稻秸秆对羊粪好氧堆肥理化特性与氮素转化的影响

Effects of rice straw on the physicochemical properties and nitrogen transformation of aerobic composting of sheep manure

为评价稻秸秆对羊粪好氧堆肥理化特性和氮素转化的影响,本研究以不同湿质量比的羊粪与稻秸秆为原料,进行好氧堆肥,羊粪与稻秸秆湿质量比分别为9∶1、8∶2、7∶3、6∶4和5∶5,研究稻秸秆与羊粪不同湿质量比组合对羊粪堆肥进程、堆肥理化性质、气体排放以及氮损失的影响,对比不同堆肥产品特性,采用主成分分析法综合评价堆肥腐熟度。研究结果表明:添加稻秸秆能够加速羊粪堆肥进程以及有机质分解,使堆肥体3 d内进入高温期,并且高温期维持了13~21 d;羊粪与稻秸秆湿质量比8∶2(C/N比为19.75)的堆肥体最高温度可达73.88℃,高温阶段(≥50℃)持续时间最长(27 d),30 d时种子发芽指数达到80%以上(81.8%);堆肥过程中O_(2)含量与温度呈负相关(R=−0.615,P<0.001);羊粪与稻秸秆湿质量比9∶1、8∶2、7∶3、6∶4和5∶5组合的总氮损失分别为20.54、17.91、17.07、15.28 g和13.26 g,表明堆肥初始C/N比越低,总氮损失率越高;羊粪堆肥时添加稻秸秆可以缩短进入高温发酵期的时间,加快堆肥进程;羊粪添加稻秸秆堆肥时初始C/N比越高,NH_(3)和N_(2)O的累计排放量越小,NH_(4)^(+)-N、NO_(3)-N和总凯氏氮(TKN)的损失率越小;主成分分析综合评价结果表明羊粪与稻秸秆按湿质量比8∶2混合堆肥最优,堆肥的腐熟速度最快。

In order to evaluate the effects of rice straw on the physicochemical properties and nitrogen transformation of sheep manure aerobic compost,sheep manure and rice straw with different wet-mass ratios were used as raw materials for aerobic composting.The wetmass ratios of sheep manure and rice straw were 9∶1,8∶2,7∶3,6∶4 and 5∶5,respectively.The effects of the combination of rice straw and sheep manure on the composting process,physical and chemical properties,gas emission,nitrogen loss of sheep manure were studied.The characteristics of different compost products were compared,and the composting maturity was comprehensively evaluated by principal component analysis.The results showed that the addition of rice straw could accelerate the composting process of sheep manure and the decomposition of organic matter,and the compost entered the high temperature period within 3 days,and the high temperature period lasted for 13-21 days.The maximum temperature of the compost with a wet mass ratio of sheep manure to rice straw of 8∶2(C/N ratio of 19.75)was 73.88℃,the duration of the high temperature stage(≥50℃)was the longest(27 days),and the seed germination index reached more than 80%(81.8%)at 30 days.The O_(2) content in composting was negatively correlated with temperature(R=−0.615,P<0.001).The total nitrogen loss of sheep manure and rice straw were 20.54,17.91,17.07,15.28 g and 13.26 g when the wet-mass ratio of sheep manure to rice straw was 9∶1,8∶2,7∶3,6∶4 and 5∶5,respectively,indicating that the lower the initial C/N ratio,the higher the total nitrogen loss rate.Adding rice straw in sheep manure composting could shorten the time of high temperature fermentation and speed up the composting process.The higher the initial C/N ratio,the smaller the cumulative emission of NH_(3) and N_(2)O,and the smaller the loss rate of NH_(4)^(+)-N,NO_(3)-N and total Kjelner nitrogen(TKN).The comprehensive evaluation results of principal component analysis showed that the mixed compost of sheep manure and rice straw was the best according to the wet-mass ratio of 8∶2,and the compost was the fastest.