Augmenting soil water storage using uncharred switchgrass and pyrolyzed biochars

Biochar is an amendment that can augment soil water storage; however, its projected cost per ton could be financially limiting at field application scales. It may be more monetarily convenient if an alternate amendment was available that could deliver similar soil enhancements. We compared two switchgrass biochars pyrolyzed at 250 and 500 °C with raw switchgrass (uncharred) on moisture storage and bulk density changes in a Norfolk loamy sand (fine‐loamy, kaolinitic, thermic Typic Kandiudult). Amendments were mixed into triplicate pots at 20 g/kg along with untreated controls. Soils were laboratory incubated at 10% moisture content (w/w) for 118 days, and the pots were irrigated three times with 1.3 pore volumes of deionized water every 30 days. Soil bulk densities were recorded before each irrigation event. Assessment of alterations in soil water storage was examined through cumulative water evaporative losses from incubation day 0 to day 33 and by monitoring soil water contents for 13 consecutive days past each irrigation event. Rankings of soil water evaporative losses were as follows: uncharred switchgrass ≤ switchgrass (500 °C) ≤ switchgrass (250 °C) < control. After the first irrigation event, uncharred switchgrass amendment significantly increased moisture storage compared with soil treated with biochar and the control. While all amendments increased water storage relative to the control, uncharred switchgrass delivered equivalent, if not slightly better, moisture storage improvements compared with the two switchgrass biochars. Uncharred switchgrass would likely not be as effective over the long term (years to decades) as pyrolyzed biochars, due to greater degradation of uncharred material.     

施用有机肥对土壤肥力的影响

在潮棕壤上进行了5年的定位试验,研究不同有机肥用量对作物产量和土壤肥力的影响。结果表明,施用有机肥处理与对照处理相比,施用有机肥有明显的增产和稳产作用。不施肥处理,除土壤全钾以外,土壤其他各项养分指标（C、N、P）均有所下降;施用有机肥能显著提高速效P、K养分含量和有机碳及全磷含量。5年时间,低量有机肥处理土壤碱解氮含量下降了9.19mg/kg,说明低量有机肥并不能保证土壤氮的供给;中量有机肥处理土壤碱解氮含量略有上升,土壤全氮收支基本平衡;高量有机肥处理土壤碱解氮含量有明显增加,土壤全氮也有较大程度的盈余。     

Effects of biochars produced from different feedstocks on soil properties and sunflower growth

The use of biochar as a soil amendment is gaining interest to mitigate climate change and improve soil fertility and crop productivity. However, studies to date show a great variability in the results depending on raw materials and pyrolysis conditions, soil characteristics, and plant species. In this study, we evaluated the effects of biochars produced from five agricultural and forestry wastes on the properties of an organic‐C‐poor, slightly acidic, and loamy sand soil and on sunflower (Helianthus annuus L.) growth. The addition of biochar, especially at high application rates, decreased soil bulk density and increased soil field capacity, which should impact positively on plant growth and water economy. Furthermore, biochar addition to soil increased dissolved organic C (wheat‐straw and olive‐tree‐pruning biochars), available P (wheat‐straw biochar), and seed germination, and decreased soil nitrate concentration in all cases. The effects of biochar addition on plant dry biomass were greatly dependent upon the biochar‐application rate and biochar type, mainly associated to its nutrient content due to the low fertility of the soil used. As a result, the addition of ash‐rich biochars (produced from wheat straw and olive‐tree pruning) increased total plant dry biomass. On the other hand, the addition of biochar increased the leaf biomass allocation and decreased the stem biomass allocation. Therefore, biochar can improve soil properties and increase crop production with a consequent benefit to agriculture. However, the use of biochar as an amendment to agricultural soils should take into account its high heterogeneity, particularly in terms of nutrient availability.     

