Mitigation of N_(2)O emissions in water-saving paddy fields:Evaluating organic fertilizer substitution and microbial mechanisms

Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.

Combined Application of Organic and Inorganic Fertilizers on Black Soil Fertility and Maize Yield

By two years （2007-2008） located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers＇ increasing production range was higher than the single chemical fertilizers＇ which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.

Combined Effect of Organic Manures and Inorganic Fertilizers on the Growth and Yield of Hybrid Rice (Palethwe-1)

We investigated the effect of combining organic and inorganic fertilizers on the growth and yield of hybrid rice (Palethwe-1) in the dry and wet seasons of 2015. Four quantities of inorganic fertilizer were used in the main plot [0%, 50%, 75%, and 100% nitrogen, phosphorus, and potassium (NPK)] based on the recommended amounts of 150 kg N ha-1, 70 kg P2O5 ha-1, and 120 kg K2O ha-1, while different organic manures were applied to subplots [no organic manure (O0), cow manure (Oc), poultry manure (Op), and vermicompost (Ov);all at 5 t·ha-1] as part of a split-plot experimental design with three replicates. In both seasons, significant differences in growth parameters including number of tillers hill-1, soil-plant analysis development (SPAD) values, total dry matter, yield, and yield components were observed in plants supplied with different inorganic fertilizers. The 100% NPK (I100) fertilizer produced the maximum yield but similar yields were achieved in plots supplied with 50% NPK (I50) and 75% NPK (I75). Significant differences in growth and yield parameters were also found in crops supplied with organic manures. Although identical quantities were supplied, Op produced the best growth parameters in both seasons including total dry matter, yield, and yield components. Oc also performed well. Combining inorganic and organic fertilizers demonstrated that I50 together with Op (5 t·ha-1) provided similar growth, total dry matter, and yield parameters to I100 in both seasons. Oc (5 t·ha-1) plus I75 also achieved similar yields to I100. This study demonstrates that the combined application of inorganic fertilizers and organic manures has the potential to reduce chemical fertilizer usage without decreasing the yield of hybrid rice, and can enhance the growth, yield, and yield components of Palethwe-1.

Effects of Integrated Organic and Inorganic Fertilizers on Yield and Growth Parameters of Rice Varieties

We investigated the effects of integrated organic and inorganic fertilizers on the growth and yield of indica rice variety Manawthukha and japonica rice variety Genkitsukushi.In a split-plot design,the two rice varieties were assigned as main plot factors,and the integrated treatments were the subplot factors,including no-N fertilizer(N0),50%chemical fertilizer(CF)(CF50),100%CF(CF100),50%CF+50%poultry manure(PM)(CF50PM50),50%CF+50%cow manure(CM)(CF50CM50),and 50%CF+50%compost(CP)(CF50CP50).CF100 was equivalent to N at 85 kg/hm2.Manure was applied based on the estimated mineralizable nitrogen(EMN)level,which is dependent on total N(%)of each manure type.Manawthukha rice plants were taller with higher tiller number and dry matter content.However,higher soil-plant analysis development(SPAD)values were measured in Genkitsukushi throughout the crop growth period,resulting in higher seed-setting rate(%)and greater yield.At the same N level,CF50PM50 application in both rice varieties resulted in higher SPAD values,plant height and tiller number than CF100.CF50PM50 containing total N more than 4%supplied synchronized N for the demands of the rice plants,resulting in maximum dry matter,yield and yield components.CF50CM50 and CF50CP50 treatments containing total N less than 4%resulted in lower yields which were similar to CF100.These results indicated that integrating organic and inorganic fertilizers enhanced growth parameters and yields of Manawthukha and Genkitsukushi,while reducing the dose of chemical fertilizer.

Calcium carbonate promotes the formation and stability of soil macroaggregates in mining areas of China

We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).

