不同秸秆还田量对土壤性状及玉米产量的影响

发布时间：2018-06-15 17:00

  本文选题：玉米 + 秸秆还田　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：农作物秸秆中含有大量矿质元素,比如碳、磷、钾、氮、钙、镁、硫和硅等元素,同时也含有大量的纤维素、半纤维素、木质素和蛋白质等有机质,是一种可资源化利用的"固体废弃物资源"。本试验的秸秆数量梯度分别为0、3750、7500、11250、15000 kg·hm-2;以不施秸秆作为对照。微区设计,微区面积5m2,三次重复。播种前按照试验方案将玉米秸秆均匀撒在小区内,用旋耕机进行深度12-15cm的常规旋耕作业。春季播种时施入玉米一次性专用复合肥600kg·hm-2(N-P2o5-K20为25-15-15),播种密度60000株·hm-2。在玉米生长时期内采集表层土壤,分析土壤物理性状、土壤养分、土壤微生物、土壤酶的动态变化及其相关性,试验结果表明:1.秸秆还田能明显的提高土壤养分,其中7500 kg·hm-2处理效果最好,在玉米完熟期时,相比于对照,土壤碱解氮提高了 38.9%,速效磷提高了 8.97%,速效钾提高了 27.31%,有机质提高了 21.3%。2.秸秆还田能明显的降低土壤容重、增加土壤孔隙度、提高土壤田间持水量、缓解水分散失,这种效果会随着秸秆还田量的增加而变化加大;其中11250、15000 kg·hm-2处理的土壤容重分别比对照降低了 11.4%、14.2%。对于土壤孔隙度,对照、3570、7500、J4、J5整体呈上升趋势,3570、7500相对于对照土壤总孔隙度的增加无显著差异,J4、J5相对于对照呈显著差异,分别提高了 8.2%、8.8%。对于田间持水量,方差分析结果表明,3570、J5相对于0田间持水量的增加无显著差异(P0.05),而7500、J4相对于对照田间持水量的增加呈显著差异,分别增加了 10.2%、11.9%。对于毛管孔隙度,随着玉米秸秆数量的增加,土壤毛管孔隙度没有太大的变化。3.秸秆还田能明显降低水分的流失和蒸发,灌水后,15000 kg·hm-2处理的土壤含水最在灌水后120小时内一直呈现急速下降的趋势,3750 kg·hm-2处理在灌水后24小时到48小时与对照均相同急速下降,48小时到120小时下降速度慢7500、11250 kg·hm-2处理则一直呈现缓慢的下降趋势。由此可见,秸秆还田可以缓解土壤水分的流失,并且随着玉米秸秆还田量的增加,其缓解效果愈好,但是当秸秆还田量超出一定的范围时,秸秆还田会加速土壤水分的流失。4.秸秆还田能够明显的增加土壤微生物的数量,土壤真菌数量在拔节期随着玉米秸秆还田量的增加表现为先下降,后上升,再下降的趋势,11250 kg·hm-2处理最多,之后快速下降。土壤放线菌数量在玉米拔节期时随着玉米秸秆还田量的增加表现为先上升后下降的趋势,11250 kg·hm-2最多,在乳熟期和完熟期,土壤放线菌数量整体都表现为上升趋势完熟期土壤放线菌数量呈先上升后下降的趋势,7500kg·hm-2处理最多。土壤细菌数量在拔节期随着玉米秸秆还田量的增加表现为先上升后下降的趋势,11250 kg·hm-2处理最多,完熟期土壤细菌数量呈先上升后下降的趋势,7500 kg·hm-2处理最多。土壤纤维素菌在拔节始期随着玉米秸秆还田量的增加表现为先下降、后上升、再下降的趋势,11250 kg·hm-2处理最多在抽雄始期和完熟期随着玉米秸秆还田量的增加表现为先上升后下降的趋势,其中11250kg·hm-2处理最多。5.秸秆还田能够增强土壤酶的活性,并且随着秸秆数量的增加,土壤酶的活性越高,当秸秆的数量达到一定的值后,其活性不再增强。秸秆还田会增加玉米生育前期土壤中蔗糖酶含量,但是随着秸秆还田时间的延长,各处理间土壤蔗糖酶的含量会慢慢的降低,在同一时期内,各处理的土壤蔗糖酶含量要高于对照。秸秆还田会增加玉米生育前期土壤中脲酶含量,但是随着秸秆还田时间的延长,各处理间土壤脲酶的含量会慢慢的降低,在同一时期内,各处理的土壤脲酶含量要高于对照。土壤纤维素酶和土壤磷酸酶在玉米生育后期随着秸秆还田量的增加呈现先上升后下降的趋势。6.适量的秸秆还田量能够有效的增加作物的产量,在7500kg·hm-2时对作物增产的效果最好。
[Abstract]:The crop straw contains a large number of mineral elements, such as carbon, phosphorus, potassium, nitrogen, calcium, magnesium, sulfur and silicon, and also contains a large amount of cellulose, hemicellulose, lignin and protein. It is a kind of "solid waste resource", which can be used for resources. The gradient of the amount of straw in this experiment is 037507500112501500 kg. Hm-2, respectively. With no straw as control. Microarea design, micro area area 5m2, three repetitions. Before sowing, the corn straw was evenly scattered in the plot, the conventional rotary tillage operation of deep 12-15cm was carried out by rotary tiller. The one time special compound fertilizer 600kg / hm-2 (N-P2o5-K20 25-15-15) was applied to the corn in spring, and the density of sowing density was 60000. Hm-2. During the period of maize growth, the soil physical properties, soil nutrients, soil microbes, and soil enzyme dynamic changes and their correlation were analyzed in the period of maize growth. The experimental results showed that 1. straw returning could obviously improve soil nutrients, and 7500 kg. Hm-2 treatment was the best. The soil alkali hydrolysable nitrogen was improved in the mature period of corn. 38.9%, the available phosphorus increased by 8.97%, the available potassium increased by 27.31%. The organic matter increased the soil bulk density, increased the soil porosity, increased the soil moisture content and alleviated the loss of water. This effect would increase with the increase of the amount of straw returning, and the soil treated with 1125015000 kg. Hm-2. Soil bulk density was 11.4% lower than that of the control, 14.2%. for soil porosity, control, 35707500, J4, J5 overall showed a rising trend, 35707500 compared with the control soil total porosity increased no significant difference, J4, J5 