This study aimed to reuse discarded coir substrates and optimize irrigation as a low-cost solution for addressing waterlogging in paddy-converted farmland. We employed a 2 × 4 factorial design, with two cultivation methods consisting of paddy soil (PS) and coir substrates (CS), and four irrigation levels (IL) set as 140% crop evapotranspiration (ETc140), 100% ETc (ETc100), 60% ETc (ETc60), and non-irrigated control (ETc0). We evaluated the growth and physiological characteristics of cabbage (Brassica oleracea L. var. Capitata), including the outer leaf growth, yield components, water use efficiency (WUE), photosynthetic parameters, chlorophyll content, proline content, malondialdehyde (MDA) content, and glucosinolates (GLs) content. The results indicated that the interaction between the CS and IL significantly improved cabbage growth, photosynthetic activity, and stress resistance compared with PS. Notably, when CS was combined with ETc100 and ETc60 irrigation levels, cabbage exhibited optimal growth parameters, and CS-ETc60 achieved the highest WUE. This study indicated that using discarded coir substrates combined with appropriate irrigation levels offers an effective and low-cost solution for mitigating waterlogging problems.

Cattle manure composting is an effective strategy for recycling agricultural waste. However, the presence of lignocellulosic materials in cattle manure–maize straw mixtures can limit the degradation efficiency during composting. This study investigated the effects of microbial inoculation on composting performance using three treatments: a lignocellulose-degrading microbial consortium (MC1), a commercial microbial inoculant (BS1), and a non-inoculated control (CK). The results showed that the MC1-treated pile entered the thermophilic phase (>50 °C) earlier than the BS1-treated pile. After 49 days of composting, the lignocellulose degradation rates in the MC1, BS1, and CK treatments were 46.25%, 37.5%, and 29.8%, respectively. Based on compost maturity indicators, including temperature, C/N ratio, pH, and electrical conductivity (EC), the composting period required to reach maturity was shortened by 8 days in the MC1 treatment compared with the BS1 treatment (37 vs. 45 days). Microbial community analysis indicated that MC1 inoculation increased the relative abundance of key microbial groups, particularly Ascomycota and Firmicutes, thereby enhancing lignocellulose degradation and accelerating composting. These findings provide insights into the application of lignocellulose-degrading microbial inoculants for improving cattle manure composting efficiency.