绿肥对植烟土壤酶活性及土壤肥力的影响

通过田间试验,研究翻压绿肥对植烟土壤酶活性及土壤肥力的影响。结果表明, 翻压绿肥能够明显提高土壤酶活性和土壤肥力水平,当绿肥翻压量在15000 kg/hm2以上时,尤其在22500~30000 kg/hm2之间时对土壤各项指标的影响更加明显。与对照相比,翻压绿肥的各处理土壤脲酶、 酸性磷酸酶、 蔗糖酶、 过氧化氢酶增幅分别为13.10%2~3.81%、 12.92%~29.38%、 75.35%~234.51%、 29.17%~37.08%; 土壤有机质、 全氮、 碱解氮、 有效磷、 速效钾、 pH、 孔隙度增幅分别为13.01%~70.41%、 6.42%~27.52%、 1.14%~10.99%、 15.97%~34.99%、 10.28%~38.30%、 2.74%~7.05%、 0.19%~2.50%,土壤容重降幅为1.47%~5.15%。简单相关分析表明,脲酶、 酸性磷酸酶、 蔗糖酶、 过氧化氢酶4种酶之间以及4种酶与土壤理化因子之间均有极显著的相关关系,而土壤酶活性之间的相互关系表明,土壤酶在促进土壤有机物质转化中不仅显示其专性特性,同时也存在共性关系; 典型相关分析结果为,第一对典型变量线性函数反映了土壤酶活性和土壤养分因子对土壤综合肥力水平的影响,第二对典型变量线性函数反映了施入绿肥对土壤内部重要的生理生化过程变化的影响; 主成分分析结果显示,第一主成分反映了土壤的综合肥力水平,所有因子均对土壤肥力水平起到了正效应,土壤酶活性能够和土壤理化因子共同评价土壤综合肥力水平。以上结果说明,翻压绿肥后土壤生物过程活跃,有利于土壤有机物质的转化和烤烟正常生长所需的营养供应。     

Impacts of biochar and processed poultry manure,applied to a calcareous soil,on the growth of bean and maize

Direct use of poultry manure on agricultural lands may cause environmental concerns, so there is a need to establish the suitability of the application of biochar derived from poultry manure for calcareous soil chemical properties and plant growth. The purpose of this study was to evaluate the effects of processed poultry manure (0, 5, 10 and 20 g/kg) and its biochar (0, 2.5, 5, 10 and 20 g/kg) on soil chemical properties of a calcareous soil and growth of bean (Phaseolus vulgaris) and maize (Zea mays) plants. In the incubation experiment, both processed poultry manure (PPM) and biochar decreased pH and the concentration of plant‐available Fe of soil but increased plant‐available P, Zn, Cu and Mn concentrations. PPM and biochar increased the concentrations of exchangeable cations (K, Ca and Mg) in soil. PPM and biochar applications increased the growth of maize and bean plants. PPM and biochar resulted in increased concentrations of N, P, K, Ca, Fe, Zn, Cu and Mn in bean plants. In maize plants, PPM and biochar applications increased the N, P, K, Zn, Cu and Mn but decreased the Ca and Mg concentrations. Results of this study reveal that poultry manure biochar can be used effectively for agricultural purposes.     

生物质炭对酸性土壤改良作用的研究进展

由于生物质炭在农业和环境中的巨大应用前景和对土壤碳的增汇减排作用,近期成为土壤学家和环境学家研究的热点。本文综述了生物质炭对热带和亚热带地区酸性土壤的改良作用及其机制,总结了生物质炭对土壤肥力和养分有效性及作物生长和产量的影响的研究进展,分析了该领域未来的发展趋势,可为酸性土壤改良和管理提供参考。     

不同用量有机肥对芒果果实品质及土壤肥力的影响

通过田间小区试验,研究了不同用量有机肥处理对芒果果实品质及果园土壤肥力的影响,旨在为生产上芒果科学施肥提供技术支持。结果表明:与不施有机肥处理(CK)比较,增施有机肥处理使果实可溶性固形物含量提高10.1%~21.6%、Vc含量提高3.1%~38.4%、可滴定酸含量下降6.6%~16.0%、固酸比提高17.9%~44.9%。增施有机肥提高了土壤有机质、全N、有效P、速效K、交换性Ca、交换性Mg、电导率及p H值,促进土壤肥力水平的提升。综合比较,以T2处理(有机肥7.5 kg/株+尿素400 g/株+高钾复合肥1.25 kg/株)对改善果实品质和改良土壤性状效果最好。     

Physical activation of biochar and its meaning for soil fertility and nutrient leaching – a greenhouse experiment

