Residual Effect of Long Term Application of Organic and Mineral Fertilizers on Selected Chemical Properties of a Savanna Alfisol

The residual effect of organic and mineral fertilizers on selected chemical properties of an Alfisol in the long term soil fertility trial established in 1950 at Samaru, Nigerian savanna was assessed. The trial was left fallow for fourteen years due to lack of funds. Topsoil was collected from plots that received three levels of cow dung （D）, nitrogen （N） and phosphorus （P） in all possible combinations. The soils were analyzed for selected chemical properties. Except for significant effect of applied P on available P, sole application of cow dung, N or P had no significant effect on all the measured soil properties. The interaction of D and P significantly affected the mean values of exchangeable Ca, Mg, K and ECEC in the range of 1.12-1.96, 0.62-1.11, 0.37-0.64 and 2.82-4.11 cmol/kg respectively. The most important results were the ability of the plot that received neither D nor P to significantly increase these parameters than the plots that received only one of the treatments. The results show that the fallow period has changed the effects of application of organic and mineral fertilizers on the soil chemical properties under continuous cultivation by modifying them towards those of a native savanna Alfisol.

Effects of Continuous Mineral and Organic Fertilizer Inputs and Ploughing on Groundnut Yield and Soil Fertility in a Groundnut-Sorghum Rotation in Central Burkina Faso

Two field experiments were conducted at Saria in the centre of Burkina Faso in order to assess the effect of chemical and organic fertilizers on yields and soil fertility on two different soils. Groundnut haulm yield, pod yield, number of pods, % 2-seeded pods, % pod rot, seed yield and 100 seeds weight as well as sorghum dry shoot and grain yields were measured. Most of the different variables were affected by continuous cropping without fertilizer application on the two soils, in particular on the coarse one. The effect of nutrient deficiencies was observed. The mineral fertilizers maintained yields, but their supply was not able to replenish the nutrient uptake by plants. The effect of compost on crop production was initially minimal, but improved during years seven and height. Tillage had also a slightly positive effect on yield, which varied with soil type. In the control plot, the content of organic matter decreased in five years and did not increase with the application of fertilizers. In contrast, addition of fertilizers increased total N and Bray-I P. Nitrogen, P, K and Ca balances were negative in almost all treatments without mineral fertilizers. Results showed that fertilizers used were inadequate for maintaining soil fertility and yields in long run. However, extra production did not provide significant profits.

Organic Carbon: A New Concept for Development of Modern Fertilizers and Plant Nutrition Theory

The development of modern fertilizers has broken the theoretical framework of traditional mineral nutrition theory,and it is urgent to take theoretical considerations.Many years of the research and development practice of new fertilizer products have provided a lot of research materials and scientific basis for the development of modern plant nutrition theory,in which the organic carbon is a major research field.This paper introduced the unique advantages of organic carbon nutrition,made clear the differences among organic fertilizer,organic nitrogen and organic carbon,and pointed out that apart from"replenishing carbon by the air(CO2)",it is of great theoretical significance and practical value to exploit a new way for fertilizing and supplementing carbon.

Modification of total and phosphorus mineralizing bacterial communities associated with Zea mays L.through plant development and fertilization regimes

Harnessing the rhizospheric microbiome,including phosphorus mineralizing bacteria(PMB),is a promising technique for maintaining sustainability and productivity in intensive agricultural systems.However,it is unclear as to which beneficial taxonomic group populations in the rhizosphere are potentially associated with the changes in soil microbiomes shifted by fertilization regimes.Herein,we analyzed the diversity and community structure of total bacteria and PMB in the rhizosphere of maize(Zea mays L.)grown in soils under 25 years of four fertilization regimes(compost,biocompost,chemical,or nonfertilized)via selective culture and Illumina sequencing of the 16S rRNA genes.Plant development explained more variations(29 and 13%,respectively)in the composition of total bacteria and PMB in the rhizosphere of maize than the different fertilization regimes.Among those genera enriched in the rhizosphere of maize,the relative abundances of Oceanobacillus,Bacillus,Achromobacter,Ensifer,Paracoccus,Ramlibacter,and Luteimonas were positively correlated with those in the bulk soil.The relative abundance of Paracoccus was significantly higher in soils fertilized by compost or biocompost than the other soils.Similar results were also observed for PMB affiliated with Ensifer,Bacillus,and Streptomyces.Although plant development was the major factor in shaping the rhizospheric microbiome of maize,fertilization regimes might have modified beneficial rhizospheric microbial taxa such as Bacillus and Ensifer.

