沼渣好氧堆肥种子发芽指数快速预测可行性分析

种子发芽指数是衡量好氧堆肥植物毒性和腐熟度的重要参数。以沼渣和猪粪为主要原料,麦秸和蘑菇渣为辅料,利用自行研制的智能型好氧堆肥反应器系统开展了联合好氧堆肥试验,基于获取的种子发芽指数和基本理化指标数据进行了相关性和回归建模分析研究。试验结果表明:种子发芽指数与挥发性固体、总碳、总氮、半纤维素和木质素干基相对含量以及碳氮比均具有显著的相关性(R≥0.83,Sig.为0.000)。所构建的一元和二元线性预测模型均具良好的拟合度(R≥0.81,Sig.为0.000),其中,以总碳和总氮为二元变量的种子发芽指数快速预测模型(R=0.92,SEP为7.58)具有最好的预测能力。该研究为种子发芽指数的快速预测分析提供了方法学支撑。     

Potential of anaerobic digestate of dairy manure in suppressing soil‐borne plant disease

Frequent use of pesticides to control soil‐borne plant disease leads to environmental pollution and the development of pesticide resistance in phytopathogens. Soil amendment is considered to have the potential of suppressing plant disease because of its biological properties. However, information on anaerobic digestate is limited. In this study, potential of antagonistic activities of anaerobic digestate against phytopathogens were investigated by detecting the amounts of antagonistic bacteria (Bacillus and Pseudomonas) in anaerobic digestates of dairy manure. The results showed that anaerobic digestion increased the total amounts of Bacillus and Pseudomonas in digestate. Bacillus suppressed growth of phytopathogens, while Pseudomonas did not show any antagonistic activities. These results indicated that Bacillus was an effective antagonistic bacterium in digestate against phytopathogens. Furthermore, two selected isolates, B11 (Bacillus subtilis) and B59 (Bacillus licheniformis), were applied in field experiments and showed significant reduction in percent infection of potato late blight (Phytophthora infestans). These results demonstrate the benefits of digestate in suppressing soil‐borne plant diseases caused by antagonistic bacteria.     

Nitrogen mineralization from digestate in comparison to sewage sludge,compost and urea in a laboratory incubated soil experiment

This paper evaluated, in a laboratory incubated soil, the properties of digestate as a nitrogen fertilizer in comparison with sewage sludge, compost and urea, this last as a typical mineral fertilizer. The incubation period lasted for 90 d and during this time, pH, CO₂ and evolution were measured. The maximum concentration of nitrate was reached in the incubated microcosm fertilized by urea (133 mg kg⁻¹ after 62 d), and that of digestate was very similar (113 mg kg⁻¹). Soil treated with compost showed a slower nitrate evolution. A significantly negative correlation was detected between cumulative nitrogen nitrified at the end of the trial, and the values of the C:N ratio of the biomasses used (compost, sludge and digestate) (mg kg⁻¹ vs . C:N, r = –0.94, n = 3, p < 0.05), and between the alkyl‐C content at the end of the experiment (mg kg⁻¹ vs . alkyl‐C, r = –0.95, n = 3, p < 0.05). As expected, pH decreases and soil respiration (CO₂ evolution) were also well correlated with the content of nitrate. Considering that about 90% of the nitrogen content in the digestate is short acting, the results obtained indicate that the nitrogen rate of mineralization in digestate is very similar to that of urea, confirming that digestate could replace traditional mineral fertilizers.     

Effects of 5 years of digestate application on biomass production and quality of cocksfoot (Dactylis glomerata L.)

Anaerobic digestion of biomass produces biogas for combustion and also provides a residual digestate. Although sometimes regarded as a waste product, the nutrient‐rich chemical composition of digestate makes it a potential organic fertilizer for agriculture. The goal of this study was to evaluate the effectiveness of digestate as a fertilizer on the biomass yield and chemical composition of cocksfoot (Dactylis glomerata L.). In a 5‐year small‐plot field experiment digestate fertilization treatments supplying 90, 180, 270, 360 and 450 kg N ha^?1 were compared with untreated plots and plots fertilized with 180 kg N ha^?1 of mineral N fertilizer. Swards fertilized with digestate produced higher biomass yield compared with the control. The same rate of nitrogen fertilizer (180 kg N ha^?1) supplied as digestate and from mineral fertilizers gave similar results on biomass yield. Herbage in swards fertilized with digestate contained less nitrogen, but the C:N ratio was much more suitable for biogas production. Digestate fertilization resulted in higher concentrations of cellulose and hemicellulose in biomass and lower contents of the inhibitors of anaerobic digestion—sulphur, calcium, magnesium and phosphorus—compared with those of swards receiving mineral fertilizers.     

