Oyster mushroom cultivation with rice and wheat straw

Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.     

油菜秸秆还田对水稻根系、分蘖和产量的影响

采用田间试验与栽培模拟试验相结合的方法,分析了油菜秸秆还田对水稻根系、分蘖和产量的影响.结果表明: 水稻移栽后0～36 d,与秸秆不还田处理相比,油菜秸秆还田处理下水稻分蘖减少1～2个,根系单株伤流量降低1.0～8.6 mg,根系谷氨酰胺合成酶(GS)、谷丙转氨酶(GPT)和谷草转氨酶(GOT) 活性分别降低0.10～6.11、0.06～0.31和0.52～0.84 μmol·g^-1·h^-1. 水稻移栽后56 d,与秸秆不还田处理相比,油菜秸秆翻埋还田处理下水稻根系单株伤流量增加3.4～11.7 mg,根系GS、GPT和GOT活性分别增加0.34～0.78、0.13～0.45和0.18～0.20 μmol·g^-1·h^-1;油菜秸秆覆盖还田处理下水稻根系单株伤流量降低19～25 mg,根系GS、GPT和GOT活性分别增加0.16～0.34、0.08～0.21和0.06～0.32 μmol·g^-1·h^-1.油菜秸秆还田处理中,全量还田处理下的水稻产量最高,其中,与全量覆盖还田相比,全量翻埋还田处理下的水稻产量增加0.13～0.48 t·hm^-2.可见,油菜秸秆还田会导致水稻生长前期根系活力下降、氮代谢酶活性降低,从而使水稻根系生长缓慢、返青延迟,但在中后期,随着根系活力和氮代谢酶活性的增强,秸秆还田会促进水稻根系生长;油菜秸秆还田对水稻产量的影响是多因素综合作用的结果,全量翻埋还田更适宜于四川油稻两熟轮作系统.     

油菜秸秆还田对水稻根系、分蘖和产量的影响

采用田间试验与栽培模拟试验相结合的方法,分析了油菜秸秆还田对水稻根系、分蘖和产量的影响.结果表明: 水稻移栽后0～36 d,与秸秆不还田处理相比,油菜秸秆还田处理下水稻分蘖减少1～2个,根系单株伤流量降低1.0～8.6 mg,根系谷氨酰胺合成酶(GS)、谷丙转氨酶(GPT)和谷草转氨酶(GOT) 活性分别降低0.10～6.11、0.06～0.31和0.52～0.84 μmol·g^-1·h^-1. 水稻移栽后56 d,与秸秆不还田处理相比,油菜秸秆翻埋还田处理下水稻根系单株伤流量增加3.4～11.7 mg,根系GS、GPT和GOT活性分别增加0.34～0.78、0.13～0.45和0.18～0.20 μmol·g^-1·h^-1;油菜秸秆覆盖还田处理下水稻根系单株伤流量降低19～25 mg,根系GS、GPT和GOT活性分别增加0.16～0.34、0.08～0.21和0.06～0.32 μmol·g^-1·h^-1.油菜秸秆还田处理中,全量还田处理下的水稻产量最高,其中,与全量覆盖还田相比,全量翻埋还田处理下的水稻产量增加0.13～0.48 t·hm^-2.可见,油菜秸秆还田会导致水稻生长前期根系活力下降、氮代谢酶活性降低,从而使水稻根系生长缓慢、返青延迟,但在中后期,随着根系活力和氮代谢酶活性的增强,秸秆还田会促进水稻根系生长;油菜秸秆还田对水稻产量的影响是多因素综合作用的结果,全量翻埋还田更适宜于四川油稻两熟轮作系统.     