减量灌水及有机无机肥配施对西北灌区玉米光合生理、籽粒产量及品质的影响

针对绿洲灌区玉米生产中普遍水肥投入大、利用效率低等问题,通过研究不同灌水量和有机无机肥等氮配施对玉米光合生理、籽粒产量和品质的影响,以期获得最佳的灌水水平和有机无机肥等氮配施比例。2021—2022年,在绿洲灌区采用两因素裂区试验设计,主区为2个灌水水平(传统灌水和减量20%灌水),副区为5个有机无机肥等氮配施比例(全施无机氮肥、75%无机氮肥+25%有机肥、50%无机氮肥+50%有机肥、25%无机氮肥+75%有机肥和全施有机肥),探究玉米光合生理、籽粒产量和品质对不同水氮管理模式的响应特征。结果表明,与传统灌水(I2)相比,减量20%灌水(I1)降低了玉米叶面积指数(leaf area index,LAI)、光合势(photosynthetic potential,LAD)、净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs),提高了胞间CO_(2)浓度(Ci)、籽粒蛋白质含量和籽粒苏氨酸含量;有机无机肥配施对玉米光合生理指标、籽粒产量和品质都有显著影响,随有机肥比例增加,有机无机肥配施对玉米的影响会逐渐从正效应变为负效应;与传统灌水结合全施无机氮肥(I2F1)相比,减量20%灌水结合75%无机氮肥+25%有机肥(I1F2)玉米平均叶面积指数(mean leaf area index,MLAI)提高了6.9%~7.1%,总光合势(total photosynthetic potential,TLAD)无显著变化;玉米吐丝期-蜡熟期LAI提高了5.0%~11.4%,吐丝期-蜡熟期LAD提高了7.5%~9.1%。I1F2较I2F1提高了玉米抽雄期-蜡熟期叶绿素含量(chlorophyll content,SPAD)、Pn、Tr和Gs,降低了Ci。2年内I1F2较I2F1玉米增产12.0%~12.5%,籽粒中蛋白含量提高了6.9%~18.9%,籽粒中苯丙氨酸、赖氨酸、苏氨酸、色氨酸、亮氨酸、异亮氨酸和缬氨酸含量分别提高了29.6%~43.3%、77.7%~93.3%、49.7%~51.5%、18.4%~28.6%、39.5%~46.0%、57.4%~78.1%和35.1%~41.3%。其他处理对玉米光合生理、籽粒产量及品质指标也有一定影响,但综合2年结果,I1F2影响更显著。因此,减量20%灌水(3240 m^(3)hm^(–2))结合75%无机化学氮肥(270 kg hm^(–2))配施25%有机肥(90 kg hm^(–2))是实现西北灌区玉米高产优质生产目标的适宜水氮管理模式。

有机无机肥配施对西北地区不同土壤类型氮素矿化影响

为揭示不同施肥措施和土壤类型对我国西北地区典型农田土壤氮素矿化特征的影响,通过室内恒温好气培养法,分别研究不施肥(CK)、单施尿素(U)、单施有机肥(M)和尿素配施有机肥(U+M)施肥模式对土壤氮素矿化动态过程的影响,并对土壤累积矿化氮量进行一级动力学方程拟合及相关性分析。结果表明,施肥和土壤类型均显著影响土壤铵态氮含量、硝态氮含量和累积矿化氮量,且两者之间存在显著的交互作用。不同类型土壤累积矿化氮量和矿化速率由大到小依次为塿土、黄绵土、黄河灌淤土、灰棕漠土。与CK处理相比,不同施肥处理显著增加土壤累积矿化氮量、矿化速率常数(k)和矿化势(N0),处理间差异显著(P<0.05)。单施尿素和尿素配施有机肥处理的累积矿化氮量和矿化速率分别较CK处理增加2.83~6.71倍和3.83~7.70倍。相关分析表明,土壤累积矿化氮量与土壤有机质含量和全氮含量呈显著正相关关系。研究结果表明,有机无机肥配施处理可显著促进西北地区不同土壤类型氮素矿化,提高氮素有效性和供氮能力,有利于保持土壤矿质氮含量,对农田氮素高效利用有重要作用。

