秸秆全量还田方式对土壤肥力及玉米生长的影响研究

发布时间：2018-05-10 05:35

本文选题：秸秆还田量 + 还田深度　；参考：《吉林农业大学》2015年硕士论文

【摘要】：本研究通过两年秸秆还田定位试验研究“种还分离模式”下秸秆还田量(秸秆占土重的0%、0.44%、0.88%、1.32%)对耕层土壤理化特性及玉米生长的影响、尼龙袋法田间原位培养试验研究不同深度土壤(0~15cm、15~30cm、30~45cm)在不同秸秆添加量(秸秆占土重的0%、0.44%、0.88%、1.32%、2.64%、5.28%)条件下的土壤腐殖质组分变化及土壤酶活性的动态变化情况,旨在探究适宜秸秆还田深度、适宜秸秆还田量,为秸秆还田培肥土壤提供理论依据。研究结果如下:(1)“种还分离模式”下,随秸秆还田量增加,耕层土壤容重逐渐降低而总孔隙度和土壤含水量逐渐增加,与不秸秆还田相比,1.32%秸秆还田量在0~10cm和10~20cm土层的土壤容重分别显著降低8.25%、11.36%,土壤总孔隙度分别显著增加8.35%、14.74%,土壤含水量分别显著提高2.49%、2.83%;秸秆还田对土壤机械稳定性团聚体影响不大,却显著降低0.01mm粒级和显著增加了0.25-0.01mm粒级土壤微团聚体的含量,使土壤特征微团聚体比例显著降低,土壤微团聚体得到改善。(2)“种还分离模式”进行两年,增加秸秆还田量,利于土壤有机碳的积累,1.32%秸秆还田量2013年、2014年两年土壤有机碳含量比未秸秆还田分别增加7.40%、14.77%;随秸秆还田量的增加,土壤水溶性物质、土壤腐殖酸、胡敏素含量增加;秸秆还田两年后,各还田处理提高了土壤的PQ值,适量增加秸秆还田量,延长施入土壤中秸秆腐解时间,可以改善土壤品质;秸秆还田使土壤WSS、HA、FA的分子结构向简单化方向发展,增加秸秆还田量更利于WSS、FA分子结构简单化,而对HA分子结构的简单化无明显影响;秸秆还田增加土壤过氧化氢酶活性,土壤脲酶、蔗糖酶的活性随秸秆还田量的增加而增加;秸秆还田,对玉米根系的生长发育无明显抑制抑制作用,最终并未造成玉米减产。(3)通过不同深度土壤不同秸秆还田量原位培养试验,秸秆还田可增加不同深度土壤的有机碳的含量,适宜范围内秸秆还田量越高,土壤有机碳含量越高;15~30cm和30~45cm土层土壤秸秆还田利于土壤有机碳的积累。深度相同时,土壤WSS有机碳含量随秸秆添加量增加而增加,30~45cm土层土壤秸秆还田更利于土壤WSS有机碳含量的提高。高量秸秆添加量(2.64%、5.28%)更有利于0~15cm、15~30cm和30~45cm土层土壤腐殖酸的积累;秸秆还田可提高各还田深度土壤的胡敏素含量;各深度土层进行秸秆还田均可提高土壤过氧化氢酶、脲酶、蔗糖酶的活性;随培养时间,在各还田深度,土壤过氧化氢酶、脲酶、蔗糖酶酶活性随培养时间先升高后降低,0~15cm、15~30cm、30~45cm土层土壤过氧化氢酶活性在培养90d时最高,0~15cm、15~30cm和30~45cm土层土壤蔗糖酶活性最高值在培养30d时。0~15cm、15~30cm土层土壤脲酶活性在培养30d时最高,而30~45cm土层土壤脲酶活性峰值出现在培养90d时。
[Abstract]:In this study, the effects of straw returning amount (0.44% of straw weight) on soil physical and chemical properties and maize growth were studied in the "seed separation model" by two years of straws returning to the field. Field in situ culture experiment with nylon bag method the changes of soil humus composition and soil enzyme activity were studied under different soil straws at different depth (0.44g / 0.88g / kg) and soil enzyme activity under different soil depth (0.440.44g / 0.88g / kg), in order to explore the optimum depth of straw returning to the field, so as to investigate the dynamic changes of soil humus composition and soil enzyme activity. The results showed that the soil humus composition and soil enzyme activity were changed in different soil depth (0.44% of the soil weight), and the soil enzyme activity of the soil was determined by using the nylon bag method. It is suitable for returning straw to soil and providing theoretical basis for returning straw to fertilize soil. The results were as follows: (1) with the increase of straw returning amount, the bulk density of topsoil gradually decreased, but the total porosity and soil water content increased. Compared with no straw returning, the soil bulk density of 1.32% straw was significantly decreased in 0~10cm and 10~20cm soil layers, the total porosity of soil increased 8.35% and 14.74%, and the soil water content increased 2.49% and 2.83%, respectively, and the soil mechanical stability aggregates were not affected by straw return, respectively, and the soil total porosity was significantly increased by 8.35% and 14.74% respectively, and the soil water content was significantly increased by 2.49% and 2.83%, respectively, and the effect of straw returning on soil mechanical stability aggregates was not significant. However, the content of soil microaggregates of 0.25-0.01mm was significantly