Effect of Different Rates and Mixtures of Solid Household Waste and Faecal Sludge-Based Composts on Soil Fertility and Productivity of Sunflower (Helianthus annuus L.) in Dschang, West Cameroon

The unbalanced and inadequate use of fertilizers is one of the causes of soil degradation. Combined with the ever-increasing population, it is necessary to find sustainable agricultural production alternatives. The present work aims to determine the effect of different rates and mixtutes of organic amendments on soil fertility and the performance of Sunflower (Helianthus annuus L.). In the field, treatments consisted of solid household waste and faecal sludge in the ratios of 3/5 (V1), and a mixture of faecal sludge and household waste in the ratio of 3/5 with 900 worms (V2). At the end of the composting process, V1, V2 composts and the poultry manure (PM) were applied at rates of 4, 5 and 6 t∙ha−1 in a randomized complete block design with three replications. Soil samples were collected before and after the experiment and analyzed. The main results revealed that at the end of the composting process, there was a progressive improvement in the physico-chemical properties of V1 and V2 composts. In particular, the C/N ratio, phosphorus (P) and total nitrogen (TN) initially at 16.49 ± 0.42 (V1, V2), 21.06 ± 0.07 mg∙kg−1 (V1, V2), 0.76% ± 0.08% (V1, V2) respectively, increased after 60 days to 12.40 ± 0.41 (V1), 9.74 ± 0.28 (V2) for C/N, 21.94 ± 0.63 mg∙kg−1 (V1) and 22.04 ± 0.04 mg∙kg−1 (V2) for P, 0.96% ± 0.0% (V1) and 1.22 ± 0.04 (V2) for TN. The application of 6 t∙ha−1of PM had the greatest influence on the diameter and weight of the flower heads (27.16 ± 4.01 t∙ha−1 and 230.83 ± 2.64 t∙ha−1), while 4 t∙ha−1 of V2 gave the tallest sunflower plants (110.07 ± 73.28 cm) as well as the diameter at the crown (19.30 ± 9.07 cm). However, CEC was most influenced by 4 t∙ha−1 of V1, while 4 t∙ha−1 of PM had the greatest effect on organic carbon and phosphorus. However, 5 t∙ha−1 of PM showed the highest sunflower production and yield (1.67 ± 0.21 t∙ha−1). The combination with 900 earthworms is recommended for composting and 5 t∙ha−1 of PM is recommended to obtain a better sunflower production.

Split Addition of Nitrogen-Rich Substrate at Thermophilic and Mesophilic Stages of Composting: Effect on Green House Gases Emission and Quality of Compost

Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH4, CO2, N2O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO2 was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH4 was highest in the mesophilic stage with N-rich substrate addition. N2O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.

Assessment of the Characteristics of the Municipal Solid Waste Compost in Lebanon

Waste management is crucial due to the fast increase of human population, causing an increase in solid waste generation which if not properly managed causes environmental problems. Around 57% of the wastes generated from homes are made up of green material (fruits, vegetables…). Thus, reusing and recycling green wastes through composting is one way of reducing the waste load to landfills. Composting is the transformation of raw organic materials into organic soil amendments that provide nutrients to crops and enhance the tilth, fertility, and productivity of soils. Aerobic windrow composting system at Sukomi Greensite facility located at Karantina is performed, where materials biodegrade under controlled conditions to produce compost. However, assessment of the quality of the compost is fundamental in order to determine its usages. Thus, regular testing of physical, chemical and biological parameters was performed for adequate monitoring purposes. The basic objective of this study was to determine the characteristics of the Lebanese municipal solid waste compost on a yearly basis and compare these characteristics amongst the years. Hence, each parameter was tested and compared to the BNQ international Canadian standards for proper classification of the compost and adequate identification of its usages. The preliminary data obtained were statistically diagnosed through principal component analysis by Spadv55 software. All the data reflected the normal content value of the studied parameters with minor differences between the years except for year 2007 which demonstrated higher levels of Potassium, Phosphate, Lead and Cadmium. The characteristics of the compost enabled it to be used as a soil amendment on all types of agricultural and landscape commodities at the adequate dosages and proper timing. This data will additionally reflect the efficiency of the solid waste management practices adopted via highlighting the importance of the implementation of the integrated solid waste management practices.