有机无机肥配施菌剂对葡萄园土壤、果实及葡萄酒品质的影响

为了减少化肥施用量,充分发挥有机肥效应并有效提高酿酒葡萄果实品质,试验设置不施肥对照(CK)、100%化肥(C_(1))、100%有机肥(O_(1))、100%有机肥+菌剂(O_(1)B)、60%化肥+40%有机肥(C_(0.6)O_(0.4))、60%化肥+40%有机肥+菌剂(C_(0.6)O_(0.4B))6个处理,除CK外,各施肥处理的氮、磷、钾养分含量一致,研究不同处理对赤霞珠葡萄园土壤养分、果实及葡萄酒基本理化性质以及酚类物质积累的影响,分析土壤环境因子与葡萄及葡萄酒品质指标的相关性,以期为酿酒葡萄的科学高效施肥提供参考依据。结果表明:与CK处理相比,O_(1)和C_(0.6)O_(0.4)处理的土壤有机质、全氮、全钾、速效钾和可溶性有机碳含量分别提高30.22%和70.65%、27.45%和31.37%、10.10%和20.11%、438.93%和491.60%。与C_(1)处理相比,有机肥配施菌剂处理(O_(1)B、C_(0.6)O_(0.4B))土壤有机质、全氮、全钾、速效钾含量分别提高了101.30%和104.78%、27.45%和47.06%、13.58%和23.12%、2.23%和15.81%。有机肥配施菌剂可显著提升葡萄园土壤肥力;与CK相比,C_(0.6)O_(0.4B)处理的葡萄果实总可溶性固形物、还原糖、糖酸比分别提高了4.93%、10.35%和49.78%;葡萄酒酒度提高了6.67%、总酸含量降低了7.93%;果皮总酚和总花色苷含量分别提高了26.98%和19.56%,葡萄酒总酚和总花色苷含量分别提高了11.13%和56.98%;冗余度分析和Spearman相关系数表明,酿酒葡萄果实和葡萄酒品质指标的变化与土壤环境因子(有机质、硝态氮、铵态氮、速效钾、有效磷)密切相关,证实了生物菌剂和有机肥共施可提高酿酒葡萄品质。综合比较,施用有机肥及菌剂可以改善土壤性状及酿酒葡萄品质,进而提高葡萄酒口感和色泽品质,其中减施化肥配施有机肥和菌剂(C_(0.6)O_(0.4B))效果最好。

有机无机氮配施对高芥酸油菜绵油309产量及品质的影响

为探究有机无机氮配施对高芥酸油菜产量及品质的影响,本试验研究了6个不同处理(纯施有机肥、纯施无机肥、20%、30%、40%、50%有机肥替代量)对高芥酸工业型油菜(绵油309)产量、品质、土壤养分及经济效益的影响,以期为高芥酸工业型油菜的高产、提质、增效生产提供理论依据。结果表明:与单施化肥相比,一定比例有机无机氮配施可以显著提升油菜产量,30%有机氮配施处理产量最高,达3501.63 kg/hm^(2),较纯施有机肥显著增产24.84%,较纯施无机肥显著增产23.47%;有机无机氮配施促进油菜主序和分枝的生长发育。30%有机氮肥替代处理下在不影响芥酸含量的同时增加含油量,进而达到显著增加单位面积芥酸和食用油脂产量的目的;还能够提高土壤氮储量,从而使土壤维持较高肥力水平,实现油菜的减肥增效,以获得更高的经济效益和环境效益。

化肥有机肥配施对黑土团聚体稳定性及其富里酸结构的影响

为探讨化肥有机肥配施对黑土团聚体稳定性及其富里酸结构的影响,依托中国科学院海伦农业生态试验站2001年设置的长期定位试验,分析不施肥(CK)、单施化肥(NPK)、化肥+15000 kg·hm-2有机肥(NPKM1)及化肥+22500 kg·hm-2有机肥(NPKM2)处理对土壤团聚体稳定性、团聚体富里酸结构及光学特性的影响。结果表明:(1)化肥有机肥配施显著提高了0~40 cm土层>0.25 mm团聚体分布比例,增强了土壤团聚体稳定性;与CK相比,NPKM1和NPKM2处理的0~20 cm土层>0.25 mm团聚体分布比例分别增加6.2%~26.3%和8.4%~50.2%。(2)土壤各粒径团聚体富里酸包含类富里酸、类胡敏酸和类蛋白质共3种荧光组分,化肥有机肥配施提高了类富里酸、类胡敏酸组分荧光强度及百分比和类蛋白质组分荧光强度,降低了类蛋白质组分荧光强度百分比;与CK相比,NPKM1和NPKM2处理>0.25 mm团聚体富里酸的类富里酸和类胡敏酸组分荧光强度分别提高7.0%~30.5%和12.8%~45.4%。同时土壤各粒径团聚体富里酸均受自生源和外生源共同作用的影响(FI(荧光指数)>1.4,0.8<BIX(自生源系数)<1.0),呈现强腐殖化和新近自生源特征(3.0<HIX(腐殖化指数)<6.0)。(3)土壤各粒径团聚体富里酸的SUVA 254、SUVA 280和E 4/E 6值随有机肥施用量增加而增加,芳香性增强,分子结构变简单。相关性分析表明,土壤团聚体富里酸荧光组分、芳香性(SUVA 254)、腐殖化程度(HIX、E 4/E 6)是影响团聚体稳定性的重要因素。因此,化肥有机肥配施通过增加团聚体富里酸荧光组分强度,提高团聚体芳香性和腐殖化程度,进而提高土壤团聚体稳定性。

