Effects of Phosphorus Application in Different Soil Layers on Root Growth, Yield, and Water-Use Efficiency of Winter Wheat Grown Under Semi-Arid Conditions

Deep phosphorus application can be a usefull measure to improve crops' performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus(P) application at different soil layers on root growth, grain yield, and water-use efficiency(WUE) of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars: one drought-sensitive(Xiaoyan 22, XY22) and one drought-tolerant(Changhan 58, CH58). The four P treatments were no P(control, CK), surface P(SP), deep P(DP), and deep-band P application(DBP). CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments(DP and DBP) than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight(RW) and root length(RL) in deep soil layer(30-100 cm) were closely positively correlated with grain yield and WUE of CH58(but not XY22), highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars(r=0.94, P<0.001). In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.

Effects of Long-Term Fertilization on Distribution of Organic Matters and Nitrogen in Cinnamon Soil Macro-Aggregates

Soil samples collected from a 25-year long-term fertilizer experiment carried out on the Earth-cumulic-Orthic Anthrosols in semi-humid farmland ecological system, were used to study the distribution of soil organic matters, total nitrogen, nitrate nitrogen, and ammoniate nitrogen in different grades of soil macro-aggregates in order to study the effects of long-term application of organic manures in combination with chemical fertilizers. It is showed that the percentage of mass of the soil macro-aggregates with long-term application of fertilizers with sizes of 5-2 mm is increased compared with that of the samples with no fertilizer. It is easier to form lager size soil macro-aggregates by the long-term application of organic manures in combination with chemical fertilizers. The contents of organic matters, total nitrogen and nitrate nitrogen are all higher after treatments with different combinations of fertilizers, while there is a little effect on the contents of ammoniate nitrogen. The contents of organic matters, total nitrogen in the grades of soil macro-aggregates from the plough layers of the treated farmland exhibited significant difference. Moreover, the contents of organic matters and total nitrogen in the soil macro-aggregates with the size of 1-0.25 mm is the highest in all treated soil samples. The contents of nitrate nitrogen in soil macro-aggregates increased with the increasing of soil macro-aggregate size except those applied with chemical fertilizer and lower amount of corn stover. The results of correlation analysis revealed that there exists a significantly positive correlation between the percentage of mass of soil macro-aggregates with the size of 5-2 mm and the contents of organic matters, total nitrogen and nitrate nitrogen in the soil samples. However, the correlation between the percentage of mass of soil macro-aggregates with the size of 1-0.25 mm and the contents of total nitrogen and nitrate nitrogen is significantly negative.The study showed that the highest contributing rates of macro-aggregates fractions to soil fertility is from the soil macro-aggregates fraction with the size of 1-0.25 mm in most of the cases.

我国奶牛场犊牛饲养管理现状调查与犊牛腹泻风险因素分析

为了对我国犊牛饲养管理现状进行阐述,同时鉴定我国规模化奶牛场中致犊牛腹泻的风险因素,本调查采用网络调查问卷和多元线性回归法,收集国内奶牛场产犊管理、初乳管理、犊牛日常饲养管理和腹泻犊牛治疗的相关信息并从中分析致犊牛腹泻的风险因素。结果显示,受访的57个奶牛场中,犊牛腹泻年平均发病率为22.53%(2.50%~97.50%,分位数:1.0%~80.0%);问卷所得信息经整理分析后展示了受访奶牛场在产犊管理、初乳管理、犊牛日常饲养管理和腹泻犊牛治疗方面的现状;风险因素分析结果显示,寒冷季节、初乳采用60℃1 h的巴氏杀菌程序、产圈垫料更换频率低于1次/2周、奶桶消毒频率低于1次/7 d、仅采用口服补液治疗腹泻犊牛均与犊牛腹泻发病率呈正相关;出生2 h和出生12 h进行脐带消毒、产圈垫料更换频率为1周1次、使用独立的产圈、使用初乳折射仪检测初乳质量、由兽医或犊牛饲养员饲喂初乳、以抗生素为主配合口服或静脉补液和以口服补液为主配合抗生素治疗犊牛腹泻与犊牛腹泻发病率呈负相关。本调查归纳总结了当前国内奶牛场犊牛饲养管理现状,分析了导致犊牛腹泻的相应风险因素,为进一步提高国内犊牛饲养管理水平提供参考。

