种还分离模式下玉米秸秆还田对土壤养分转化的影响

发布时间：2018-05-16 17:42

本文选题：玉米秸秆 + 种还分离　；参考：《吉林农业大学》2017年硕士论文

【摘要】：通过田间原位模拟和微区秸秆还田的方式对种还分离模式下玉米秸秆还田对土壤养分转化的影响进行了研究,田间原位模拟试验设置了四个水平秸秆还田量0%(秸秆未还田)、0.44%(常规还田全量)、0.88%(种还分离全量)和1.32%(常规还田3倍量)以及三个不同还田深度0-15cm、15-30cm、30-45cm交叉处理,微区秸秆还田中也设置同样的四个水平秸秆还田量处理,将微区分成玉米种植区和秸秆还田区两部分。对试验中各处理土壤NPK、微量元素、有机酸以及微区处理中玉米根系特征和产量进行了研究,研究结果如下:(1)种还分离模式下的玉米秸秆还田可以促进土壤有效态氮、磷、钾含量的提高。其中碱解氮以30-45cm土层增加最为显著,速效磷和速效钾以0-15cm增加最为显著,速效钾含量的提高主要表现为交换性钾含量的提高,水溶性钾仅在0-15cm土层增加显著,并且对速效磷含量的提高主要通过促进其他的形态的磷转化为速效磷,但各处理的秸秆还田对土壤全磷和缓效钾均无明显影响。同时,种还分离模式下的玉米秸秆还田能够减少土壤中等活性有机磷,增加土壤中稳定性有机磷,促进土壤有机磷向着中稳定性有机磷的方向转化。此外,种还分离模式下玉米秸秆还田能够通过提高土壤养分的有效性为下季玉米生长提供更多可以直接吸收利用的养分,秸秆还田1a后,玉米种植区土壤NPK的有效性均显著提高,其中土壤碱解氮分别增加了4.3%、14.3%和20.0%,速效磷增加了68.9%、60.2%、88.5%,速效钾分别增加了14.7%、32.0%和29.8%。(2)种还分离模式下的玉米秸秆还田有利于提高土壤铁、锌的有效性,对有效锰含量无明显影响,不利于土壤有效铜的积累。其中土壤有效铁和和有效锌含量在0-15cm和15-30cm土层均未随着秸秆还田量的增加而升高,土壤有效铁含量在30-45cm土层随着秸秆还田量的增加而升高,有效锌含量在30-45cm土层随着秸秆还田量的增加而降低。土壤有效锰各处理之间均无显著差异,有效铜含量在15-30cm和30-45cm土层随着秸秆还田量的增加呈降低趋势,但差异不显著。种还分离模式下的玉米秸秆还田能够增加下季玉米生长有效铁和锌的供应,秸秆还田1a后,玉米种植区土壤有效铁和有效性含量均显著升高,其中土壤有效铁分别增加了18.3%、23.6%、32.3%,土壤有效锌分别增加了41.5%、37.8、59.3%。(3)种还分离模式下玉米秸秆还田能够促进土壤有机酸的积累。其中,到秸秆还田30d时,土壤有机酸含量经历了一个复杂的过程,0-15cm土层土壤有机酸含量高于对照,30-45cm土层土壤有机酸含量低于对照,随着秸秆还田时间的增加,各处理土壤有机酸含量均显著升高,在还田90d到150d时,土壤有机酸含量均处在较高水平,还田150d到360d时,各处理的土壤有机酸含量均显著降低。同时,种还分离模式下的玉米秸秆还田能够增加下季玉米生长中土壤有机酸含量,秸秆还田1a后,玉米种植区土壤有机酸含量分别增加了6.8%、14.5%和11.6%。此外,土壤有机酸含量的增加有助于部分土壤速效养分的提高,土壤有机酸和土壤速效钾、速效磷、有效铁、有效锌在0-15cm土层中表现出显著正相关,土壤有机酸和速效磷、有效铁在30-45cm土层显著正相关。(4)种还分离模式下玉米秸秆还田能够促进苗期玉米根系生长发育,增加玉米根干重、根体积、总根长和根表面积,提高玉米产量。其中各处理玉米根干重分别增加了7.9%、12.2%和8.6%,根体积分别增加了1.9%、14.0%和10.4%,总根长分别增加了3.0%、6.6%和6.9%,根表面积分别增加了8.5%、18.2%和16.7%,同时R1和R3处理的玉米产量分别增加了7.1%和21.2%。
[Abstract]:The effect of corn straw returning to soil nutrient conversion was studied in the field in situ simulation and microarea straw returning to the field. In the field, the field in situ simulation test set four horizontal straw returning amount 0% (straw not returning field), 0.44% (conventional field total), 0.88% (species also separated total) and 1.32% (3 times the conventional return field). As well as three different returning field depth 0-15cm, 15-30cm, 30-45cm cross treatment, the same four horizontal straw returning treatments were set in the microarea straw returning, and the micro area was divided into two parts of corn planting area and straw returning area. The characteristics and production of maize root system in soil NPK, trace elements, organic acids and micro area treatment were treated in the experiment. The research results are as follows: (1) the returning of corn straw to field under the mode of separation can promote the increase of soil available nitrogen, phosphorus and potassium. The most significant increase of alkali hydrolysable nitrogen in the 30-45cm soil layer, the most significant increase of available phosphorus and available potassium with 0-15cm, the increase of the content of quick effect potassium is mainly the extraction of exchangeable potassium content. High, water-soluble potassium only increased in the 0-15cm soil layer, and the increase of available phosphorus content mainly through the promotion of other forms of phosphorus conversion to available phosphorus, but the treatments of straw returning to soil all phosphorus and slow available potassium were not significantly affected. Increase soil stable organophosphorus and promote the transformation of soil organophosphorus to stable organophosphorus. In addition, corn straw returning can provide more nutrients for next