【作者】 杨彩红；

【导师】 黄高宝； 柴强；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2010， 博士

【摘要】 间作种植具有充分利用多种资源、提高单位面积作物产量的优点,在我国西北地区广泛应用。近年来,受水资源紧缺的严重制约,间作应用面临重大挑战,间作节水灌溉技术亟待深入研究。交替灌溉具有提高作物水分利用效率,创造提高作物水分利用效率的根系系统,有利于提高水分补偿效应、降低无效蒸发和渗漏。本研究通过大田试验和根箱试验,研究了交替灌溉对西北主导间作模式小麦/玉米、小麦/蚕豆的水分利用特征,并对影响间作群体水分利用效率的机理进行了探讨。主要结论如下:1、交替灌溉小麦间作玉米可显著提高土地利用率和作物产量,交替灌间作比之传统灌间作具有更大的提高土地利用率的潜力。连续四年的大田试验表明,交替灌溉小麦间作玉米的土地当量比(LER)变化在1.22~1.52,且除2008年外,其它年度的交替灌溉间作LER比同等灌水水平下的常规灌溉提高了2.33%~17.83%。交替灌溉间作有利于提高小麦、玉米的经济产量,间作小麦产量达到了单作的55.37%~74.88%、间作玉米产量达到了单作的66.63%~78.87%。2、交替灌溉间作并未显著增加复合群体的耗水量。2006-2009年度,与单作耗水量的加权平均相比,交替灌间作耗水量分别增加了0.28%~0.92%、4.29%~5.94%、14.36%~19.19%、12.72%~18.13%;交替灌间作耗水量较同等灌水水平下常规灌间作的增幅分别为0.44%、4.43%、3.59%、-19.28%。交替灌溉可显著提高间作作物的水分利用效率,各年度交替灌溉间作水分利用效率分别较单作水分利用效率的加权平均提高了32.70%~47.10%、31.16%~34.39%、7.84%~20.30%、14.42%~22.52%;与常规灌溉间作水分利用效率相比,中灌水水平交替灌溉间作水分利用效率分别增加了17.55%、0.09%、0.53%、27.10%。3、影响交替灌溉间作作物水分利用效率变化的因子主要包括土壤棵间蒸发量占总耗水量比重、叶日积和根密度。2008年交替灌溉间作在低、中、高三个灌水水平下的棵间蒸发量占总耗水量比重分别较单作小麦提高了11.71%、9.55%、6.00%,较单作玉米分别提高了5.72%、6.19%、6.18%。2009年中、低灌水水平交替灌溉间作棵间蒸发量占总耗水量比重较单作小麦增加了7.17%、4.13%,较单作玉米增加了2.01%、3.50%。2007和2008年度,交替灌溉间作叶日积(LAID)在低、中、高三个灌水水平下分别较单作小麦提高了102.79%、105.83%、109.14%和60.04%、54.49%、54.18%。2009年度交替灌溉间作LAID在低、中两个灌水水平下分别较单作小麦提高了76.16%、61.31%。交替灌溉间作影响作物根系的时空分布,并在不同时期形成了对土壤空间的叠加利用。小麦灌浆期,间作小麦根系遍布两作物根区地下部的整个剖面,纵向分布已达80 cm以下,横向分布已进入玉米根区整个地下部空间,表现为根重密度为0.07的等值线深达50 cm以下,根重密度为0.01的等值线最大深度达到80 cm以下,根重密度为0.04的根系侧向进入玉米根区20-40 cm。4、交替灌溉影响间作群体产量和水分利用效率的主要生理生化机制是提高了脯氨酸含量、增强了SOD活性、POD活性和根系活力。交替灌溉间作小麦的脯氨酸含量较常规灌溉平均提高了38.26%,交替灌溉单作小麦和蚕豆分别平均增加了35.31%和24.07%。生育期内交替灌溉单作小麦、单作蚕豆、间作小麦、间作蚕豆SOD活性分别较常规灌溉增加了17.24%~22.62%、21.53%~41.35%、7.86%~25.11%、7.92%~16.14%;POD活性分别较常规灌增加了3.88%~24.53%、0.44%~29.76%、13.73%~35.36%、8.79%~22.74%;根系活力分别较常规灌溉提高了6.41%~29.98%、5.71%~11.39%、6.09%~22.65%、7.62%~20.08%。更多还原

