玉米秸秆炭和典型农业废弃物混合成型与燃烧特性试验

以玉米秸秆炭和玉米秸秆、苹果枝、沼渣、菌渣为原料,在成型压力为6 MPa的条件下,研究了不同混配比例混合燃料的成型特性,并在此基础上探讨了特定混配比例下的混合样品燃烧特性。研究结果表明:农业废弃物质量分数、种类对混合成型燃料稳定性均有影响,农业废弃物占70%比例时混合成型燃料的抗跌碎强度均大于99.50%;玉米秸秆对成型燃料的稳定性影响最为明显,其质量分数大于30%时,成型燃料抗跌碎强度达到99.68%以上,而沼渣和菌渣质量分数大于50%时,其成型燃料的抗跌碎强度分别超过99.11%和99.71%;苹果枝质量分数大于60%,其成型燃料抗跌碎强度超过99.34%;4种成型燃料的能量密度与原料相比分别提高14.93、11.36、11.74、14.53 GJ/m~3;堆积密度分别提高792.99、596.92、605.63、820.12 kg/m~3。该研究为农业废弃物新型成型燃料的开发提供了基础支撑。     

不同氮水平下秸秆、生物质炭添加对旱作农田土壤酸解有机氮组分的影响

为探明不同氮水平下秸秆、生物质炭添加对陇中黄土高原旱作农田土壤酸解有机氮组分的影响,2014年在定西市安定区李家堡镇布设的不同氮水平下秸秆、生物质炭添加定位试验(共9个处理),利用Bremner分级法,对该试验2018年收获后的土壤有机氮组分进行测定与分析。结果表明:在0～30 cm土层(0～5、5～10、10～30 cm土层),各处理酸解总有机氮、酸解氨态氮、酸解氨基酸态氮、酸解未知态氮含量均随土层的加深而降低,酸解氨基糖态氮含量随土层的加深而增加;较之无炭处理(CN0、CN50、CN100处理的均值),生物质炭添加(BN0、BN50、BN100处理的均值)处理可提升酸解总有机氮含量10.12%、9.14%、7.61%(土层由上至下),提升酸解氨态氮含量15.02%、16.25%、17.19%(土层由上至下),提升酸解氨基酸态氮含量13.31%、11.84%、8.74%(土层由上至下),其中BN100处理下对其提升效应最显著;较之无炭处理(CN0、CN50、CN100处理的均值),秸秆添加处理(SN0、SN50、SN100处理的均值)可提升酸解氨基糖态氮含量26.46%、26.51%、25.78%(土层由上至下),其中SN100处理下对其提升效应最显著;不同处理下,有机氮各形态的分布趋势为酸解氨基酸态氮酸解氨态氮酸解未知态氮酸解氨基糖态氮。总之,BN100处理对酸解氨基酸态氮、酸解氨态氮提升效应最显著,进而增加土壤供氮潜力,可筛选为该区春小麦栽培的合理施肥方式。     

