生产力调控对翌年苹果园土壤水分和苹果叶片光合特性的影响

以盛果期‘长枝富士’为试验材料, 以生产力调控翌年苹果(Malus pumila)树坐果期为主要观测期, 对不同生产力水平下果园土壤水分状况及苹果叶片光合特性进行了研究。结果表明: 在生产力调控范围内, 土壤剖面各个层次土壤含水量均随着生产力水平的减小而增加, 其中在60 cm处达到最大增量, 为31.02%; 而在600 cm范围内土壤贮水量最大能够提高15.41%。随着生产力水平的降低, “光合午休”现象减弱, 净光合速率(P_n)增加, 最大增幅为25.71%, 下午时段的蒸腾速率(T_r)下降迅速, 水分利用效率(WUE)最大提高34.12%。通过相关分析表明, 土壤贮水量(WSC)与P_n、T_r、WUE之间均达到显著相关, 其相关系数分别为: 0.973^**、-0.543^*和0.992^**。土壤贮水量(x)与水分利用效率(y)之间符合y = 0.002 3x - 1.480 6, R²= 0.984 4^**的回归模型。通过生产力调控可以改善土壤水分状况和果树光合能力, 提高WUE。

Effects of controlling apple orchard productivity on soil moisture and photosynthetic characteristics

Aims Our objective is to explore the effects of controlling productivity on resource use in an apple orchard in order to improve sustainability and efficiency. Methods We investigated the effects of different productivities (3.6 × 10⁵, 3.15 × 10⁵, 2.7 × 10⁵, 2.25 × 10⁵ and 1.8 × 10⁵ ind·hm^–2) on soil moisture and photosynthetic characteristics in ‘Fuji’ apple trees during the fruit-bearing period using a neutron probe (503DR) and Li-6400 portable photosynthetic analysis system. Important findings Soil moisture at every soil layer increased with decreased productivity, with the maximum increment of 31.02% at the 60 cm depth. Within the 600 cm profile, water storage capacity could increase 15.41%. With decreased productivity, midday depression of photosynthesis was abated, net photosynthetic rate (P_n) increased, the highest P_n increased 25.71% compared with the control treatment (3.6 × 10⁵ ind·hm^–2), the transpiration rate (T_r) was decreased in the afternoon and the optimum water use efficiency (WUE) was improved by 34.12% compared with the control. There were significant correlations between water storage capacity (WSC) and P_n, T_r and WUE (Pearson correlation coefficients of 0.973^**, -0.543^* and 0.992^**, respectively). The regression model of WSC (x) and WUE (y) was y = 0.002 3x – 1.480 6, R² = 0.984 4^**. Controlling productivity improved soil moisture and photosynthetic characteristics and increased WUE, improving harmonious, sustainable development of nature, the economy and society in the apple production area.