The slow alteration of the surface of charred biomass (biochar) over time may contribute to an improved nutrient retention and thus fertility of tropical soils. Here, we investigated soils from temperate climates and investigated whether a technical steam activation of biochar could accelerate its positive effects on nutrient retention and uptake by plants relative to nonactivated biochar. To this aim, we performed microcosm experiments with sandy or silty soil, mixed with 2.0, 7.5 and 15.0 g/kg soil of fine (<2 mm) or coarse‐sized (2–10 mm) biochar from beech wood (Fagus sp.). After initial fertilizer (NPK), ashes and excess nutrients were leached with water, and the microcosms were planted for 142 days with Italian Ryegrass (Lolium multiflorum ssp. italicum). Thereafter, leachate, soil and plant samples were analysed for their nutrient contents. The results showed that biochar additions of ≤15 g/kg soil left elevated contents of available P and N in the surface soil but reduced their uptake into the plants. As a result, total biomass production was unchanged. Different particle size and application amounts influenced these findings only marginally. Nitrate leaching was enhanced in the sandy soil (+41% for nitrate, but reduced in the silty soil ?17%) and P was immobilized. Hence, the fertility of the temperate soils under study was only marginally affected by pure biochar amendments. Steam activation, however, almost doubled the positive effects of biochars in all instances, thus being an interesting option for future biochar applications.     

Low-cost and environmental-friendly Triticum aestivum-derived biochar for improving plant growth and soil fertility

ABSTRACT

Biochar and biochar–fertilizer concoction is imperative to subjugate reduced plant growth and soil fertility depletion which is a constraint for sustainable agriculture. The aspiration of the current research was to determine the plant growth response to wheat straw-derived biochar annexation in soils from two regions: Rawalpindi (semi-arid) and Thar (arid). Wheat straw (Triticum aestivum) was pyrolyzed at 300°C in a low-cost biochar retort kiln at different concentration rates (0%, 1%, 3%, and 7% by mass). Growth trend of Sorghum bicolor was observed in these soils for 40 days in a greenhouse. Fertilizer (NPK) (8.58% N, 4.39% P, and 3.48% K) was added to soil on the third day of seed germination. Soil physicochemical analysis, plant growth, and dry matter yield evaluation after the treatment signified the concomitant increase in dry matter yield along with enhanced soil fertility and plant growth.     

生物质炭与有机物料配施的土壤培肥效果及对玉米生长的影响

生物质炭作为一种多功能的土壤培肥材料被广泛应用,但其与传统有机物料的对比及配施研究还比较少。通过盆栽试验,研究了生物质炭与秸秆、发酵鸡粪单施及配施对壤质潮土和砂土养分含量、酶活性及玉米生长的影响,并采用主成分分析方法对3种有机物料的培肥效果进行综合评价。试验设6个处理,分别为不添加有机物料(CK)、添加生物质炭(BC)、小麦秸秆(WS)、发酵鸡粪(CM)、秸秆和生物质炭(WS+BC)、鸡粪和生物质炭(CM+BC)。研究结果表明,各处理均增加了砂土玉米生物量和株高,3种有机物料的提升幅度排序为:鸡粪生物质炭秸秆,鸡粪还可增加壤质潮土玉米生物量和株高。添加生物质炭和有机物料还可提高土壤有机质含量,其中生物质炭的提升幅度最大。此外,3种有机物料对土壤养分和酶活性的影响各异,单施鸡粪分别增加壤质潮土和砂土的碱解氮22.08%和26.67%,速效磷91.92%和53.65%,脲酶活性40.54%和36.94%;单施生物质炭分别增加壤质潮土和砂土速效磷83.52%和89.91%,速效钾79.38%和127.02%,过氧化氢酶活性3.41%和11.22%,却降低了土壤碱解氮含量,且与鸡粪配施后会抑制鸡粪中氮的有效性;单施秸秆分别增加壤质潮土和砂土速效钾49.48%和63.02%,β-葡糖苷酶活性51.86%和59.09%;生物质炭与鸡粪或秸秆配施可以更均衡地提升土壤肥力。通过主成分分析和相关分析发现,玉米生物量和株高与土壤氮、磷供应正变化的第2主成分(PC2)得分呈极显著正相关关系。因此,3种有机物料中,鸡粪对土壤氮、磷含量及相关酶活性影响最大;秸秆对土壤钾以及纤维素分解相关酶影响较大,而生物质炭对土壤肥力的提升作用更均衡,且土壤肥力综合得分最高。秸秆或鸡粪配施生物质炭可以更全面地提高土壤肥力。     

Effects of sugarcane residue and green manure practices in sugarcane-ratoon-wheat sequence on productivity,soil fertility and soil biological properties

In a field experiment conducted during 2002 to 2004 in silty clay loam soil at Pantnagar, India, treatment of trash burning + Sesbania aculeata green manure (GM) incorporation gave the highest increases of 50.6 and 17.7% in ratoon cane yield and 15.0 and 19.4% in wheat grain yield over trash removal and trash burning treatments, respectively. Soil organic C and available N after ratoon and wheat crops were highest with trash removal + GM incorporation and available P and K with trash removal + GM mulch. The different treatments of trash and GM management were also superior to trash removal and trash burning in organic C and available N and P in soil at termination of the study. Soil microbial biomass C and dehydrogenase activity at the end were at a maximum with trash burning + GM mulch and trash removal + GM mulch treatments, respectively. Compared to trash removal and trash burning, counts of bacteria in soil after ratoon and wheat crops were significantly more only with different GM treatments; however, all GM and trash application treatments recorded significantly higher counts of fungi and actinomycetes. Irrespective of the treatments, population of total bacteria in soil decreased, while that of fungi and actinomycetes increased as compared to their initial counts following sugarcane-ratoon-wheat sequence.     