生物炭对亏缺灌溉下温室重壤土栽培番茄产量及品质的影响

探究生物炭对亏缺灌溉下温室重壤土栽培番茄产量和品质的影响，确定番茄产量和综合品质最优的灌水量及生物炭添加量，为重壤土地区温室番茄栽培提供灌水及生物炭施加依据。采用桶栽试验，设置3个生物炭添加量（0，3%，6%，按干土重的百分比计）和3个灌水水平（充分灌溉W1：75%~85%θ_f；中度亏缺W2：55%~65%θ_f；重度亏缺W3：40%~50%θ_f。θ_f为田间持水量），共9个处理。结果表明：无生物炭添加时，亏缺灌溉下番茄产量降低了13.8%~54.0%（P＜0.05），果实硬度、果色指数、VC、可溶性固形物、有机酸含量等营养品质指标均显著降低，果型指数、番茄红素则呈现增加的趋势，灌溉水利用效率在重度亏缺下降低了10.9%（P＜0.05）；在充分灌溉条件下添加生物炭，番茄产量和灌溉水利用效率分别提高了12.3%~22.0%和23.3%~28.6%，可溶性固形物含量降低了6.4%~17.7%（P＜0.05），对VC、番茄红素、有机酸含量及外观品质无显著影响；在亏缺灌溉条件下添加生物炭不利于增产，C1W3、C2W3处理产量较C0W3处理分别降低了37.6%（P<0.05）、17.1%（P>0.05），但外观品质指标、VC、可溶性固形物均有一定幅度的提升，对灌溉水利用效率的影响表现为低添加量时降低而高添加量时提高。综合分析表明，各灌水水平下添加生物炭均能提高番茄品质的综合排名，充分灌溉下生物炭低添加量效果较好，而亏缺灌溉下高添加量较优，尤其是C2W2处理，番茄品质综合排名可达到充分灌溉的效果。综合考虑番茄品质、产量及灌溉水利用效率，C1W1处理（灌水水平为75%~85%θ_f，施炭量为3%）为最优处理。     

不同配料颗粒秸秆施用对土壤速效养分及小麦生长的影响

我国西北地区气温较低，秸秆直接还田腐解慢、养分循环慢、当季利用率低、影响作物出苗，导致秸秆还田率不高。针对以上问题，本研究以小麦秸秆为原料，以硫磺粉（养分活化剂）和麦秸生物炭（养分吸附剂）为外源添加材料，制成秸秆颗粒。硫磺粉的添加质量比为3%（WS3）、5%（WS5）、10%（WS10），生物质炭的添加质量比为5%（WC5）、10%（WC10）、15%（WC15），以秸秆颗粒（WK）、剪碎秸秆（W，W6）及无秸秆（CK）为对照，通过盆栽试验探究了秸秆颗粒对土壤速效养分及小麦生长的影响。结果表明：秸秆颗粒较剪碎秸秆处理相比，能显著提高土壤速效养分及小麦生物量和植株全量氮、磷、钾含量，添加硫磺或生物炭的秸秆颗粒提升效果更明显。各处理土壤硝态氮含量以WS3处理最高，较W处理提高14.44%；铵态氮含量以WC5处理最高，较W处理提高40.93%；速效磷含量以WS10处理最高，较W处理提高23.42%；速效钾含量以WC5处理最高，较W处理提高9.05%；差异均达显著水平（P<0.05）。小麦生物量以WS5处理最高，较WK处理提高29.61%；全氮含量以WS10最高，较WK处理提高11.44%；全磷含量以WS10处理最高，较WK处理提高21.82%；全钾含量以WC15最高，较WK处理提高12.53%；差异均达显著水平（P<0.05）。综上可知，秸秆颗粒在西北地区实现秸秆还田和养分循环，维持土壤肥力等方面具有很大应用前景。     

Steam explosion of crop straws improves the characteristics of biochar as a soil amendment

Five crop straws(wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210°C, 2.5 MPa and then pyrolyzed at 500°C for 2 h. Steam explosion(SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area(SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity(AEC)(6.88–11.44 cmol kg~(–1)) and point of zero net charges(PZNC)(pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.     

Short‐term releases of CO2 from newly mixed biochar and calcareous soil

The work aimed to quantify native organic C mobilized in one calcareous soil in the 21 days after addition of biochar at a range of large to very large applications. The experiment was carried out in unplanted microcosms, and CO₂ flux was used as a measure of net mineralization. A rapid methodological approach, which does not require ¹³C as a tracer, was used to assess any priming effects induced by the biochar. The amount of CO₂‐C mobilized was small relative to the amount of biochar C and proportional to the amount of the biochar added. The additional CO₂‐C was similar to the content of the water‐soluble organic carbon in the biochar added with each application. No interaction with native soil C, that is priming effect, was observed.     

