【作者】 韩娟；

【导师】 贾志宽；

【作者基本信息】 西北农林科技大学 ， 植物资源学， 2013， 博士

【摘要】 北方旱作农业区是中国21世纪粮食生产的重点开发地区,降水时空分布的不均衡以及季节性干旱严重制约了该区农业生产力的提高。沟垄集雨种植技术是一种通过在田间修筑沟垄,垄面覆膜,沟内种植作物,实现降水由垄面向沟内汇集的田间集水农业技术。该技术能有效改善作物水分供应状况,促进作物生长,提高产量和水分利用效率,已成为提高旱区作物生产力的重要措施之一。本研究于2007～2010年通过田间点位试验系统研究了旱作区沟垄集雨覆膜(FM)和传统平作(CK)种植下玉米田及垄覆膜沟内不覆(PF)和平作不覆膜(CK)冬小麦田的土壤水温动态变化以及作物产量,随后利用田间观测数据对DNDC模型改进、验证和敏感性分析,结合GIS技术,分别模拟2001-2010年沟垄集雨覆膜(RH)和传统平作(CK)种植下陕西省旱作玉米田土壤水分、玉米产量时空变化规律,以确定沟垄集雨覆膜模式在区域尺度上的农田水分调控效果及增产效应。1.沟垄集雨种植农田土壤水温状况、产量及水分利用效率1)FM处理能显著的提高0-200cm土层土壤储水量,3年春玉米生育期,FM处理0-200cm土层3年平均土壤储水量分别较CK增加了40.07mm,提高幅度为10.56%；3年冬小麦全生育期,PF处理0-200cm土层3年平均土壤储水量较CK增加了17.17mm,提高幅度为5.26%。沟垄集雨种植模式对于0-100cm土层土壤蓄水保墒效果高于100-200cm土层。3年春玉米全生育期,FM和CK处理0～20cm和20～60cm土层土壤水分动态变化规律相似,随着降雨量的大小而波动剧烈,60-120cm和120～200cm土层土壤水分受降雨量影响较小,变化较为平缓。3年冬小麦生育期,PF和CK处理0-20cm和20～100cm土层土壤水分随着降雨量的高低变化明显,100-200cm土层土壤水分基本不受到降雨量的影响,因而变化平缓。2)春玉米播后60天,FM处理显著地提高了0-20cm土层平均温度,较CK增加了1.76℃,其中,FM处理0-20cm土层在14：00时增温效果最好,其温度较CK提高了1.950C,说明沟垄集雨覆膜种植能够显著提高玉米生长前期的土壤温度。而不同土层土壤温度的日变化结果表明,FM和CK处理土壤温度在4个土层(5cm、10cm、15cm和20cm)的变化趋势一致,土壤温度均随着土壤深度的加深逐渐降低,5cm和10cm的土壤温度变化幅度较大,其中,5cm土温最敏感,15cm和20cm的土壤温度变化幅度较小。3)沟垄集雨覆膜种植显著提高了玉米和冬小麦的产量。FM处理的春玉米3年平均产量、千粒重、穗粒数、穗长和水分利用效率较CK处理显著增加,其产量、千粒重、穗粒数、穗长和水分利用效率分别较CK处理提高了20.37%、8.82%、11.31%、8.48%和23.48%。由于光热条件和降雨量的不同,春玉米各年际间产量水平不同,表现为2010年>2008年>2009年,FM处理较CK增产和提高水分利用效率效果均表现为2008年>2010年>2009年。PF处理冬小麦3年平均产量、千粒重、穗粒数、穗数和水分利用效率分别较CK提高了19.85%、3.68%、5.70%、10.54%和19.81%。PF处理冬小麦产量较对照增产效果表现为2008～2009年>2009-2010年>2007-2008年。2. DNDC模型的改进、验证及敏感性分析1)本研究将沟垄集雨覆膜作为一种农田管理措施,并与土壤水文学和生物地球化学过程结合后加入模型,用于计算新版本DNDC模型的土壤水热状况,种植模式的持续时间和土壤表面的地膜覆盖率作为2个输入参数,使DNDC模型具备了模拟沟垄集雨覆膜种植模式下土壤水热运动和产量效应的能力。2)利用2008-2010年陕西合阳沟垄集雨覆膜(FM)和传统平作(CK)2种处理下田间土壤温度、土壤湿度及作物产量观测数据对模型进行校正和验证。验证结果表明,新版本DNDC很好地再现了FM和CK处理下春玉米田土壤温度、土壤湿度的动态变化规律及产量,模拟值和观测值相关性显著。3)敏感性分析结果表明,在沟垄集雨覆膜种植和传统平作2种模式下,气象因素(降雨量、气温)、土壤质地及施氮肥量对作物产量的影响程度并不相同,在传统平作模式下,作物产量对参数敏感度从大到小依次是降雨量、氮肥施用量、土壤质地和气温,而在沟垄集雨覆膜种植模式下,作物产量对参数敏感度从大到小依次是氮肥施用量、降雨量、土壤质地和气温,沟垄集雨覆膜种植模式降低了作物产量对降雨量的敏感度。对于降雨量较少的地区来说,沟垄集雨覆膜种植对作物增产效应高于降雨量较多的地区。3.沟垄集雨种植下陕西省土壤水分效应及玉米产量模拟1)2001～2010年陕西省的年均降雨量为609.2mm,降雨量从北至南呈现出逐渐递增的趋势,陕西南部地区的降雨量最高,其次是关中地区,陕西北部地区的降雨量最低。从2001至2010年,12个代表点的年降雨量并没有明显增加或者减少趋势,其中降雨量为700mm以上的地区年际间波动剧烈。2)10年玉米田土壤年蒸发量的模拟结果表明,沟垄集雨覆膜和平作种植模式的空间变化规律并不一致。与平作相比,沟垄集雨种植模式下土壤年蒸发量190mm以上的地区从94个县减至16个县,其余地区的土壤年蒸发量均在190mm以下。12个代表点玉米沟垄集雨种植模式下土壤蒸发量显著低于平作模式,年平均土壤蒸发量较平作降低了67.62%。3)沟垄集雨覆膜和平作种植玉米模式下,陕西省各地区10年平均土壤储水量从北至南均呈现出逐渐增加的趋势,与年均降雨量的趋势相同。与平作相比,沟垄集雨覆膜种植模式年均土壤储水量85mm以下的地区由17个县减少至12个县,其中,平作和沟垄集雨覆膜种植模式年均土壤储水量最小值分别为59mm和79mm；沟垄集雨覆膜种植模式年均土壤储水量145mm以上的地区由16个县增加至20个县。除了年均降雨量为700mm以上的洛南、镇安和平利,其余9个代表点的年土壤储水量随着降雨量大小而波动剧烈。4)10年平均水分胁迫从北至南呈现出逐渐减弱的趋势,在年均降雨量在500mm以下的地区最严重,年均降雨量为700mm以上的地区,2种种植模式下玉米生长均无水分胁迫现象,主要是因为降雨量的增加减弱了水分的胁迫。和平作种植模式相比,由于实行沟垄集雨覆膜种植模式,陕西北部6个县和中部14个县10年平均土壤水分胁迫减弱,逐渐接近1。5)产量模拟结果表明：第一,沟垄集雨覆膜和传统平作种植模式下陕西省玉米10a平均产量分别为1320万t.a-1和1140万t·a-1。与平作相比,实行沟垄集雨覆膜种植后,陕西省10年平均产量增加了180万t·a-1,提高幅度为16%；第二,陕西北部年均降雨量低于500mm的地区增产效果最高,产量增加了2000～3500kg·hm-2,而且降雨量偏少年份的增产效应高于降雨量较多的年份；第三,从北至南呈现出逐渐降低的趋势,与年均降雨量的空间分布规律相反；第四,陕西南部年均降雨量为700～800mm的地区,沟垄集雨覆膜种植模式的增产效应较小,与平作模式相比,产量增加了1～1000kg·hm-2;第五,陕西南部年均降雨量高于800mm的地区,沟垄集雨覆膜种植模式对产量的提高具有负效应。更多还原

