稻龟综合种养土壤磷营养物质分析研究

Analysis of the soil phosphorus nutrient in the rice-tortoise co-culture system

为了探索稻龟综合种养稻田土壤磷营养水平与利用情况,检测了土壤不同形态磷含量、微生物种类与数量等参数。结果显示,稻龟RT2组和RT3组快速地利用总磷和有机质,其降幅与稻田对照组(CG)极具统计学意义差异(P<0.01),土壤有效磷浓度也极显著地高于对照组(CG),有效磷与总磷、有机质的相关性随着稻田中华草龟养殖密度(2.7~3.3只/m^2)的增加而增强,呈直线相关性,拟合回归方程为Y=0.029928X1+14.75773X2-0.03891(Y为总磷g·kg^-1,X1为有机质g·kg^-1,X2为有效磷g·kg^-1);稻龟综合种养还能极显著地提高土壤细菌总数(P<0.01),降低厌氧菌含量,提升有机磷、无机磷和硝化菌数量,改变土壤微生物菌落的分布与丰度,削弱土壤总磷和有效磷与厌氧菌的强负相关性,促进磷肥释放。因此,适宜密度的稻龟综合种养可改变土壤微生物菌群结构,增加土壤磷肥,促进土壤磷营养物质的释放与利用。

To study the level and utilization of phosphorus nutrition in rice-tortoise co-culture system,the different forms of phosphorus nutrition content,microbial species and quantity in soil were detected in the experiment.The results showed that rice-tortoise co-culture system(RT2 and RT3)could rapidly utilize total phosphorus and organic matter,with a significant decrease compared with CG(P<0.01).The concentration of soil available phosphorus in rice-tortoise co-culture system was significantly higher than that in CG(P<0.01).The total phosphorus and organic matter of the soil in rice-tortoise co-culture system was right linear correlation with the density(2.7~3.3 ind./m^2)of Chinese tortoise,and the relationship between them was expressed as:y=0.029928X1+14.75773X2-0.03891(y:total phosphorus g·kg^-1;X1:organic matter g·kg^-1;X2:effective phosphorus g·kg^-1).Also,in rice-tortoise co-culture system,the total number of soil bacteria was significantly increased(P<0.01),the anaerobic bacteria was reduced,and the number of organic phosphorus,inorganic phosphorus and nitrifying bacteria was enhanced;the distribution and abundance of soil microbial community were changed;and the strong negative correlation between soil total phosphorus,available phosphorus and soil anaerobic bacteria was weakened.Therefore,the rice-tortoise co-culture system with suitabledensity of tortoises can change microbial community structure,promoting the release and utilization of phosphorus nutrients.