Effect of Fertilizers on the Productivity of Maize (Zea mays L.) Cultivated in the Zinder Region (Niger Republic)

Maize constitutes one of the most important crops in Niger’s fight for food security, and it is cultivated in all regions of the country. However, maize cultivation is declining due to low soil fertility. This study focused on evaluating the impact of fertilizers on maize plant production in Zinder. The fertilizer effect was evaluated based on 21 quantitative and 9 qualitative descriptors proposed by IBPGR and CIMMYT 1991. The experiment was conducted during the rainy season in the experimental domain of Université André Salifou following randomized complete block designs with three repetitions. Seven fertilizer treatments, including two organic, two mineral, two combinations of fertilizers, and a control treatment, were applied. The analysis shows that fertilizers had positive effects on the earliness and productivity of the selected variety. The best yield of dry corn cob (7480 kg/ha) was recorded on organic fertilizer of composted poultry manure, which is equal to 4.8 times that obtained with the control (1561 kg/ha), followed by the mineral fertilizer NPK combined with composted cow dung with 6395.231 kg/ha. Therefore, the use of fertilizers could be an appropriate alternative to overcome the negative consequences of yield declines in the corn production system in the Zinder region.

Carbon and Nitrogen Mineralization Kinetics from Organically-Amended Upland Purplish Soil

The application of organic amendments in upland soils may influence soil carbon (C) and nitrogen (N) mineralization, which are very important for understanding plant nutrition. However, the kinetics of C and N mineralization from organically amended upland purplish soils has been poorly studied. Therefore, this study investigates C and N mineralization kinetics in organically amended upland purplish soils. Incubation experiments were conducted using soil samples collected from experimental plots that have been under long-term organic amendment fertilization, which includes: Organic manure (OM), crop residues (CR), combined organic manure with inorganic fertilizers (OMNPK), combined crop residue with inorganic fertilizers (CRNPK), conventional inorganic fertilizer (NPK), and no fertilizer (CK). The results showed that organically amended treatments increased C and N mineralization rates by 8 - 24% and 17 - 33%, respectively, compared with NPK. Likewise, the amount of potentially mineralizable carbon (Co) and nitrogen (No) increased by 4 - 9% and 15 - 20%, respectively, compared to the conventional NPK treatment. The rate constants for labile C (kC) and N (kN) were 6 - 29% and 3 - 27% higher than the NPK treatment, respectively. In addition, the initial potential rate of C (Co × kC) and N (No × kN) in organically amended soils were 10 - 37% and 18 - 52% higher compared to NPK. This study tried to show that the mechanisms of N supply was direct application of mineral N fertilizer and mineralization of organic N, while the N retention was reducing soil active N loss and storing more active N in cropland of purplish soil. These results suggest that the long-term application of organic amendments to upland soils may increase nutrient bioavailability.

Effects of chemical fertilizer combined with organic manure on Fuji apple quality,yield and soil fertility in apple orchard on the Loess Plateau of China

To evaluate the effects of chemical fertilizer combined with organic manure on apple yield,quality and soil fertility,an experiment was conducted in an apple orchard on the Loess Plateau of China.Six treatments,i.e.,1)no nitrogen(N)with chemical phosphorus(P)and potassium(K)(PK),2)no P with chemical N and K(NK),3)no K with chemical N and P(NP),4)N,P and K chemical fertilizers only(NPK),5)swine manure(M)only(M),and 6)half chemical fertilizers combined with half swine manure(NPKM)were included with three replications for each.The NPKM treatment achieved 36.9 t/ha average annual yield,which was 42.5%greater than the yield of PK treatment.The average annual yields followed the sequence of NPKM>NPK>M>NK>NP>PK.In NPKM treatment 71.3%of the collected apples had an apple diameter greater than 80 mm compared with 58.2%,41.5%and 37.2%in NK,PK and NP treatments,respectively.The sugar to acid(S:A)ratio was the greatest in NPKM treatment.The results of Vitamin C,soluble solid and firmness showed that NPKM treatment had the highest values.The concentration of soil organic carbon(SOC)in the 0 to 20 cm depth of soil was significantly affected by addition of M.Compared to the antecedent soil properties,the SOCS in the NPKM and M treatments were increased by 28.8%,29.4%,and TN contents were 56.5,49.8%more for soil at 0-20 cm depths,respectively.The major soil nutrients of N,P and K were also significantly increased by M and NPKM treatments in surface soil for five years.The data support the conclusion that,for a production of 35-40 t/ha in an apple orchard on the Loess Plateau of China,the 25-30 t/ha organic manure,160-200 kg/ha N,100-150 kg/ha P2O5 and 120-160 kg/ha K2O were the most suitable fertilizer application.The finding will be helpful for harmonious development of apple production technology,economic income increase for farmers,and improvement of the apple orchard ecosystem.

