Influence of Applied Cattle Manure on Winter Wheat (Triticum aestivum L.) Grain Yield,Soil pH and Soil Organic Carbon

ABSTRACT

Animal manure is used in crop production to improve crop yield and soil properties. The impact of cattle manure applied in one year on yield and soil properties in the subsequent years has not been extensively studied. This work evaluated the effect of manure application on winter wheat grain yield (Triticum aestivum L.), soil organic carbon (SOC), and soil pH. Cattle manure was applied once every four years at a rate of 267 kg N ha^?1. Grain yield and soil samples (0–15 cm) were collected annually from the Magruder Plots, Oklahoma. Soil samples were analyzed using a glass electrode (pH) and LECO dry combustion analyzer (SOC). The highest yield (2.8 Mg ha^?1) occurred in the second year after manure application. Yield in the second year exceeded yield in the first year by 66%. Yields in the third and fourth year were similar to yields in the other years. No changes in soil pH and SOC were observed in each of the four years that constituted the manure application cycle. Cattle manure (267 kg N ha^?1) could be applied once to serve a four-year period without major yield differences while also improving soil pH and SOC when compared to the check.     

有机肥与化肥长期配施对作物产量和灌漠土养分库的影响

根据河西走廊灌漠土上连续27 a的长期定位试验数据,研究了河西绿洲区灌漠土有机肥和化肥长期配施对作物产量和土壤养分库的影响。结果表明,有机肥与化肥长期配施增加了作物产量和产量的稳定性;7种施肥方式(单施氮、NP配施、NPK配施、单施有机肥、有机肥+N、有机肥+NP、有机肥+NPK)中,以有机肥与NP或NPK肥配施效果为最佳。长期有机肥和化肥配施增加了N,P,K养分投入量、养分携出量和盈余量;有机肥与化肥配施21~25 a后,土壤有机质、全氮和全磷含量分别提高了10.0%~16.0%,58.1%~69.0%和13.4%~31.1%,速效氮、速效磷和速效钾含量分别提高了45.7%~79.0%,172.2%~287.8%和21.4%~38.8%,均显著高于对照和单施化肥处理;有机肥与化肥配施处理中,以有机肥与NPK肥配施改善土壤肥力的效果最理想。     

Variability on Yield,Nutritional Status,Soil Fertility,and Potassium-Use Efficiency by Soybean Cultivar in Acidic Soil

The use of cultivar with nutrient-use efficiency is an important strategy in the management of plant nutritional status, particularly potassium (K), because its high demand and the progressive impoverishment caused by the use of inadequate amounts cause frequent deficiency symptoms observed in soybean [Glycine max (L.) Merrill] crops. This study was conducted in greenhouse conditions in a completely randomized design with four replicates in an Typic Quartzipsamment soil aimed to assess the effect of applying two rates of K (50 and 200 mg kg^?1) on growth, shoot dry weight yield (SDWY) and seed yield (SY), nutritional status, yield components, and efficiency of K use in eleven cultivars of different characteristics and growth habits. The SDWY, SY, number of seeds per pod, number of pods, and estimated 100-seed weight showed significant interaction between cultivar and the K rates, with greater values at the rate 200 mg K kg^?1. Similarly, the concentration of nitrogen (N), phosphorus (P), K, calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in leaves and grains varied according to the K rates and in the cultivar. The most K-use efficient cultivars were BMX Magna RR, BRS 232, BRS 284, BRS 294RR, NA 5909RR, and Vmax RR, whereas FTS Campo Mourão RR was inefficient. Regarding response to fertilization, the cultivars Vmax RR, BMX Magna RR, NA 5909RR, BRS 284, and BRS 294RR were found to be efficient and responsive, whereas the cultivar FTS Campo Mourão RR, BRS 232, BMX Potência RR, BRS 295RR, TMG 1066RR, and TMG 1067RR are inefficient and responsive to K application in the soil.     

