Crop Productivity and Resource Use Efficiency under Conservation Tillage in a Dry Land Spring Wheat-field Pea Rotation System

论文摘要

水土流失严重和生产力水平低下是黄土高原西部半干旱旱农区发展的主要制约因素。黄土质地疏松,抗蚀能力差,雨量少而集中,是造成该区水土流失严重和土地生产力水平低下的自然原因,而传统农业的精耕细作更加剧了水土流失,限制了生产力水平的提高。因此,采取适宜的保护性耕作措施,增加有机质的归还率,尽量减少农田水分的非生产性消耗,提高水分的生产效率,既可以提高生产力水平,又可以减少水土流失,改善生态环境。而要在黄土高原西部半干旱地区发展保护性耕作,必须首先研究不同保护性耕作措施在该特殊自然环境中的适应性,诸如其对作物生产力、土壤状况及资源利用效率等的影响及其内在机理。为此,本研究从2001年8月开始,在黄土高原西部典型的半干旱区,位于甘肃省定西市安定区李家堡镇的甘肃农业大学定西旱农生态综合试验站,结合小麦→豌豆年间轮作布设了六种不同耕作模式的田间长期定位试验,开展了对保护性耕作的适应性及其内在机理的系统研究。这些不同的耕作模式包括:传统耕作（T）、免耕秸秆不还田（NT）、传统耕作+秸秆还田（TS）、免耕+秸秆覆盖（NTS）、传统耕作+地膜覆盖（TP）和免耕+地膜覆盖（NTP）。本文主要研究了保护性耕作措施对土壤温度、土壤水分及水温和谐性的影响,对作物生产力的影响及其机理,对水分利用效率、氮素利用效率及作物生产的经济效益的影响。结果表明:1)免耕秸秆覆盖（NTS）能显著提高小麦→豌豆轮作系统的经济产量,但免耕秸秆不还田处理（NT）的产量最低。2002-2005年间NTS豌豆的平均产量为1.76 t/ha,比T,NT,TS,TP和NTP分别提高14%,24%,17%,5%和9%;四年间NTS小麦的平均产量为2.44 t/ha,比T,NT,TS,TP和NTP分别提高16%,26%,14%,3%和6%;两个小麦→豌豆轮作周期NTS的平均产量为8.41 t/ha,比T,NT,TS,TP和NTP分别提高16%,25%,15%,4%和7%。2)在免耕秸秆覆盖模式中,留在免耕地表的秸秆确实降低了小麦生长期间下午14:00 0-25cm土壤剖面的平均温度,但这一温度降低并没有延缓小麦的萌发出苗,而且该模式下经济产量不仅没有降低,反而有所提高。小麦生长期间下午14:00 0-25cm土壤剖面的温度平均值NTS比T,NT,TS,TP和NTP分别降低0.9°C,1.1°C,1.0°C,0.3°C,0.3°C和0.6°C。这可能是NTS中秸秆下面热流降低所致,但NTS中小麦生长状况比其他模式都好,产量也最高。因此,免耕秸秆覆盖模式中的温度降低不会对作物生长造成不利的影响。3)黄土高原西部半干旱区,水分贮存在土壤上层比在下层对作物更有效;免耕秸秆覆盖表层0-10 cm土壤水分含量相对于传统耕作最多可以提高90%;虽然不