Urban Soil Compaction Remediation by Shallow Tillage and Compost in Hydroseeded Lawn

Construction activities often involve removal of topsoil and compaction of the exposed soil by heavy equipments. Such compacted soils with low organic matter can lead to low infiltration and poor vegetation establishment. The objective of this study was to investigate the efficacy of tillage (shallow till) and compost on soil physical and biological properties in a hydroseeded lawn as a post-construction best management practice for soil compaction remediation. The experimental site received a total of four land treatments in five replicated trials and it was hydroseeded with common Bermuda grass: 1) No Tillage + Compost (NT-C), 2) No Tillage + No Compost (NT-NC;control), 3) Tillage + Compost (T-C), and 4) Tillage + No Compost (T-NC). Bulk density (BD), infiltration rate (IR), and wet aggregate stability (WAS) in each plot were measured to assess soil physical properties while soil organic matter (SOM) and enzyme activity (β-glucosidase, acid-phosphatase, and alkaline-phosphatase) were measured for soil biological properties. Over a 15-months of monitoring period, the shallow tillage loosened the soil initially, but its effect on BD without compost was diminished to control plot level (NT-NC) within 4 months after hydroseeding. Both tillage and compost led to an increase in IR, and it remained higher than control by 2 - 3 times throughout the observation period. The WAS and β-glucosidase activity decreased in tilled plot unless there was compost application. Turfgrass showed greener leaves and aggregated roots in the compost-amended plots (NT-C and T-C). Our results suggest that compost application plays a key role in improving soil physical and biological properties in hydroseeded lawns from construction sites.

Analysis of the Fertilizing and Bioremediation Potential of Leaf Litter Compost Amendment in Different Soils through Indexing Method

This research study explored the efficacy of leaf litter compost as a sustainable soil amendment with the objective of promoting soil health and mitigating the accumulation of potentially toxic elements. The investigation encompassed the impact of various organic compost amendments, including leaf compost, cow dung manure, kitchen waste compost, municipal organic waste compost, and vermicompost. The study employed Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to evaluate soil nutrient levels and concentrations of Potentially Toxic Elements (PTEs) such as arsenic, chromium, cadmium, mercury, lead, nickel, and lithium. The fertilization and bioremediation potential of these compost amendments are quantified using an indexing method. Results indicated a substantial increase in overall nutrient levels (carbon, nitrogen, phosphorus, potassium, and sulfur) in soils treated with leaf compost and other organic composts. Fertility indices (FI) are notably higher in compost-amended soils (ranging from 2.667 to 3.938) compared to those amended with chemical fertilizers (ranging from 2.250 to 2.813) across all soil samples. Furthermore, the mean concentrations of PTEs were significantly lower in soils treated with leaf compost and other organic compost amendments compared to those treated with chemical fertilizers amendments. The assessment through the indexing method revealed a high clean index (CI) for leaf compost amendment (ranging from 3.407 to 3.58), whereas the chemical fertilizer amendment exhibits a relatively lower CI (ranging from 2.78 to 3.20). Consequently, leaf compost and other organic composts exhibit the potential to enhance sustainable productivity, promoting soil health and environmental safety by improving nutrient levels and remediating potentially toxic elements in the soil.

Evaluation of Cobalt Application Combined with Gypsum and Compost as a Regulator of Cabbage Plant Tolerance to Soil Salinity