有机-无机肥配施对新疆核桃园土壤和叶片养分的影响

[目的]研究有机-无机肥配施对核桃园土壤和叶片养分的影响,筛选影响叶片养分的主要土壤化学因子,为新疆核桃园土壤养分资源高效管理提供科学依据。[方法]以新疆喀什地区叶城县核桃主栽区的10年生‘温185’核桃为研究对象,采用单因素完全随机区组设计,以当地主要的化肥施用类型(磷酸氢二铵和硫酸钾,YD)为对照,探究有机-无机肥配施(矿源黄腐酸钾和中量元素水溶肥,YZ)对核桃园土壤化学特性和叶片矿质元素的影响。[结果]与YD施肥措施相比,YZ处理显著降低了土壤pH、盐离子含量,提高了叶片矿质元素含量,但具有季节性差异。其中,5月,YZ处理显著提高了土壤NO_(3)^(-)-N(460.22%)、AK(46.46%)和叶片N(12.16%)、K(17.46%)、Zn(21.88%)元素含量;7月,YZ处理显著降低了土壤pH(2.21%)、EC(27.25%)、Cl^(-)-S(23.37%)、NH_(4)^(+)-N(61.09%)、AP(30.03%)、Na^(+)(13.24%)和叶片Cl^(-)-L(15.94%)元素含量(p<0.05),相反,显著提高了叶片N(4.16%)、P(13.25%)、Ca(20.73%)、Mg(44.04%)、Na(66.67%)、Fe(24.62%)、Mn(52.47%)、B(31.85%)元素含量(p<0.05);9月,YZ处理显著降低了土壤EC(20.45%)、NH_(4)^(+)-N(37.31%)、AP(21.74%)、Na^(+)(11.36%)含量(p<0.05),相反,显著提高了OM(22.17%)、NO_(3)^(-)-N(59.09%)、AK(56.47%)含量(p<0.05)。线性回归分析结果表明,土壤pH、Na+和Cl^(-)-S是新疆核桃园中影响核桃叶片矿质元素含量的重要土壤化学因子,增施有机肥并且降低土壤pH,有利于叶片N、P、K、Na、Fe、Zn元素的积累。[结论]YD处理提高了土壤EC、Na^(+)、Cl^(-)-S、NH_(4)^(+)-N等盐离子含量,长期施用可能会加剧新疆核桃园的土壤盐渍化水平;YZ处理可显著降低土壤pH、Na^(+)、EC、NH_(4)^(+)-N等盐离子含量,提高了叶片N、P、K、Fe等矿质元素含量,建议在新疆核桃主栽区核桃园,7月之前可通过有机-无机肥配施降低土壤盐渍化水平来减轻盐碱危害,同时平衡叶片矿质元素含量,而应尽量避免长期单一施用化肥。

