米林县不同种植年限蔬菜大棚土壤pH和无机氮变化特征研究

发布时间：2018-03-18 08:32

本文选题：土壤pH值　切入点：硝态氮　出处：《农业环境科学学报》2016年12期 　论文类型：期刊论文

【摘要】：为阐明露地与不同种植年限大棚土壤pH值及无机氮含量变化特征,给保护性耕作土壤的可持续利用提供科学依据,以米林县不同种植年限蔬菜大棚(1 a、4 a和6 a)和相邻露地为研究对象,研究了露地和不同种植年限蔬菜大棚(0~20 cm表层)和(0~70cm剖面)土壤无机氮浓度及pH值分布特征。结果表明:土壤硝态氮浓度表现为,1 a大棚4 a大棚6 a大棚露地;铵态氮浓度表现为,6 a大棚4 a大棚露地1 a大棚;pH值分布为,1 a大棚露地4 a大棚6 a大棚。随着剖面土壤层次的加深,大棚土壤硝态氮及矿化氮浓度呈降低趋势,露地土壤硝态氮浓度呈先增加后降低的趋势,露地土壤铵态氮及矿化氮浓度呈先降低后增加的趋势;与露地相比,大棚土壤铵态氮、硝态氮浓度及pH值具有更大的垂直空间变异性。土壤pH值随土壤深度的增加,露地表现为逐渐增加的趋势,而蔬菜大棚呈先降低后增大的趋势。大棚土壤pH值与硝态氮和铵态氮含量之间存在负相关,露地土壤pH值与硝态氮和铵态氮含量之间存在正相关关系。在林芝区域大棚生产过程中,表层土壤酸化现象加重,且增加了土壤无机氮的积累,故在生产管理中宜适当减少氮肥的供应。
[Abstract]:In order to elucidate the variation characteristics of pH value and inorganic nitrogen content in open field and greenhouse soil with different planting years, and provide scientific basis for sustainable utilization of conservation tillage soil. The vegetable greenhouse of different planting years in Milin County was used as the research object. The distribution characteristics of inorganic nitrogen concentration and pH value in open field and vegetable greenhouse with different planting years were studied. The concentration of ammonium nitrogen showed that the pH value of the shed in the open field of the greenhouse for 6 years was the same as that in the open field for 1 year. The concentration of nitrate nitrogen and mineralized nitrogen in the greenhouse soil decreased with the deepening of the soil layer in the profile, and the pH value of the shed was distributed in the open field of the greenhouse for 1 year and the shed for 4 years was the shed for 6 years. The nitrate concentration of open soil increased first and then decreased, and the concentration of ammonium and mineralized nitrogen decreased first and then increased, compared with that in open field, the concentration of ammonium nitrogen in greenhouse soil decreased first and then increased. The concentration of nitrate and pH value have greater vertical spatial variability, and the soil pH value increases gradually with the increase of soil depth. However, there was a negative correlation between pH value and nitrate and ammonium content in greenhouse soil. There was a positive correlation between pH value and nitrate and ammonium content in open soil. During greenhouse production in Linzhi area, acidification in surface soil increased and inorganic nitrogen accumulation in soil increased. Therefore, in production management should be appropriate to reduce the supply of nitrogen fertilizer.
【作者单位】：西藏大学农牧学院西藏高原气候变化与土壤圈物质循环研究中心;
【基金】：国家自然科学基金项目(41161052,41461052) 西藏大学农牧学院研究生创新项目计划(Yjs2016-7,YJS2015-09)
【分类号】：S153

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