Impact of Organic Soil Amendments on the Physical Characteristics and Yield Components of Potato （Solanum tuberosurn L.） in the Highlands of Cameroon

A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.

Response of Soil Microbial Properties to Long-Term Application of Organic and Inorganic Amendments in a Tropical Soil (Saria, Burkina Faso)

Soil microbial biomass carbon (MBC), β-glucosidase, acid phosphatase and fluorescein diacetate (FDA) activities and bacterial community structure were assessed in a long-term (26 years) experiment, at physiological stages of sorghum growth, comparing different management methods for organic (manure, straw residues) and inorganic (urea) amendments at the INERA field station in Saria (Burkina Faso). Annual application of manure led to the highest soil microbial biomass and enzyme activities. Investigations indicated that only microbial biomass and β-glucosidase activities were affected during the cropping season. Phosphatase and FDA enzyme activities did not depend on the crop development stages. The application of N fertilizer modified phosphatase and FDA enzyme activities, the activities being higher in soils amended with N fertilizer. The bacterial community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) targeting the eubacterial 16S rRNA gene. Cluster analysis of PCR-DGGE patterns showed two major clusters, the first containing the mineral fertilization and straw treatments and the second, the straw + urea, manure and manure + urea treatments. Sorghum grain yields were the highest for manure treatments. In this long-term experiment, applying straw did not produce a better grain yield than that obtained in the un-amended plot.

Organo-mineral complexes in soil colloids:Implications for carbon storage in saline-alkaline paddy soils from an eight-year field experiment

The combination of organic carbon(OC) and reactive minerals is a crucial mechanism of soil carbon(C) storage, which is regulated by the formation of organo-mineral complexes on the surface of soil colloids. The effect of organic fertilizer on the storage mechanism of OC in soil colloids was studied through an 8-year field experiment, which included four treatments: i) no fertilization(control, CK), ii) only mineral N, P, and K fertilization(NPK), iii) NPK plus a low level(450 kg C ha^(-1)year^(-1)) of organic fertilization(NPKC1), and iv) NPK plus a high level(900 kg C ha^(-1)year^(-1)) of organic fertilization(NPKC2). The main results indicated that organic fertilizer addition significantly increased the content of aromatic-C, which was 158.7% and 140.0% higher in soil colloids than in bulk soil in the NPKC1 and NPKC2 treatments, respectively. X-ray photoelectron spectroscopy further demonstrated that the relative proportion of C=C group on the surface of soil colloids was increased by 20.1% and 19.1% in the NPKC1 and NPKC2 treatments, respectively,compared with the CK. In addition, compared with the NPK treatment, the content of reactive minerals(such as Fe and Al oxides) significantly increased with organic fertilization, which was positively correlated with C=C group in soil colloids. This indicates that aromatic-C may be retained by the formation of aromatic-mineral complexes with reactive minerals in soil colloids. Organic fertilization also significantly increased OC storage efficiency(OCSE), which was significantly higher in the NPKC1 treatment than in the NPKC2 treatment. Therefore, a moderate amount of organic fertilizer application is a better agronomic practice to increase OCSE and OC storage in saline-alkaline paddy soils.

