果园生态系统生产力调控

以黄土沟壑区果园生态系统为研究对象,针对黄土高原果业生产波动性大,生态系统恶化等问题,通过调控果树的生殖生长量,研究了果园生态系统生产力调控及系统响应.结果表明:生产力水平高的处理对土壤深层的水分利用增强,但降低了土壤深层贮水量,从而进一步加重土壤干燥化程度;以生殖生长调控为手段的生产力调控能够显著改善果实的单果重、果实硬度、着色指数等外在品质,果品优果率可提高12.9%～23.5%;通过生产力调控,果业生产经济效益显著提高,果园生态系统健康状况得到维持,果树生产波动性缓解.确定挂果2.25×10~5个/hm~2的生产力水平为黄土沟壑区盛果期果园生态系统的适宜生产力水平.

Effect of controlling productivity on an apple orchard ecosystem

Apples are one of the main agricultural crops on China's Loess Plateau. Producers want to maximum productivity;however extremely high levels of production can influence the orchard ecosystem and affect apple tree growth, yield quality and stability, and economic return. This is one of the most important problems in the orchard ecosystem. This field study compared the effect of five levels of productivity on soil moisture, apple quality, apple yield, and economic return from orchards in the Loess Plateau. Productivity in treatment (Ⅰ) (CK) was 3.6×10~5 ind · hm~(-2). Productivity in the other four treatments was limited to the following levels: treatment (Ⅱ) = 3.15×10~5 ind · hm~(-2), treatment (Ⅲ) = 2.7×10~5 ind · hm~(-2), treatment (Ⅳ) = 2.25×10~5 ind · hm~(-2), and treatment (Ⅴ) = 1.8×10~5 ind · hm~(-2). The results showed that the deep soil layer water use efficiency increased as productivity increased. However, deep soil layer water storage capacity decreased and desiccation of deep soil layers increased as productivity increased. The use of control methods to reduce productivity resulted in improvements in individual apple weight, firmness, and color. Based on external quality, the percentage of excellent fruit was 13%～24% higher in treatments with adjusted productivity levels compared to the unadjusted control treatment. In conclusion, these results indicated that controlling productivity increased sustainability, apple quality, economic return, and ecological benefit and reduced fluctuations in production. The optimum production level for mature orchards in the Gully Region of the Loess Plateau was 2.25×10~5 ind · hm~(-2).