水保所知识产出(1956---)知识库

Long-term imbalance of water demand over supply in drylands can result in serious ecological issues such as
severe soil desiccation, posing a great challenge to sustainable development of dryland orchards. This study
examined the effects of multi-intensity summer pruning on water balance, production and water use efficiency of
apple orchards on China’s Loess Plateau using in situ measurements and the process-based MAESPA model. A
field experiment with four intensities representing no (0% or control), light (10%), moderate (25%) and heavy
(40%) pruning of branches was carried out in three replicates under each treatment. The pruning intensities
dictated transpiration, soil moisture and drainage. Although light pruning had weak impacts on these factors,
moderate and heavy pruning significantly reduced growing-season transpiration by an average 10.4% and
28.5%, respectively. However, the effects progressively faded away with time at both diurnal and seasonal scales.
Moderate and heavy pruning also increased soil water content in the 20–180 cm by an average 18.3% and 20.8%,
respectively, and thus enhanced drainage below 180 cm (>220 mm), relative to light pruning and control (<170
mm). Furthermore, light and moderate pruning clearly promoted apple yield and water use efficiency whereas
heavy pruning significantly reduced (24.7%) apple yield. Thus, moderate pruning can be a good choice for apple
orchards in normal precipitation years while heavy pruning may be an alternative in severe drought years. The
MAESPA model reliably simulated seasonal variations of transpiration (R 2 : 0.799–0.910, root mean square error
(RMSE): 0.111–0.207 mm), soil evaporation (R 2 : 0.368–0.628, RMSE: 0.468–1.076 mm), and profile soil water
content (R 2 : 0.400–0.894, RMSE: 0.005–0.024 cm 3 cm −3 ) for all treatments and can be used as a tool to quantify
the effects of pruning on hydrological processes in dryland apple orchards. This study provides insights into the
development of a sustainable management strategy in dryland orchards.