地膜覆盖与施肥条件下土壤氮素在团聚体中的分布特征
发布时间：2018-10-04 23:23
【摘要】：土壤团聚体是土壤发生物质转化和能量交换的场所,土壤功能主要依靠良好的团聚体结构来实现。地膜覆盖通过对土壤温度和水分的作用改变了土壤的基本理化特征,在实现作物高产同时产生了地力消耗过大的问题。施肥是地膜覆盖条件下提高土壤地力的一个重要措施。然而关于地膜覆盖与施肥条件下土壤团聚体及其养分在土壤剖面的分布特征仍不太清楚。本研究基于辽宁省沈阳农业大学后山棕壤长期定位试验基地,开展长期地膜覆盖与施肥对不同土层团聚体中氮素影响的研究,以期为土壤可持续利用和农业可持续发展提供科学依据和实践指导。本研究选用裸地条件下不施肥、单施氮肥和单施有机肥处理及地膜覆盖条件下与之相对应的施肥处理;采用干筛法将土壤团聚体分为2 mm、1-2 mm、0.25-1 mm、0.25 mm 四个粒级;分析不同土层(0-20 cm,20-40 cm,40-60 cm)土壤团聚体中氮素的含量及储量。主要研究结果如下:(1)土壤团聚体均以0.25-1 mm为优势粒级,占土壤干重量33.96%-47.97%;0.25 mm粒级团聚体比例最低,其比例不超过10%。覆膜与裸地相比显著增加了表层(0-20 cm)土壤1-2 mm团聚体比例,却降低了 0.25-1 mm团聚体比例。与不施肥和单施化肥相比较,施用有机肥增加了大团聚体(2mm)的含量。(2)同一土层土壤全氮主要分布在0.25-1 mm粒级团聚体中(储量平均为1.02thm-2);其次为1-2 mm和2 mm粒级团聚体,其比例平均分别为29.43%和21.02%;0.25 mm粒级团聚体最低,其比例小于3.69%。表层(0-20 cm)土壤有机肥的施用增加了大团聚体全氮的储量,且裸地2 mm粒级团聚体氮储量较覆膜增加32.31%,而0.25mm粒级却降低31.82%;不施肥处理覆膜和裸地对团聚体氮储量分布的影响与施有机肥正好相反。(3)土壤大团聚体(0.25 mm)中铵态氮储量主要在0-40 cm 土层积累。土壤铵态氮平均约有20.02%和20.49%分配到2 mm和1-2 mm粒级团聚体;0.25-1 mm团聚体中铵态氮的比例占25.89%-33.59%;0.25 mm粒级团聚体中铵态氮的比例仅有9.25%。团聚体中铵态氮储量不受地膜覆盖及其与土层深度交互作用的影响(P0.05)。0-40 cm土层,氮肥的施用增加了各级团聚体中铵态氮储量,而有机肥的施用却降低了各级团聚体中铵态氮的储量。(4)土壤团聚体中硝态氮储量随土层深度的加深而降低(除裸地施氮肥处理外)。裸地施氮肥处理各粒级团聚体硝态氮储量主要集中在20-40 cm 土层。底层40-60 cm硝态氮储量比表层0-20 cm 土层低35.65%-42.63%。氮肥的施用显著增加了各级团聚体中硝态氮储量,与覆膜相比,裸地显著增加表层(0-20 cm)土壤团聚体中硝态氮储量(P0.05)。在20-60 cm 土层,不施肥处理团聚体硝态氮储量不受覆膜的影响(P0.05)。以上研究结果表明,大团聚体是土壤氮素的主要载体,对氮素有较强的富集能力和物理保护作用。地膜覆盖改变了土壤的温度和水分条件,影响了作物对硝态氮的吸收利用,减少了其在土壤剖面团聚体中的累积,而铵态氮的变化不受覆膜温度和湿度条件变化的影响。长期化学氮肥的施用引起铵态氮和硝态氮的在土壤剖面团聚体的富集。因此地膜覆盖与施有机肥是促进作物高产,保证土壤可持续利用和农业可持续发展的有利措施。
[Abstract]:The soil aggregate is the place where the soil undergoes material conversion and energy exchange, and the soil function mainly depends on the good aggregate structure. By changing the basic physical and chemical characteristics of the soil by the action of soil temperature and moisture, the invention solves the problems of great power consumption at the same time of realizing high yield of crops. Fertilization is an important measure to improve soil ground force under the condition of fertilization. However, the distribution characteristics of soil aggregates and their nutrient in soil profiles were not very clear under the conditions of fertilization and fertilization. This study was based on the long-term positioning test base of brown earth in the back mountain of Shenyang Agricultural University in Liaoning Province, and carried out a study on the effects of long-term fertilization and fertilization on nitrogen in different soil layers, with a view to providing scientific basis and practical guidance for the sustainable utilization of soil and the sustainable development of agriculture. The soil aggregates were divided into 2 mm, 1-2 mm, 0. 25-1 mm, 0. 25 mm size fractions by dry sieving method, and different soil layers (0-20 cm, 20-40 cm) were analyzed. 40-60 cm) The content and reserves of nitrogen in soil aggregates. The main results are as follows: (1) The soil aggregate is 0. 25-1 mm as the dominant size, accounting for 33. 96% -47. 97% of the dry weight of the soil; 0. 25 mm, the proportion of the agglomerate is the lowest, and the proportion is not more than 10%. Compared with bare ground, the ratio of 1-2 mm agglomerate of surface layer (0-20 cm) was significantly increased, but the ratio of 0. 