牛粪对杨树人工林土壤生物学性状及其生长的影响

[目的]探讨施用牛粪对杨树人工林土壤生物学性状与生长的作用效果,为土壤培肥制度的建立及杨树人工林的合理施肥提供理论依据。[方法]通过3a大田试验,研究CK(对照,不施肥)、CF(单施化肥)、CM(牛粪)和CM+CF(牛粪和化肥各提供50%的氮)等处理对杨树人工林土壤理化特征、微生物数量、微生物量碳氮、活性有机碳、碳库管理指数(CPMI)及生长的影响。[结果]与CF处理相比,CM+CF处理显著提高了土壤中细菌数、真菌数、微生物总量和微生物量碳、氮含量,其中微生物量碳、氮含量分别较CF处理显著提高42.20%和43.75%;CM+CF处理还能明显提高土壤中碱解氮、速效磷、速效钾和交换性Mg含量,并显著降低土壤pH值。同时,CM处理使土壤总有机碳含量达最高值,而CM+CF处理使土壤的低活性、中活性、高活性有机碳含量和CPMI最高,其中CPMI分别较CK,CF和CM处理显著高出52.76,47.16,25.89。此外,CM+CF处理使杨树人工林的材积平均生长率达到45.36%,并显著高于其他处理。与CM+CF处理相比,CM处理对土壤和材积的影响效果较小。[结论]牛粪与化肥配施有助于改善杨树人工林土壤的生物学性状,有利于促进林木生长。     

有机无机肥料配合施用对设施番茄产量、品质及土壤硝态氮淋失的影响

利用田间小区试验,研究了有机无机肥配合施用模式对番茄产量、品质及氮素在土壤中累积和淋失的影响。结果表明：（1）与肥料用量较高的习惯施肥处理相比,大幅减少肥料施用的不同有机无机肥配合施用模式均能保证番茄产量稳定,显著提高经济效益,平均增收19127元·hm^-2其中（3／4）化肥N＋（1／4）猪粪N模式处理经济效益最高。（2）施用有机肥的3个有机无机肥配合施用模式处理可降低番茄果实中的硝酸盐含量,较全部施用化肥处理和习惯施肥处理的分别降低5．4％和7．0％;施用有机肥的3个有机无机肥料配合施用模式处理可提高番茄果实中Vc的含量,较全部施用化肥处理的提高9．4％。（3）与番茄种植前相比,番茄收获后土壤硝态氮含量总体上表现出表层增加、深层降低的趋势;大幅减施肥料的有机无机肥配合施用模式处理各土层硝态氮含量均低于习惯施肥处理相应土层硝态氮含量。（4）有机无机肥配合施用模式可显著降低渗漏水中硝态氮渗漏量,较全部施用化肥处理和习惯施肥处理的平均分别降低35．5％和55．1％。在试验条件下,综合考虑产量、经济效益和环境效益的适宜有机无机肥料配合施用模式为（3／4）化肥N＋（1／4）猪粪N模式处理。     

配施有机肥对茶园土壤性状及茶叶产质量的影响

通过连续4年(2009-2012)的田间定位试验,研究了配施不同比例有机肥对茶园土壤性状及茶叶产、质量的影响,筛选了适宜茶园的施肥结构。结果表明:配施有机肥显著提高茶园土壤pH,有效阻控茶园土壤酸化;提高茶园土壤有机质、全氮、碱解氮、有效磷和速效钾含量,提高幅度随着有机肥施用比例的增加而增加。配施有机肥处理土壤微生物生物量碳(SMBC)、氮(SMBN)分别比对照处理提高41.70%~72.23%和49.66%~75.63%,土壤微生物商(SMBC/SOC)和微生物生物量氮占土壤总有机氮的比例(SMBN/TN)分别比对照处理提高38.46%~43.85%和16.84%~72.96%;土壤基础呼吸量以全量施用有机肥处理最低,75%有机肥配施25%化肥处理最高;配施有机肥处理土壤呼吸商比对照处理降低20.94%~50.12%。适当的施肥结构促进茶树生长和提高茶叶品质,茶叶产量及品质以25%~50%有机肥配施75%~50%化肥处理较优。综合施肥结构对土壤基础性状、生物学性状和茶叶产量品质的影响,初步认为25%~50%有机肥配施75%~50%化肥(以氮素投入量计)是茶园系统较优的有机肥配施模式。     