【Abstract】 The dryland farming area in northern China is the key development area for grain production in twenty-first century. The imbalance spatial and temporal distribution of rainfall and seasonal drought seriously restrict the increase of agricultural productivity in this area. Rainfall harvesting with ridge and furrow is a field rainfall harvesting technology, which can collect the rainfall from plastic-covered ridges serving as a rainfall harvesting zone to the furrows serving as a planting zone. This technology can effectively improve the supply of water for crops, promote the growth of crops, and increase the yield and efficiency of water use, which has become one of vital measures to improve the productivity of arid crops.Through the combined methods of the field point tests from2007to2010, DNDC modeling and GIS technology, this research studied on the differences of soil temperature and moisture and yield between rainfall harvesting with ridge and furrow and traditional flat planting in the arid farming area. DNDC modeling was improved, validated and sensitivity analysed with field observation data. With GIS technology, the spatial and temporal variations of soil moisture, yield of maize for both plastic-covered ridge-furrow for rainfall harvesting and traditional flat planting in the arid farming area in Shaanxi province from2001to2010were simulated, in order to determine the farmland water control effects and yield effects of the ridge-furrow planting for rainfall harvesting system on a regional scale.1. The soil temperature and moisture, yield and efficiency of water use of rainfall harvesting with ridge and furrow system1) The treatment of plastic-covered ridge and furrow planting for rainfall harvesting significantly increased the water storage of the soil from0to200cm. For3years of spring maize growth period, the mean of soil water storage treated with FM on the0-200cm soil was increased40.07mm, which was increased by10.56%, compared to the control. For3years of the whole growth period of winter wheat, compared to the control, the mean of soil water storage treated with FM on the0-200cm soil was increased17.17mm, which was increased by5.26%. The plastic-covered ridge and furrow planting mode for rainfall harvesting had more effect to the soil moisture conservation for0-100cm soil than for100-200cm soil. For3years of the whole growth period of spring maize,0-20cm soil retreated with FM and CK had the similar dynamic variations of soil moisture, compared the soil of20-60cm with the same treatments, which had jagged fluctuations with the variations of the amount of rainfall. However, the moisture of60-120cm and120-200cm soil was less affected by the amount of rainfall, which had flat fluctuations. For3years of growth period of winter wheat, the moisture of0-20cm soil and20-100cm soil retreated with FM and CK changed obviously with the variations of the amount of rainfall. However, the moisture of100-200cm soil water was not influenced much by the amount of rainfall, which had gentle changes.2) For spring maize,60days after sowing, compared with CK, the mean temperature of the0-20cm soil was dramatically increased by1.76℃when treated with FM, which had the best effect at2pm, with an increase of1.95℃. It was demonstrated that plastic-covered ridge and furrow planting for rainfall harvesting significantly increased the soil temperature during the earlier growth stage of maize. While the daily variation of soil temperature at different soil layers indicated that soil temperature in four soil layers (5cm,10cm,15cm,20cm) showed the same trend for FM treatment and CK, soil temperature increased with soil depth reduction. Out of them, the temperature of soil at5cm and10cm changed greatly, and the one at5cm was most sensitive. The temperature of soil at15cm and20cm had small changes.3) The plastic-covered ridge and furrow planting for rainfall harvesting significantly increased the yield of maize and winter wheat. Compared to CK, the mean yield,1000-grain weight, grain number per spike, spike length and