increased, the proportion of soil characteristic microaggregates was significantly decreased, and the soil microaggregates were improved by "seed return separation model" for two years, and the amount of straw returned to the field was increased, but the grain size of 0.25-0.01mm was significantly decreased and the proportion of soil microaggregates was significantly decreased, and the proportion of soil microaggregates was significantly decreased. In 2013, the soil organic carbon content increased 7.40 ~ 14.77% than that of no straw in 2014, and the soil water soluble substance, humic acid and humin content increased with the increase of straw return. Two years after returning straw to the field, the PQ value of soil was increased, the amount of straw returned to the field was increased, the decomposition time of straw was prolonged, and the soil quality was improved, and the molecular structure of soil WSS-HAFA was simplified. Increasing the amount of straw returning to the field is more conducive to simplifying the molecular structure of WSSFA, but has no obvious effect on the simplification of the molecular structure of HA, and increases the activity of soil catalase, soil urease and sucrase with the increase of the amount of straw returning to the field. Straw returning to the field had no obvious inhibition on the growth and development of maize root system, and did not result in the yield reduction of maize. The return of straw to soil can increase the content of organic carbon in different depth soil. The higher the amount of straw returning to soil, the higher the content of organic carbon in soil, and the higher the content of soil organic carbon is, the higher the content of soil organic carbon is in the suitable range, and the return of soil straw to 30~45cm soil layer is beneficial to the accumulation of soil organic carbon. At the same depth, the content of soil WSS organic carbon increased with the increase of straw addition, and the return of soil straw to the field was more favorable to the increase of soil WSS organic carbon content. The content of humic acid in the soil layer of 0 ~ 15 cm ~ (15 ~ (30) cm) and 30~45cm soil layer was increased, the content of humin in each depth of soil was increased, and the catalase and urease of soil could be increased by returning straw to each depth of soil layer. The activity of sucrase, soil catalase, urease, soil catalase, urease, soil catalase, urease, soil catalase, urease, The activity of sucrase increased firstly and then decreased with the culture time. The highest soil catalase activity was in the soil layer of 1530cm and 1530cm of 30~45cm soil layer at 90 days and the highest value of urease activity in the soil layer of 1530cm soil layer was highest at 30 days after the culture, and the highest value was found in the soil layer of 1530cm soil layer, the highest level was the soil layer of 1530cm soil layer of 30~45cm soil layer at the culture time of 90d. The highest level of soil catalase activity was found in the soil layer of 30d culture. However, the peak of urease activity in 30~45cm soil layer appeared at 90 days after culture.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4;S513

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