两种秸秆醋液对尖孢镰刀菌和立枯丝核菌的抑菌作用

本研究以玉米秸秆醋液、水稻秸秆醋液为供试材料,研究不同稀释度的秸秆醋液对尖孢镰刀菌(Fusarium oxysporum)和立枯丝核菌(Rhizoctonia solani)的抑制作用,测定其可溶性蛋白和可溶性糖。结果表明,50倍稀释液对2种病原菌的抑制率为100%,即2种病原菌在50倍稀释处理的秸秆醋液中不能生长。玉米秸秆醋液对尖孢镰刀菌中可溶性蛋白的影响不显著,对立枯丝核菌中可溶性蛋白的影响表现为先升高后降低。水稻秸秆醋液对尖孢镰刀菌中可溶性蛋白的影响是先升高后降低,对立枯丝核菌中可溶性蛋白的影响是逐渐累积。高浓度的水稻秸秆醋液可提高2种菌体内可溶性糖含量,100倍稀释的玉米秸秆醋液可提高尖孢镰刀菌体内的可溶糖含量,玉米秸秆醋液对立枯丝核菌的可溶性糖含量基本不会产生影响。本研究为秸秆醋液在农业生产上的推广应用等提供科学依据。     

NO formation during agricultural straw combustion

NO formation during combustion of four typical kinds of straw (wheat straw, rice straw, cotton stalk and corn stalk) which belong to soft straw and hard straw was studied in a tubular quartz fixed bed reactor under conditions relevant to grate boiler combustion. Regarding the real situation in biomass fired power plants in China, NO formation from blended straw combustion was also investigated. Nitrogen transfer during blended straw pyrolysis was performed using a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The results show that NO conversion for the four straws during combustion is distinctive. Over 70% fuel-N converts into NO for cotton stalk, while only 37% for wheat straw under the same condition. When wheat straw and cotton stalk were mixed, N-NO conversion increases. The limestone addition promotes NO emission during cotton stalk combustion. The presence of SO₂ in atmosphere suppresses NO formation from straw combustion.     

微生物菌剂对秸秆降解及秸秆中微生物变化规律的影响

为明确不同微生物菌剂对秸秆降解率及秸秆降解过程中秸秆周围微生物变化规律的影响，在温室大棚内进行不同微生物菌剂降解秸秆试验。以玉米秸秆为基质，设玉米秸秆（对照组）、玉米秸秆+哈茨木霉（Trichoderma harzianum）（处理1）、玉米秸秆+哈茨木霉+地衣芽胞杆菌(Bacillus licheniformis)（处理2）三个处理。研究结果显示，单独用哈茨木霉处理可显著提高秸秆降解率，前期作用尤其明显；在秸秆降解的前30 d，秸秆降解率与秸秆中可培养真菌、细菌、放线菌呈显著正相关。不同微生物菌剂对秸秆中可培养微生物数量变化有显著影响，单独接种哈茨木霉后，秸秆中可培养真菌、细菌、放线菌数在前30 d显著高于对照组和混合菌剂处理，不同处理可培养活菌数均在90～120 d达到峰值，然后开始下降。研究结果表明，不同微生物菌剂对秸秆降解有显著影响，单独用哈茨木霉处理可显著提高秸秆降解率；不同处理对秸秆中可培养真菌、细菌、放线菌的影响有显著差异。可为秸秆降解与微生物相关性研究提供参考。     

家蝇幼虫对两种秸秆的消化及利用研究

本文旨在探明家蝇Musca domestic幼虫对高粱秸秆和小麦秸秆营养成分利用和木质纤维素的降解情况,以及不同配比秸秆饲料对家蝇生物学指标的影响,为今后产业化利用家蝇来生物降解秸秆类有机废弃物奠定理论基础.本研究采用70％高粱秸秆粉、70％麦秸秆粉和纯麦麸作为饲料,每种饲料各设置对照组、发酵组和家蝇幼虫取食组3种处理...     

Solid-state anaerobic digestion of spent wheat straw from horse stall

The spent wheat straw from horse stall bedding has lower cellulose and hemicellulose contents, but higher volatile fatty acid content than raw wheat straw. Biogas production from solid-state anaerobic digestion (SS-AD) of spent wheat straw and raw wheat straw was compared in this study. The SS-AD tests were conducted at 22% total solids (TS) content using inoculum from a liquid AD system at three feedstock-to-inoculum (F/I) ratios of 2.0, 4.0, and 6.0. Daily methane yields of spent wheat straw peaked 8 and 3 days earlier than those of raw wheat straw at F/I ratios of 2.0 and 4.0, respectively. The highest methane yield of 150.0 L/kg volatile solids (VS) was obtained from spent wheat straw at an F/I ratio of 4.0, which was 56.2% higher than that of raw wheat straw. The corresponding cellulose and hemicellulose degradation of spent wheat straw was 24.1% and 49.4% higher than those of raw wheat straw, respectively.     