Yield,Yield Components,Soil Chemical Properties,Plant Physiology,and Phosphorus Use Efficiency in Soybean Genotypes

Expansion of soybean [Glycine max (L.) Merrill] cultivated in Brazil to regions with low fertility soils gave rise to studies on the possibility of obtaining highly productive cultivars with high nutrient use efficiency. An experiment in greenhouse conditions was conducted to assess phosphorus (P) use efficiency (PUE) by 13 soybean genotypes. The genotypes were grown in an Ustoxix Quartzipsamment with two P rates [0 (no P application) and 150 mg P kg^?1], whose source was monoammonium phosphate (MAP, P₂O₅ 44%). Shoot dry weight (SDW), grain yield (GY), grain harvest index (GHI), relative yield (RY), and physiological components (photosynthetic rate, stomatal conductance, respiratory rate, and internal CO₂ concentration) were influenced by soybean genotypes and P rates. Genotypes BMX Apolo RR, BRS 360RR, BRS 378RR, CD 219RR, DM 2302RR, TMG 7161RR, and Vtop RR were classified as non-efficient and non-responsive to P application, while BMX Potência RR, Vmax RR, FPS Solar RR, NA 5909RR, TMG 1066RR, and M 6210 IPRO were classified as efficient and responsive. Phosphorus application increased the values of physiological components, which was not observed for N, K, Ca, Mg, and S concentration in the leaves and grains. Soybean genotypes selection for increased P efficiency could help growers overcome the problem of soybean cultivation on new areas or degraded pastures.     

牛粪有机肥替代化肥对茶叶产量、品质及茶园土壤肥力的影响

有机肥的施用是改善茶叶品质、提高茶叶产量的重要措施之一,牛粪资源化利用有助于降低对农业生态环境的污染,为探讨牛粪有机肥对茶叶产量和品质的影响,通过连续2年（2019—2020年）的田间定位试验,研究了不同比例牛粪有机肥替代化肥对六安瓜片乌牛早茶叶内外品质、产量及茶园土壤肥力的影响,筛选了适宜茶园的牛粪有机肥替代化肥比例。结果表明：全部化肥处理乌牛早茶叶产量最高,为821.87 kg/hm²,其次是牛粪有机肥完全替代化肥处理,为817.13 kg/hm²,随着牛粪有机肥替代比例增加,乌牛早茶叶的产量呈现上升趋势,且施肥处理乌牛早茶叶产量增幅为20.40%~44.01%;牛粪有机肥替代70%氮肥及牛粪有机肥全部替代氮肥处理下乌牛早茶叶内在成分及感官品质总体得分均最佳;牛粪有机肥替代化肥可以提高茶园土壤pH,随着牛粪有机肥替代比例升高,土壤有机质、全氮含量均呈现上升趋势,碱解氮、速效钾、有效磷含量均呈现先上升后下降趋势,且在牛粪有机肥替代70%氮肥处理下达到最高;牛粪有机肥替代化肥增加了茶园土壤脲酶、蔗糖酶、酸性磷酸酶及蛋白酶的活性,且牛粪有机肥替代70%氮肥处理下其土壤酶的活性较高。综合牛粪有机肥替代化肥对乌牛早茶叶产量品质、生物学性状及土壤肥力的影响,牛粪有机肥替代70%~100%氮肥是茶园系统较优的有机肥替代化肥模式。     