season corn growth by increasing soil nutrient availability, and soil NPK in corn planting area after 1a. The soil alkali hydrolysable nitrogen increased by 4.3%, 14.3% and 20% respectively, and the available phosphorus increased by 68.9%, 60.2%, 88.5%, and the available potassium was increased by 14.7%, 32% and 29.8%. (2). The returning of corn straw to the field was beneficial to improve the efficiency of soil iron and zinc, and had no obvious effect on the content of effective manganese, which was not beneficial to the soil. The soil effective iron and effective zinc content in 0-15cm and 15-30cm soil layer did not increase with the increase of the amount of straw returning, the soil available iron content increased with the increase of the amount of straw returning in the 30-45cm soil layer, and the effective zinc content decreased with the increase of the amount of straw returning in the 30-45cm soil layer. There is no significant difference between the rational and effective copper content in 15-30cm and 30-45cm soil layer with the increase of the amount of straw returning, but the difference is not significant. The returning of corn straw to the field can increase the supply of effective iron and zinc for the growth of the next season corn, and the soil available iron and effective content in the corn planting area after returning to the field of 1a. The soil effective iron increased by 18.3%, 23.6%, 32.3%, and the soil effective zinc increased by 41.5%, respectively. The soil organic acid accumulation could be promoted by the returning of corn straw to the field under 37.8,59.3%. (3). The organic acid content of soil had undergone a complex process when the straw returned to field 30d, and the soil layer of 0-15cm soil had a complex process. The organic acid content of soil layer in 30-45cm soil layer was lower than that of control. The organic acid content in each treatment soil increased significantly with the increase of straw returning time. The organic acid content of soil was at a high level when returning to the field from 90d to 150D. The soil organic acid content of each treated soil decreased significantly when the field was 150D to 360D. The return of corn straw to field under the model could increase the content of soil organic acid in the growth of Maize in the next season. After returning to the field for 1a, the soil organic acid content increased by 6.8%, 14.5% and 11.6%., respectively. The increase of soil organic acid content was helpful to the improvement of some soil available nutrients, soil organic acid and soil quick available potassium. Effective phosphorus, effective iron, effective zinc showed significant positive correlation in the 0-15cm soil layer, soil organic acid and available phosphorus, effective iron in the 30-45cm soil layer significantly positive correlation. (4) under the separation mode corn straw returning can promote the seedling growth and development of maize root, increase the root dry weight of Maize, root volume, root length and root surface area, improve maize yield. The root dry weight of each treatment increased by 7.9%, 12.2% and 8.6% respectively, the root volume increased by 1.9%, 14% and 10.4%, the total root length increased by 3%, 6.6% and 6.9% respectively, and the root surface area increased by 8.5%, 18.2% and 16.7%, while the maize yield of R1 and R3 increased respectively by 7.1% and 21.2%., respectively.

【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S158

【参考文献】