In response to the global food crisis and the imperative to address soil degradation, the international agricultural policy is actively working to alleviate the adverse impacts of soil salinity. As part of this initiative, a field trial spanning two consecutive seasons (2019/20-2020/21) was conducted under saline conditions. The primary objective was to evaluate the influence of various compost sources, including vermicompost at a rate of 0.5 ton·fed-1 and plant residues compost at a rate of 5.0 ton·fed-1, as main plots. Subplots were established by applying agricultural gypsum, both in the presence and absence of gypsum requirements. Additionally, sub-subplots were created by externally applying cobalt at a rate of 10.0 mg·L-1, with one sub-subplot receiving foliar cobalt application and the other not. The trial sought to assess the growth performance, chemical composition, enzymatic antioxidants, yield, and quality of cabbage plants (Brassica oleracea var. capitata L.) cultivated in saline soil. According to the findings, cabbage plants exhibited the most favorable response in terms of plant height, chlorophyll content, carotene levels, leaf area, nitrogen (N), phosphorus (P), potassium (K), head yield, vitamin C, and total dissolved solids (TDS) when treated with vermicompost, followed by plant compost. Conversely, plants grown without compost exhibited the least improvement in performance. Cabbage treated with agricultural gypsum requirements showed better performance than those without gypsum amendment. Moreover, plants subjected to cobalt spray demonstrated the highest growth, yield, and quality parameters compared to those without cobalt foliar application. In contrast, the control group (plants without the studied treatments) displayed the highest levels of enzymatic antioxidants, specifically catalase and peroxidase. This indicates that soil salinity stress led to an increase in catalase and peroxidase production in cabbage plants as a defense against the harmful impact of reactive oxygen species (ROS) resulting from soil salinity stress. The applied treatments (compost, gypsum, and cobalt) led to a reduction in the cabbage plant’s inherent production of catalase and peroxidase. Generally, the combined treatment of vermicompost × gypsum requirements × cobalt proved effective in mitigating the detrimental effects of soil salinity on cabbage plants. These findings hold significance for farmers and policymakers aiming to enhance agricultural productivity in regions affected by soil salinity. Additionally, further research can explore the long-term effects of these treatments on soil health and crop sustainability.

玉米秸秆堆腐还田对黑土区土壤性状的影响

本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田,连续施用3年,检测土壤有机质、碱解氮、速效磷、速效钾、土壤孔隙度、土壤容重等指标。在基本农田和棚室保护地进行为期2年的应用试验。结果表明:120 d秸秆失重率达到31.53%。施用腐熟秸秆3年,土壤有机质提高了4.06~6.31 g/kg、土壤中碱解氮提高了15.08~27.35 mg/kg、速效磷提高了18.11~21.95 mg/kg、速效钾提高63.97~89.93 mg/kg;土壤容重降低了0.10~0.14 g/cm^(3)、土壤田间持水量提高了7.51%~9.24%(V/V)、土壤孔隙度提高了3.69%~5.27%(V/V),且差异显著(P≤0.05)。基本农田和棚室保护地应用试验中,速效养分与有机质有所增长,土壤容重与田间持水量变化显著。逐年施用腐熟秸秆对于提高土壤有机质含量、速效养分具有显著作用。同时,施用腐熟秸秆能够降低土壤容重,提高土壤孔隙度与田间持水量,改善土壤板结问题。腐熟秸秆在改良与保育黑土性质方面具有良好的作用。

滚筒式堆肥反应器通风搅拌系统设计与试验

针对有机废弃物堆肥过程中物料溶氧效率低导致的堆体起温速率慢、发酵不彻底等问题,设计了一种高效堆肥通风搅拌系统,该系统由分段式通风系统和组合式搅拌装置构成,通过对两个主要装置进行理论设计和DEM-FEM耦合仿真,实现堆肥通风和搅拌工艺优化。结果显示,通风系统中的最大应力出现在通风管上,为13.064 MPa,最大形变量为0.038126 mm,搅拌装置中最大应力出现在抄板上,为190.31 MPa,最大形变量为0.34417 mm,符合设计要求。在此基础上,以食物垃圾和梧桐叶为原料,进行为期14 d的堆肥试验,监测堆肥过程中关键参数变化并测定发酵产物相关指标,完成通风搅拌系统性能验证试验。试验结果表明:使用该通风搅拌系统的滚筒式堆肥反应器,其内部堆体温度在3 d时达到53.34℃,堆肥过程中堆体最高温度可达69.56℃,堆体高温期(大于50℃)可持续6 d以上;试验结束后其产物含水率降至27.21%、pH值升至8.4、种子发芽指数最高可达131.4%,符合有机肥料测定标准(NY/T 525—2021),滚筒反应器运行成本仅65.51元/t。