论文目录

• LIST OF FIGURE
• LIST OF TABLE
• 摘要
• SUMMARY
• INTRODUCTION
• 1 LITERATURE REVIEW
• 1.1 DEFINITION OF CONSERVATION TILLAGE
• 1.1.1 Stubble retention and crop residue mulch
• 1.1.2 No-till or minimum tillage
• 1.1.3 Conservation tillage
• 1.1.4 Conservation agriculture
• 1.2 HISTORY OF CONSERVATION TILLAGE
• 1.3 BENEFITS OF CONSERVATION TILLAGE ON CONTROL SOIL AND WATER EROSION
• 1.3.1 Conservation tillage effects on soil water conserving
• 1.3.2 Improving soil quality
• 1.3.3 Conservation tillage effects on soil and water erosion
• 1.4 SOIL TEMPERATURE AND CROP EARLY GROWTH UNDER CONSERVATION TILLAGE
• 1.5 CROP PRODUCTIVITY UNDER CONSERVATION TILLAGE
• 1.6 RESOURCES USE EFFICIENCY UNDER CONSERVATION TILLAGE
• 1.6.1 Water use efficiency
• 1.6.2 Nitrogen use efficiency
• 1.6.3 Profitability of conservation tillage
• 1.7 ADOPTION OF CONSERVATION TILLAGE
• 2 MATERIALS AND METHODOLOGY
• 2.1 SITE DESCRIPTION
• 2.2 EXPERIMENTAL DESIGN
• 2.3 CROP MANAGEMENT
• 2.3.1 Sowing time and sowing rate
• 2.3.2 Crop harvest
• 2.3.3 Basal fertilizers
• 2.3.4 Weeds and diseases management
• 2.4 MEASUREMENTS
• 2.4.1 Weather data collection
• 2.4.2 Crop measurements
• 2.4.3 Plant chemical analysis and methods
• 2.4.4 Nitrogen fixation of field pea
• 2.4.5 Soil measurements
• 2.5 CALCULATION FOR RESOURCE USE EFFICIENCY
• 2.5.1 Evapotranspiration （ET）
• 2.5.2 Water use efficiency （WUE）
• 2.5.3 Nitrogen use efficiency （NUE）
• 2.5.4 Nitrogen balance
• 2.6 STATISTICAL ANALYSIS
• 3 CONSERVATION TILLAGE EFFECTS ON SOIL TEMPERATURE IN SPRING WHEAT FIELD
• 3.1 AIR TEMPERATURE CHARACTERISTICS
• 3.1.1 Solar radiation
• 3.1.2 Long-term maximum and minimum air temperature
• 3.1.3 Monthly air temperature in research period
• 3.2 SOIL TEMPERATURE AT A SUNNY OR CLOUDY DAY
• 3.3 SOIL TEMPERATURE DURING CROP GROWING SEASON
• 3.4 SOIL TEMPERATURE DURING FALLOW
• 4 SOIL WATER DYNAMICS UNDER CONSERVATION TILLAGE
• 4.1 RAINFALL IN THE RESEARCH PERIOD
• 4.2 SOIL WATER CHARACTERISTICS
• 4.2.1 Drainage Upper Limit （DUL）
• 4.2.2 Crop lower Limit （CLL）
• 4.2.3 Plant available water content （PAWC）
• 4.3 VERTICAL SOIL WATER PROFILE
• 4.3.1 Soil water profile at sowing
• 4.3.2 Soil water profile at anthesis
• 4.3.3 Soil water profile at maturity
• 4.4 SEASONAL SOIL WATER DYNAMICS
• 4.5 EVAPOTRANSPIRATION （ET） IN CROP GROWING SEASONS
• 4.6 CROPS’WATER CONSUMPTION DYNAMICS AT DIFFERENT PHENOLOGY
• 4.6.1 Water consumption of spring wheat
• 4.6.2 Water consumption of field pea
• 5 CROP PRODUCTIVITY OF SPRING WHEAT – FIELD PEA ROTATION UNDER CONSERVATION TILLAGE
• 5.1 STATISTIC ANALYSIS RESULTS
• 5.2 PHENOLOGICAL DEVELOPMENT
• 5.2.1 Field pea
• 5.2.2 Spring wheat
• 5.3 CROP ESTABLISHMENT
• 5.4 DRY MATTER PRODUCTION
• 5.4.1 Dry matter at seedling
• 5.4.2 Dry matter at anthesis
• 5.4.3 Dry matter at maturity
• 5.5 GRAIN YIELD
• 5.6 HARVEST INDEX （HI）
• 5.7 1000 GRAIN WEIGHT （1000GWT）
• 5.8 GRAIN PROTEIN CONTENT （PROTEIN%）
• 6 RESOURCES USE EFFICIENCY OF DIFFERENT CONSERVATION TILLAGE SYSTEMS
• 6.1 WATER USE EFFICIENCY （WUE）
• 6.2 NITROGEN FIXATION
• 6.3 NITROGEN FERTILIZER USE EFFICIENCY AND NITROGEN BALANCE
• 6.3.1 Nitrogen use efficiency of spring wheat
• 6.3.2 Nitrogen balance
• 6.4 PROFITABILITY OF DIFFERENT CONSERVATION TILLAGE SYSTEMS
• 7 GENERAL DISCUSSION
• 7.1 EFFECT OF TILLAGE AND STUBBLE RETENTION ON GRAIN YIELD
• 7.2 EFFECT OF STUBBLE RETENTION ON SOIL TEMPERATURE
• 7.3 EFFECT OF SOIL WATER AVAILABILITY ON CROP PRODUCTION UNDER CONSERVATION TILLAGE
• 7.4 EFFECT OF TILLAGE AND STUBBLE RETENTION ON WATER USE EFFICIENCY ANDNITROGEN USE EFFICIENCY
• 7.5 HARMONY BETWEEN SOIL WATER AND TEMPERATURE CAN BE IMPROVED BY NO-TILL WITH STUBBLE RETENTION
• 7.6 NO-TILL WITH STUBBLE RETENTION IS ONE OF THE MOST PROFITABLE PRACTICE FOR THE WESTERN LOESS PLATEAU
• REFERENCES
• 作者简介
• 导师简介
• 攻读博士学位期间发表的论文和科研成果