本文選題：秸稈還田量 + 還田深度��； 參考：《吉林農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：本研究通過兩年秸稈還田定位試驗(yàn)研究“種還分離模式”下秸稈還田量(秸稈占土重的0%、0.44%、0.88%、1.32%)對耕層土壤理化特性及玉米生長的影響、尼龍袋法田間原位培養(yǎng)試驗(yàn)研究不同深度土壤(0~15cm、15~30cm、30~45cm)在不同秸稈添加量(秸稈占土重的0%、0.44%、0.88%、1.32%、2.64%、5.28%)條件下的土壤腐殖質(zhì)組分變化及土壤酶活性的動態(tài)變化情況,旨在探究適宜秸稈還田深度、適宜秸稈還田量,為秸稈還田培肥土壤提供理論依據(jù)。研究結(jié)果如下:(1)“種還分離模式”下,隨秸稈還田量增加,耕層土壤容重逐漸降低而總孔隙度和土壤含水量逐漸增加,與不秸稈還田相比,1.32%秸稈還田量在0~10cm和10~20cm土層的土壤容重分別顯著降低8.25%、11.36%,土壤總孔隙度分別顯著增加8.35%、14.74%,土壤含水量分別顯著提高2.49%、2.83%;秸稈還田對土壤機(jī)械穩(wěn)定性團(tuán)聚體影響不大,卻顯著降低0.01mm粒級和顯著增加了0.25-0.01mm粒級土壤微團(tuán)聚體的含量,使土壤特征微團(tuán)聚體比例顯著降低,土壤微團(tuán)聚體得到改善。(2)“種還分離模式”進(jìn)行兩年,增加秸稈還田量,利于土壤有機(jī)碳的積累,1.32%秸稈還田量2013年、2014年兩年土壤有機(jī)碳含量比未秸稈還田分別增加7.40%、14.77%;隨秸稈還田量的增加,土壤水溶性物質(zhì)、土壤腐殖酸、胡敏素含量增加;秸稈還田兩年后,各還田處理提高了土壤的PQ值,適量增加秸稈還田量,延長施入土壤中秸稈腐解時間,可以改善土壤品質(zhì);秸稈還田使土壤WSS、HA、FA的分子結(jié)構(gòu)向簡單化方向發(fā)展,增加秸稈還田量更利于WSS、FA分子結(jié)構(gòu)簡單化,而對HA分子結(jié)構(gòu)的簡單化無明顯影響;秸稈還田增加土壤過氧化氫酶活性,土壤脲酶、蔗糖酶的活性隨秸稈還田量的增加而增加;秸稈還田,對玉米根系的生長發(fā)育無明顯抑制抑制作用,最終并未造成玉米減產(chǎn)。(3)通過不同深度土壤不同秸稈還田量原位培養(yǎng)試驗(yàn),秸稈還田可增加不同深度土壤的有機(jī)碳的含量,適宜范圍內(nèi)秸稈還田量越高,土壤有機(jī)碳含量越高;15~30cm和30~45cm土層土壤秸稈還田利于土壤有機(jī)碳的積累。深度相同時,土壤WSS有機(jī)碳含量隨秸稈添加量增加而增加,30~45cm土層土壤秸稈還田更利于土壤WSS有機(jī)碳含量的提高。高量秸稈添加量(2.64%、5.28%)更有利于0~15cm、15~30cm和30~45cm土層土壤腐殖酸的積累;秸稈還田可提高各還田深度土壤的胡敏素含量;各深度土層進(jìn)行秸稈還田均可提高土壤過氧化氫酶、脲酶、蔗糖酶的活性;隨培養(yǎng)時間,在各還田深度,土壤過氧化氫酶、脲酶、蔗糖酶酶活性隨培養(yǎng)時間先升高后降低,0~15cm、15~30cm、30~45cm土層土壤過氧化氫酶活性在培養(yǎng)90d時最高,0~15cm、15~30cm和30~45cm土層土壤蔗糖酶活性最高值在培養(yǎng)30d時。0~15cm、15~30cm土層土壤脲酶活性在培養(yǎng)30d時最高,而30~45cm土層土壤脲酶活性峰值出現(xiàn)在培養(yǎng)90d時。
[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.
【學(xué)位授予單位】：吉林農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S141.4;S513

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