根区局部控水无压地下灌溉技术对黄瓜和番茄产量及其品质影响的研究

根区局部控水无压低下灌溉技术（简称无压灌溉）是把带有出水器的毛管埋在作物根区,利用土壤吸力对作物进行“主动灌溉”,满足生育期需水要求.其适宜压力变化范围-4～8 cm,埋深10～30 cm,出水器孔径3～8 mm.通过2 a的温室大棚种植黄瓜、番茄,采用无压灌溉和沟灌对比试验,研究了黄瓜、番茄生育期内根区土壤水分运动和变化规律、作物耗水量及其规律、作物产量和水分生产率关系以及不同灌溉方式对作物品质影响的机理.研究表明无压灌溉改善了设施内作物的生存环境,为作物根系提供了充足的氧气,使根系与大气很好地进行能量交换,让根系生存在一个更加适宜的环境中,从而影响光合同化产物向不同组织器官的分配,调节了作物的生长发育,改善产品品质.与沟灌相比,无压灌溉并不降低作物产量,且能够提高作物水分利用率和水分生产率,使黄瓜、番茄的维生素C、可溶性糖、总糖和无机磷含量明显提高,具有以水调质功效.

YIELD AND QUALITY OF TOMATO AND CUCUMBER UNDER NON-PRESSURE SUBSURFACE DRIP IRRIGATION AT CROP ROOT ZONE

Non-pressure Subsurface Drip Irrigation at Crop Root Zone(shortened as Non-pressure Irrigation),is a method of local water control irrigation,having pipes with fine apertures buried at the crop root zones.Water oozing out through the apertures under the suction of soil irrigates the crop and satisfies its need during growth.Optimal parameters of the system are-4 to(8 cm) in pressure,10 to 30 cm in depth of buried pipe,and 3 to 8 mm in diameter of the aperture.Comparison between non-pressure irrigation and furrow irrigation was carried out to study their effects on movement and variation of soil water,evapotranspiration,relationship between crop yield and water productivity and mechanism of effect of irrigation pattern on quality of tomato and cucumber in greenhouse in 2004 and 2005.The results show that non-pressure irrigation improved living conditions of the crops,and left enough oxygen in the root zone so that quality of the crops was raised due to improved distribution of photosynthetic assimilates to different organs.Compared with furrow irrigation,non-pressure irrigation did not decrease crop yield,but improved water availability and productivity,and in turn significantly raised contents of vitamin C,soluble sugar,total sugar and inorganic phosphorus,demonstrating its function of adjusting quality with water.