连续施用商品有机肥对耕地质量及蔬菜产量的影响

本试验采用连续3茬蔬菜种植试验,研究无肥、纯化肥、化肥配施不同量有机肥对耕地质量及各蔬菜产量的影响。结果表明,长期施用商品有机肥可导致砷、铅、铬在蔬菜地表层土壤中积累,且积累量随有机肥施用量的增加而增加;施用商品有机肥能降低碱性土壤的pH值,有利于作物正常生长;施用化肥配商品有机肥不仅能显著增加土壤中有机质、碱解氮、有效磷和速效钾的含量,还能显著增加包心菜、小青菜和玉米的产量,且随商品有机肥用量的增加而增加,表明肥料投入与土壤肥力和蔬菜产量呈正比。     

长期施有机肥和化肥对潮土胡敏酸结构特征的影响

以河南封丘长期肥料试验为平台,选择有机肥(OM)、化肥NPK(NPK)和不施肥(CK)3种处理,研究了不同施肥措施对潮土胡敏酸(HA)结构特征的影响。HA样品经提取纯化后,采用一系列固态~(13)C核磁共振(NMR)技术并结合元素分析和稳定碳同位素(δ~(13)C)技术对其结构进行定量表征。其中NMR技术包括高速多重倾斜幅度交叉极化/魔角自旋(multiCP/MAS)、偶极相移、化学位移各向异性过滤和质子碳编辑技术。结果表明:长期施有机肥和NPK肥增加了HA的饱和程度、氧化程度和极性,但缩合程度降低;HA的δ~(13)C值降低,表明有新的有机碳进入HA中。潮土HA以脂肪族化合物为主,烷基比例最高,占全碳的24.1%~26.3%;δ64~44处同时存在含氮烷基和甲氧基,且含氮烷基比例更高;另外异头碳和烷氧基中的非质子碳比例均很低。HA的芳香族成分中,δ142~113芳香碳以质子碳为主,且有少量质子芳香碳存在于δ113~93。结果还表明施肥均降低了HA的羧基和δ142~113芳香碳比例,增加了烷氧基和甲氧基比例;施有机肥还增加了酚碳和含氮烷基比例,降低了烷基比例。本研究表明长期施用有机肥和NPK肥使潮土HA结构向着疏水性程度和分解程度降低的方向发展;OM和NPK处理均使糖类物质增加,OM处理还使木质素和多肽增加,脂类物质降低。不同施肥模式下HA的形成机制不同。     

猪粪有机肥施用对潮土速效养分含量及团聚体分布的影响

针对集约化养殖畜禽粪便无序排放产生的环境问题,采用连续2年的盆栽试验,以猪粪有机肥为研究对象,设计5个有机肥施用水平(0、6.7、13.3、26.7、40.0 g·kg~(-1)土),研究了猪粪有机肥施用对潮土有机碳、速效养分含量及土壤团聚体分布的影响,为畜禽粪便田间消纳和合理施用提供理论依据。研究结果表明,土壤中有机碳、碱解氮、速效磷和速效钾含量均随有机肥施用量的增加而呈现逐渐升高趋势,且第二年土壤中各指标增加更加明显,第二年施肥处理各速效养分含量分别比第一年高2.7%~54.0%、6.7%~34.6%、36.8%~159.5%、20.3%~35.7%;土壤有机碳含量与外源有机碳投入量之间存在着显著的线性关系,有机肥施用可以显著提高生菜产量,且具有明显的后效作用。2年试验中,土壤团聚体以0.053~0.25 mm和0.053 mm小团聚体所占比例较大,且随有机肥施用量增加呈现降低趋势,而0.25~0.5 mm和0.5 mm大团聚体含量却随有机肥施用量增加呈升高趋势,可见,施用有机肥可促进大团聚体的形成,在有机肥施加量为40.0 g·kg~(-1)土时,土壤中0.25 mm团聚体的含量最高,土壤团聚体平均重量直径(MWD)和几何平均直径(GWD)最大,土壤的团聚化作用最强,土壤结构最稳定。     

