根系分区交替灌溉不同交替周期对苹果树

以11~12年生苹果树为研究对象，于2006~2007年在烟台市农科院果树研究所试验果园进行了根系分区交替灌溉（APRI）试验，研究了APRI灌溉模式下不同交替灌溉周期对苹果树生长、产量、品质及水分利用效率的影响。结果表明，APRI处理的苹果树湿润一侧土壤含水量随深度增加而减少，并出现明显拐点，交替周期愈短拐点愈接近地表，干旱一侧则随深度增加而增大，二者含水量最大差值出现在土壤表层0~10 cm。每2周交替灌溉1次的APRI1处理的叶水势、净光合速率、蒸腾速率和气孔导度稍有降低，但与对照均没有明显差异，而每4周交替灌溉1次的APRI2和APRI3处理的上述指标则显著低于对照（P < 0.05）。APRI处理显著抑制植株的新梢生长，但对果实直径没有显著影响。APRI1和APRI2处理的苹果产量比对照和APRI3下降了11.1 %~14.8 %，但供水量减少了50 %，水分利用效率提高了71 %~80 %，而且显著提高了可溶性固形物含量和果实干物质含量，使果实含酸量降低，果实硬度增加，果实品质明显改善。由此可以推断采用根系分区交替灌溉并进行适宜的交替周期处理（如本试验中的APRI1）可以达到大量节水、提高苹果品质而不明显降低产量的目的，是苹果生产中一种切实可行的灌溉方式，值得旱地苹果园大力推广。

Effects of different alternate cycling on the growth, yield and quality of apple trees under conditions of alternate partial root-zone irrigation

This study was conducted to evaluate the effects of different alternative irrigation cycle on plant growth, yield and quality and water use efficiency of 11 and 12-year-old apple trees (Malus pumila Mill. cv. Hongjingfu) subjected to control and alternative partial rootzone irrigation (APRI) in Yantai Fruit Research Academy of Agricultural Science from 2006 to 2007. The results showed that in APRI treatments, the soil moisture content in the wet side of apple trees decreased with increasing soil depth, and obviously the alternate shorter period, inflexion point more near the surface, while that in the dry side was adverse, with the maximum difference occurred in 0~10 cm soil surface layer. For APRI1 treatment (irrigation with 50 % of the control, on one side of the root system and switched every 2 weeks), the leaves water potential, net photosynthetic rate, transpiration rate and stomatal conductance were slightly low, but no significant differences existed compared to CK (irrigated with 100 % on both sides of the root system). The indices above-mentioned for both APRI2 (irrigation with 50 % of the control, on one side of the root system and switched every 2 weeks) and APRI3 (irrigation with 100 % of the control, on one side of the root system and switched every four weeks) were significantly lower than that of those in the control (P < 0.05). The APRI treatments significantly inhibited the shoot growth of apple trees, but had no significant influence on fruit diameter. Apple yield was significantly higher in both of the control and APRI3 treatments, compared to APRI1 and APRI2 treatments. The slight APRI-induced yield reduction (11.1 %~14.8 %) compared to the control was achieved 50 % reduction in the total amount of water applied, which resulted in a water use efficiency increased by 71 %~80 % under APRI1 and APRI2 treatments, compared to the control and APRI3. Furthermore, the APRI1 and APRI2 treatments induced the significant increases of the soluble solids content, dry matter content and fruit hardness, and the decrease of fruit acid content, which made the fruit quality improved obviously. It was concluded that APRI1 had the potential for use in apple orchard as a high-quality efficient irrigation pattern in arid land.