Replacing Fallow with Continuous Cropping Reduces Crop Water Productivity of Semiarid Wheat
Replacing Fallow with Continuous Cropping Reduces Crop Water Productivity of Semiarid Wheat
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DOI：
10.2134/agronj2012.0165
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发表时间：
2013-01-01
期刊：
影响因子：
2.1
通讯作者：
Murray, L.
中科院分区：
文献类型：
--
作者：
Aiken, R. M.;O'Brien, D. M.;Murray, L.
供水常常限制半干旱种植系统的作物产量;缺水可限制受干旱影响的半湿润地区的产量。在半干旱小麦（Triticum aestivum L.）中-根据种植制度，用作物取代未耕种的休耕期可以提高降水利用效率，但降低小麦产量。研究了半干旱区冬小麦不同种植顺序和环境因素对水分利用、水分生产率和净收益的影响。建立了一项田间研究，以评估8个3年作物序列，包括小麦阶段，然后是饲料谷物阶段（玉米[Zea mays L.]或粒用高粱[Sorghum bicolor（L.）Moench]）和油籽相（OS;春油菜[甘蓝型油菜L.]，大豆[Glycine max（L.）Merr.]，向日葵[向日葵L.]，或无[休耕]）。标准测量包括作物水分利用（WU），开花期冠层叶面积指数，生物量，谷物产量和产量构成因素。净收益（NR）计算为作物收入和总运营成本之间的差额。替代未种植休耕期与OS作物减少水分生产率的反应WW（生物量，粮食产量，和NR）分别为18%，31%和56%，相对于WW休耕后生长。这些反应，连作对应的减少在所有组成部分的水分限制产量生产函数。观察到的适度水分生产率（0.28-0.62 kg m（-3）），相对于报告的0.6至1.7 kg m（-3）的全球范围，表明通过管理和遗传增益提高小麦水分生产率的机会。
Water supply frequently limits crop yield in semiarid cropping systems; water deficits can restrict yields in drought-affected subhumid regions. In semiarid wheat (Triticum aestivum L.)-based cropping systems, replacing an uncropped fallow period with a crop can increase precipitation use efficiency but reduce wheat productivity. Our objective was to analyze crop sequence and environmental effects on water use, components of water productivity, and net returns of winter wheat (WW) in a semiarid region. A field study was established to evaluate eight 3-yr crop sequences, including a wheat phase followed by a feed grain phase (corn [Zea mays L.] or grain sorghum [Sorghum bicolor (L.) Moench]) and an oilseed phase (OS; spring canola [Brassica napus L.], soybean [Glycine max (L.) Merr.], sunflower [Helianthus annuus L.], or none [fallow]). Standard measurements included crop water use (WU), canopy leaf area index at anthesis, biomass, grain yield, and yield components. Net return (NR) was calculated as the difference between crop revenue and total operating costs. Replacing an uncropped fallow period with an OS crop reduced water productivity responses of WW (biomass, grain yield, and NR) by 18, 31, and 56%, respectively, relative to that of WW grown aft er fallow. These responses to continuous cropping corresponded to reductions in all components of a water-limiting yield production function. The modest water productivity observed (0.28-0.62 kg m(-3)), relative to a reported global range of 0.6 to 1.7 kg m(-3), indicates opportunity to improve wheat water productivity through management and genetic gain.