分子筛结构设计及酸性调控在合成气催化转化中的应用研究进展

合成气催化转化是生物质或煤炭资源化清洁利用的重要路径,由此可获得烯烃和芳烃等多种高附加值碳氢化合物。分子筛由于具有独特的亚纳米孔道、可控活性位及分子择形性等优点,常被作为载体或直接作为活性组分用于催化合成气转化中C−C的形成和断裂等关键步骤。本综述总结了以分子筛负载金属、氧化物-分子筛(OX-ZEO)双功能以及核壳结构催化剂等直接催化转化合成气制备碳氢化合物的研究进展。重点介绍分子筛结构和酸性对反应路径和机理以及产物分布的影响,并展望分子筛催化合成气转化的未来发展方向。

利用内窥镜术中图像训练深度学习模型用于预测泌尿系结石成分

目的利用泌尿系结石内窥镜手术术中图像进行深度学习(deep learning,DL)来预测泌尿系结石的成分,以帮助医生改善术中决策,减少结石成分红外光谱检测为患者带来的经济负担。方法收集2021年1月—2022年1月接受内窥镜碎石手术并进行了结石成分红外光谱检测的181例患者的资料。剔除缺少术中图像或图像不清晰以及罕见结石的患者后,作者得到了61例患者共812张术中图像。作者从中筛选出305张无明显重复的图像,将它们纳入三种结石成分类别:草酸钙结石、碳酸磷灰石、无水尿酸结石。每位患者的术中图像均包括结石的表面和核心。作者使用深度卷积神经网络(convolutional neural networks,CNNs)ResNet-101对每张图像进行分类。结果结石成分预测精确度如下:草酸钙结石100%(n=172)、碳酸磷灰石98%(n=89)、无水尿酸结石97%(n=44)。模型总体加权召回率为99%。结论作者的研究初步证明深度学习模型能够准确在内窥镜术中图像中识别泌尿系结石成分,比手术医生在术中进行肉眼识别更准确、更快速,并且成本低廉。但该研究受限于样本量较少,具有一定的局限性。

胃癌术后早期肠内营养对术后炎症反应及肠屏障功能的影响

目的:观察不同营养支持治疗对病人术后炎症反应和肠屏障功能的影响,以期为胃癌术后营养支持治疗提供参考。方法:纳入2017年1月至2019年12月接受胃癌根治术的病人,依据病人术后营养支持治疗方式不同分为观察组(术后早期肠内营养)和对照组(全胃肠外营养)。比较两组术后康复情况,分析两组术后3 d外周血炎症介质及肠屏障功能指标,并进一步分析炎症指标与肠屏障指标间的相关性。结果:共纳入观察组病人46例,对照组43例。观察组病人术后首次排气时间(t=2.015,P=0.047)、恢复经口饮食时间(t=2.692,P=0.009)和术后住院日(t=2.934,P=0.004)均显著短于对照组。观察组病人术后全身炎症反应综合征发生率显著低于对照组病人[(13.04%,6/46)vs(32.56%,14/43),χ^2=4.858,P=0.028]。观察组病人术后3 dC-反应蛋白(t=4.978,P<0.01)、白介素6(t=4.070,P<0.01)及肿瘤坏死因子α(t=8.795,P<0.01)、血D-乳酸(t=5.267,P<0.01)和肠脂肪酸结合蛋白(t=6.373,P<0.01)水平均显著低于对照组。病人术后3 d外周血IL-6与D-乳酸(r=0.825,P<0.01)和IFABP(r=0.766,P<0.01)均呈现显著正相关关系。结论:术后早期肠内营养支持治疗可加速胃癌病人术后康复,保护术后肠屏障功能并抑制系统性炎症反应程度。