efficiency of water use of the spring maize treated with FM were significantly increased by20.37%,8.82%,11.31%,8.48%, and23.48%, respectively. Due to the variations of the illumination and the amount of rainfall, there were variations in yield of spring maize among different years. The yield in2010was greater than the one in2008, which was greater than the one in2009. Compared to CK, the increased yield and efficiency of water use with FM treatment in2008were greats than those in2010, which were greater than those in2009. The yield,1000-grain weight, grain number per spike, spike number and water use efficiency of winter wheat treated with PF were increased than those of CK by19.85%,3.68%,5.70%,10.54%and19.81%, respectively. Compared the CK, the increased yield of winter wheat with FM treatment in2008-2009was greater than that in2009-2010, which was greater than that in2007-2008.2. Improvement, validation and sensitivity analysis of DNDC modeling1) In this research, the plastic-covered ridge and furrow planting for rainfall harvesting served as a measure of farmland management, which was combined with pedohydrology and biogeochemical process to calculate the temperature and moisture of soil in the new version DNDC modeling. Furthermore, duration of planting pattern and the rate plastic-covered ridge were used as two parameters, which made the DNDC modeling get the ability to simulate the moisture and temperature of soil and productivity effects with the plastic-covered ridge and furrow planting for rainfall harvesting system.2) DNDC modeling was corrected and validated with the observation data of soil temperature, soil moisture and crop yield under both plastic-covered ridge and furrow planting for rainfall harvesting (FM) and conventional flat planting (CK) conditions from2008to2010in Heyang, Shaanxi province. The results showed that new version DNDC modeling represented the dynamic variations of the temperature and moisture of soil and yield of spring maize under FM and CK treatments, and the simulated value and observation value were significantly correlated.3) The sensitivity analysis results showed that the effects of meteorological factors, such as the amount of rainfall and temperature, the soil texture and the amount of nitrogen fertilizer on crop yield were not the identical under FM and CK treatments. For CK, sensitivity of crop yield to the parameters from large to small was the amount of rainfall, the amount of nitrogen fertilizer, soil texture and temperature. However, for FM, sensitivity of crop yield to the parameters from large to small were the amount of nitrogen fertilizer, the amount of rainfall, soil texture and temperature, which demonstrated that FM treatment could relieve the effects of the amount of rainfall to crop yield. FM in the area lacking of rainfall is more effective to increase crop yield than in the area with enough rainfall.3. Modeling of soil moisture effects and maize yield with ridge and furrow planting for rainfall harvesting in Shaanxi province1) The mean amount of rainfall was609.2mm between2001and2010, which gradually increased from north to south in Shaanxi province. The southwest area of Shaanxi province had the most amount of rainfall, followed by Guanzhong area, and the north of Shaanxi province had the least amount of rainfall. The annual rainfall of12locations did not show any obvious increase or decrease trend from2001to2000. However, the locations with the amount of rainfall over700mm had great inter-annual fluctuation.2) The simulated results of maize farmland