华北平原小麦—玉米体系不同养分管理模式产量与养分效率评价

发布时间：2018-03-24 23:33

本文选题：产量　切入点：养分效率　出处：《中国农业大学》2017年博士论文

【摘要】：华北平原作是我国粮食主产区之一,主要种植体系是冬小麦-夏玉米周年轮作,在保证全国粮食安全中有重要作用。该地区小麦玉米生产面临着单产徘徊不前,肥料、水等外源物质投入过量的问题,既降低资源效率又造成环境问题。为了建立该地区可持续冬小麦-夏玉米作体系,于2007年在中国农业大学高产高效现代农业研究示范基地开始了包括三种养分管理模式的长期定位试验,分别为以有机肥作为养分来源的在我国有2000多年历史的低投入模式、基于小麦玉米高产创建技术的高投入模式和基于土壤-作物综合管理技术实现养分紧循环的优化模式。本文基于该试验前八个轮作周期的数据,从作物生产力、资源效率、土壤质量和环境影响等方面对不同模式进行了综合分析,主要得出如下结论:(1)低投入模式养分缺乏严重,尤其是氮,显著降低地上部生物量和籽粒产量,冬小麦和夏玉米籽粒产量分别只有2.56和6.56 t ha-1。优化和高投入模式冬小麦和夏玉米籽粒产量平均比低投入模式增加186%和44%,198%和42%,二者之间通常差异不显著。(2)因生长季气候条件的不同,处理和年型对冬小麦和夏玉米的影响程度不同。二者对冬小麦和夏玉米收获期秸秆产量、籽粒产量、产量构成和收获指数差异的贡献率分别在10%～74%和22%～60%,1%～53%和16%～69%之间。处理对冬小麦的影响大于年型,对夏玉米的影响则小于年型,或二者相当。(3)低养分投入量使低投入模式养分效率通常很高,是一个高效低产体系,不能满足粮食需求。优化模式冬小麦季养分投入量比高投入模式节省54%～62%,夏玉米季节省45%～53%,在保证粮食产量的同时提高养分效率。优化模式冬小麦季、夏玉米季和周年氮、磷和钾吸收效率平均在0.53～2.53kg kg-1之间,偏生产力平均在57～13kg kg-1之间。但在秸秆还田条件下,三种模式均存在养分盈余。(4)试验所在地降水不能满足冬小麦-夏玉米体系水分需求,需通过灌溉补充。水分消耗量的降低和/或籽粒产量的增加使优化和高投入模式的水分利用效率平均比低投入模式提高78%～152%和 66%～165%。(5)整体而言,三种养分管理模式土壤肥力均有所提高,但高投入模式存在磷淋洗、酸化和盐渍化程度增强的风险。不同处理对酶活性、微生物量碳和氮有显著影响,但是对磷脂脂肪酸影响很小。(6)低投入模式土壤无机氮含量一直较低,环境风险小。大量氮肥投入增加高投入模式土壤无机氮含量,向深层土壤(90 cm)淋洗明显,淋洗深度可达300cm。与其相比,优化氮肥用量可减少作物收获后0-90 cm 土层无机氮残留量32～284.5 kg ha-1,使无机氮的累积高峰保持在0-30 cm土层。综上所述,优化模式既节省了大量投入又保证了产量。虽然仍存在养分盈余,但实现了养分效率的提高,降低环境风险,同时保持了土壤肥力,具有重要实践意义。
[Abstract]:The North China Plain is one of the main grain producing areas in China, and the main planting system is the annual rotation of winter wheat and summer corn, which plays an important role in ensuring the national grain security. In order to establish a sustainable winter wheat-summer maize cropping system in this area, the problem of excessive input of water and other foreign substances will not only reduce the efficiency of resources but also cause environmental problems. In 2007, a long-term positioning experiment including three nutrient management models was started in the demonstration base of high yield and high efficiency modern agriculture of China Agricultural University, which is a low input model with organic fertilizer as a nutrient source in China for more than 2000 years. High input model based on high yield of wheat and maize and optimization model of nutrient tight cycling based on integrated soil-crop management technology. Based on the data of the first eight rotation periods of the experiment, this paper analyzed the crop productivity and resource efficiency. The comprehensive analysis of different models in soil quality and environmental impact showed that the nutrient deficiency of the low input model was serious, especially nitrogen, which significantly reduced the aboveground biomass and grain yield. The grain yields of winter wheat and summer maize were only 2.56 and 6.56 t ha-1, respectively. The grain yield of winter wheat and summer maize increased by 18.6% and 44% and 42%, respectively, compared with the low input model, and the difference between them was not significant. (2) because of the growing season, the grain yield of winter wheat and summer maize was increased by 18.6% and 44%, respectively. Different climatic conditions, The effects of treatment and year type on winter wheat and summer maize were different, and they had different effects on straw yield and grain yield at harvest stage of winter wheat and summer corn. The contribution rates of the difference in yield composition and harvest index were 1074% and 220.60%, respectively, between 53% and 1669%. The effect of treatment on winter wheat was greater than that on annual type, and the effect on summer maize was smaller than that on summer maize. Or the two are equivalent. (3) low nutrient input makes the low input model usually very efficient, and it is a highly efficient and low yield system. The nutrient input in winter wheat season is less than that in high input mode, and in summer maize season, it saves 45553 and increases nutrient efficiency while ensuring grain yield. The optimized model can save nitrogen in winter wheat season, summer corn season and annual nitrogen in winter wheat season, summer corn season and annual nitrogen, and improve the nutrient efficiency of winter wheat season, summer corn season and annual nitrogen. The average uptake efficiency of phosphorus and potassium was between 0.53~2.53kg kg-1 and the average productivity of 57~13kg kg-1. However, under the condition of straw returning to the field, there was nutrient surplus in all the three models. The precipitation in the site of the experiment could not meet the water demand of winter wheat-summer maize system. The decrease in water consumption and / or the increase in grain yield through irrigation supplementation increase the water use efficiency of the optimized and high-input models by an average of 780.152% and 660.165% compared to the low-input model.) overall, the water use efficiency of the optimized and high-input models is 78% higher than that of the low-input model. The soil fertility of all three nutrient management models increased, but the high input model had the risk of phosphorus leaching, acidification and salinization. Different treatments had significant effects on enzyme activity, microbial biomass carbon and nitrogen. However, the effect on phospholipid fatty acids was very small. (6) the inorganic nitrogen content in the low input model soil was lower and the environmental risk was small. A large amount of nitrogen fertilizer input increased the inorganic nitrogen content in the high input model soil, and then reached 90 cm to the deep soil. The elution depth can reach 300 cm. Compared with it, optimizing the amount of nitrogen fertilizer can reduce the residual amount of inorganic nitrogen in 0-90 cm soil layer after harvest, and keep the accumulation peak of inorganic nitrogen in 0-30 cm soil layer, so that the accumulation peak of inorganic nitrogen can be maintained in 0-30 cm soil layer. The optimization model not only saves a large amount of input but also ensures the yield. Although there is still a nutrient surplus, it can improve nutrient efficiency, reduce environmental risk and maintain soil fertility, which is of great practical significance.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S513;S512.1

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