常规尿素掺混控释尿素一次施用对旱作春玉米产量及氮素利用的影响

【目的】通过田间试验研究施氮量和施肥方式对旱作春玉米产量、经济效益、干物质累积量、氮素累积利用和土壤无机氮残留的影响,为春玉米高产及高效施肥提供理论支撑。【方法】本研究采用裂区试验,以施肥方式为主处理,包括常规尿素一次施肥(OF)、常规尿素分次施肥(TF)和常规尿素掺混控释尿素一次施肥(MF);施氮量为副处理,设0、60、120、180、240、300 kg/hm^(2)6个施氮水平(N0、N60、N120、N180、N240、N300)。在玉米十叶期(V10)、吐丝期(R1)、灌浆期(R3)、成熟期(R6)分别采集植株样品,测定植株生物量,并按器官分类测定不同部位的氮含量。【结果】1)3种施肥方式下,随着施氮量的增加产量逐渐增加,当施氮量达到240 kg/hm^(2)后,产量不再显著增加。MF施氮处理的平均产量较OF和TF处理分别显著提高了5.0%和4.2%,经济效益分别提高了7.9%和25.7%。2)增施氮肥显著增加了干物质累积量,当施氮量达到240 kg/hm^(2)后,收获期干物质累积量不再显著增加。N240处理吐丝期和收获期的干物质累积量MF较OF分别增加了19.5%和12.5%。3)增施氮肥显著增加了花前、花后和氮素总累积量。MF方式的N240处理氮素总累积量较OF和TF方式分别显著增加了32.7%、20.9%。4)增施氮肥显著增加了收获期茎、叶、籽粒氮含量以及茎氮、叶氮转移量。相同施氮量下,收获期茎、叶、籽粒氮含量和茎、叶氮向籽粒的转移量都表现为MF>TF>OF,且MF方式显著高于OF方式。5)相比OF和TF方式,MF方式显著提高了氮肥农学效率、偏生产力和表观回收率,显著降低了无机氮残留和氮表观损失。【结论】常规尿素掺混控释尿素一次施肥方式在施氮量为240 kg/hm^(2)时,显著提高了春玉米的产量、经济效益、氮素累积量和肥料利用率,降低了土壤无机氮残留,为当地高产和高效施肥的最佳方式。

制首乌多糖Fe(Ⅲ)配合物的合成及吸附动力学研究

目的:制首乌多糖的制备,确定和优化制首乌多糖Fe(Ⅲ)配合物的合成工艺条件,研究其吸附动力学特征。方法:采用水提醇沉法、脱色及透析方法,从制首乌中提取、精制制首乌多糖,制首乌多糖水溶液与FeCl3在碱性的条件下反应,制备制首乌多糖铁配合物(PIC)。采用邻菲罗啉分光光度法,分析不同条件下PIC中Fe(Ⅲ)的含量变化,研究制首乌多糖对Fe(Ⅲ)的吸附动力学特征,对其结构进行红外光谱鉴定。结果:所制得PIC为红褐色粉末,pH值3~12,易溶于水,不溶于有机溶剂。在同一温度、不同时间下,制首乌多糖对Fe(Ⅲ)的吸附量随时间不断增大,于1 h后基本达到稳定;在同一时间、不同温度下制首乌多糖对Fe(Ⅲ)的吸附量随温度的升高而逐渐增大。通过红外光谱检测分析,制首乌多糖可与金属离子铁(Ⅲ)生成稳定配合物,发生配合基团以羟基为主,铁以聚合β-FeOOH铁核结构形式存在于PIC中。结论:制首乌多糖与金属铁离子结合,可形成稳定的PIC,温度和时间可能是影响PIC制备工艺的关键因素;PIC为新型口服补铁剂的开发提供思路。