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。

青藏高原高寒草地土壤速效氮矿化能力对温度和有机肥添加的响应

青藏高原高寒草地土壤氮素矿化是影响全球碳氮循环和草地生态系统演替的关键过程。本研究通过不同温度(5、15和25℃)和有机氮添加梯度(0、15、45和75 kg·hm^(−2))的室内培养试验,测定土壤氮矿化速率、矿化势以及矿化反应速率常数对处理的响应,旨在探究温度和有机肥添加对青藏高原高寒草地土壤速效氮供应能力的影响。结果表明:土壤氮素矿化量随温度的升高而增加,25℃下明显高于15和5℃;有机氮添加(15~45 kg·hm^(−2))显著提高了土壤铵态氮的矿化量,继续增加至75 kg·hm^(−2)时,氮素矿化能力降低;土壤氮矿化速率随培养时间的增加先增加后降低,添加有机氮可以增加高寒草地土壤氮素矿化速率,在氮素添加量为45 kg·hm^(−2)时达到峰值;温度决定了高寒草地土壤氮素矿化势,对矿化速率常数k没有明显影响。综上所述,添加15~45 kg·hm^(−2)有机氮及较高的温度条件有利于提高青藏高原高寒草地土壤速效氮的矿化能力,这为高寒草原地区的草地管理和有机肥施用提供了理论依据。

优化施肥促进华北麦玉轮作系统土壤有机碳积累

为揭示不同施肥方式对华北小麦-玉米轮作种植系统土壤有机碳库的影响,本研究将“小麦-玉米”作为一个施肥单元,于2014年10月开展田间定位试验,采用二因素裂区设计,以冬小麦-夏玉米两季作物磷钾肥分配比(A)为主区,设磷钾肥全部施入小麦季(A1)和小麦季∶玉米季为2∶1(A2)两个水平,以两季作物总施氮量(B)为裂区,设施纯氮450 kg·hm^(-2)(B1)和600 kg·hm^(-2)(B2)两个水平,同时以两季作物全生育期不施肥为对照,共5个处理,于2022年10月玉米收获后采集0~20 cm土壤样品,分析研究8 a后不同施肥方式对该种植系统土壤有机碳库的影响。结果表明:除A1B2处理下土壤总有机碳(SOC)和微生物量碳(MBC)含量与CK处理差异不显著外,4种施肥处理下SOC、颗粒态有机碳(POC)、活性有机碳(LOC)、可溶性有机碳(DOC)、MBC含量和SOC储量均显著高于CK,增幅分别达8%~55%、75%~237%、98%~214%、42%~66%、21%~50%和3%~29%。4种施肥处理中A2B1处理下SOC及其活性组分含量和SOC储量均显著高于A1B1和A1B2,而与A2B2处理在LOC、DOC、MBC含量和SOC储量间差异不显著。同时,A2B1处理下土壤碳库管理指数(CPMI)最高。对于SOC矿化指标而言,SOC累积矿化量(C_(m))、潜在可矿化碳(C_(p))和SOC矿化效率(C_(p)/SOC)均表现为A1B1>A1B2>CK>A2B1>A2B2,且除A2B1和A2B2处理间C_(p)/SOC差异不显著,C_(m)和C_(p)在各处理间差异均显著。相关分析研究表明,β-1,4纤维二糖苷酶活性以及土壤全氮、碱解氮、速效磷和速效钾均为提高SOC及其活性组分含量以及CPMI的关键因子,而碳累积输入量可通过增加SOC含量降低C_(p)/SOC。综上,本试验条件下,磷钾肥在小麦季和玉米季2∶1的分配比,配合两季作物450 kg·hm^(-2)的总施氮量,可增加麦玉轮作系统SOC及其活性组分含量,提升土壤养分有效性,降低SOC矿化分解,同时,该施肥方式下较高的碳累积输入量可增加SOC含量,降低C_(p)/SOC,最终实现SOC储量增加。

不同增氧措施对牛粪有机肥矿化及烟叶生长的影响

通过增氧措施提升有机肥矿化速率,满足烤烟生长发育的需肥规律。本研究从2种物理增氧(打孔增氧与泵增氧)与3种化学增氧(过氧化钙、过氧化氢和过碳酸钠)中筛选出最利于土壤酶活性和烟株生长的增氧方式,在此基础上明确最佳增氧时间和增氧剂浓度。开展不同增氧方式田间试验,从田间产量、产值、有机肥矿化率及土壤微生物群落结构等方面评价增氧效果。结果表明:(1)综合烟株长势、农艺性状和土壤生态多样性等指标发现,化学增氧和物理增氧方式分别以过氧化钙增氧和泵增氧效果最佳。(2)牛粪有机肥增氧时间以12 h/d最优,过氧化钙用量以40 g/株为最优,二者根部干质量分别为对照的1.92倍和1.24倍。(3)田间应用牛粪有机肥联合过氧化钙增氧,遵义、毕节和黔西南的烟叶产值分别增加10.47%、12.48%和18.82%。过氧化钙增氧烟叶化学成分综合评分分别增加13.97、3.38和19.95分,工业可用性提升4.5个百分点。(4)与对照相比,打孔增氧使有机肥氮矿化率增加31.6%~57.1%,过氧化钙处理有机肥氮矿化率增加95.0%~138.9%。综上所述,打孔增氧和过氧化钙增氧可应用于田间生产,以提高碳氮转化效率,改善土壤微生物功能多样性,提升烟叶产量和品质。