喷施木醋酸对苹果树叶片和果实品质的影响

为探索木醋酸在苹果生产中作为植物生长调节剂的功能和作用,通过木醋酸及其与沼液耦合喷施苹果树,研究木醋酸和其沼醋耦合液对苹果树叶片生长及苹果品质的影响,结果表明:单施木醋酸,苹果树叶绿素的质量分数为47.72mg/g,比对照高4.57%;叶面积为32.57cm2,比对照高8.49%;百叶厚度为5.03cm,比对照高1.21%;百叶鲜质量为75.16g,比对照高6.96%;百叶干质量为32.59g,比对照高0.59%。单施木醋酸平均单果质量为210.2g,比对照高3.8%;相对体积质量为0.89,比对照高3.49%;可溶性糖质量分数为11.4g/100g,比对照高11.8%;总酸质量分数为2.93g/kg,比对照低0.68%;维生素C质量分数为1.25mg/100g,比对照高17.92%;蛋白质质量分数为0.38g/100g,比对照高5.56%,除相对体积质量外其他指标均达到差异显著水平。证实木醋酸及其与沼液耦合喷施,对促进苹果树叶片生长发育和提高苹果品质具有较好的协同增效作用。     

大中型沼气工程沼渣沼液利用意愿现状调研及问题分析

本文收集整理了四川、安徽等六个省市自治区的数百家农户走访资料,初步了解了当前农户利用沼渣沼液的现状及利用意愿,并分析讨论了影响广大农户利用沼渣沼液的主要因素。     

沼液酸化贮存技术研究进展

酸化贮存技术在降低沼液养分损失与气体减排方面具有优势，系统梳理沼液酸化贮存技术研究进展可为规范沼液贮存方式，协同降低养分损失与气体排放技术实施提供数据支撑。采用文献数据整理的方式，对酸化技术影响因素，酸化对沼液特性的影响效果与作用机理，酸化对多种气体减排效果的影响进行总结和分析。结果表明:1)酸化剂、酸化目标pH、贮存时间、方式、温度均会影响酸化贮存作用效果；2)酸化会通过降低沼液pH，改变缓冲物质之间的平衡，促进无机矿物质的溶解与有机物的降解，降低微生物活性与氨气(NH₃)排放量等方式影响沼液性质和降低养分损失；3)沼液酸化剂的科学选择、酸化技术参数的规范设定、酸化贮存过程的元素各化学形态转化机理以及酸化沼液产品的还田效果等有待深入研究。     

鸡粪沼渣好氧堆肥颗粒尺度下氧气渗透深度表征

利用傅里叶变换显微红外光谱技术对鸡粪沼渣好氧堆肥颗粒尺度下氧气渗透深度进行了量化表征。用于表征鸡粪沼渣颗粒氧气渗透深度的显微红外透射光谱法的光谱采集范围为750~4 000 cm~(-1),光谱分辨率16 cm~(-1),像素点尺寸6.25μm×6.25μm,扫描次数8次。鸡粪沼渣好氧堆肥样品经冷冻干燥处理后,应采用石蜡切片技术制成12μm薄片,选取2 856 cm~(-1)和1 640 cm~(-1)代表脂肪类化合物,1 568 cm~(-1)和3 001 cm~(-1)代表芳香族化合物作为氧气渗透深度边界判定特征波长,且氧气渗透深度终点定义为差分曲线迅速下降处。鸡粪沼渣颗粒氧气渗透深度较小,介于7~20μm范围内动态变化,其符合指数关系式。研究结果表明,采用傅里叶显微红外透射光谱法判定好氧堆肥颗粒氧气渗透深度具有可行性,但应根据不同物料特性,选用适用的方法和技术参数。     

连续闭式循环氨脱除工艺响应面法优化

针对两阶段闭式循环氨脱除工艺处理猪粪厌氧消化液耗时、耗碱、难以达到工业化大量污水处理的需求问题,进行了连续闭式循环氨脱除工艺的试验研究。试验结果表明,对于起始氨氮质量浓度为(1 444±37)mg/L的猪粪厌氧消化液,在气流量为530 L/h、液流量为445 m L/h、气液比为2 036条件下,氨氮脱除率可达(66.81±0.24)%。经RSM优化的模型能够很好地分析和预测该工艺及系统条件下猪粪厌氧消化液的氨氮去除结果。所选自变量对于氨氮脱除的影响力从大到小依次为:气液比、液流量、气流量。研究结果可为猪粪厌氧消化液的连续处理提供依据。