作物高效用水生理生态调控机制研究

Physio-ecological regulating mechanisms for highly efficient water use of crops

  • 摘要: 提高作物对水分的高效利用是解决我国农业水资源短缺的根本出路。本文从作物高效用水的品种差异、作物不同生育时期对水分的响应差异、气孔导度对作物叶片奢侈蒸腾的调控、不同抗旱类型作物在应对水分胁迫的生理生态策略差异等4个方面,主要对国内研究进展及发展趋势进行了综述。根据本研究组多年研究结果,提出了3项作物高效用水的配套栽培技术,主要包括:1)调整种植结构,提高作物周年用水效率技术。利用作物及品种的用水特性、产量差、效率差,根据地下水压采目标,构建合理的作物种植结构与轮作方式,提高作物周年对水资源的利用效率。以太行山前高产区为例,冬小麦-夏谷子/春甘薯两年3熟制是一种产量、水分经济利用效率均较高的种植结构。2)活化播期,拓宽播种阈值,提高作物雨水利用效率技术。通过选用合适品种拓宽播期、等墒、找墒、保墒拓展利用土壤水分的时空范围、播量变量调节等,提高作物雨水利用效率。通过技术组装与配套,冬小麦只要在11月底之前播种,产量与常规种植没有显著差异。3)覆盖保墒,提高旱地作物高效用水技术。其中,小麦-玉米土下覆膜一膜两用丰产节水模式通过调节土壤温度、水分、盐分、抑制杂草等多项调控,显著提高了雨养农田作物产量与水分利用效率。在环渤海低平原沧州地区,该技术模式在没有任何灌溉条件下的周年产量达15 910.20~16 965.90 kg·hm-2,比对照增产10.52%~41.44%。深入探讨作物高效用水的生理生态基础、进一步研发提高作物水分利用的新技术、统一作物高效用水的量化标准和充分利用非常规水将是今后相当长一段时期的重点研究方向。

     

    Abstract: The North China Plain (NCP) is a severe water shortage region and one of the important grain crop production bases in China. With the rapid rise of China's national economy, the water shortage of agriculture production has acutely increased. To reduce the exploitation of groundwater and resolves problems in agricultural water resources, a series of water-saving measures have been proposed and developed. However, improving crop water use efficiency has been among the most basic requirements to this goal. This paper therefore reviewed four aspects of research progresses of improving crop water use efficiency. They included the varieties difference in high water use, response difference of crops at different growth stages to water, regulation of stomatal conductance on excessive transpiration of crop leaves, differences in physio-ecological strategies of different drought-resistant corps to water stress. On this base, three integrated cultivation techniques were advanced according to our research results. The first was adjustment of planting structure to improve annual water use efficiency of crops. To gain this goal, it was important to establish rational planting structures and rotation patterns based on difference in water consumption characterizes, yield and economic efficiency of crops/varieties. In the high-yield region of the piedmont of Mountain Taihang, the pattern of three-cropping in two years of winter wheat-summer millet/spring sweet potato was a planting structure with high yield-and economic-water use efficiencies. The second cultivation technique was activation and broadening of sowing date thresholds via increase seeding rate and mulching to increase rainwater use efficiency. In our research, grain yield of winter wheat was not significantly different regarding sowing date-before December or in early October under intensive seeding and soil-coated film mulching in the Bohai Lowland Plain. The third aspect was improving crop water use efficiency in rain-fed fields by coating soils with film mulch. The pattern of subsoil plastic film mulch dual used by winter wheat and summer maize significantly inhibited soil evaporation and salt accumulation, increased seed emergence rate, promoted aboveground biomass and increased grain yield and water use efficiency of two crops in dry lands. In the Bohai Lowland Plain, this cropping pattern made use of rainwater and slight saline water. Grain yield of winter wheat-summer maize was up to 15 910-16 966 kg·hm-2, which represented an increase of 10.52%-41.44% over that under no mulching. In the future, disruptive innovations such as new quantitative standards for high crop water use efficiency and utilization of unconventional water resources can lead to significant breakthroughs in agricultural water saving.

     

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