发酵饲料对蛋鸡粪便堆肥氨气排放与微生物群落的影响

为探究饲喂发酵饲料对蛋鸡粪便堆肥腐熟、氨气排放及微生物群落组成的影响,以饲喂基础日粮蛋鸡为对照组(T1),试验组蛋鸡分别饲喂基础日粮加2.5%(T2)、5.0%(T3)和10.0%(T4)的发酵饲料,收集各组鸡粪进行好氧堆肥试验。结果表明:随堆肥进行,各组堆肥温度均先升高再降低,pH在高温期快速从7.0左右升至9.1。至堆肥结束,T3组和T4组的种子发芽指数分别为99.4%和87.1%,远高于T1组的57.7%,达到有机肥标准。氨气日排放量在高温期达到峰值,随后逐渐降低;氨气总排放量T3组最低,为14.43 mg·kg^(-1),较T1组低0.76 mg·kg^(-1)。微生物生物信息学分析显示,添加发酵饲料降低了蛋鸡粪便中细菌的多样性,主要的细菌门为厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、放线菌门(Actinobacteriota)和变形菌门(Proteobacteria),其中T2、T3和T4组的乳杆菌属相对丰度较T1组分别增加20.61%、6.62%和8.13%。随堆肥进行厚壁菌门的丰度降低,其他菌门的丰度增加。研究表明,蛋鸡日粮添加5.0%的发酵饲料可提高蛋鸡粪便中乳杆菌属丰度,促进蛋鸡粪便的堆肥腐熟,并可减少堆肥过程中氨气的总排放量。

不同热解温度稻壳生物炭对羊粪堆肥腐熟度及温室气体排放的影响

为优化羊粪堆肥腐熟度与温室气体减排协同的技术工艺参数,以2种不同热解温度制备的稻壳生物炭为堆肥辅料,与羊粪、食用菌渣混合,进行了43 d的堆肥试验。设置了3个处理,羊粪与食用菌渣质量比9∶1混合体作为预备物料,在预备物料上分别添加450、650℃热解的稻壳生物炭(占预备物料质量百分比15%)为BC450、BC650处理,在预备物料上添加未热解炭化的稻壳(与稻壳生物炭同等体积)为CK处理。监测了堆肥温度、腐熟度指标(NH_(4)^(+)-N/NO_(3)^(-)-N、EC值、种子发芽指数)、温室气体(CH_(4)、CO_(2)、N_(2)O)排放的变化动态,分析了不同热解温度稻壳生物炭对堆肥腐熟度与温室气体减排的协同效果。结果表明:添加450、650℃热解的稻壳生物炭,缩短了堆肥体NH_(4)^(+)-N/NO_(3)^(-)-N、T值、EC值及种子发芽指数达到腐熟度推荐值的所需时间,与CK处理相比,BC450、BC650处理的腐熟周期分别缩短了15.0%、32.5%;羊粪堆置43 d后,BC450、BC650处理的综合温室效应较CK处理分别显著降低了6.56%、24.36%,且BC650处理综合温室效应比BC450处理显著降低了19.05%(P<0.05);添加稻壳生物炭对羊粪堆肥腐熟度及温室气体减排具有协同促进作用,建议优选650℃制备的稻壳生物炭。

