Biological conservation measures are better than engineering conservation measures in improving soil quality of eroded orchards in southern China

Abstract

Both biological and engineering measures have proven to be effective soil and water conservation practices for eroded environments, whereas how the soil quality varies with them remains unclear. In this study, we measured soil properties in the 0-to-100-cm soil layer of eroded orchards in southern China after 17-yr of application of different conservation measures. The purpose of the experiment was to examine the effect of biological (grass planting, intercropping) and engineering measures (terrace) on the soil quality of eroded orchards. We selected an orchard plot with traditional clean-tillage as control. In comparison, soil pH, organic carbon, total phosphorus, microbial carbon, available potassium, and available microelements contents increased significantly in orchards with biological measures, and the improvements were more dramatic in orchards planting grass in strips. However, biological measures significantly reduced the mean weight diameter of aggregates. Engineering measures significantly increased the soil pH of orchards but decreased the contents of available iron and available manganese. The soil quality index (SQI)

Experiment and meta-analysis on the effects of grass cultivation in the orchard on fruit yield and quality

“…Firstly, the grass has an interception effect on rainfall and reduces surface runoff. Secondly, after grass cultivation, the total soil porosity increases and the soil bulk density decreases under the action of the grass root system, thereby increasing the water storage capacity of the soil (Qin et al, 2022);…”

“…The grass exudates and the residual branch decomposition promote the increase of organic matter, create a suitable environment for the growth and reproduction of microorganisms, increase the number of microorganisms, and further increases the activity of soil enzymes, which is beneficial for soil microorganisms to participate in nutrient cycling, organic matter decomposition and energy flow (Li et al, 2022;Qin et al, 2022);…”

Why Have China’s Poverty Eradication Policy Resulted in the Decline of Arable Land in Poverty-Stricken Areas?

“…For instance, the construction of terraces on sloping terrain, vegetation belts, and protective forest belts is undertaken to slow down water flow and prevent soil erosion. Rational irrigation management measures, such as drip irrigation and spray irrigation, can also be implemented to reduce water wastage and enhance irrigation efficiency [57,58]. Such actions serve the dual purpose of safeguarding and restoring the ecological environment while ensuring high-quality agricultural production.…”