秸秆还田和腐熟有机肥对水稻土培肥效果对比分析

为探讨秸秆还田对土壤肥力的影响,该文以18年的定位试验为基础,通过对直接施用秸秆、有机肥以及化肥、有机肥配施等6个处理小区的土壤进行采样,分析了秸秆还田同有机肥培肥方式对土壤理化性质、养分状况与作物产量等方面的影响,着重探讨了秸秆直接还田同传统的施用腐熟有机肥对土壤的培肥效果差异。结果表明直接施用作物秸秆同施用腐熟有机肥对土壤的培肥效果基本相同,均对土壤理化性质有很大的改善,同时可提高作物的产量,因此秸秆直接还田基本可以代替施用腐熟有机肥培肥土壤。     

不同秸秆还土方式对旱地土壤培肥和玉米产量的影响

采用田间小区试验研究了秸秆还土方式对旱地土壤培肥和玉米产量的影响。结果表明,秸秆翻压与覆盖均有明显培肥土壤,提高玉米产量的作用,但两种还土方式之间的差异不明显。     

秸秆微波水热炭和活性炭理化及电化学特性

为了解秸秆微波酸催化水热炭和碱活化活性炭形成机制和理化特性演变规律,该研究开展了不同柠檬酸质量分数下的秸秆微波水热和活性炭的制备试验,并研究了水热炭和活性炭理化及其电化学特性。结果表明,随柠檬酸质量分数的增加,秸秆水热炭的产率、挥发份和H含量减少,而其灰分、固定碳、C和高位热值增加,且酸质量分数为10%后趋于稳定。柠檬酸质量分数为10%时,水热炭的碳微球结构最丰富,其比表面积和孔体积最大,且以中孔为主。10%柠檬酸水热炭在900℃下经KOH活化后的活性炭产率为8%～11%,活化气体产率为32%～35%,且以CO和H2为主。900 ℃活性炭的比表面积为1 250～1 570 m2/g,总孔体积为1.00～1.20 cm3/g,孔径为3.55～4.10 nm,且以中孔和微孔为主。当电流密度为1 A/g,水稻、玉米和油菜秸秆活性炭的比电容分别为160.54、150.12和155.17 F/g,且循环5 000次后的电容保持率分别为91.04%、88.12%和89.06%,表现出较好的循环稳定性。水稻秸秆水热炭和活性炭的产率、灰分、碳转化率、能量转化率、比表面积、总孔体积、比电容和电容保持率最大。     

水稻栽后施绿肥对其生长发育及土壤肥力的影响

水稻栽后在行间施绿肥，既保持了深施绿肥培肥土壤的作用，又克服了栽前常规施绿肥影响水稻生长发育，甚至造成当季减产的弊端。     

紫云英与化肥配施对稻田土壤养分和微生物学特性的影响

在安徽沿江双季稻区,通过4年田间定位试验研究了不同用量紫云英绿肥与化肥配施对水稻产量、土壤肥力和土壤微生物数量及活度的影响。结果表明,施用紫云英绿肥比不施肥增产40.75%~92.10%,比单施化肥处理增产26.30%~36.49%;与纯施化肥相比较,施用紫云英处理的微生物总量增加了48.26%~115.78%,微生物活度增加了5.88%~29.41%,且施用紫云英土壤全N、碱解N、有效P、速效K和有机质含量均较高。简单相关分析表明,土壤微生物特性与土壤全N、碱解N之间具有极显著的相关性。施肥土壤有机质含量与细菌总数之间无直接相关性,而与真菌、放线菌数量及微生物活度正相关。土壤微生物及土壤养分分析发现,化肥量70%与紫云英22 500 kg·hm-2配施比较适宜于安徽沿江双季稻区早稻生产。     

Effects of biochar amendment on greenhouse gas emissions,net ecosystem carbon budget and properties of an acidic soil under intensive vegetable production

