压砂西瓜对氮素的响应及压砂地土壤活性氮变化特征研究

发布时间：2018-03-06 07:06

本文选题：压砂西瓜　切入点：氮素响应　出处：《宁夏大学》2017年硕士论文　论文类型：学位论文

【摘要】：压砂地作为西北地区特有的耕作方式,近年来在主营压砂地宁夏地区面积日趋增多。种植压砂西瓜为当地农户带来经济效益的同时也带动当地第三产业的发展。氮素作为植物重要的营养元素,是影响压砂西瓜生长、产量和品质的重要因素。硝态氮、铵态氮和可溶性有机氮作为土壤中重要的氮素源,不仅协调着土壤的健康性和营养性,而且也为作物吸收养分起到关键性作用。探讨压砂西瓜对氮素的响应以及压砂土壤中各活性氮的分布变化、供给转化以及其它因素影响可为压砂地合理施用氮肥、提高压砂瓜产量和品质,压砂地可持续发展及科学管理提供理论依据。设置不同氮素水平进行压砂地田间试验,来研究压砂西瓜的生长发育、压砂西瓜对N养分的吸收、压砂西瓜营养诊断及氮素对压砂地土壤活性氮的影响,以期明确氮素对压砂西瓜和压砂土壤活性氮的作用。取得主要结论有:1、适量施氮促进并协调了压砂西瓜营养生长和生殖生长,在施氮75.00-112.50 kg hm-2时压砂西瓜生长、产量及品质均最佳。2、从苗期到成熟期,各部位氮含量根茎基部叶中部叶顶部叶。氮素含量呈“W”型变化,坐瓜期吸收最多;施氮对压砂西瓜氮含量的影响因生育期与吸收元素和施氮量关系的不同而异,苗期至坐瓜期,氮素供给下压砂西瓜吸收氮素含量较高,且在供氮99.63-226.00kghm-2时吸收量最高。而从膨瓜期至成熟期,随施氮量增多对氮吸收量增多。3、伸蔓期至膨瓜期叶片SPAD值水平较高,此时期适量施氮有助于不同部位叶片叶绿素的累积和光合作用的进行,而过量则使叶片SPAD值降低;同时,整个生育期中部叶片SPAD值保持较高和较稳定水平,并且与施氮水平之间呈稳定的报酬递减关系,与植株全氮相关性稳定,因此可以作为压砂西瓜氮素营养诊断的指示器官。4、随压砂西瓜生长及压砂土壤土层深度的不同,施氮对含水量及各活性氮的增减有所不同。在施氮为37.5-75 kg hm-2时,60-100 cm各土层含水量显著增多;施氮会增加不同生育期不同土层硝态氮和可溶性有机氮的含量。铵态氮因施氮量不同有不同程度的增减,膨瓜期至成熟期40-100 cm各土层的铵态氮含量增多且在施氮150 kg hm-2显著。
[Abstract]:As a special farming method in Northwest China, sand compaction land, In recent years, the area of Ningxia area is increasing in the main sand compaction area. Planting sand watermelon not only brings economic benefit to local farmers, but also promotes the development of local tertiary industry. Nitrogen, as an important nutrient element of plants, affects the growth of sand-pressed watermelon. Nitrate nitrogen, ammonium nitrogen and soluble organic nitrogen are important nitrogen sources in soil, which not only coordinate the health and nutrition of the soil. It also plays a key role in nutrient uptake of crops. The response of sand watermelon to nitrogen and the distribution of active nitrogen in sand compaction soil are discussed. The effects of supply transformation and other factors on the rational application of nitrogen fertilizer in sand compaction soil are discussed. In order to improve the yield and quality of barbed watermelon, to provide theoretical basis for sustainable development and scientific management of barbed watermelon, different nitrogen levels were set up to study the growth and development of sand-pressed watermelon, and the absorption of N nutrient by sand-pressed watermelon. Nutrition diagnosis of sand watermelon and effect of nitrogen on soil active nitrogen in sandy soil. In order to clarify the effect of nitrogen on sand watermelon and sand soil active nitrogen, the main conclusions were as follows: 1, proper application of nitrogen promoted and coordinated the vegetative growth and reproductive growth of sand pressed watermelon, and the growth of sand pressed watermelon was 75.00-112.50 kg / hm-2. The yield and quality were the best. From seedling stage to maturity stage, the nitrogen content of each part was the top leaf of the middle leaf of rhizome, stem and basal leaf. The nitrogen content changed in "W" type and absorbed the most in sitting melon stage. The effect of nitrogen application on N content of watermelon was different from growth stage to absorbing element and nitrogen application amount. From seedling stage to sitting stage, the nitrogen content of sand watermelon was higher than that of sand watermelon under nitrogen supply. The absorption of nitrogen was the highest at 99.63-226.00 kghm-2, and the SPAD level of leaves increased with the increase of nitrogen application from the stage of expanding melon to the mature stage, and the SPAD value of leaves from the extension stage to the stage of expanding melon was higher than that of the control group. At the same time, suitable nitrogen application could contribute to chlorophyll accumulation and photosynthesis in different parts of leaves, while excessive amount of nitrogen could decrease SPAD value of leaves, at the same time, the SPAD value of leaves in the middle part of the growth period remained higher and more stable. And the relationship between N application level and nitrogen level is stable, and the correlation with plant total nitrogen is stable. Therefore, it can be used as indicator organ of nitrogen nutrition diagnosis of sand watermelon, with the growth of sand watermelon and the depth of soil layer of sand compacted watermelon being different. The increase and decrease of water content and active nitrogen were different when the nitrogen application was 37.5-75 kg hm-2. The water content of 60-100 cm soil layer increased significantly when the application of nitrogen was 37.5-75 kg hm-2. Application of nitrogen increased the contents of nitrate and soluble organic nitrogen in different soil layers at different growth stages. Ammonium nitrogen increased in different degrees with different nitrogen application rates, and increased in 40 ~ 100cm soil layers from the stage of expanding melon to maturity, and was significantly increased in 150kg hm-2.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S651;S153

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