有机肥减量配施外源碳基肥对设施菜地氨挥发及黄瓜产量的影响

针对我国农业源氨排放过高的问题,本研究通过探究有机肥减量配施外源碳基肥(生物炭及腐植酸)对设施菜地土壤氨挥发及黄瓜产量的影响,并结合高通量qPCR基因芯片技术,研究影响氨挥发的微生物学机制,明晰设施菜地有效的氨减排措施。以天津市武清区设施菜地为研究对象,本研究共设置5个处理:不施氮CK、推荐施肥量N1(37500 kg·hm^(-2)有机肥)、推荐施肥量配施腐植酸N1F(37500kg·hm^(-2)有机肥+2250kg·hm^(-2)腐植酸)、推荐施肥量配施生物炭N1B(37500kg·hm^(-2)有机肥+40t·hm^(-2)生物炭)、农民常规用量N_(2)(60000 kg·hm^(-2)有机肥)。结果表明:不同处理氨挥发动态基本一致,N_(2)处理氨挥发速率处于较高水平。随着施肥量的增加,土壤氨挥发累积量逐渐增加,氨挥发累积量从高到低依次为N_(2)、N1、N1B、N1F、CK,N1F处理和N1B处理较N_(2)处理显著降低了24.5%和21.0%的氨挥发累积量(P<0.05)。N_(2)处理土壤在末果期铵态氮含量显著高于其他处理;N1、N1F、N1B处理在盛果期和末果期土壤硝态氮含量显著高于N_(2)处理。施肥以及配施生物炭和腐植酸均能显著增加AOA-amoA基因丰度,与CK相比,N1、N_(2)的AOA-amoA基因丰度显著提高(P<0.05);与N_(2)、N1相比,N1F和N1B处理AOA-amoA基因丰度显著提高(P<0.05)。推荐施肥量增加了土壤AOB-amoA的基因丰度,配施腐植酸和生物炭无显著影响。Mantel test+结果表明,NH4-N含量、AOA-amoA、AOB-amoA能够显著影响设施菜地土壤氨挥发。减量施肥配施生物炭和腐植酸能够在一定程度上降低设施菜地土壤的氨挥发量,且腐植酸配施效果更好,并能够有效固持土壤的无机氮。N1、N1F、N1B各处理保证了作物产量并较N_(2)处理显著提高了氮素利用率。综合考虑农学和环境效益,有机肥减量配施腐植酸N1F为适宜的施肥方式。

煤矸石资源综合利用制有机肥工程设计与研究

针对矿区煤矸石资源的排弃会造成大量的资源浪费,且排弃及存储堆放过程中对环境造成污染,渗滤液对地下水形成影响。辽宁亚太固废研究院提出了煤矸石资源综合利用制有机肥科的科研项目,通过自主研发的生产工艺技术,多次实验分析得到有机肥料配方,利用煤矸石为主要原材料,配加营养土、腐植酸、黏合剂、菌剂等作为原材料,经过生产加工成环保农业有机肥料。项目开发设计共2套生产工艺技术,1号、2号生产线为10万t/a颗粒状土壤增效颗粒,3号、4号生产线为40万t/a粉剂状土壤增强颗粒。煤矸石资源综合利用项目的实施将煤矸石固废进行了资源再利用,实现了节约矿产资源,改善水土流失,保护生态环境的目标。