Studies on ammonia-treated straw. II. Fixation of ammonia in treated straw by spraying with acids

Ammonia-treated barley straw (NH₃ straw) was sprayed with either formic, acetic or phosphoric acid immediately after opening the stack in order to capture the excess ammonia. The amount of acid applied was estimated to neutralize 100% of the ammonia added to the straw (30 kg NH₃/t straw). After spraying with acid the straw was stored in plastic bags for about 8 weeks at room temperature (15–20° C). When bags of NH₃ straw treated with acids were opened, there was very little smell of ammonia whereas there was a very strong smell from the bag of NH₃ straw without acid added.The nitrogen content of the straw (g/100 g DM) was for untreated straw, 0.88, NH₃ straw without acid, 2.50, and NH₃ straw with added formic acid, 3.49, acetic acid, 3.81, and phosphoric acid, 2.27. The digestibility of organic matter determined in sheep was 47.3, 60.5, 59.0, 60.4 and 51.3 following the same order as above.It is concluded that spraying NH₃ straw with organic acids effectively reduces the loss of ammonia and increases the nitrogen content of the straw. Another advantage of this is that the air pollution with ammonia which may occur in the barn when the straw is not well aired is effectively prevented.Spraying with organic acids had no negative effect on the digestibility of the straw. The nitrogen supply and the digestibility of nitrogen in the animal seemed to be markedly improved.     

大气CO2浓度升高对稻季土壤中麦秸降解及氮素分趋的影响

利用中国唯一的稻麦轮作FACE(free-air carbon dioxide enrichment,开放式空气CO2浓度增高)试验平台,研究大气CO2浓度升高对稻季土壤中小麦秸秆降解速率及其氮素分趋的影响.试验设置Ambient(目前空气对照)和FACE(Ambient+200 μmol·mol-1)两个CO2浓度以及低氮处理(LN,150 kg·hm-2)和高氮处理(HN,250 kg·hm-2)两个氮肥水平,在稻季之初按标记麦秸/土壤重量比0.3%添加15N标记小麦秸秆,根据水稻生长时期依次采样测定秸秆降解速率,并通过分析土壤全氮、植株全氮及其15N丰度来观察已降解秸秆的氮素分趋情况.结果发现,大气CO2浓度升高对高氮处理土壤中小麦秸秆降解速率没有显著影响,但显著促进了低氮处理土壤中小麦秸秆的降解(p < 0.05),使其提高到与高氮处理土壤相当水平;大气CO2浓度升高显著增加了已降解秸秆中氮素的流失,在高氮处理土壤中尤为严重,而对植物吸收已降解秸秆中的氮素没有显著影响.结果表明,大气CO2浓度升高在土壤氮素相对不足时会加速土壤中小麦秸秆的降解,而在土壤氮素相对充足时又会加大降解秸秆中氮素的流失.     

黑龙江不同玉米秸秆还田方式下土壤动物群落结构及其对秸秆降解的影响

以黑龙江省海伦市典型黑土耕地为试验样区,研究黑土区不同秸秆还田方式下土壤动物群落结构特征及其在秸秆降解中的作用。实验选取6目、30目、260目降解袋,设置5个处理:17kg玉米秸秆+2kg水还田+含微生物100%浓度催腐剂(样方A)、8.5kg玉米秸秆+1kg水还田+含微生物50%浓度催腐剂(样方B)、原始样方(样方C)、8.5kg玉米秸秆+1kg水还田(样方D)、17kg玉米秸秆+2kg水还田(样方E),并于2009—2011每年9月份测定不同样方的玉米秸秆降解率和微生物数量。结果表明:所有样方累积秸秆降解率都达55%以上,秸秆降解率从高到低排序依次为:样方A>样方B>样方C>样方D>样方E;对秸秆降解起主要作用的动物类群为中小型土壤动物中的甲螨亚目、中气门亚目和节跳虫科,约占土壤动物个体数的86.70%;不同处理样方中,土壤动物群落结构相似;相同处理样方中,不同规格的降解袋中土壤动物个数与类群差异显著(P<0.001);不同孔径降解袋中土壤动物的个数、类群数、多样性基本都与秸秆降解率呈正相关,进一步表明土壤动物对秸秆降解具有促进作用。     

