher than that of N1 treatment, which was the major reason why the nitrate accumulation of N2 was higher than N1. But the nitrate couldn’t be used by crop and was easy to leaching. The residual soil nitrate content in wheat season had significant influence on soil nitrate accumulation of maize field, especially the soil nitrate accumulation in 0-60 soil layer. So more soil nitrate accumulation in wheat season, more soil nitrate accumulation in maize season.3 Effects of tillage systems and nitrogen applied amount on wheat growth and development and yield of wheat and maize3.1 Effects of tillage systems and nitrogen applied amount on wheat growth and developmentIn the second year of experiment, there was no significant difference in the wheat flag leaf photosynthesis rate, flag leaf senescence characteristics, photosynthate transferring amount, photosynthate transferring ratio and dry matter accumulation of between R, H and C. In the third year, the photosynthate transfering amount and dry matter accumulation amount of R and H were significantly lower than that of C.Wheat flag leaf under Z treatment had better photosynthesis characteristics and physiological characteristics in the later growth stage. but the flag leaf photosynthate transferring amount and transferring ratio were lower than that of other tillage treatments. This showed that wheat of Z matured later, and inhibited the transfer of photosynthate from nutrient organs to kernels, whose dry matter accumulation was significantly lower than other tillage systems.In the second year, there was no significant effect on the photosynthesis characteristics, senescence characteristics and photosynthate transfer of flag leaf between N1 and N2 treatment. While in the third year the photosynthate transfering amount and transferring ratio of flag leaf under N2 level was higher thant that of N1.3.2 Effects of tillage systems and nitrogen applied amount on yield of wheat and maizeThere was no significant difference of yield among three treatments (R, H and C) after two years experiment, but in the third year, crop yield of C treatment was higher than that of R and H. In this experiment, crop yield of Z was remarkably the lowest. Nitrogen fertilizer had different influence on crop yield in different years. There was no significant effect on crop yield under N1 and N2 level in the first and second year, but in the third year, crop yield of N1 was lower than that of N2. Meanwhile, under N2 level, yield of C treatment was higher than that of H and Z, while under N1 level, crop yield of H was notably higher than that of C treatment, but there was no difference between the yield of R and C treatments.The residual nitrogen fertilizer of wheat season had significant effect on maize yield, and the influence of N2 was greater than N1. The effect became remarkable in the second year and in the third year. The crop yield of R and H treatments was higher than that of C treatment under N2 level, but under N1 level, the crop yield of R and H was lower than that of C treatment, meanwhile, crop yield of Z treatment was lower than that of C treatment.There was significant effect of nitrogen applied amount in wheat season on crop yield, and the yield of N2 treatment was obviously higher than that of N1. The yield of R and H was higher than that of C under N2 level, especially the R treatment. Under N1 level, the yield of R was equal to that of R, while the crop yield of Z was significantly lower than that of C treatment under both N1 and N2 level.4 Effects of tillage systems and nitrogen applied amount on the quality of wheat and maize kernel4.1 Effects of tillage systems on the quality of wheat and maize kernelThere was no significant effect of tillage systems on protein content, wet gluten content and gluten index. While the effect of tillage systems on globulin content in protein fractions was the most obvious and on albumins was less obvious. The sedimentation volume and dough stability time of R and H were higher than that of C. The wheat amylose starch was easier to be affected by tillage systems than amylopectin starch. The wheat kernel starch content of R was higher than that of C, while that of Z and H was lower than that of C. And the wheat kernel starch content of Z was the lowest. There was no significant effect on maize protein content and starch content between C, R and H. The maize starch content of Z varied most among different years. Compared with C, the maize kernel protein content of Z became less as time went.4.2 Effects of nitrogen fertilizer amount on the quality of wheat and maize kernelThere was no significant difference between N1and N2 in wheat kernel protein content in the first year. The wheat kernel protein content of N1 was significantly lower than that of N2 in the second year and third year of Z and in the third year of H. Among protein components, globuln content was affected most significantly, while albumins content was affected less. The sedimentation volume of N2 was higher than that of N1. There was no significant difference between N1 and N2 in wet gluten content, gluten index and farimograph index, which showed that N1and N2 had no significant effects on wheat kernel protein quality. The grain amylose and amylopectin content of N1 and N2 of wheat kernel were different. And the total starch content of wheat kernel of N1 was higher that of N2. There was no significant aftereffect on maize kernel starch and protein content of N-fertilizer in wheat season. This showed that compared with N2, N1 had no significant effect on crop quality.5 Effects of long-term tillage and nitrogen fertilizer on crop nitrogen absorption and utilizationThe results of 15N in 2005 showed that the N-fertilizer utilized efficiency of H was the highest, while that of Z was the lowest. But Z increased absorption of nitrogen from soil significantly. H increased N-fertilizer apparent use efficiency and N-productive efficiency significantly of wheat. The N-physiological use efficiency, N-productive efficiency and N-fertilizer apparent use efficiency of wheat of R, H and Z in N1 level were significantly higher than that of N2 level. While the N-physiological use efficiency, N-productive efficiency and N-fertilizer apparent use efficiency of C of wheat in N2 level were significantly higher than that of N1 level. This showed that R, H and Z could use N fertilizer more efficiently than C in wheat season, among which H was the best.There were some significant effects of nitrogen fertilizer in wheat season on the N-fertilizer utilized efficiency in maize season. The N-fertilizer utilized efficiency in maize season of R and H was higher than that of N and C. Considering the N-fertilizer utilized efficiency in a whole year, H was better than other three tillage systems, while C was the worst. The N-fertilizer utilized efficiency in a whole year of N2 was higher than that of N1 in C and R, and N1 was higher than that of N2 in H and Z.6 Tillage systems adaptability and suitable amount of nitrogenPreliminary conclusion could got that R and H were suitable for short time (1~2 years) in high-yield and irrigation conditions, while Z was not suitable. Nitrogen applied amount of 168kg·hm-2 was enough to maintain a higher yield and better kernel wheat quality.更多还原