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The rapid expansion of citrus orchards and their increased cultivation intensity have accelerated soil erosion, which has impeded the achievement of Sustainable Development Goals. In citrus orchards, the benefits of soil and water conservation measures for alleviating soil erosion have been widely tested at the plot scale. These studies provide crucial information, but they inevitably involve considerable uncertainty and cannot fully characterize the efficacy of soil and water conservation measures. Given the seriousness of soil erosion in citrus orchards and the uncertain factors in the efficiency of soil and water conservation measures, data published in the literature were collected. A meta-analysis of 346 plots (representing 4443 events) for runoff and 307 plots (representing 3596 events) for soil loss was conducted to evaluate the effectiveness of soil and water conservation measures in citrus orchards. This study aims to (i) summarize the level of soil erosion in citrus orchards worldwide, (ii) explore the influence of soil and water conservation measures on soil erosion control in citrus orchards and (iii) identify the trade-offs between runoff reduction and soil loss reduction. The results showed that the citrus orchards without soil and water conservation measures had a probability of approximately 80% of exceeding tolerable levels of soil loss. The effectiveness of soil and water conservation measures in reducing soil erosion decreased in the order biological measures + engineering measures > engineering measures > biological measures. The trade-off between runoff reduction and soil loss reduction showed that soil and water conservation measures provide better soil loss control than runoff control. Overall, besides considering the ecological benefits of soil and water conservation measures, decision maker should also consider the economic benefits to obtain an optimal citrus orchard management for farmers.

The hot deformation behavior of GH690 alloy is investigated in the temperature range of 950–1200 °C and a strain rate of 10 −3 s −1 to 2 s −1 . It is found that the flow stress increases with strain, and then decreases as it reaches a peak flow stress. On the basis of the experiment data, processing maps are developed using the dynamic materials model (DMM). The processing maps exhibit two domains. One is the stable region occurring in the temperature range of 1120–1180 °C and the strain rate of 0.0325–0.447 s −1 , the other is the instability zone occurring in the temperature range of 950–1180 °C and the strain rate of 0.18–2 s −1 . Under the guidance of the processing maps, a rolling experiment is carried out, and it is found that the yield strength, ultimate tensile strength and elongation of the plate are 565 MPa, 685 MPa and 51.13% respectively.

The hot deformation behavior of GH625 is investigated by a compression test in the temperature range of 950-1150 °C and the strain rate of 10−3-5 s−1. It is found that the flow stress behavior is described by the hyperbolic sine constitutive equation with average activation energy of 421 kJ/mol. Through the flow stresses’ curves, the processing maps are constructed and analyzed according to the dynamic materials model. In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate, and the maps exhibit a significant feature with a domain of dynamic recrystallization occurring at the temperature range of 950-1150 °C and in the strain rate range of 0.005-0.13 s−1, which are the optimum parameters for hot working of the alloy. Meanwhile, the instability zones of flow behavior can also be recognized by the maps.