【作者】 樊兆博；

【导师】 林杉；

【作者基本信息】 中国农业大学 ， 植物营养学， 2014， 博士

【摘要】 长期以来,设施菜地氮素投入量远超作物需求量,由此造成的资源浪费、环境污染、土壤质量退化等问题也日益严重。传统大水漫灌可能是导致过量施肥的根本原因,基于传统灌溉基础上的氮素调控,未能大幅度降低设施菜地氮素投入量,仍然存在氮素淋洗损失的风险。滴灌施肥作为一项将施肥与灌溉相结合的灌溉施肥技术,可以从数量和时间上精确控制施肥量和灌溉量,已在欧美等农业发达国家大面积推广和应用。然而,由于我国蔬菜养分需求规律等基础资料的不完善,对灌溉施肥制度的研究重视不足,滴灌施肥措施在设施蔬菜生产中的应用尚未普及。为此,本研究以山东寿光一年两季设施番茄种植体系为研究对象,对比分析了传统漫灌施肥和滴灌施肥两种栽培管理体系下,不同生长季番茄产量、产量年际变异、水氮利用效率、土壤硝态氮残留量和经济效益,旨在为实现设施蔬菜的可持续发展提供理论依据。于2008-2013年,在山东寿光中国农业大学寿光蔬菜研究院示范基地,布置了包括二个主处理(滴灌施肥,传统漫灌施肥)和三个副处理(不添加秸秆、添加C3植物小麦秸秆、添加C4植物玉米秸秆)的长期定位试验。通过测定番茄产量、氮素表观平衡、土壤硝态氮残留量和淋洗量、土壤呼吸、土壤有机碳和全氮及其自然丰度等指标,评价两种栽培体系的生产效益、环境效益和经济效益。获得以下主要结论：1)与传统漫灌施肥体系相比,滴灌施肥体系减少了78%氮肥和46%水分投入量,增加了6%的番茄产量；显著提高了氮肥偏生产力和灌溉水利用效率,增加了22%的经济效益。滴灌施肥体系显著提高了番茄的总果数,密度的增加是产量提高的主要原因。此外,添加秸秆有利于番茄产量的增加。2)秋冬季,滴灌施肥体系显著增加0-50cm土层新生根根长密度,且产量年际间变异显著低于传统漫灌施肥体系；冬春季,两种栽培体系间新生根根长密度和产量年际间变异差异均不显著。相对而言,滴灌施肥体系是一个相对稳定的生产体系。3)传统漫灌施肥体系平均每季氮素表观损失高达398kg N/ha,而滴灌施肥体系仅为70kg N/ha;0-90cm土层,平均每季硝态氮残留量传统漫灌施肥体系高达819kg N/ha,而滴灌施肥体系仅为412kgN/ha。4)传统漫灌施肥体系平均每季硝态氮淋洗量为240kg N/ha;滴灌施肥体系仅为17kg N/ha,显著低于传统漫灌施肥体系。传统漫灌施肥体系每次灌溉后1-2天,是硝态氮淋洗发生的主要时期,过量灌溉是导致过量施肥的根本原因。两栽培体系下,添加秸秆有利于降低了氮素淋洗。5)两种栽培体系的土壤有机碳和全氮含量差异不显著,添加秸秆有利于增加土壤有机碳。添加秸秆显著提高了土壤呼吸速率,体系间土壤呼吸累积排放量差异不显著。更多还原

【Abstract】 Nitrogen input has been more than actual needs of crop since ever, which resulted increasingly serious problems of resources waste, environmental pollution and soil quality degradation. Excessive nitrogen input may result from flooding irrigation. Optimized nitrogen management, under conventional flooding irrigation conditions, failed to significantly decrease nitrogen input in greenhouse vegetable production and increase risking of nitrogen leaching losses. As a combination of the fertilization and irrigation, fertigation technique can have precise control of the amount of irrigation and fertilization, which has applied in Europe and other developed countries. However, due to inadequate reference of vegetable nutrition needs and other basic information, the study of irrigation and fertilization regime is insufficient, the application of fertigation in greenhouse vegetable production has not yet universal in our country. The greenhouse tomato double-cropping system at Shouguang, Shandong were studied to compare the tomato yield, the inter-annual variation of yield, water and nitrogen use efficiency, soil nitrate leaching and economic benefic under conventional flooding irrigation system (CI) and drip irrigation system (DI), so that provide a theoretical basis for achieving sustainable development greenhouse vegetables. A long-term field experiment was conducted in Vegetable Research Institute of China Agricultural University in Shouguang, Shandong from2008to2013, which included two main treatments (drip fertigation, conventional flooding irrigation and fertilization) and three vice treatments (without straw, with wheat straw and with corn straw). Tomato yield, apparent N balance, soil nitrate residues and leaching, soil respiration, soil organic carbon and soil total nitrogen and the natural abundance were investigated to study the productivity, environmental and economic effect of systems on these traits. The results are as following:1) Compared with CI, fertilizer N and water inputs were reduced by78%and46%under DI, respectively, while nitrogen partial productivity and irrigation water use efficiency were significantly increased. Tomato yield and economic benefits were increased by6%and22%with DI. Total number of tomato fruits was significantly increased in DI, increasing of planting density was the main reason of yield improvement. Straw application was helpful to increase tomato yield in two cultivation systems.2) In autumn-winter growing season, the root length density of new developed roots in0-50cm soil layer was significantly higher in DI, and the inter-annual variation of yield was significantly lower than CI. No significant differences were found among two cultivation systems for the root length density of new developed roots and the inter-annual variation of yield in winter-spring growing season. Comparatively speaking, drip irrigation and fertilization was a relatively stable production system.3) The average seasonal apparent nitrogen loss was398kg N/ha in CI, while it was only70kg N/ha in DI. The average seasonal nitrate residue was819kg N/ha at the depth of0-90cm in CI, while it was only412kg N/ha in DI.4) Total nitrate leaching loss reached240kg N/ha in CI, while it was only17kg N/ha in DI. One to two days after flooding irrigation was the main period of nitrate leaching in CI. Conventional flooding irrigation was a major contributor to excessive N inputs in greenhouse vegetable production. Straw application was helpful to reduce nitrate leaching.5) No significant differences were found among two cultivation systems for soil organic carbon and soil total nitrogen. However, the application of straw was helpful to improve soil organic matter accumulation in greenhouses. Straw application significantly increased soil respiration rate, while there no significant differences were found among two cultivation systems for accumulated CO2emission.更多还原