| In order to use the water resources efficiently, increase the efficiency of the walnut cultivation, determine the effects of aquasorb applying methods and quantity in walnut planting, grafted seedlings of ’Lvling’ walnut were used as material, not applied aquasorb was as the control, the effects of aquasorb application techniques that 3 application positions that were applied to the bottom, to the middle and bottom, to the bottom, middle, upper part of the seedling and 4 application quantities that were 15 g, 25 g, 35 g, 45 g per plant on the survival of walnut, shoot lengths, soil volumetric water contents, root proline contents, root activities, soil physical properties, photosynthesis rates and transpiration rates were studied. The results showed that:1. The walnut seedlings survival rates of all the applied aquasorb treatments were 100%, that of the control was 90%, and those of all the aquasorb treatments were significantly higher than the control.2.In May, the total shoot lengths per plant of applied L type aquasorb to the middle and botto, applied XL type aquasorb to the bottom were significantly higher than that of the control, which were 20.29 cm, 21.63 cm respectively. In September, the total shoot lengths per plant of applied 15 g L type aquasorb and 25 g XL type aquasorb were significantly higher than that of the control, which were 69.68 cm, 85.54 cm respectively,the control was 51.28 cm.3.From April to July, the soil volumetric water contents of applied XL type aquasorb to the bottom, middle, upper were significantly higher than the control. In April, after applied XL type aquasorb to the bottom, middle, upper, the soil volumetric water contents in 0~20 cm, 20~40 cm, 40~60 cm soil layers were higher, that were 38.53%, 43.55%, 32.92% respectively; In May and June, the soil volumetric water contents of applied XL type aquasorb to the bottom, middle, upper were still higher than the control; In July, the soil volumetric water contents of applied L type aquasorb to the bottom, middle, upper in 0~20 cm, 20~40 cm, 40~60 cm soil layers were the highest, which were 27.33%, 37.88%, 38.93% respectively.The soil volumetric water contents of applied 35 g L and 35 g XL type aquasorb were the highest during April to May; From July to August, the soil volumetric water contents of applied 25 g L type aquasorb was significantly higher than that of the control; In April, May and August, the soil volumetric water contents in 0~20 cm, 20~40 cm, 40~60 cm soil layers increased by two types of aquasorb application quantities increased, but the soil volumetric water contents decreased when the application quantities reached to 35 g.4.Root proline contents of applied L and XL types aquasorb to the bottom were the highest, which were 90.93 μg·g-1, 153.60 μg·g-1 respectively, but root proline contents of aquasorb applied to the different part were significantly lower than the control, that was 231.93 μg·g-1;Root activity of applied L type aquasorb to the bottom, middle, upper was 68.85 μg·g-1·h-1, it was significantly higher than the control. Root proline contents of applied two types of aquasorb and quantities were significantly lower than the control. There were no significant differences of root activities among the different aquasorb applied quantities and the control. The capillary water holding capacities of applied XL type aquasorb to the bottom, middle, upper in 0~20 cm,20~40 cm soil layers were the highest, they were significantly higher than the control, which were 23.86%,22.15% respectively. In 0-20 cm soil layer, the capillary water holding capacities of applied 15 g and 25 g L type aquasorb were significantly highest than the control, which were 23.09%,21.95%; The saturated water contents of applied 45 g L type aquasorb in 0~20 cm, 20~40 cm soil layers were significantly higher than the control, which were 43.16%,42.23%.5.The soil bulk densities of applied XL type aquasorb to the bottom, middle, upper in 0~20cm soil layer reduced 0.1107 g·cm-3 compared with the control; The soil bulk densities of applied L type aquasorb to the bottom and XL type aquasorb to the bottom, middle, upper in 20~40 cm soil layer were 1.393 g·cm-3, 1.3477 g·cm-3 respectively. The soil bulk densities of applying 15 g, 35 g L type aquasorb and 25 g XL type aquasorb in 20~40 cm were significantly lower than the control, which were 1.3384 g·cm-3, 1.3892 g·cm-3, 1.3715 g·cm-3 respectively.6. The photosynthetic rate daily variations were bimodal curves except applied XL type aquasorb to the bottom, middle, upper, which was unimodal curve, the peaks appeared at about 10 o ’clock and 14 o ’clock, and at 12 o ’clock appeared the phenomenon of " midday depression ".The photosynthetic rates of applied L and XL types aquasorb increased by the aquasorb application quantities increased, but decreased when the application quantity reached to 35 g, and photosynthetic rates of other treatments were lower than the control and their variations slowly.7. The leaf transpiration of applied L type aquasorb to the bottom was the lowest, and the transpiration rate of the control appeared peaks in 10 o ’clock and 14 o ’clock, at 12 o ’clock appeared troughs in a day, there hadn’t this kind of dramatic changes of the other treatments. The transpiration rates of applying 15 g L and 15 g XL types aquasorb appeared peak in 14 o ’clock, and were higher than the other treatments, which were 5.435 mmolï¹'m-2ï¹'s-1, 5.740 mmolï¹'m-2ï¹'s-1 respectively. |
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