灌溉与有机肥处理对冬小麦水分利用效率的影响

探究不同灌溉量和有机无机肥配施的组合处理对冬小麦生长及水分利用效率的影响,为冬小麦的科学施肥管理提供参考。以关中地区冬小麦‘小偃22’为研究对象,通过田间试验,采用等氮原则对有机肥与无机肥进行不同比例配施(F1,100%无机肥;F2,24%有机肥+76%无机肥;F3,48%有机肥+52%无机肥),结合2个水平的灌溉(充分灌溉W1和亏缺灌溉W2),共设计6个灌溉施肥组合处理(W1F1、W1F2、W1F3、W2F1、W2F2和W2F3)。通过测定冬小麦的生长指标(植株株高和叶面积指数)、0~200 cm土层土壤体积含水率(以20 cm为深度间隔)和小麦的产量及构成要素(干物质量、穗长、有效穗数、千粒质量和籽粒产量),分析灌水量与有机无机肥配施对冬小麦生长及水分利用效率(WUE)的影响。结果表明:(1)充分灌溉(W1)条件下,F2、F3处理株高较F1处理分别提高3.4%~21.2%和0.8%~15.9%,叶面积指数提高5.7%~18.5%和16.8%~47.4%,干物质量提高12.1%~26.1%和21.1%~36.0%,穗长提高12.5%和14.5%,有效穗数提高6.6%和9.3%,千粒质量提高18.3%和24.4%,籽粒产量提高14.8%和28.6%,WUE提高14.6%和27.5%;亏缺灌溉(W2)条件下,与F1处理相比,F2、F3处理株高分别提高8.5%~16.2%和0.5%~10.6%,叶面积指数提高4.9%~20.7%和17.0%~50.0%,干物质量提高7.7%~25.7%和15.0%~34.6%,穗长提高12.3%和18.5%,有效穗数提高7.4%和18.0%,千粒质量提高15.3%和25.1%,籽粒产量提高13.1%和31.8%,WUE提高21.4%和35.2%。在相同灌溉水平下,有机无机肥配施处理可以提高土壤体积含水率。(2)W2F2处理对冬小麦株高增长最有效,灌浆期达最大值,较W1F1处理增长10.4%;W2F3处理对冬小麦叶面积指数、干物质量、穗长、有效穗数、千粒质量影响最大,成熟期较W1F1处理分别提高23.6%、39.0%、20.3%、18.4%和33.1%。(3)W2F3处理对冬小麦籽粒产量和WUE的影响最为显著,W1F1、W1F2、W1F3、W2F1和W2F2处理籽粒产量分别提高了35.5%、18.0%、5.3%、31.8%和16.6%;W1F1、W1F2、W1F3、W2F1和W2F2处理WUE分别提高了52.6%、33.2%、19.7%、35.2%和21.4%。亏缺灌溉与48%有机肥+52%无机肥组合处理的冬小麦籽粒产量和WUE最高,该灌溉施肥管理方案为关中平原及环境相似地区冬小麦的科学施肥管理提供了科学依据。

粪/菌秸秆条带混施对黑土有机无机复合体组成及有机碳分布特征的影响

为探究玉米秸秆混施畜禽粪/生物菌剂条带还田条件下黑土有机无机复合体组成及有机碳分布变化特征,本研究于2020年4月在吉林省榆树市黑土区按等碳原则进行1次条带施肥,第2年条带变苗带不施肥,秸秆原位粉碎后,将下茬作物播种行上的秸秆向两侧休闲带堆放形成秸秆覆盖条带,进行连续两年的秸秆原位还田试验。本试验共设4个处理,即条带秸秆覆盖+鸡粪(SO)、条带秸秆覆盖+牛粪(SN)、条带秸秆覆盖+生物菌剂(SJ)和条带秸秆覆盖(SCK)。采用胶散分组法提取有机无机复合体,分为水质分散组(G0)、钠质分散组(G1)和超声分散组(G2)。结果表明:添加畜禽粪及菌剂的处理土壤各组分复合体及其碳含量相比SCK有所增加,SJ处理增加最多,2022年SJ处理G0复合体含量和其碳含量分别增加38 g∙kg^(−1)和1.74 g∙kg^(−1)。各畜禽粪及菌剂处理不同组分复合体含量及其有机碳含量存在一定差异。2021年,SJ和SO处理G1复合体含量相比SN处理显著增加33.46~37.66 g∙kg^(−1),有机碳含量增加0.69~0.78 g∙kg^(−1);SJ、SO处理G2复合体有机碳含量相比SN处理也显著增加。2022年,SJ、SO处理G0复合体有机碳含量与SN处理相比增加显著,其最高增加量为1.02 g∙kg^(−1);SJ处理G1复合体含量相比SO、SN处理分别显著增加41.25 g∙kg^(−1)、49.92 g∙kg^(−1);SJ处理G2复合体有机碳含量最高。两年间,SJ处理G0复合体含量相比SO处理增加23.35~23.74 g∙kg^(−1)。扫描电镜和X射线衍射物相分析结果表明,粪/菌秸秆混施有效保持了复合体表面结构,提高了有机碳转化率。综上,玉米秸秆混施生物菌剂处理更有利于土壤肥力的提升和土壤碳固存的增强,可选为最优还田模式。

