Abstract:

To clarify the effects of chemical fertilizer replaced by biogas slurry on the growth, development, and yield of different rice types, conventional japonica rice Nangeng 5718 and hybrid indica rice Quanyou 169 were used as materials for experiments. Treatments included partial replacement of chemical fertilizer with biogas slurry and complete replacement of chemical fertilizer with biogas slurry, with conventional chemical fertilizer treatment as the control (CF). The effects of different fertilization dose and timing on rice traits such as tillering dynamics, plant height, dry matter weight, and yield were systematically analyzed. The results showed that compared with the CF treatment, T1 treatment had no significant effect on the plant height of both rice varieties but reduced their tiller number. Treatments T2-T4 significantly increased the plant height and tiller number of both varieties. Treatments T1-T4 had no significant effect on the length of the first and second internodes for both varieties (except the T3 treatment for Quanyou 169), but increased stem and leaf weight, panicle weight, and total weight for both varieties. Compared with the CF treatment, all treatments with replacement of chemical fertilizer with biogas slurry biogas increased the yield of both rice varieties. Specifically, treatments T2-T4 increased yield by 7.9%-19.1% for Quanyou 169 and 8.7%-17.5% for Nangeng 5718, primarily by increasing the number of effective panicles. For Nangeng 5718, T4 treatment significantly increased 29.9% in grains per panicle compared with T3 treatment due to staged fertilization. For both varieties, the T3 treatment improved the seed-setting rate compared with T2 treatment due to additional grain fertilizer. In conclusion, chemical fertilizers replaced by biogas slurry can increase yield while reducing chemical fertilizer usage, providing a scientific basis for the resource utilization of biogas slurry and green rice cultivation.

Key words: biogas slurry, rice, fertilization, agronomic traits, yield