25-1 mm agglomerate was decreased. The application of organic fertilizer increased the content of large aggregates (2mm) compared with non-fertilization and single-application fertilizers. (2) The total nitrogen of soil in the same soil layer is mainly distributed in 0. 25-1 mm size-size aggregates (reserves average is 1. 02thm-2); secondly, it is 1-2 mm and 2 mm size-size aggregates, and their proportion is 29. 43% and 21. 02% respectively; 0. 25 mm size fraction aggregates are the lowest, and the proportion is less than 3.69%. The application of the surface layer (0-20 cm) of soil organic fertilizer increased the total nitrogen reserve of the large aggregate, and the nitrogen reserve of the 2 mm size agglomerate was increased by 32.31%, while the size of 0. 25mm decreased by 31. 82%, and the effect of the non-fertilization treatment film and bare ground on the distribution of the nitrogen reserve of the aggregate was the reverse of the application of the organic fertilizer. (3) In the soil mass aggregate (0. 25 mm), the reserves were mainly accumulated in 0-40 cm soil layer. The average soil moisture content was about 20.02% and 20.49%, which was distributed to 2 mm and 1-2 mm size aggregates, and the proportion of cryolite in 0. 25-1 mm aggregates was 25. 89% -33. 59%; 0. 25 mm was only 9.25%. The mineral reserves in the aggregates were not influenced by the soil depth and the depth of soil layer (P0.05). The application of nitrogen fertilizer increased the reserves of the aggregates in the aggregates at all levels, while the application of the organic fertilizer reduced the reserves of the aggregates in the aggregates at all levels. (4) The amount of nitrate nitrogen in soil aggregate decreased with the depth of soil layer (except for bare application of nitrogen fertilizer). The N-N reserves of each size-size aggregate are mainly concentrated in 20-40cm soil layer by applying nitrogen fertilizer to bare land. The nitrogen reserve of 40-60cm in the bottom layer is 35. 65% -42. 63% lower than that of 0-20cm soil layer in the surface layer. The application of nitrogen fertilizer significantly increased the nitrate nitrogen reserves in the aggregates at all levels. Compared with the tectorial membrane, the nitrate nitrogen reserve of the surface layer (0-20 cm) was significantly increased (P <0.05). In the 20-60cm soil layer, the N-N reserves of the non-fertilizer-treated aggregates were not affected by the coating film (P0.05). The above results show that large aggregates are the main carriers of soil nitrogen and have strong enrichment and physical protection effects on nitrogen. The temperature and moisture conditions of the soil were changed, which affected the absorption and utilization of nitrate nitrogen in crops, reduced their accumulation in soil profile aggregates, and did not affect the change of film temperature and humidity conditions. The application of long-term chemical nitrogen fertilizer results in the enrichment of nitrate nitrogen and nitrate nitrogen in soil profile aggregates. Therefore, fertilization and organic fertilizer are the main measures to promote the high yield of crops and ensure the sustainable utilization of soil and the sustainable development of agriculture.