绿肥翻压对烟田土壤理化性状及土壤微生物量的影响

试验于2003年9月至10月河南烟区的襄城县、舞阳县、叶县、罗山县4个试验点种植绿肥,2004年3月进行翻压,以研究绿肥对土壤容重、土壤pH值等理化性质的影响以及对土壤微生物的影响。试验结果表明,绿肥翻压可以有效地降低土壤的容重和土壤的pH值,提高土壤的有机质,同时能促进土壤中微生物数量的大量增加。与空白对照相比,各个处理土壤容重降幅为0.03~0.1 g/cm3,土壤pH值的降幅一般都在0.1~0.6,土壤有机质含量提高0.08%~0.1%。因此利用烟田冬季休闲空间种植和翻压绿肥,可作为提高土壤肥力、改善烟田土壤环境、实现烟叶生产可持续性发展的一个重要措施。     

有机肥对设施菜地土壤磷素状况的影响

以辽宁沈阳市郊某设施菜地土壤为研究对象,通过设置不同有机肥用量处理(0,20,60thm-2)的小区实验,系统研究不同有机肥处理对不同本底肥力设施菜地土壤全磷、速效磷含量变化的影响。研究结果表明,有机肥能够提高不同肥力设施菜地土壤0～20cm土层全磷含量,其中P1全磷含量与CK相比增加2.7～19.5%,P2增加7.6～33.6%。土壤0～20cm速效磷含量也随有机肥施用量的增加而明显增加,P2即有机肥施用量60thm-2时,不同肥力设施菜地土壤在黄瓜拉秧期速效磷含量与CK、P1之间均达显著差异(P<0.05)。本实验条件下,施用有机肥20thm-2,可保持施肥当季中肥力与高肥力设施菜地土壤磷素水平;当地常规有机肥施用量60thm-2可显著提高设施菜地土壤全磷与速效磷含量,从而加剧高肥力土壤磷素的累积,并对环境造成压力。     

The Effects of Short-Term Compost Application On Soil Chemical Properties and on Nutritional Status of Maize Plant

Compost may improve the soil quality and contribute to C sequestration. The short-term effects of compost application on soil properties of soil cropped with maize are reported here. Soil plots to which mature compost was added (at 50 Mg ha^?1 and 85 Mg ha^?1) were analyzed for total organic carbon (TOC), nutrients, heavy metals and other soil properties. In addition, maize plants were weighed at the end of the trial and analyzed for carbon (C), nitrogen (N), phosphorus (P) and heavy metals. The results demonstrate that soil amended with compost has an increased TOC content. The increase was proportional to the amount of compost used. At the highest dose used, compost also increased soil N and P content and the pH. Moreover, after compost application, the total heavy metal contents in soils did not increase. There was no difference between the maize yield from compost treated plots and the control plots. However, maize grains were found to be C, N and P enriched due to the increased nutrient status of the amended soil. In conclusion, the addition of mature compost improves soil properties by increasing the soil TOC content and this depends on the characteristics and the amount of compost used.     

Impact of Chemical Amendment of Dairy Cattle Slurry on Soil Phosphorus Dynamics Following Application to Five Soils

A 9-month incubation study was conducted to investigate the effectiveness of amending dairy cattle slurry with either alum, lime, poly-aluminum chloride (PAC), or ferric chloride (FeCl₃) in reducing water-extractable P (WEP) levels in five soils (four mineral and one organic). Alum, lime, and PAC were the most effective amendments in decreasing WEP (compared to a slurry-control) for the four mineral soils (by an average of 47% at the end the 9-month incubation period). In comparison, FeCl₃ increased WEP (compared to the slurry-control) by an average of 35% at the end the study. None of the amendments examined effectively reduced WEP of the organic soil. No amendment reduced soil-test P [(Morgan’s P (P_m) and Mehlich 3 P (M3P)] compared to the soil-only treatment. Alum maintained the greatest levels of M3P across the four mineral soils with the least risk of P loss to overlying water.     