Properties of medium density fiberboards made from renewable biomass

The goal of this study was to determine the comparative properties of dry-formed medium density fiberboards (MDF) made from renewable biomass (wheat and soybean straw) and those from conventional soft wood fiber. The MDF properties evaluated were modulus of elasticity, modulus of rupture, internal bond strength, thickness swell, and screw holding capacity. The results show that MDF made from wheat straw fiber and soy straw fiber have weaker mechanical and water resistance properties than those made from softwood fiber. Soybean straw is comparable to wheat straw in terms of both mechanical and water resistance properties to make MDF. Water resistance of MDF decreased drastically with increasing straw fiber composition. Wheat straw fiber and soybean straw fiber should be physically or chemically treated to increase their water resistance property for MDF production.     

秸秆还田对甘蔗地土壤优先流运动特征的影响

秸秆还田措施可改变田间土壤环境,在一定程度上影响作物生长.为探究不同秸秆还田措施对田间土壤优先流的影响,以秸秆覆盖(CM)、秸秆焚烧覆盖(BM)和无秸秆覆盖(CK)3种处理方式下的甘蔗地为研究对象,通过野外染色示踪试验,结合图像解析技术和生态学景观格局分析方法对广西不同秸秆还田措施下的甘蔗地土壤优先流运动特征进行研究....     

秸秆还田的效果、问题与对策

农作物秸秆还田是改善土壤理化性质、增加微生物和酶活性、促进作物增产的有效措施,也是农作物秸秆资源化利用的一种重要方式,但秸秆还田也可能会导致作物出苗率降低、加重作物病虫害发生、引起土壤重金属等有毒有害物质积累等负面影响。目前秸秆以直接还田为主,亦有少量通过堆沤、垫圈等方式间接还田。秸秆在土壤中的腐解速度及还田效果主要取决于秸秆的化学组成特别是C/N、土壤微生物状况、土壤温度及水分含量等。下一步,必须强化秸秆还田方法、快速腐解条件及制剂、对下季作物病害影响及防控、农机农艺配套、缓解全球变化能力等研究,完善相关技术与方法,促进秸秆还田快速推广应用。     

秸秆还田配施化肥对土壤肥力及鲜食甘薯产量和品质的影响

通过2017和2018两年的田间试验研究了小麦秸秆还田和施肥对土壤肥力、酶活性以及鲜食甘薯产量和品质的影响。试验设5个处理:秸秆不还田+常规施肥(CK)、小麦秸秆半量还田+常规施肥(50%S)、小麦秸秆全量还田+不施肥(100%S-F)、小麦秸秆全量还田+常规施肥(100%S)、小麦秸秆全量还田+常规施肥+150 kg·hm^-2氮肥(100%S+N)。结果表明:秸秆还田施肥处理显著提高了土壤中的有效磷、碱解氮、总氮和有机质含量,显著提高了土壤过氧化氢酶、碱性磷酸酶、脲酶和蔗糖酶活性。秸秆还田施肥处理均显著提高了薯块产量、单薯鲜重和商品薯率,其中50%S处理下薯块产量最低。2年的秸秆还田处理下,薯块产量和商品薯率均在100%S处理下最高。2年的秸秆还田施肥处理总体上提高了甘薯的淀粉和蛋白质含量,但100%S和100%S+N处理均降低了甘薯还原糖和可溶性糖含量。可见,小麦秸秆全量还田的效果优于半量还田,与常规施肥配合下薯块产量和商品薯率最高,但影响食用口感,实际生产中可适当减少氮肥用量。     

