Abstract:

To explore the effect of morchella waste returning on rice production and its potential to replace chemical nitrogen fertilizer in “rice-morchella rotation”，a pot experiment was set up in 2022. Three treatments were designed in the experiment, which were “morchella waste returning to paddy field + conventional fertilization(H1)”, “morchella waste returning to paddy field + nitrogen fertilizer 10% reduction (H2)”, “no morchella waste returning to paddy filed + conventional fertilization (CK)”. The rice yield and yield components, dry matter accumulation, nitrogen uptake and utilization efficiency of plant, the changes of soil organic matter, pH value and available nitrogen content were measured, and the production effect of nitrogen reduction with morchella waste returning was analyzed. The results showed that compared with CK, the rice yield of H1 was increased by 4.0% and that of H2 was decreased by 0.32%. The rice yield components of H1 were better than those of CK, which concrete embodied that the effective panicle number, grain number per panicle, seed setting rate and the spike rate of H1 were increased by 3.1%, 1.7%, 3.7% and 6.1%, respectively. The effective panicle number, grain number per panicle and seed setting rate of H2 were decreased by 1.0%, 0.6% and 0.4%, respectively, while the thousand-grain weight and spike rate were increased by 1.3% and 6.4%. However, there was no significant difference in yield and its components among H1, H2 and CK (P>0.05). There was no significant difference in dry matter accumulation at different stages and nitrogen content, nitrogen uptake, nitrogen dry matter production efficiency and nitrogen grain production efficiency at maturity among different treatments (P>0.05). The returning of morchella waste was beneficial to improve the content of soil organic matter and ammonium nitrogen in paddy field. The soil organic matter content of H1 and H2 at rice mature period were both higher than that of CK, and the difference between H1 and CK was significant (P<0.05). The soil ammonium nitrogen content of H1 and H2 was 28.8 % and 7.7 % higher than that of CK (P<0.05). There was no significant difference in nitrate nitrogen content among treatments (P>0.05). Based on the indexes such as dry matter accumulation, nitrogen uptake and utilization efficiency，soil fertility and so on, morchella waste consumption and utilization in paddy field in rice-morchella rotation did not affect the rice growth and yield formation, and had positive effects on paddy soil fertility. Therefore, 10% nitrogen fertilizer reduction (replacing 10% chemical nitrogen) with the morchella waste returning to the paddy field in rice production had no significant effect on the stability of rice yield.

Key words: rice, morchella waste, nitrogen fertilizer, yield, soil fertility