【Abstract】 Intercropping, due to the more effective use of resources and high productivity, is practiced widely in northwestern China. In recent years, however, the shortage of water resources is increasing continually; the application of intercropping has become big challenge. Therefore, water-saving irrigation technologies for intercropping pending further study. Alternative irrigation technology can significantly improve water use efficiency of crops, creates special root system favorable for improving crop water use efficiency and helps to improve water compensate effects. Our works reported here are aiming at investigating yield, water use efficiency and water use mechanism in wheat/maize intercropping and wheat/faba-bean intercropping through field experiment and simulation experiment. The main results were obtained as the following:1. Land utilization rate, crops yield of wheat/maize intercropping were significantly increased under alternate irrigation. Land equivalent ratio (LER) of wheat/maize intercropping under alternate irrigation was varying in the range of 1.22~1.52 during 2006-2009, indicating that wheat/maize intercropping under alternate irrigation can improve land utilization rate. Apart from 2008, LER of alternative irrgated wheat/maize intercropping at medium irrigation level was increased by 2.33%~17.83% than conventional irrigation during consecutive four years. Yield of wheat/maize intercropping under alternate irrigation was increased by 51.12%~99.44% than sole wheat, and increased by 2.01%~31.74% than sole maize.2. Water consumptionn of wheat and maize was not significantly influenced by alternative irrigated wheat/maize intercropping. Compared to weighted average water consumption of sole cropping, water consumption of alternative irrigated wheat/maize intercropping was increased by 0.28%~0.92%, 4.29%~5.94%, 14.36%~19.19%, 12.72%~18.13% in 2006-2009 growing seasons, and water consumption of alternative irrigated wheat/maize intercropping was increased by 0.44%, 4.43%, 3.59%, -19.28% than wheat/maize under conventional irrigation at the same irrigation level. Water use efficiency of alternative irrigated wheat/maize intercropping was increased by 32.70%~47.10%, 31.16%~34.39%, 7.84%~20.30%, 14.42%~22.52% than weighted average sole cropping, and increased by 17.55%, 0.09%, 0.53%, 27.10% than wheat/maize intercropping under conventional irrigation at the medium irrigation level.3. The changes of water use efficiency in the alternative irrigated wheat/maize intercropping could be attributed to amount of soil evaporation propotion to evapotranspiration (E/ET), leaf area duration (LAID) and root weight density. In 2008 growing seasons, compared to sole wheat, E/ET of wheat/maize intercropping under alternate irrigation was increased by 11.71%, 9.55%, 6.00%, and increased by 5.72%, 6.19%, 6.18% than sole maize at low, medium, high irrigation level, respectively. E/ET of wheat/maize intercropping under alternate irrigation was increased by 7.17%, 4.13% than sole wheat, and 2.01%, 3.50% than sole maize at medium, low irrigation in 2009 growing seasons. LAID of alternative irrigated wheat/maize intercropping was improved by 102.78%, 105.83%, 109.14% and 60.04%, 54.49%, 54.18% than sole wheat at low, medium, high irrigation level respectively in 2007 and 2008 growing seasons. In 2009 growing season, LAID of alternative irrigated wheat/maize intercropping was improved by 76.16%、61.31% than sole wheat at medium, low irrigation level respectively.The niche differentiation in time and space of root distribution is the main mechanism for yield and water use efficiency. Root of intercropped wheat extended maize underground space in the coexistance period of wheat and maize, and root growth reached 80 cm in soil depth. Root weight density with its 0.07 root isoline reaching above 50 cm, and root isoline of 0.04 extend maize rootzone 20-40 cm.4. Increased proline content, SOD activity, POD activity and root activity were the main mechanism for improved yield and water use efficiency in alternative irrigated intercropping system. The proline content of intercropped wheat under alternate irrigation was increased by 38.3%, and sole wheat, sole faba bean averagely increased by 35.31%, 24.07% than conventional irrigation respectively. SOD activity of sole wheat, sole faba bean, intercropped wheat, intercropped faba bean under alternate irrigation was increased by 17.24%~22.62%, 21.53%~41.35%, 7.86%~25.11%, 7.92%~16.14%, POD activity was increased by 3.88%~24.53%, 0.44%~29.76%, 13.73%~35.36%, 8.79%~22.74%, and root activity was increased by 6.41%~29.98%, 5.71%~11.39%, 6.09%~22.65%, 7.62% ~20.08% than conventional irrigation during the growing period, respectively.更多还原