有机肥等氮替代化肥对玉米产量和氮素吸收利用效率的影响

有机肥替施部分化肥是实现我国化肥零增长并保持作物高产稳产的重要途径之一。以等养分条件为基础,研究不同比例有机肥等氮替代基施化肥对玉米产量以及氮素吸收利用的影响,为云南红壤坡耕地有机肥的合理利用及玉米施肥结构的调整提供科学依据。通过田间小区试验,分别设置不施肥处理(CK)、施用100%化肥处理(NPK)及4个基施有机肥等氮替代化肥处理,替代率分别为10%(T₁),20%(T₂),30%(T₃),40%(T₄),分析玉米产量、吸氮量以及氮肥利用率等指标在不同施肥处理下的变化情况。结果表明:与NPK处理相比,不同比例有机肥替代化肥的处理能在一定程度上提高玉米籽粒、秸秆生物量,玉米籽粒产量提高达6.07%～19.53%,秸秆生物量提高达2.16%～21.76%,且有机肥替代30%的化肥处理下的玉米籽粒产量和秸秆生物量最高,分别达到7 653 kg/hm²,16 530 kg/hm²,较其他施肥处理有一定的显著性; 有机肥替代化肥的处理均提高了玉米籽粒和秸秆的吸氮量,各施肥处理下的玉米地上部氮素平均积累量从大到小依次为T₃(292 kg/hm²)>T₂(248 kg/hm²)>T₁(212 kg/hm²)>T₄(203 kg/hm²)>NPK(176 kg/hm²)>CK(52 kg/hm²),T₃处理较NPK,T₁,T₂,T₄处理下的玉米地上部分吸氮量分别提高了39.90%,27.37%,15.01%,30.38%; 与NPK处理相比,有机肥替代化肥的处理均提高了氮肥偏生产力、氮肥贡献率、氮肥表观利用率、氮肥的农学利用率,提高比例分别为5.00%～21.80%,2.44%～9.48%,20.48%～94.02%,7.54%～32.86%,且T₃处理下的各氮素利用率指标均显著高于其他施肥处理。综上,有机肥与化肥配施可提高玉米的籽粒产量和生物产量,且提高玉米的吸氮量及氮素利用效率,且以有机肥等氮替代30%基施化肥的配施效果最好,可作为云南红壤坡耕地玉米增产和氮肥增效的合理施肥模式。     

增减施有机肥对红壤性水稻土团聚体稳定性及胶结物的影响

利用具有35a的长期定位试验,在保证原定位试验继续正常开展的前提下,将原化肥处理改施有机肥,原有机肥处理改施化肥或增施有机肥,分析增减施有机肥后耕层土壤团聚体稳定性总有机碳(TOC)及其组分和铁铝氧化物的变化与作用关系,探究胶结物对红壤性水稻土团聚体稳定性变化的影响。结果表明:化肥(CF)及常量有机肥(NOM)处理增施有机肥后,团聚体平均重量直径(MWD)变化不明显,易氧化有机碳(EOC)分别升高87.44%和20.53%;高量有机肥(HOM)及NOM处理减施有机肥后,MWD分别显著降低8.39%和6.80%,高改化(H-C)处理的TOC、轻组有机碳(LFOC)及粗颗粒态有机碳(cPOC)含量显著降低,而常改化(N-C)处理的TOC及其组分变化不明显。无论增施还是减施有机肥,铁铝氧化物含量的变化规律不明显。相关及结构方程模型分析表明,大于0.25mm团聚体含量是影响团聚体稳定性的唯一直接影响因素;影响MWD及大于0.25mm团聚体含量的效应系数由大到小依次为:易氧化有机碳、轻组有机碳、游离氧化铁、络合态铁。因此,大于0.25mm大团聚体在红壤性水稻土的团聚体稳定性中发挥主导作用,有机碳...     

