Ending composting during the thermophilic phase improves cultivation substrate properties and increasing winter cucumber yield

In the world, 10 billion tons of solid wastes were produced each year. Composting is a better method for solid waste management. Vegetable production now tends to be soilless cultivation. However, completed compost is not suitable for vegetable cultivation. So we studied bagasse (BS), corncobs (CC) and sawdust (SD) as composting materials and investigated stopping in the thermophilic phase for different durations (35, 45, and 65 days). Subsequently, cucumbers were transplanted into nine composted samples mixed with vermiculite at a ratio of 1:1 (v/v). The results obtained during the composting of the three composts (BS, CC and SD) showed that composting for 35 and 45 days increased the root temperature by 1.0-2.2 °C during January and February compared to the effects of composting for 65 days. In addition, microbial community numbers were significantly increased (P < 0.05) by composting for 35 and 45 days compared to those observed when composting for 65 days. Additionally, composting for 35 and 45 days resulted in the highest net leaf photosynthesis rate, total dry matter and cucumber yield among all treatments. Bacterial community numbers, net photosynthesis rate and physico-chemical parameters (bulk density, water-holding porosity, pH, total K (TK) and TOC) had a positive correlation with yield. Therefore, composting for 35 days creates a suitable substrate for cucumber production and facilitates the use of agricultural waste to achieve significant ecological and economic benefits.