粉碎粒径对番茄和辣椒秸秆堆肥木质纤维素降解特征的影响

为探索茄果类蔬菜秸秆在菜田就近进行好氧堆肥粉碎条件,研究了2种粉碎粒径(碾压粉碎2~5 cm、切割粉碎1~2 cm)对3种蔬菜秸秆(番茄、辣椒及二者混合秸秆)堆肥的木质纤维素降解特征的影响。结果表明,番茄、辣椒和混合秸秆在堆肥过程中木质纤维素组分降解率由高到底依次为半纤维素>纤维素>木质素,大粒径处理能够降低堆肥初始木质纤维素的含量,同时加快纤维素和半纤维素在堆肥后期的降解;小粒径处理则能够提高堆肥积温,促进木质素的降解。冗余分析表明,纤维素和半纤维素降解是促进全碳降解的关键因素。大粒径处理的3种秸秆初始全氮、全磷、全钾和腐植酸含量显著高于小粒径处理,且在堆肥结束时大粒径处理的氮、磷、钾总养分含量(8.03%)和腐植酸含量(12.15%)仍显著高于小粒径处理(6.88%、9.44%)。在生产中,蔬菜产地可选择秸秆还田机碾压粉碎至2~5 cm粒径或容重0.3 g/cm^(3)下的粉碎粒径对茄果类蔬菜秸秆进行堆肥,有助于木质纤维素的降解和堆肥质量的提高。

番茄秸秆堆肥添加量对番茄幼苗生长及根系形态的影响

【目的】我国是番茄生产大国,番茄秸秆废弃物产生量逐年增加,急需无害化处理和利用。试验将番茄秸秆进行高温好氧发酵形成有机肥料,在番茄种植底肥中添加不同用量番茄秸秆堆肥(TS),通过分析番茄幼苗生长、根系形态土壤养分含量变化,优化番茄堆肥施用方案,旨在探索番茄秸秆废弃物肥料化利用技术。【方法】采用盆栽的方法,按照堆肥与干土质量比,设置1%、2%、3%、4%添加量处理,分析定植30 d的番茄幼苗植株生长指标、根系形态指标和根际养分含量以及相关关系。【结果】相比不添加对照CK,1%添加量番茄秸秆堆肥(TS)处理的番茄幼苗株高、茎粗、全株干物质量和壮苗指数均显著低于CK,其根系在>5 mm径级范围内的根表面积、投影面积和根体积也低于CK。TS 2%处理能显著增加番茄幼苗根长、根体积和根表面积,降低根系平均直径,但对地上部生长和物质积累没有显著影响。3%TS和4%TS处理能够显著增加番茄幼苗植株株高、茎粗和全株干物质量的积累,二者之间没有显著差异,但3%TS处理在提高番茄幼苗根体积和根表面积上显著高于4%TS处理。径级范围在0~0.5 mm和0.5~2.0 mm的根系对番茄根系长度的贡献率最大,添加番茄秸秆堆肥处理能够增加<0.5 cm和0.5~2.0 mm径级范围的根系长度,增加0.5~2.0 mm径级范围的根表面积和投影面积,其中3%TS处理增加幅度最高。3%TS和4%TS处理能够提高番茄幼苗根际土壤全碳、全氮和速效养分含量,其中土壤速效磷养分含量增幅最高,冗余分析RDA表明土壤速效磷是影响番茄幼苗根系形态建成的关键土壤环境因子。【结论】在日光温室番茄生产中,在底肥中添加干质量比3%的番茄秸秆堆肥可显著改善土壤养分环境,增加番茄幼苗根系生物量,促进地上部物质积累。

荔枝剪枝堆肥和蚯蚓粪作为巨大普里斯特氏菌载体的研究

为探讨荔枝茎秆堆肥与蚯蚓粪替代草炭作为巨大普里斯特氏菌载体的可行性,以荔枝剪枝堆肥、蚯蚓粪和草炭为原料构建6种微生物载体(ST1、ST2、ST3、ST4、ST5、ST6,三者质量比分别为6∶2∶2、4∶2∶4、2∶2∶6、6∶3∶1、4∶3∶3、2∶3∶5),以草炭为对照,巨大普里斯特氏菌为目标微生物,动态监测载体中有效活菌数,获得适宜巨大普里斯特氏菌存活的载体;在此基础上,分别设置含水量20%、30%、40%,温度20、30、40、50℃和接种浓度10^(6)、10^(7)、10^(8)cfu·mL^(-1),动态监测载体中有效活菌数,优化载体含水量、温度和接种浓度。结果表明:随着培养时间的延长,各载体中活菌数均呈先降低后升高的趋势,其中ST2、ST5载体长期培养后活菌数高,且草炭添加量低,是适宜的巨大普里斯特氏菌载体。随着载体含水量、温度的升高,培养的60 d过程中ST2和ST5载体活菌数均呈先升高后降低的趋势,在30%含水量(ST22.46×10^(8)cfu·g^(-1)、ST51.81×10^(8)cfu·g^(-1))以及30℃(ST23.44×10^(8)cfu·g^(-1)、ST51.87×10^(8)cfu·g^(-1))、40℃(ST28.50×10^(7)cfu·g^(-1)、ST57.13×10^(7)cfu·g^(-1))温度下的活菌数最高。此外,各培养时期的载体活菌数均随着接种浓度的升高而升高,培养60 d后,ST2、ST5载体活菌数分别达3.63×10^(8)、3.33×10^(8)cfu·g^(-1)。研究表明,载体ST2和ST5适宜代替草炭作为巨大普里斯特氏菌的载体,且在30%载体含水量、30~40℃温度和10^(8)cfu·mL^(-1)接种浓度下效果最佳。