soil evaporation during10years showed that the spatial variation of plastic-covered ridge and furrow planting for rainfall harvesting was not consistent with that of flat planting. Compared to flat planting, the locations with over190mm of annual soil evaporation decreased from94districts to16districts with ridge-furrow planting for rainfall harvesting system, with the rest of the locations with that under190mm. The maize farmland soil evaporation of12locations with ridge and furrow planting for rainfall harvesting system were significantly lower than those with flat planting. The mean annual soil evaporation compared to flat planting decreased by67.62%.3) With the modes of plastic-covered ridge and furrow planting for rainfall harvesting and flat planting of maize, the average soil water storage in various regions10a of Shaanxi province showed a gradually increasing trend from north to south, which was the same as the trend of the average annual amount of rainfall. Compared to flat planting, the locations with less than85mm of annual soil water storage decreased from17districts to12districts with ridge and furrow planting for rainfall harvesting system. Out of them, the minimum annual soil water storage with flat planting and with ridge-furrow planting for rainfall harvesting system were59mm and79mm respectively. The locations with over145mm of the annual soil water storage with ridge and furrow planting for rainfall harvesting system increased from16to20. Except for Luonan, Zhen’an and Pingli with over700mm of the annual average rainfall, the annual soil water storage of the rest of9locations fluctuated seriously upon the amount of rainfall.4) The average moisture stress of10a represented a gradually decreasing trend from north to south, which was most serious in the area with annual rainfall below500mm. While in the locations with an average annual rainfall over700mm, there were no moisture stress during the growth of maize with the two kinds of planting modes, which was due to the moisture stress relieved by the increasing of rainfall. Compared to flat planting, with plastic-covered ridge and furrow planting for rainfall harvesting system, the average moisture stress of10a in6districts in north of Shaanxi and14districts in central of Shaanxi relieved, which gradually closed to1.5) The results of simulated yield demonstrated that:a. the average yield of maize in Shaanxi province with plastic-covered ridge and furrow planting for rainfall harvesting system and flat planting were13.2M tons and11.4M tons per annual, respectively. Compared to flat planting, with plastic-covered ridge and furrow planting for rainfall harvesting system, the average yield of10a in Shaanxi province increased1.8M tons, which increased by16%. b. The increased yield effect was most significant in the areas in north of Shaanxi, with the average annual rainfall less than500mm, and the yield increased2000to3500kg·hm-2. The effect during the year lack of rainfall was higher than the one with more rainfall, c. a trend of gradual decrease from north to south was represented, in contrast with the space distribution of the average annual rainfall. d. In south of Shaanxi areas with700to800mm of the average annual rainfall, the effect of increasing yield with ridge-furrow planting for rainfall harvesting system was lower, with the yield increased1to1000kg·hm-2. e, In south of Shaanxi areas with over800mm of the average annual rainfall, ridge and furrow planting for rainfall harvesting system had a negative effect on yield increasing.更多还原