牛粪与化肥配施比例对苹果园土壤有机碳库和酶活性的影响

【目的】研究牛粪化肥配施比例对苹果园土壤活性有机碳组分和酶活性的影响,揭示不同配施比例对土壤碳库的影响,为苹果园牛粪与化肥的科学配施及土壤质量改善提供理论支撑。【方法】选取中国农业科学院果树研究所砬山施肥试验平台中不施肥(CK)、100%化肥(CF100)、25%牛粪配施75%化肥(CM25CF75)、50%牛粪配施50%化肥(CM50CF50)、75%牛粪配施25%化肥(CM75CF25)、100%牛粪(CM100)6个处理,分别测定施肥区(F)与非施肥区(NF)土壤活性有机碳组分(颗粒有机碳,POC;微生物量碳,MBC;易氧化有机碳,ROC)和酶活性(α-D-葡萄糖苷酶,AG;β-D-葡萄糖苷酶,BG;纤维素酶,CBH;过氧化物酶,PER;脲酶,UR)等相关指标。【结果】(1)牛粪化肥配施后施肥区土壤SOC、POC和ROC的含量随着牛粪施入比例的增加而增加;CM50CF50处理的MBC含量最高,比CK提高了139.7%。非施肥区,CF100、CM25CF75、CM50CF50、CM75CF25处理与CK相比土壤POC含量分别下降了32.8%、28.4%、21.6%、14.7%,CM50CF50和CM75CF25处理ROC含量分别下降了31.5%和17.4%。同一处理施肥区活性有机碳组分含量明显高于非施肥区。(2)CM25CF75、CM50CF50、CM75CF25、CM100处理施肥区土壤α-D-葡萄糖苷酶活性较CK分别提高了87.7%、68.4%、278.1%、331.6%;CM25CF75处理β-D-葡萄糖苷酶活性最高(39.00μg·g^(-1)·h^(-1));脲酶活性随牛粪施入比例的增加先升高后降低。牛粪化肥配施非施肥区土壤α-D-葡萄糖苷酶和脲酶活性也显著提高。(3)牛粪化肥配施显著提高了施肥区土壤POC/SOC和碳库管理指数(CPMI),CM25CF75、CM50CF50、CM75CF25、CM100处理的碳库管理指数分别提高了19.7%、38.3%、56.2%、103.5%。非施肥区牛粪化肥配施碳库管理指数显著下降。同一处理施肥区土壤碳库管理指数明显高于非施肥区。(4)相关分析和主成分分析表明,施肥区土壤中活性有机碳组分与α-D-葡萄糖苷酶活性呈显著正相关,牛粪比例的提高对土壤活性有机碳的提高贡献较大。【结论】牛粪化肥配施对于苹果园施肥区土壤的改善效果大于非施肥区。高比例的牛粪(配施比例在50%以上)能够提高土壤有机碳各组分含量和促进土壤酶活性增强,是苹果园科学施肥的较好的配施比例。

烤烟根际磷库特征及其对有机无机肥配施的响应

为综合分析烤烟根际土壤磷库特征及其对有机无机肥配施的响应,通过田间小区试验,分析比较了烤烟产量、产值、不同等级烤烟比例以及根际土壤磷库特征的差异。结果表明,有机无机肥配施显著提高了烤烟的产量、产值、上等烟比例以及不同形态的磷组分含量。与常规施肥(处理2)相比,化肥减量20%配施有机肥(处理3)、配施生物有机肥(处理4)以及化肥减量30%配施有机肥和生物有机肥(处理5)的产量、产值和上等烟比例平均显著增加了30.00%、59.57%和82.42%,活性磷、中活性磷、稳定性磷以及难溶性磷含量平均显著增加了48.36%、67.15%、16.51%和12.46%,其中活性磷对烤烟产量的形成贡献最大,占到了所有磷组分可解释量的68.23%,以树脂磷Resin-Pi为首要贡献因子,占到了活性磷组分可解释量的68.70%,其次为17.30%的活性磷NaHCO_(3)-Pi和14.10%的活性磷NaHCO_(3)-Po,特别是处理4,各磷组分含量最高,显著增加烤烟产量、产值和上等烟比例的同时,显著降低了中下等烟比例,体现出化肥减量配施生物有机肥的明显产量优势和减肥增效效应。