规模化养鸡场鸡粪“两段式”好氧堆肥工艺研究

好氧堆肥是鸡粪资源化利用的重要途径,它不仅能够解决鸡粪污染问题,还能够产生有机肥用于土壤改良,增强土壤肥力。但在工程应用上,传统的槽式堆肥发酵周期长,而罐式堆肥又常因物料含水率过高而难以启动,发酵效果不甚理想。本研究设计了一种“两段式”好氧堆肥工艺,通过初级发酵槽(第一阶段)发酵降低了物料含水率,从而实现了物料在立式发酵罐(第二阶段)内的快速腐熟。应用该工艺的示范工程已完成建设并稳定运行,对发酵完成后的物料进行腐熟度评价,发现物料的pH、含水率、有机质、蛔虫卵死亡率、种子发芽指数等评价指标均已满足要求,可作为肥料使用。

稻壳炭强化城市污泥蚯蚓堆肥过程中重金属变化特征

为探讨稻壳炭强化蚯蚓堆肥对污泥性质和重金属的影响,本研究以城市污泥为研究对象,添加不同比例稻壳炭对蚯蚓堆肥进行强化处理,探究不同生物炭剂量(污泥干质量的2%、4%、6%、8%)对城市污泥蚯蚓堆肥过程中重金属有效态以及赋存形态的影响。结果表明:堆肥过程中pH呈先上升后降低的趋势,电导率先降低后升高,有机质呈下降趋势;与对照组(不添加稻壳炭)相比,添加不同比例稻壳炭强化后的电导率、有机质分别降低28.96%~47.46%、2.84%~18.87%;稻壳炭强化的污泥堆肥中养分增加,总氮、总磷和总钾在8%添加量时分别提高9.89%、24.39%和2.51%。当稻壳炭添加到蚯蚓堆肥后,重金属从易迁移转化形态向稳定态转化,在8%添加比例时,Cd、Cu、Ni的残渣态占比较对照组分别提高3.57、19.12、9.27个百分点,有效态分别降低56.25%、34.22%、28.20%;添加4%稻壳炭使Pb由可交换态、碳酸盐结合态向稳定的有机结合态转化,且有效态降低27.69%。相关性分析发现稻壳炭强化蚯蚓堆肥,升高堆体pH降低了污泥中Cd、Cu、Ni、Pb有效态含量。研究表明,稻壳炭强化蚯蚓堆肥可显著提升城市污泥营养元素,改善理化性质,提高污泥中重金属钝化效率。

