稻龟生态系统中稻田土壤养分动态变化及生产效果研究

Study on Dynamic Changes of Paddy Soil Nutrients and Its Production Benefits in Ricetortoise(Chinemys reevesii)Co-culture System

通过设置池塘单养草龟、水稻单作和稻龟综合种养试验,比较分析稻龟生态系统中稻田土壤养分动态变化及生产效果。结果表明:(1)除pH值外,池塘单养草龟组(TM组)土壤中有机质、全氮、水解氮、全磷、有效磷、全钾和速效钾等各养分含量在返青期、拔节孕穗期、灌浆期、成熟末期均显著高于水稻单作组(RM组)和稻龟综合种养组(RT组),与RM组相比,RT组显著增加了土壤中的有机质、全氮、全磷和全钾的积累;(2)RT组稻谷产量比RM组高24.48%(P<0.05);(3)草龟增重与土壤养分无明显相关关系,而水稻产量与土壤养分呈显著或极显著正相关关系,土壤全氮、全磷、全钾、水解氮、有效磷和速效钾等养分之间也存在着一定的正相关关系,RT组草龟生长性能优于TM组,其水稻生长性能也优于RM组。综上所述,稻龟综合种养可以提高土壤肥力和稻田利用附加值,具有良好的社会、经济和生态效益,是一种值得推广的生态农业新模式。

The dynamic change of paddy soil nutrients and its production benefits in rice-tortoise(Chinem;ys reevesii)co-culture system were investigated by constructing three experimental groups including TM group(tortoise monoculture,stocking density was 67500 tortoises/hm2),RM group(rice monoculture,stocking density was 0 tortoises/hm2)and RT group(rice-tortoise co-culture,stocking density was 27000 tortoises/hm2).The results showed as followed:(1)Except for the pH value,the parameters including organic matter,total nitrogen,hydrolyzable nitrogen,total phosphorus,available phosphorus,total potassium and available potassium in soil of TM group were significantly higher than those of RM and RT groups during the returning green stage(July 3,2019),jointing-booting stage(August 6,2019),filling stage(August 26,2019)and ripening ending stage(September 16,2019);the accumulation of organic matter,total nitrogen,total phosphorus and total potassium in soil of RT group significantly increased in comparison with RM group.(2)The rice yield in RT group was 24.48%higher than that in RM group(P<0.05).(3)There was a certain positive correlation between organic matter,total nitrogen,hydrolyzable nitrogen,total phosphorus,available phosphorus,total potassium and available potassium in paddy field;the above parameters had no significant correlation with the weight gain of tortoises,but had significantly or extremely significantly positive correlation with rice yield.Moreover,RT group was superior to TM group in tortoise growth performance,and better than RM group in rice growth.To sum up,rice-tortoise co-culture system could not only improve soil fertility,but also increase the added value of rice field utilization;as a new mode of ecological agriculture with good social,economic and ecological benefits,it is worth promotion.