有机肥和化肥长期施用对土壤活性有机氮组分及酶活性的影响

本文以中国农业科学院山东禹城长期定位施肥试验为平台,研究了长期施用有机肥和化肥26年后对土壤活性氮库不同组分[颗粒有机氮(POM-N)、可溶性有机氮(DON)、微生物量氮(SMBN)及轻组有机氮(LFOM-N)]及土壤酶活性的影响。结果表明,与不施肥相比,长期施肥显著提高了土壤全氮、颗粒有机氮、可溶性有机氮、微生物量氮以及轻组有机氮的含量,长期施有机肥效果好于化肥,施用高量有机肥效果好于施用常量有机肥。常量施用量下,50%有机肥和50%化肥配施处理其土壤全氮和活性有机氮库各组分含量与高量化肥处理的相当。长期施化肥处理土壤全氮及活性有机氮库各组分含量随施肥量的增加而显著增高。POM-N对土壤全氮的贡献率最高,且明显受施肥方式的影响,LFOM-N对土壤全氮的贡献率不随施肥方式的改变而变化。长期施肥处理土壤脲酶、碱性磷酸酶和蔗糖酶活性显著增加,它们之间及与土壤全氮、速效磷及有机碳含量间呈现显著或极显著相关性,脲酶活性与土壤各活性氮组分间也存在显著或极显著相关性;但长期施肥后土壤过氧化氢酶的活性低于不施肥处理。

有机肥料氮替代部分化肥氮对稻谷产量的影响及替代率

【目的】试图探索出有机肥料氮替代化肥氮的最适替代率,为研制水稻专用有机无机复合肥奠定基础。【方法】试验在江苏省常熟市进行,采用田间试验研究4个氮用量下(0、180、240和270kg·hm-2)有机肥料氮替代部分化肥氮对水稻(4007和常优1号)产量、氮肥利用率和土壤矿质态氮的影响。【结果】(1)与单施化学氮肥相比,氮用量为180kg·hm-2并且有机肥料氮的替代率在15%～30%或氮用量为240kg·hm-2并且有机肥料氮的替代率在10%～20%时,能够显著提高水稻的稻谷产量。两个水稻品种(4007和常优1号)的稻谷产量分别达到8242～10187kg·hm-2和10048～11654kg·hm-2;(2)与单施化肥相比,氮用量在180kg·hm-2并且有机肥料氮的替代率在15%～30%或氮用量在240kg·hm-2并且有机肥料氮的替代率在10%～20%时,两个水稻品种的氮素累积量分别为172.6～256.4kg·hm-2、185.9～235.6kg·hm-2,显著高于单施化学氮肥处理,此时,氮肥利用率也达最高,分别为36.6%～48.1%、34.3%～40.0%;(3)与单施化学氮肥相比,氮用量在180kg·hm-2并且有机肥料氮的替代率在15%～30%或者氮用量在240kg·hm-2并且有机肥料氮的替代率在10%～20%时可以获得较为平稳的氮素供应过程。【结论】有机肥料氮与化肥氮配施能获得比单施化学氮肥处理更高或持平的稻谷产量并有效地提高水稻的氮肥利用率。

有机肥与化肥配合施用土壤微生物量氮动态、来源和供氮特征

【目的】揭示有机氮肥的矿化-固持周转过程机理,为合理施用有机肥和化肥提供科学依据。【方法】运用同位素15N交叉标记示踪技术,通过盆栽试验,研究单施化肥、单施猪粪、猪粪与化肥配施、玉米秸与化肥配施、麦秸与化肥配施等5种施肥方式下,土壤中微生物量氮在玉米各生育时期的数量、来源的动态变化以及对玉米的供氮特征。【结果】各处理在同一生育期微生物量氮差异的原因主要是所施肥料种类的不同。不同处理的土壤微生物量氮在玉米各个生育期数量与来源不同,施入的有机肥对土壤微生物量氮贡献大,化肥对土壤微生物量氮的贡献较小,土壤氮仍是构成微生物量氮的主要来源。作物和土壤微生物对土壤氮素存在竞争关系,在氮素胁迫条件下,竞争作用突出,其竞争强度取决于氮源和能源的供应强度以及土壤氮素转化过程。同一处理的土壤微生物量氮在玉米的各个生育期数量差异很大,当土壤中微生物的碳源(能源)物质与氮源物质充足时微生物对氮素的竞争能力较强,作物的竞争能力较弱,随着土壤氮素转化过程的改变,作物的竞争能力逐渐增强,并显著超过微生物,微生物量氮减少。【结论】有机肥与化肥配合施用比单独施用化肥能降低土壤微生物量氮来自土壤氮的百分比;与单施有机肥相比能提高土壤微生物量氮来自土壤氮的百分比。