Cadmium (Cd) in contaminated soil not only enters surface water via rainfall runoff but also penetrates groundwater, adversely affecting human health through the food chain. This research examined three kinds of soil from Luoping County in southwestern China, with different Cd pollution levels. Simulated rainfall and soil column leaching experiments were conducted to explore the risks and factors influencing Cd loss in surface runoff and underground leaching water at different ground slopes (6°, 12°, 18°, and 24°), rainfall intensities (30, 60, and 90 mm∙h−1), and soil profile conditions. The results show that the risk of soil Cd runoff loss increased at a higher rainfall intensity or Cd pollution degree, reaching a peak at a ground slope of 18°. The main factor affecting soil Cd runoff loss was rainfall intensity followed by Cd soil pollution degree and slope. The risk of soil Cd leaching loss was mainly determined by the leaching time and soil depth. The primary factor affecting soil Cd leaching loss was leaching time, followed by soil depth. The soil organic matter (SOM) concentration and pH minimally affected soil Cd loss. The research results provide a theoretical basis for risk management and control of cadmium loss in contaminated soil, and indicate that the environment-friendly water treatment method of high concentration Cd polluted runoff deserves attention.

To improve the utilisation of mushroom residue waste resources and identify a replaceable matrix material for peat, 10 different formula substrates and three commercially available substrates were examined to determine their physiochemical properties. Furthermore, the correlation and influence of these physicochemical properties on the substrates were explored. Pot experiments were conducted using Brassica campestris L. ssp. chinensis Makino var. communis Tsen et Lee (cabbage), Brassica chinensis L. (pakchoi), Cucumis sativus L. (cucumber), and Cucurbita moschata Duch. ex-Poiret (pumpkin). The results showed that the matrix was most significantly affected by water-holding porosity, aeration porosity, air-water ratio, total porosity, pH, electrical conductivity (EC), available phosphorous (AP), and available potassium (AK). The random forest (RFF) model indicated that pH and total nitrogen (TN) had the strongest influence on the plant height and stem diameter of the cabbage. Moreover, pH, water-holding porosity, and total porosity most significantly influenced the plant height, stem diameter, and seedling vigour index. AP and air-water ratio substantially affected the root length and root-to-crown ratio of the cucumbers, while EC, air-water ratio, and AP influenced the stem diameter, root length, and seedling vigour index of the pumpkin most. The biological characteristics of the four vegetables during the pot experiment indicated that the overall effect of the 10 substrates supplemented with perlite and vermiculite was better than in the basic group. Of these, T2 (mushroom waste: sawdust: catalyst: vermiculite = 8:2:5:5) displayed the best result and could be used as an alternative for peat seedling.