Abstract:

Six treatments were set to study the effects of photosynthetic bacteria （PSB） alone and in combination with urea on soil physical and chemical properties, enzyme activities, and the agronomic traits, yield and quality of rice Xingengyi 7. The six treatments are: T1, urea 0 kg/667 m²+ PSB 54 kg/667 m²; T2, urea 25 kg/667 m²+ PSB 54 kg/667 m²; T3, urea 30 kg/667 m²+ PSB 54 kg/667 m²; T4, urea 35 kg/667 m²+ PSB 54 kg/667 m²; T5, urea 40 kg/667 m²+ PSB 54 kg kg/667 m²; CK, urea 0 kg/667 m²+ PSB 0 kg/667 m². The results showed that compared with CK, the soil organic carbon content of T1 treatment increased significantly, while total phosphorus content decreased significantly; the soil urease and nitrate reductase activities of T1 treatment decreased significantly, while the activity of nitrite reductase increased significantly; the rice yield of T1 treatment increased significantly, 5.19% higher than that of CK. With the increase of urea dosage, various factors in the soil decreased. Among them, the contents of nitrate nitrogen and organic matter in the T3 and T4 treatments were significantly higher than those in the T1, T2 and T5 treatments. With the increase of urea dosage, soil urease activity showed a very significant linear growth trend, nitrite reductase and nitrate reductase activities first decreased and then increased, but the difference between treatments was not significant. With the increase of urea dosage, rice panicle length, plant height, yield and head rice rate showed a linear increase trend, while the milled rice rate first increased and then decreased. Pearson correlation analysis showed that urea and nitrate nitrogen had a very significant or significant positive correlation with urease activity, and ammonia nitrogen content had a significant positive correlation with nitrate reductase activity. Multi-factor correlation analysis showed that urea was the main influencing factor in soil enzyme activity. Soil enzyme activities play a major role in the agronomic traits, yield and quality of rice. In summary, the application of PSB on its own or combined with urea could significantly activate the soil enzymes involved in nitrogen transformation, thereby promoting the increase in yield and processing quality of rice.

Key words: rice, photosynthetic bacteria, urea, soil enzyme activity, yield, processing quality

摘要：

以新粳伊7号为试验材料,设置6个处理（T1,尿素施用量0+光合细菌54 kg/667 m²;T2,尿素施用量25 kg/667 m²+光合细菌54 kg/667 m²;T3,尿素施用量30 kg/667 m²+光合细菌54 kg/667 m²;T4,尿素施用量35 kg/667 m²+光合细菌54 kg/667 m²;T5,尿素施用量40 kg/667 m²+光合细菌54 kg/667 m²;CK,不添加尿素、光合细菌）,研究了光合细菌单独施用及与尿素联合施用对水稻农艺性状、产量和稻米品质的影响。结果表明,与CK相比,T1处理土壤有机质含量显著升高,而总磷含量显著下降;T1处理土壤尿酶和硝酸还原酶活性显著下降,而亚硝酸还原酶活性显著升高;T1处理水稻产量较CK显著增产5.19%。随尿素用量增加,土壤各因子含量下降,其中,T3、 T4处理的硝态氮、有机质含量显著高于T1、T2和T5处理;随尿素用量增加,土壤脲酶活性呈现出极显著线性增长趋势,亚硝酸还原酶和硝酸还原酶活性先降低后上升,但处理间差异均不显著;随尿素用量增加,水稻穗长、株高、产量和整精米率呈线性增加趋势,而精米率先上升后降低。Pearson相关分析显示,尿素和硝态氮与脲酶活性呈极显著或显著正相关,氨态氮与硝酸还原酶活性呈显著正相关。多因子相关分析显示,尿素为土壤酶活性的主要影响因素。土壤酶活性对水稻农艺性状、产量和稻米品质起主要影响作用。综上,单一使用光合细菌或者与尿素联合施用能够显著激活土壤氮转化酶活性,从而改善水稻农艺性状,促进产量增加和加工品质提升。

关键词: 水稻, 光合细菌, 尿素, 土壤酶活性, 产量, 加工品质