Effects of rotted corn straw on soil environment, yield, and quality of cucumber

Aiming at solving the problems of soil environment deterioration and the decline of both yield and quality caused by excessive application of chemical fertilizer, we investigated the effects of rotted corn straw on the soil environment of root zone, yield and quality of cucumber with 'Jinyou 35' cucumber as the experimental material. There were three treatments, namely, combined application of rotted corn straw and chemical fertilizer (T₁, the total nitrogen fertilizer application were 450 kg N·hm^-2, of which 9000 kg·hm^-2 rotted corn straw was used as the subsoil fertilizer, and the rest was supplemented with chemical fertilizer), pure chemical fertilizer (T₂, the total nitrogen fertilizer application was the same as T₁) and no fertilization (control). The results showed that the content of soil organic matter in root zone soil in T₁ treatment was much higher, but no difference between T₂ treatment and the control, after two continuous plantings in one year. The concentrations of soil alkaline nitrogen, available phosphorus, available potassium of T₁ and T₂ in cucumber root zone were higher than that in the control. T₁ treatment had lower bulk density, but markedly higher porosity and respiratory rate than T₂ treatment and the control in root zone soil. The electric conductivity of T₁ treatment was higher than that of the control, but significantly lower than T₂ treatment. There was no significant difference in pH among the three treatments. The quantity of bacteria and actinomycetes in cucumber rhizosphere soil were the highest in T₁, and the lowest in the control. However, the highest quantity of fungi was found in T₂. The enzyme activities of rhizosphere soil in T₁ treatment were markedly higher than those of the control, whereas those of T₂ treatment were significantly lower or had no significant difference relative to the control. The cucumber root dry weight and root activity of T₁ were significantly higher than that of the control. The yield of T₁ treatment increased by 10.1%, and fruit quality improved obviously. The root activity of T₂ treatment was also significantly higher than that in the control. There was no significant difference in root dry weight and yield between T₂ treatment and the control. Furthermore, T₂ treatment revealed a decrease in fruit quality relative to T₁ treatment. These results suggested that the combined application of rotted corn straw and chemical fertilizer could improve soil environment, promote root growth, enhance root activity and improve yield and quality of cucumber in solar-greenhouse, which could be popularized and applied in protected cucumber production.