施氮对关中还田玉米秸秆腐解和养分释放特征的影响

在陕西关中平原的冬小麦-夏玉米轮作区,采用尼龙网袋田间填埋与¹⁵N同位素标记玉米秸秆相结合的方法,设置不施氮和施氮200 kg·hm^-2两个处理,研究施氮对小麦生长期内还田玉米秸秆腐解的影响以及腐解过程中秸秆碳、氮、磷、钾的养分释放.结果表明: 从小麦播种到越冬期,施用氮肥对秸秆碳和干物质分解无显著影响,但可促进秸秆中磷的释放,抑制氮和钾的释放.灌浆到成熟期,氮肥对秸秆腐解及其N、P、K养分的释放无显著影响,但秸秆碳的释放显著增加.不同生育期,玉米秸秆碳的释放与干物质分解变化趋势一致,C/N逐渐下降.种植一季小麦后,秸秆干物质累计腐解率不足50%;秸秆碳释放率为47.9%～51.1%,不施氮和施氮处理的秸秆C/N分别由32.2降低到20.2和17.9.小麦收获时,秸秆氮、磷、钾均为净释放,氮释放量为7.2～9.4 kg·hm^-2,占秸秆氮的12.7%～16.6%;磷释放量为1.29～1.44 kg·hm^-2,占29.0%～32.4%;钾的释放量大、释放快,越冬前超过80%,成熟时释放量为51.8～52.5 kg·hm^-2,占90.5%～91.7%.在秸秆还田条件下,应考虑秸秆归还的钾,减少小麦钾肥用量,适量补充氮、磷.     

The use of 13C-NMR for studies of wheat straw decomposition

13C-NMR was used to study the field decomposition of surface retained and incorporated wheat straw. Results showed decreasing proportions of straw carbon as carbohydrate and increasing proportions of aromatic compounds during straw decomposition. These changes were greater for the surface retained straw, however greater relative microbial contamination of incorporated straw may have affected results. The cost of 13C-NMR may lessen its role in studies of this nature.     

The intake of steers and heifers fed on mixtures of alkali-treated or untreated straw with grass silage

Two experiments were made to investigate the intake of cattle when offered straw and silage mixtures.In a trial of changeover design 12 Friesian castrates (steers) were offered five diets. These were grass silage alone or mixed with untreated or NaOH treated straw supplying 20 or 40% of the total dry matter. The addition of 20% straw to the diet significantly reduced dry matter intake, and a further reduction occurred at 40%. Treating the straw with NaOh did not increase dry matter intake but led to an associated increase in digestible organic matter intake.Twelve Ayrshire heifers were given four diets in a trial of changeover design. The diets were silage only and three straw : silage mixtures in which straw provided 40% of the dry matter. The straws were untreated, NaOH treated or KOH treated. Untreated straw markedly depressed dry matter intake; NaOH raised the digestibility of straw and thus increased digestible organic matter intake significantly. The dry matter intake of the heifers was much greater than anticipated with the KOH treated straw : silage mixture and was similar to that achieved with silage only.     

低温秸秆降解复合微生物菌剂的研究进展

我国东北地区冬季寒冷,秸秆产量巨大,但综合利用率较低,利用高酶活性微生物将低温环境中的秸秆降解变废为宝,是一项循环利用的有效途径。研究表明,通过生物学技术手段,筛选高酶活性菌株,深入研究降解机理,优化功能微生物培养条件,提高纤维素酶活性,是提高降解率,秸秆资源化利用的最佳途径。复合微生物菌剂产生的酶活值普遍高于单一微生物菌,真菌菌丝体产生的酶活值高于细菌。实际应用中,选择适合的复合菌剂是低温环境下提高秸秆降解效率的有效途径。系统地归纳了低温条件下降解秸秆的微生物技术、分析了不同条件下降解秸秆的菌株类型和促进秸秆纤维素降解菌酶活力特征、并总结了低温环境下生物菌剂降解秸秆的技术应用效果,旨为低温环境下秸秆的资源化利用提供一定的技术参考。     

平菇类食用菌对农作物秸秆生物降解转化饲料的研究进展

综述了近年来国内外利用平菇类食用菌降解农作物秸秆的有关研究进展情况,主要包括限制秸秆饲料化的主要因素及提高秸秆饲料利用率的途径,平菇类食用菌降解秸秆的优势及其降解秸秆转化饲料的效果。并就笔者课题组近年来的研究总结了利用平菇类食用菌降解农作物秸秆的制约因素,以加快其应用于实际生产中。