Biochar addition to soils has been frequently proposed as a means to increase soil fertility and carbon (C) sequestration. However, the effect of biochar addition on greenhouse gas emissions from intensively managed soils under vegetable production at the field scale is poorly understood. The effects of wheat straw biochar amendment with mineral fertilizer or an enhanced‐efficiency fertilizer (mixture of urea and nitrapyrin) on N₂O efflux and the net ecosystem C budget were investigated for an acidic soil in southeast China over a 1‐yr period. Biochar addition did not affect the annual N₂O emissions (26–28 kg N/ha), but reduced seasonal N₂O emissions during the cold period. Biochar increased soil organic C and CO₂ efflux on average by 61 and 19%, respectively. Biochar addition greatly increased C gain in the acidic soil (average 11.1 Mg C/ha) compared with treatments without biochar addition (average ?2.2 Mg C/ha). Biochar amendment did not increase yield‐scaled N₂O emissions after application of mineral fertilizer, but it decreased yield‐scaled N₂O by 15% after nitrapyrin addition. Our results suggest that biochar amendment of acidic soil under intensive vegetable cultivation contributes to soil C sequestration, but has only small effects on both plant growth and greenhouse gas emissions.     

不同种类绿肥翻压对土壤肥力的影响

通过模拟试验,研究了旱地翻压箭筈豌豆（Vicia sativa L.）、苕子（Vicia villosa Roth. Var.）和山黧豆（Lathyrus palustris l. Var. Pilosus ledeb）三种绿肥对土壤肥力特性的影响。试验结果表明,在绿肥翻压腐解过程中,土壤pH（原始pH值为5.95）均呈现出先升高后降低最后趋于平缓的趋势,在翻压0～25 d内高于不翻压绿肥对照,之后始终低于对照。翻压绿肥处理的土壤有机碳含量均高于对照,增幅为1.6%～6.2%。土壤无机氮含量显著高于对照,无机氮形态0～20 d以铵态氮为主,30～70 d以硝态氮为主,翻压70 d时,硝态氮含量较对照增加了15倍以上。翻压绿肥后土壤速效磷的含量均高于对照,增幅为11.9%～37.7%。翻压绿肥的土壤速效钾含量在翻压15 d时达最高且均比对照增加1.5倍以上。不同绿肥对土壤养分特性的影响不同,山黧豆处理的土壤pH变化幅度最大,土壤有机碳和无机氮含量最高,箭筈豌豆处理的土壤速效钾和速效磷含量最高。本试验条件下,三种绿肥翻压均能够改变土壤pH值,提高土壤硝态氮和速效钾含量,土壤有机碳和速效磷含量略有增加。     

定位化肥牛粪配施对设施蔬菜产量和土壤肥力的影响

采用定位施肥方式,连续多次在同一保护地块化肥减量配施牛粪,通过大棚蔬菜种植试验,设置对照(CK,单施复合肥2250 kg/hm2)、低(L,66.7％CK+有机肥30000 kg/hm2)、中(M,33.3％CK+有机肥4500 kg/hm2)及高(H,单施有机肥60000 kg/hm2)4个不同化肥减量配施有机肥底肥...     

不同有机物料培肥对渭北旱塬土壤微生物学特性及土壤肥力的影响

通过田间试验,研究了施用不同有机物料对渭北旱塬耕地土壤微生物学特性及土壤肥力的影响。结果表明,化肥与不同有机物料配合施用,土壤微生物学特性［微生物量碳（MBC）、微生物量氮（MBN）、脲酶、碱性磷酸酶］以及部分土壤养分状况（全氮、速效磷、速效钾、阳离子交换量）比单施化肥处理均得到进一步改善。化肥配施秸秆堆肥处理效果最明显,其中微生物量碳增加了41.96%,微生物量氮增加了54.55%,脲酶活性增加了19.71%,碱性磷酸酶活性增加了7.35%,速效磷增加了63.12%;而且土壤微生物量碳、氮与速效磷、阳离子交换量呈显著正相关,微生物商（qMB）、脲酶活性、碱性磷酸酶活性与全氮、速效氮、速效钾含量呈显著相关;同时SMBC、SMBN、qMB等与作物产量密切相关（相关系数分别为0.85,0.74,0.82）。因此,化肥配施秸秆堆肥处理在渭北旱地雨热条件下对于全面提升土壤质量具有重要的意义;同时该区域土壤中微生物量碳氮与土壤养分状况、作物产量具有很好的一致性,可以表征土壤肥力状况及生产力水平。