生物炭对植烟土壤养分的影响

为探讨生物炭作为土壤改良剂对植烟土壤养分含量的影响,以湖南烟区主要栽培品种云烟87为试验材料,通过大田试验研究了不同的生物炭用量(CK:0 kg/hm~2;T1:3 000 kg/hm~2;T2:3 750 kg/hm~2;T3:4 500kg/hm~2)下植烟土壤中的养分含量。结果表明:施用生物炭能够显著提高植烟土壤有机质、碱解氮、铵态氮及速效钾含量,且随着生物炭施用量的增加呈先升高后降低的趋势,从改良土壤肥力效果来看,生物炭施用量在3 750 kg/hm~2的水平下较为适宜。     

Biochar Mitigates Salinity Stress in Potato

A pot experiment was conducted in a climate‐controlled greenhouse to investigate the growth, physiology and yield of potato in response to salinity stress under biochar amendment. It was hypothesized that addition of biochar may improve plant growth and yield by mitigating the negative effect of salinity through its high sorption ability. From tuber bulking to harvesting, the plants were exposed to three saline irrigations, that is 0, 25 and 50 mm NaCl solutions, respectively, and two levels of biochar (0 % and 5 % W/W) treatments. An adsorption study was also conducted to study the Na⁺ adsorption capability of biochar. Results indicated that biochar was capable to ameliorate salinity stress by adsorbing Na⁺. Increasing salinity level resulted in significant reductions of shoot biomass, root length and volume, tuber yield, photosynthetic rate (A_n), stomatal conductance (g_s), midday leaf water potential, but increased abscisic acid (ABA) concentration in both leaf and xylem sap. At each salinity level, incorporation of biochar increased shoot biomass, root length and volume, tuber yield, A_n, g_s, midday leaf water potential, and decreased ABA concentration in the leaf and xylem sap as compared with the respective non‐biochar control. Decreased Na⁺, Na⁺/K⁺ ratio and increased K⁺ content in xylem with biochar amendment also indicated its ameliorative effects on potato plants in response to salinity stress. The results suggested that incorporation of biochar might be a promising approach for enhancing crop productivity in salt‐affected soils.     

Effects of Addition of Three Types of Biochar on the Soil Nitrogen Balance and Cotton Yield

The objective of this study was to determine the effect of biochar addition on the soil N balance and cotton yield in a drip-irrigated cotton field. The experiment included four soil amendments: control, cotton straw biochar, corn cob biochar, and poultry manure biochar. The biochar was applied at a rate of 4.5 t·hm^－2 except control. The results showed that all three types of biochar significantly reduced both the apparent soil N loss and the N surplus. The effect of cotton straw biochar treatment was most significant, relative to the control. Plant nitrogen uptake differed significantly between the different treatments, decreasing in the order cotton straw biochar > poultry manure biochar > corn cob biochar. Cotton yield also differed significantly between the different treatments, decreasing in the order poultry manure biochar > corn cob biochar, and cotton straw biochar.     

秸秆生物炭对黄土区农田土壤养分和作物生长的影响

旨在探索生物炭对黄土区农田的具体应用效果。采用大田试验，在不施氮肥和施氮肥(187.5 kg/hm2)处理下，分别设计了不同生物炭用量(0、6、12、24、48 t/hm2)试验，来观察对黄土高原农田土壤养分和玉米生长的影响。结果发现：当施入187.5 kg/hm2氮肥时，24~48 t/hm2范围内的生物炭施用量对土壤养分促进作用效果最佳，其中48 t/hm2时全氮超出对照26.6%，碱解氮可超过对照约27.67%；6~12 t/hm2的范围时，玉米茎粗、叶绿素在生长中期均相对处于优势，且玉米养分含量和产量结果优于生物炭量大的处理。不施氮的情况下，生物炭也可促进土壤和玉米籽粒养分的积累。其中6~12 t/hm2时，土壤和玉米籽粒养分含量相对较高；24~48 t/hm2时玉米产量结果最佳，比对照高1468.2 kg/hm2，约13.39%。结果表明，生物炭的添加对土壤的养分影响较大，且一定程度上依赖于氮肥的投入情况。