The Regulatory Effect Of Interval-border Irrigation On Grain Yield And Quality And Water Use Efficiency Of Winter Wheat

The research was carried out from 2007 to 2008 at the experimental station of Shandong Agricultural University and Qianzhuliu village, Longkou city, Shandong Province. A winter wheat varieties with strong gluten (Jimai 20) was chossened as experimental material and subjected to different irrigation frequency: 1 irrigation (at sowing), 2 irrigation (at sowing and Jointing),3 irrigation (at sowing, before winter and Jointing), and 4 irrigation (at sowing, before winter, jointing and grain-filling). Under different irrigation frequency, the effects of interval-border irrigation on wheat grain yield, quality, water use efficiency were investigated. The main results are as follows:1. The effects of interval-border irrigation on grain yieldThe experimental result showed that both the yield of conventional irrigation and interval-border irrigation presented the trend of increasing first decreasing then with added irrigation frequency under the condition of 141.7mm rainfall in Taian and 195mm rainfall in Longkou during whole growth period. The yield with 3 irrigation was the highest and 1 irrigation was the lowest. With the same irrigation, there was no significant difference in the grain yield between the two irrigation methods.2. The effects of interval-border irrigation on some physiological indexesAs showed by the result in Taian, the photosynthetic rate and content of chlorophyll of non-irrigation border are lower than that of irrigation border during grain filling, the photosynthetic rate and the chlorophyll content of treatment W4 was lower than that of treatment W3. The water potential of flag leaf increased with added irrigation frequency, during early grain filling, there was no difference in the water potential of flag leaf between treatment W3 and W4, and the water potential of treatment W4 exceeded over treatment W3 after irrigation at grain filling. Grain water content increased with added irrigation frequency, the grain of non-irrigation border dehydrated more quickly than irrigation border.3. The effects of interval-border irrigation on the grain qualityIn Taian,the content of grain protein, gliadin, albumin, globulin and glutenin presented the trend of decreasing first and increasing then with added irrigation frequency,and that of 1 irrigation was the highest.In longkou, there was no significant difference in the content of gliadin,albumin,globulin , glutenin ,the ratio of glutenin to gliadin, wet gluten content, water absorption, dough development time and dough stability time between different irrigation frequency and irrigation methods with the same irrigation frequency.4. The effects of interval-border irrigation on the water use efficiencyIt was found that water can leak from irrigation border to non-irrigation border.The effect of side leak 25cm away from the irrigation border was obvious, 45cm away from the irrigation border take second place and 70cm away from the irrigation border was the lest. The side leak decreased with the increased soil depth.The irrigation water use efficiency and soil water consumption ratio to total water consumption decreased significantly, while the total water consumption and irrigation consumption ratio to total with conventional irrigation and interval-border irrigation increased with added irrigation frequency, The water use efficiency with 1 irrigation was the highest. The water use efficiency, irrigation water use efficiency, soil water consumption ratio to total water consumption of interval-border irrigation were higher than that of the conventional irrigation with the same irrigation frequency, the total water consumption and irrigation consumption ratio to decreased total water consumption under interval-border irrigation was significantly low compared with conventional irrigation.With 2 and 3 irrigation, the total water consumption of interval-border irrigation decreased by 33.7 mm and 67.5 mm, 25% and 33.3% less than that of conventional irrigation, respectively. But no significant difference was found in the yield between them. 101.2 mm water was saved using the interval-border irrigation with 4 irrigations, 37.5% less than that of conventional irrigation, but the grain yield of the two irrigation methods was lower than that of 3 irrigation. The daily water consumption of conventional irrigation and interval-border irrigation presented the trend of increasing first decreasing then and peaked from jointing to flowering.The water consumption, water consumption mode index and daily water consumption of different treatments during the period from planting to before winter were the least. Except for the period from planting to before winter,the daily water consumption of interval-border irrigation were lower than that of conventional irrigation under the same irrigation frequency.5. The effects of interval-border irrigation on the leaking of soil NO3--N. Under 37 mm rainfall from flowering to maturity, the content NO3--N of treatment W1,W2 and W3 at maturity significantly decreased at 0-20 cm soil and increased at 20-60 cm soil compared with that at flowering, and there were no significantly differences below 60 cm soil. The content NO3--N with irrigation and non- irrigation border of treatment W4 increased in 20-200 cm soil and no difference was observed below 100 cm soil compared with that at flowering. It was proved that large precipitation and irrigation accelerated NO3--N moving downward in all treatments, which was obvious for irrigation border but not significant for non-irrigation border below in 100cm soil.