稻秸秆对羊粪好氧堆肥理化特性与氮素转化的影响

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。

小麦秸秆添加量对羊粪条垛式堆肥进程的影响

用肉羊养殖场的羊粪和小麦秸秆作为堆肥原料进行条垛式堆肥试验,监测堆肥过程中堆料有机质、C/N、pH值、种子发芽指数(GI)、温度等指标的变化,探究羊粪条垛式堆肥的最佳秸秆添加量。结果表明:鲜羊粪堆肥时添加1.5%~4.5%的小麦秸秆,可增加高温保持时间7~9天,达到26~28天,最高温度提高4℃,达到63℃;可加快堆料水分的蒸发速度,降低堆料含水率8.08%~31.06%;可降低堆肥产品的pH值,从9.12下降到8.88;可提高种子发芽指数21.85%~33.93%,提高堆肥产品的C/N 10%~30%。由此可知,添加1.5%~4.5%的小麦秸秆,可加快羊粪的腐熟速度,但当秸秆添加量大于1.5%时,堆肥产品的C/N大于20,不利用微生物的分解利用,因此,在羊粪堆肥时,小麦秸秆的最佳添加量为1.5%。研究结果将为优化羊粪堆肥技术工艺,提高羊粪堆肥腐熟速度提供技术支持。

基于蚯蚓密度调控污泥堆肥重金属有效性研究

目的为探讨不同蚯蚓投放密度对污泥中重金属有效性的影响,为污泥蚯蚓堆肥提供新思路。方法以不同密度赤子爱胜蚓(0,10,20,40条)和0g,25g,50g稻壳为添加剂对2kg污泥进行堆肥,探究不同蚯蚓投放密度下生活污泥重金属有效性变化。结果在一定稻壳添加量下,随蚯蚓密度增加,污泥pH(酸碱度)、OM(有机质)、TN(总氮)、TP(总磷)降低,EC(电导率)增加,随稻壳添加量逐渐增加,与蚯蚓协同作用下污泥pH、OM、TN、TP继续降低;在一定稻壳添加量下,随蚯蚓投放密度增加,污泥Cu、Zn、Pb、Cd总量降低,其中,50g稻壳协同40条蚯蚓堆肥时,Cu、Cd总量降低幅度达到最大,分别为34.04%、35.85%;在一定稻壳添加量下,随蚯蚓投放密度增加,污泥有效态Cu、Zn有升高趋势,有效态Cd有所降低,有效态Pb显著降低(P<0.05),其中,50g稻壳协同40条蚯蚓堆肥时,对污泥中Pb有效性钝化效果最显著,降低达到42.43%;通过相关性和回归分析可知,蚯蚓投放密度增加,通过改变EC影响Cu有效性、改变TN和TP影响Pb、Zn和Cd有效性。结论50g稻壳协同40条蚯蚓共同处理污泥时,对污泥中重金属活性降低效果最佳。

新型多格室粪便堆肥反应器设计与试验

针对常规粪便堆肥反应器进料自动化程度不高、堆肥效率低和产物质量差的问题,设计并构建出一种“连续进料—反应—出料”运行模式的新型多格室粪便堆肥反应器。对反应器的通风单元、加热单元进行优化设计,并以厕所粪便为处理对象,进行反应器运行性能试验。试验结果表明,经反应器堆肥处理后,粪便臭味减弱、颜色由棕黄色变为棕褐色,堆料高温期(≥50℃)维持在6 d以上,反应器不同运行阶段堆肥产品的种子发芽指数分别为104%、81%和128%,表明堆肥成品已实现完全腐熟和无害化。堆肥产品总养分、有机质和种子发芽指数均达到相关要求。

不同原料配比对芦笋秸秆堆肥发酵效果的影响

为促进芦笋秸秆资源化利用,通过加入不同比例的鸭粪和稻壳于芦笋秸秆中,进行资源化堆肥效果的试验研究。以发酵温度、pH、发芽指数、有机质、氮、磷、钾等为评价指标,研究鸭粪和稻壳添加对堆肥发酵过程的影响。结果表明:单一芦笋秸秆堆肥发酵过程,无高温阶段,未能达到发酵堆肥要求。添加不同比例的鸭粪和稻壳均能促进芦笋秸秆堆肥发酵,高温维持时间12~13 d,高温阶段平均温度为56.3~60.4℃,发酵周期21~29 d,发酵30 d结束时,发芽指数达到了92%~118%,pH>8.0,有机质含量50.70%~57.02%,氮磷钾总养分含量4.64%~5.20%。综合各项指标,在本试验条件下,70%芦笋秸秆+10%鸭粪+20%稻壳粉的配比发酵效果优于其他配比,更适合芦笋秸秆发酵。