土壤改良剂对冷浸田土壤特性和水稻群体质量的影响

以南方典型冷浸田为研究对象, 在明沟排水的基础上, 通过田间定位试验, 以不施土壤改良剂为对照, 研究了施用不同土壤改良剂(自研的脱硫灰改良剂、生物活性炭, 市售的土壤改良剂石灰、硅钙肥、腐植酸)对冷浸田氧化还原电位、土壤呼吸强度、土壤微生物数量、水稻群体构建及产量构成因素的影响。结果表明, 施用改良剂能够改善土壤理化性状, 提升土壤速效养分和pH，但除脱硫灰处理外, 其他改良剂处理对土壤Eh未产生显著影响。施用不同土壤改良剂在水稻各生育期均能有效增强土壤微生物呼吸强度和放线菌数量, 并且放线菌数量达到差异性显著水平(P<0.05), 生物活性炭处理下土壤呼吸强度和放线菌数量分别较对照增加67.6%和127.6%。各土壤改良剂处理与CK相比较均有助于提高叶片SPAD、茎蘖数、水稻干物质积累量、成穗数、穗粒数、产量结实率和根系伤流速率。其中以脱硫灰和生物活性炭处理改良效果最佳, 抽穗后29 d时，根系伤流速率较CK分别提高45.4%和39.1%, 叶片SPAD分别增加27.4%和22.5%; 成熟期水稻成穗数较对照提高12.1%和10.7%，干物质积累量增加68.8%和50.5%，产量分别增加12.8%和10.3%。综上所述, 土壤改良剂可有效改善冷浸田土壤特性及水稻群体质量, 脱硫灰和生物活性炭处理的改良效果最明显, 增产幅度最大。

Effects of soil amendments on soil properties and population quality of rice in cold waterlogged paddy field

Long-term waterlogging with large amounts of reducing toxic substances of cold waterlogged soils and nutrient unavailability has often resulted in deteriorated rice growth, reduced rice resistance to adversities, inhibited root growth/activity and reduced rice yield. To explore feasible means of suppressing the negative effects of cold waterlogged paddy soils, a location experiment consisting an open-ditch drainage was conducted to study the effects of different soil amendments (self-developed desulphurization ash, biomass charcoal; and marketed lime, silicon-calcium fertilizer and humic acid) on soil Eh and respiration intensity, microbial quantity and population structure, and rice yield and yield components. The results showed that different soil amendments enhanced soil available nutrients contents and pH, while they did not significantly affected Eh except desulphurization ash treatment. All soil amendments increased respiration intensity and soil microbes at different growth stages of rice, with a significant (P

< 0.05) increase in actinomycete population over CK. The respiration intensity and actinomycete population under biomass charcoal treatment were increased by 67.6% and 127.6% respectively. All soil amendments increased rice leaf SPAD, tiller number, dry matter accumulation, panicle number, grain number per panicle, yield, and root bleeding rate. Desulfurization ash and biomass charcoal treatments presented most obvious effects. At 29 days after heading, the rate of root bleeding under desulfurization ash and biomass charcoal treatments increased by 45.4% and 39.1%, respectively. Also leaf SPAD at 29 days after heading was 27.4% and 22.5% higher under desulfurization ash and biomass charcoal treatments over that under CK respectively. Dry matter accumulation increased by 68.5% and 50.5%, panicle number by 12.1% and 10.7%, and yield by 12.8% and 10.3% at maturity stage under desulfurization ash and biomass charcoal treatments over those under CK, respectively. In conclusion, different soil amendments differently improved soil properties and rice quality. Desulphurization ash and biomass charcoal amendments had the best effects.