relative to the control showed significant differences, respectively, increased by 8.2%, 8.8% respectively. For field water holding, variance analysis showed that 3570, J5 phase There was no significant difference in the increase of 0 field water holding capacity (P0.05), while 7500, the increase of J4 compared with the control field water holding capacity was significantly different, the increase of 10.2%, 11.9%. for capillary porosity, with the increase of the number of corn straw, soil capillary porosity did not change too much,.3. straw returning can significantly reduce the loss of water and evaporation After irrigation, the soil water cut treated by 15000 kg hm-2 was the most rapid decline in 120 hours after irrigation, and 3750 kg. Hm-2 treatment decreased rapidly from 24 to 48 hours after irrigation, and slowed down from 48 to 120 hours and slowed down slowly by 750011250 kg. Straw returning can alleviate soil water loss, and with the increase of corn straw returning, the effect of soil moisture loss is better, but when the amount of straw returning is beyond a certain range, straw returning will accelerate the loss of soil water,.4. straw returning can obviously increase the number of soil microorganism, the number of soil fungi in jointing stage with the jointing period. The increase of corn straw returning amount was first descending, then rising and then decreasing, 11250 kg hm-2 treatment was most, and then decreased rapidly. The amount of soil actinomycetes in the Maize Jointing period increased with the increase of corn straw returning, 11250 kg. Hm-2 most, in the milk ripening period and the mature period, soil line The number of bacteria on the whole showed a trend of rising and decreasing in the amount of soil actinomycetes in the uptrend, 7500kg. Hm-2 treatment was the most. The number of soil bacteria increased first and then decreased with the increase of corn straw returning. 11250 kg. Hm-2 treatment was the most, and the number of soil bacteria in the completion period increased first. The decline trend, 7500 kg. Hm-2 treatment most. The soil cellulose bacteria in the beginning of jointing stage with the increase of corn straw returning, then rise, then rise, then descend trend, 11250 kg. Hm-2 treatment at most in the beginning and finish stage with the increase of corn straw returning to the first increase then decline trend, of which 11250kg The activity of soil enzyme can be enhanced by hm-2 treatment with most.5. straw returning, and the activity of soil enzyme is higher with the increase of straw number. When the number of straw reaches a certain value, its activity no longer increases. Straw returning will increase the content of sucrase in the soil of early maize growth, but with the extension of the straw returning time, each treatment will be treated. In the same period, the content of invertase in soil was higher than that of control in the same period. Straw returning would increase the soil urease content in the early period of maize growth, but the soil urease content in each treatment will slowly decrease with the time of returning the field, and the treatment will be treated in the same period. Soil urease content was higher than that of control. Soil cellulase and soil phosphatase showed a trend of rising and then decreasing with the increase of straw returning in the late period of maize growth..6. amount of straw returning amount could effectively increase crop yield, and the effect of increasing crop yield at 7500kg hm-2 was the best.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S513;S141.4
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本文编号：2022762