部分有机肥代替化肥对中强筋小麦产量及品质的影响

为探索淮北麦区高产、优质中强筋小麦在保持产量和品质情况下的绿色施肥方式。以中强筋小麦‘徐麦44’为材料,研究设计3种施肥方式:单施化肥(T_(1))、1/3有机肥+2/3化肥配施(T_(2))、单施有机肥(T_(3)),通过对籽粒蛋白质含量、粉质质量指数、面粉吸水率、面团的形成时间和稳定时间、粉质质量指数等粉质参数、淀粉含量、淀粉糊化特性、籽粒容重进行测定,并进行差异显著性检验,分析施肥对产量及品质的影响。结果表明,T_(2)处理的产量及其三因素、籽粒容重、沉降值、吸水率、淀粉含量、糊化特性与T_(1)处理相比均无显著差异,而籽粒蛋白质含量、形成时间、稳定时间、粉质质量指数均显著高于T_(1)处理,弱化度显著低于T_(1)处理;与T_(1)、T_(2)处理相比,T_(3)处理显著降低了中强筋小麦的产量及其三因素、蛋白质含量、容重、沉降值以及粉质参数,但是增加了籽粒的淀粉含量和糊化特性相关参数。T_(2)处理在减少化肥施用量的情况下能够稳定小麦产量与品质,甚至在有些品质参数上有所提升,提高了中强筋小麦的面筋强度及加工品质,这在淮北麦区高产、优质中强筋小麦生产绿色施肥方式的探索上有一定指导意义。

不同施肥措施臭氧浓度升高对不同水稻品种光合特性的影响

近地层臭氧(O_(3))已严重威胁到作物生产,而施肥可以调节土壤的养分平衡,进而促进作物生长。以两个水稻品种(徽两优898和南粳9108)为研究对象,利用开顶式气室,设置2个O_(3)浓度处理(NF:环境大气为对照;NF40:环境大气+40 nmol/mol O_(3)),每个O_(3)处理下嵌套设置3个肥料处理(Ino:施无机肥处理,270 kg N hm^(-2) a^(-1);Red:减施无机肥30%处理,189 kg N hm^(-2) a^(-1);Com:有机无机肥配施处理,Red+有机肥鸡粪5000 kg hm^(-2) a^(-1)),通过测定不同生育期水稻光合参数,探究不同肥料处理下O_(3)对水稻不同生育阶段光合生理的影响。结果表明,NF40对水稻营养生长阶段的饱和光合速率(A_(sat))没有显著影响,而显著地降低了水稻灌浆期的A_(sat)。基于两个水稻品种的A_(sat)和相对叶绿素含量(SPAD)相对减少量与O_(3)累积剂量关系的斜率,发现杂交稻徽两优898(A_(sat)和SPAD的斜率:-1.55和-0.98)比常规稻南粳9108(A_(sat)和SPAD的斜率:-0.92和0.06)对O_(3)更敏感。此外,基于不同O_(3)处理下水稻的气孔导度(g_(s))和胞间二氧化碳浓度(C_(i)),可以看出O_(3)造成南粳9108光合速率降低的主要是非气孔因素,而徽两优898光合的降低是由气孔因素和非气孔因素共同限制。与Ino处理相比,Red处理主要通过降低叶片SPAD进而显著地抑制两种水稻品种的A_(sat),但Ino处理和Com处理间A_(sat)没有显著差异,说明有机无机肥配施能部分缓解减施无机肥造成水稻光合的降低。O_(3)和肥料处理对两个水稻的所有光合参数都没有显著的交互影响,表明短期有机无机肥配施并不能有效缓解O_(3)对作物造成的负面影响。在O_(3)污染背景下,研究结果可以为通过合理的农田氮肥管理措施减缓O_(3)造成的作物减产提供理论依据。

牛粪有机肥与化肥配施对土壤重金属形态的影响

为缓解畜牧业产能的提高和日益严峻的畜禽粪污污染之间的矛盾,充分挖掘畜禽粪污肥料化利用的潜力,避免过量施用对环境带来的潜在重金属危害,本试验采用牛粪有机肥为研究对象进行盆栽试验,根据牛粪有机肥和化肥的不同配施比例,设置5个处理,测定收获后不同处理土壤中重金属铜、锌各形态质量分数,并进行土壤有机碳和pH的测定。结果表明,与CK组相比,配施牛粪有机肥可以降低土壤中重金属Cu、Zn的总质量分数,DF1处理组降低幅度最大,分别下降了25.54%、39.20%;与CK组相比,DF1和DF2处理组可交换态Cu分配率从15.86%分别提高至28.13%、42.02%,促进残渣态向可交换态转化,DF2处理组对分配率的提高幅度最大;与CK组相比,CD和DF1处理组残渣态Zn分配率分别降低至39.27%、38.40%,DF2处理组变化幅度最大,降低至24.33%。配施牛粪有机肥后,土壤pH、有机碳含量有上升趋势,其中土壤有机碳与土壤中有效态铜、锌的分配率变化趋势呈正相关,相关性显著(P<0.05),同时土壤有效态锌与土壤pH的变化趋势呈正相关,相关性显著(P<0.05),但重金属铜的有效态与pH的相关性不显著(P>0.05)。施用牛粪有机肥时应严格遵循测土配方算出的实际需求量,避免过量施用,增加土壤环境的重金属污染风险。