长期施用有机-无机肥对太湖流域土壤肥力的影响

通过长期田间定位试验研究了不同处理的有机无机肥施用对稻-麦轮作体系生产力和土壤肥力的影响.5年试验结果表明:施用有机肥和施用化肥体系均能达到较高的产量水平.单施N肥和NPK配合施用在试验前2年系统生产力(水稻+小麦) 没有显著差异.不同施肥处理对土壤养分有显著影响.施肥尤其是有机无机肥混施能显著增加土壤中碱解N、速效P和速效K含量.土壤中N以NO3--N形式存在,有机肥的施入显著降低了土壤中NH4+-N的含量.土壤速效K与速效P含量呈极显著相关,说明这些速效养分的同源性,可能是由有机肥施用带入土壤中的.土壤中碱解N与NO3--N含量呈显著的相关,而与NH4+-N含量没有关系,土壤速效P与有效态Fe含量呈显著相关.     

土层置换对草甸土理化性状及作物产量的影响

研究旨在探讨土层置换对土壤物理性质和化学性质的变化及对作物产量的影响,这对作物高产具有重要意义。试验地点选在黑龙江省宝清县草甸土上,以玉米绥玉7、马铃薯克新13和甜菜德国KWS3418为材料,设置土层置换和浅翻深松2个处理,分析不同处理对土壤含水率、硬度、土壤三相、速效养分及产量的影响。结果表明:与浅翻深松处理相比,土层置换处理后2年内,明显改善土壤物理性质,0~40 cm土层土壤含水率分别提高3.7%和3.0%;土壤硬度分别下降17.6%和21.6%。20~40 cm土壤固相分别降低0.3%和0.7%;液相分别提高3.7%和1.1%;气相分别提高2.0%和4.2%。进而容重降低,提高土壤通透性。土层置换处理改善20~40 cm土层土壤化学性质,提高土壤速效养分。20~40 cm土层平均养分变化为:碱解氮分别提高48.4%和46.0%;速效钾分别提高12.9%和38.9%;速效磷分别提高11.9%和15.6%。土壤不同层次物理和化学性质的改变能够提高作物产量,与浅翻深松处理相比,2011年、2012年玉米分别增产31.6%、17.9%,马铃薯分别增产70.5%、25.0%,甜菜分别增产12.4%和38.9%,差异达到显著水平。综合以上分析表明,土层置换处理后土壤2个作物生育期内能够改善心土层土壤物理性状、化学性状,从而提高作物产量。因此土层置换技术可为低产土壤改良及作物高产提供理论依据和技术支持。     

不同有机肥输入量对黑土密度分组中碳、氮分配的影响

为阐明不同有机肥施用量对黑土密度组分中碳、氮分配特征的影响,探讨合理调控土壤质量的施肥模式。以黑龙江省海伦国家野外科学观测研究站上进行了10年的田间定位试验土壤为研究对象,采用密度分组和腐殖质化学分组相结合的方法,探讨和分析不同有机肥施用量下土壤各密度组分中有机碳、氮的消长变化以及重组中腐殖物质的组成特征。结果表明:与试验初期相比,经过10年单施化肥处理,土壤总有机碳和全氮、各密度组分中有机碳氮以及腐殖物质各组分的含量均显著下降,而有机无机配施能够提升土壤总有机碳和全氮的含量水平,改善密度组分中有机碳氮的分配特征,土壤总有机碳、全氮和各密度组分中有机碳氮对不同有机肥施用量的响应有所差异。随着有机肥施用量的增加,土壤总有机碳和全氮的含量呈逐渐升高的趋势,二者与有机肥施用量之间达到极显著的线性相关(P<0.01);低量有机肥(7.5,15t/(hm2.a))配施化肥仅增加了土壤游离态轻组有机碳、氮的含量,并未造成闭蓄态轻组和重组中有机碳、氮的积累,而高量有机肥(22.5t/(hm2.a))配施化肥后,促进了土壤各密度组分中有机碳、氮的形成和积累;此外,低量有机肥有利于土壤富里酸的积累,高量有机肥有助于胡敏酸和胡敏素的积累,从而提高了土壤有机质的腐殖化程度,增强了土壤有机质的稳定性。在东北黑土区,加大有机肥的施用量是提高土壤肥力和土壤固碳能力的有效途径。