Enah在胃癌组织中的表达及临床价值研究

目的:分析Enah蛋白在胃癌中的表达及临床价值,以期为胃癌的诊疗提供参考。方法:纳入行胃癌根治术病人97例,使用免疫组化标记胃癌组织和癌旁组织内的Enah,并计算目标蛋白光密度值,分析2种组织中Enah的表达差异。以胃癌组织内Enah表达量的中位数为界,将病人分为Enah高表达组(n=48)和低表达组(n=49),比较2组临床病理学参数及术后5年生存率。采用Cox回归模型分析Enah是否为胃癌术后5年死亡的独立危险因素。结果:胃癌组织中Enah相对表达量高于癌旁组织(P<0.01)。Enah高表达组在病理分级为G3~G4、T分期为3~4期、CEA≥5μg/L及CA19-9≥37 kU/L的比例均高于Enah低表达组(P<0.05)。Enah高表达组术后5年生存率明显低于Enah低表达组(P<0.01)。Cox多元回归模型分析得出:病理分级为G3~G4、Enah高表达及CA19-9≥37 kU/L是影响胃癌术后5年生存率的独立危险因素(P<0.05~P<0.01)。结论:Enah在胃癌组织中呈现高表达,并与肿瘤进展相关,对预后判断具有一定价值。

直肠癌预防性回肠造口还纳术后早期肠内营养对肠功能康复的影响研究

目的:探讨早期肠内营养(EEN)治疗对行造口还纳术的直肠癌预防性回肠造口病人术后康复过程的影响。方法:收集2018年1月至2021年12月在蚌埠医学院第一附属医院胃肠外科行造口还纳术的直肠癌根治术后的病人资料,依据术后是否行EEN治疗分为观察组(EEN)和对照组(非EN)。观察组术后12~24 h开始给予EN治疗[20~30 kcal/(kg·d)]。比较两组术后腹泻、胃肠功能恢复、粪便钙卫蛋白和肠屏障功能等指标。结果:所纳入的观察组(n=46)和对照组(n=44)一般资料未见显著差异(P>0.05),两组术后均出现不同程度的腹泻,但观察组术后5 d(χ^(2)=25.760,P<0.01)和10 d(χ^(2)=14.870,P<0.01)仍存在腹泻的比例,以及需要使用止泻剂(χ^(2)=10.180,P=0.001)的比例均低于对照组。同时,观察组恢复正常饮食时间(t=5.701;P<0.01)和术后住院日(t=7.343,P<0.01)短于对照组。术后5 d,两组外周血炎症指标未见显著差异(P>0.05),观察组病人粪便钙卫蛋白(t=11.690,P<0.01)、血清D-乳酸(D-Lactate;t=6.160,P<0.01)和肠脂肪酸结合蛋白(IFABP;t=6.583,P<0.01)水平低于对照组,且病人粪便钙卫蛋白水平与D-Lactate(r=0.833,P<0.01)和IFABP(r=0.842,P<0.01)均呈正相关关系。结论:术后早期EN可有效改善回肠造口还纳术后腹泻症状、结肠炎症和肠屏障功能,加速术后康复进程。

华东覆盆子生态适宜性区划研究

目的:预测华东覆盆子生态适宜性分布区,进行生态适宜性区划研究,为华东覆盆子的品质区划及生产区划提供依据,并探索影响华东覆盆子分布的主要生态因子,为其生态栽培研究提供理论依据。方法:以华东覆盆子的分布位点信息及生态因子数据为基础,利用最大熵模型(Maxent)及Gis制图软件进行生态适宜性预测,并对生态适宜区进行划分。结果:降水和气温是影响华东覆盆子全国分布的主要生态因子;华东覆盆子分布适宜区主要集中于华东地区长江以南的安徽南部、浙江、福建北部、江西东北部及江苏西南部,最适宜区主要集中在安徽皖南山区黄山山脉至浙江西部天目山一带、浙江东部山区、福建武夷山、江西东北部山区、江苏西南部地区。结论:本研究结果可以为华东覆盆子的道地药材生产布局及生态种植研究提供依据,并对扩大商品开发所需华东覆盆子原料产区具有一定的指导意义。