旱作区农田土壤AM真菌对长期有机无机施肥的响应

AM真菌群落动态变化对于长期有效的土壤生态系统管理非常重要。为揭示旱作区农田土壤丛枝菌根(AM)真菌对长期有机、无机培肥管理的响应机制,利用单因素随机区组设计,基于连续11年的定位试验及高通量测序方法,研究了不施肥(T0)、长期单施化肥(T1)、长期化肥与牛粪有机肥(T2)和长期化肥与羊粪有机肥(T3)对土壤的影响,比较了土壤AM真菌群落组成及多样性间的差异,探究了驱动土壤AM真菌群落组成及多样性变化的土壤环境因子及其相互作用效应。结果表明:随培肥时间延长,与T0处理相比,T2、T3处理的土壤全氮、有机质含量显著增加,pH显著下降(P<0.05);与2018年相比,2021年的T0、T1和T3处理土壤全磷和速效钾含量显著下降。有机无机肥配施下,球囊霉属(Glomus)和类球囊霉属(Paraglomus)是土壤AM真菌的优势属,但近明球囊霉属(Claroideoglomus)的相对丰度显著下降,从优势属变为非优势属。近明球囊霉属较球囊霉属和类球囊霉属相对丰度而言,更容易受长期培肥影响而发生显著改变。连续有机无机肥配施到2018年后,T2、T3处理的土壤近明球囊霉属和两性球囊霉属(Ambispora)的相对丰度与T0间有显著差异(P<0.05);培肥至2021年后,T2、T3处理土壤近明球囊霉属和两性球囊霉属的相对丰度与T0处理间无显著差异。随培肥时间延长,不同处理间土壤AM真菌群落的α多样性差异消失。NMDS分析结果表明:长期培肥改变了土壤AM真菌群落的β多样性,但T2与T3处理间土壤AM真菌群落相似性较一致。连续培肥改变了土壤AM真菌群落结构组成和多样性,驱动AM真菌群落变化的土壤环境因子由土壤全氮、pH转变为土壤全磷。长期有机无机培肥没有同步提升土壤全磷、速效钾等主要理化性状。随培肥年限增加,驱动土壤AM真菌群落结构和多样性变化的土壤因子发生了显著改变,AM真菌群落会随土壤环境因子的变化倾向于更加敏感的驱动因子。

化肥减量配施有机肥对玉米产量、养分吸收及氮素利用效率的影响

【目的】探讨山西旱地玉米化肥减量配施有机肥的可行性与适宜化肥减量比例。【方法】于2021—2023年进行田间定位试验,研究CK(不施任何肥)、NPK(全化肥)、化肥减量(40%、30%、20%)生物炭有机肥替代(SWC40、SWC30、SWC20)和精致有机肥替代(JZ40、JZ30、JZ20)对玉米产量、养分吸收及氮素利用效率的影响。【结果】适当比例下化肥减量配施有机肥能显著增加玉米籽粒产量和地上部生物量,提高养分累积吸收量及氮素利用效率。与NPK处理相比,2021、2022、2023年,SWC40处理籽粒产量分别显著提高14.69%、9.88%、25.62%,JZ30处理籽粒产量与NPK处理无显著差异。2023年,SWC40处理籽粒氮、磷、钾素累积吸收量分别为145.64、38.30、38.07kg/hm^(2),与NPK处理相比,SWC40处理玉米籽粒氮、磷、钾素累积吸收量显著增加38.36%、56.14%、46.59%;SWC40处理地上部氮、磷、钾素累积吸收量分别为311.79、69.49、204.22 kg/hm^(2),较NPK处理显著增加了64.08%、84.32%、84.43%。SWC40处理氮肥农学利用率、氮肥偏生产力、氮肥贡献率和氮肥表观利用率为6.80kg/kg、15.64kg/kg、43.53%、31.01%,较NPK处理显著提高了49.78%、16.80%、29.48%、165.49%。【结论】化肥减量配施生物炭有机肥相较精致有机肥效果更佳,化肥减量40%配施生物炭有机肥为最优处理,化肥减量30%配施精致有机肥化肥次之,可作为玉米增产、氮肥增效的合理施肥方案。