【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】：S153
，
本文编号：2252292
[Abstract]:The soil aggregate is the place where the soil undergoes material conversion and energy exchange, and the soil function mainly depends on the good aggregate structure. By changing the basic physical and chemical characteristics of the soil by the action of soil temperature and moisture, the invention solves the problems of great power consumption at the same time of realizing high yield of crops. Fertilization is an important measure to improve soil ground force under the condition of fertilization. However, the distribution characteristics of soil aggregates and their nutrient in soil profiles were not very clear under the conditions of fertilization and fertilization. This study was based on the long-term positioning test base of brown earth in the back mountain of Shenyang Agricultural University in Liaoning Province, and carried out a study on the effects of long-term fertilization and fertilization on nitrogen in different soil layers, with a view to providing scientific basis and practical guidance for the sustainable utilization of soil and the sustainable development of agriculture. The soil aggregates were divided into 2 mm, 1-2 mm, 0. 25-1 mm, 0. 25 mm size fractions by dry sieving method, and different soil layers (0-20 cm, 20-40 cm) were analyzed. 40-60 cm) The content and reserves of nitrogen in soil aggregates. The main results are as follows: (1) The soil aggregate is 0. 25-1 mm as the dominant size, accounting for 33. 96% -47. 97% of the dry weight of the soil; 0. 25 mm, the proportion of the agglomerate is the lowest, and the proportion is not more than 10%. Compared with bare ground, the ratio of 1-2 mm agglomerate of surface layer (0-20 cm) was significantly increased, but the ratio of 0. 25-1 mm agglomerate was decreased. The application of organic fertilizer increased the content of large aggregates (2mm) compared with non-fertilization and single-application fertilizers. (2) The total nitrogen of soil in the same soil layer is mainly distributed in 0. 25-1 mm size-size aggregates (reserves average is 1. 02thm-2); secondly, it is 1-2 mm and 2 mm size-size aggregates, and their proportion is 29. 43% and 21. 02% respectively; 0. 25 mm size fraction aggregates are the lowest, and the proportion is less than 3.69%. The application of the surface layer (0-20 cm) of soil organic fertilizer increased the total nitrogen reserve of the large aggregate, and the nitrogen reserve of the 2 mm size agglomerate was increased by 32.31%, while the size of 0. 25mm decreased by 31. 82%, and the effect of the non-fertilization treatment film and bare ground on the distribution of the nitrogen reserve of the aggregate was the reverse of the application of the organic fertilizer. (3) In the soil mass aggregate (0. 25 mm), the reserves were mainly accumulated in 0-40 cm soil layer. The average soil moisture content was about 20.02% and 20.49%, which was distributed to 2 mm and 1-2 mm size aggregates, and the proportion of cryolite in 0. 25-1 mm aggregates was 25. 89% -33. 59%; 0. 25 mm was only 9.25%. The mineral reserves in the aggregates were not influenced by the soil depth and the depth of soil layer (P0.05). The application of nitrogen fertilizer increased the reserves of the aggregates in the aggregates at all levels, while the application of the organic fertilizer reduced the reserves of the aggregates in the aggregates at all levels. (4) The amount of nitrate nitrogen in soil aggregate decreased with the depth of soil layer (except for bare application of nitrogen fertilizer). The N-N reserves of each size-size aggregate are mainly concentrated in 20-40cm soil layer by applying nitrogen fertilizer to bare land. The nitrogen reserve of 40-60cm in the bottom layer is 35. 65% -42. 63% lower than that of 0-20cm soil layer in the surface layer. The application of nitrogen fertilizer significantly increased the nitrate nitrogen reserves in the aggregates at all levels. Compared with the tectorial membrane, the nitrate nitrogen reserve of the surface layer (0-20 cm) was significantly increased (P <0.05). In the 20-60cm soil layer, the N-N reserves of the non-fertilizer-treated aggregates were not affected by the coating film (P0.05). The above results show that large aggregates are the main carriers of soil nitrogen and have strong enrichment and physical protection effects on nitrogen. The temperature and moisture conditions of the soil were changed, which affected the absorption and utilization of nitrate nitrogen in crops, reduced their accumulation in soil profile aggregates, and did not affect the change of film temperature and humidity conditions. The application of long-term chemical nitrogen fertilizer results in the enrichment of nitrate nitrogen and nitrate nitrogen in soil profile aggregates. Therefore, fertilization and organic fertilizer are the main measures to promote the high yield of crops and ensure the sustainable utilization of soil and the sustainable development of agriculture.
【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】：S153
，
本文编号：2252292
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