透明质酸面部微整形致视功能障碍的临床观察

目的观察使用透明质酸进行面部微整形所致视功能障碍患者的临床表现、治疗效果等。方法回顾性分析2013年1月至2017年12月我院眼科诊治的因面部微整形行透明质酸注射所致视功能障碍患者13例13眼的临床资料,包括一般情况、病史、临床检查结果、治疗效果及危险因素等。结果13例患者全是女性,年龄21～40岁,平均26.7岁。注射部位位于眉间者7例、鼻部者4例、额部者2例。13例全是单眼发病,突然发病者10眼;严重视功能障碍者9眼,包括无光感4眼,光感2眼,手动1眼,数指2眼;另外4眼视力0. 1。经眼底照相和荧光素眼底血管造影确诊为眼动脉阻塞者3眼、视网膜中央动脉阻塞者4眼、视网膜分支动脉阻塞者1眼、睫状后动脉阻塞者2眼、视网膜中央动脉阻塞合并睫状后动脉阻塞者1眼和眼底动脉血管痉挛者2眼。6例患者合并眼球运动障碍或面部外观异常。经治疗后,视力从0.1恢复到0.3、0.5、0.6者各1眼,光感恢复到手动者1眼,其他9眼视力未见改善。结论透明质酸面部微整形所致视功能障碍多发生于年轻女性,多数突然发病,视功能障碍严重,主要是眼底动脉阻塞。治疗后多数患者视功能恢复效果不明显。

白及叶斑灰霉病病原鉴定及药剂筛选

目的:分离、鉴定白及叶斑灰霉病病原菌,并对其药剂敏感性进行筛选。方法:采用组织分离法分离、纯化并结合回接实验确定病原菌,通过形态学和分子生物学方法对病原菌进行鉴定,然后对病原菌进行室内药剂筛选。结果:从白及病变叶片中分离一株病原菌,形态学和分子生物学鉴定为白及叶斑灰霉病菌(Botrytis cinerea);该病菌对白及幼苗具有较高致病力,且对多菌灵表现为中度耐药性,对异菌脲、腐霉利和恶霉灵也具有较低抗性,但对咪鲜胺极为敏感。结论:所分离的白及叶斑灰霉病菌对白及幼苗具有较高致病力,生产实践中应针对灰霉病发病特点加强环境因子调控,并及时喷施敏感药剂咪鲜胺加以防控,以减少损失。

中医药治疗高血压伴失眠疗效的系统评价

目的系统评价中医药治疗高血压伴失眠患者的临床疗效,为高血压伴失眠患者治疗提供参考意见。方法计算机检索中国知网(CNKI)、万方数据库(WanFang Data)、维普中文科技期刊数据库(VIP)、Pubmed数据库、Cochrane图书馆、医学文摘数据库(Embase),搜集中药结合基础降压治疗与西医镇静安眠药结合基础降压治疗的临床随机对照试验(randomized controlled trial,RCT),检索时间限定为各数据库建库至2020年6月,2名研究者根据纳入标准和排除标准筛选符合研究要求的文献,采用Cochrane偏倚风险评估工具评估纳入文献的方法学质量,并使用RevMan 5.3软件进行Meta分析。结果共纳入随机对照试验18项,包含患者1790例。Meta分析显示,试验组的治疗效果优于对照组,试验组匹兹堡睡眠质量指数(Pittsburgh sleep quality index,PSQI)量表的总分、睡眠障碍量表(Sleep Dysfunction Rating Scale,SDRS)评分低于对照组,辅助降压效果优于对照组,治疗后失眠复发率较低,且不良反应发生少。结论中药治疗高血压伴失眠患者能够改善患者睡眠质量,降低患者血压水平。受纳入研究数量和质量限制,这一结论仍需高质量、大样本、多中心、随机双盲对照研究予以验证。

浅析OBE理论下的工科院校人才培养路径

随着社会经济的发展,社会对工程类人才的需求日益强烈,这就要求工科院校在人才培养方面要进行改革创新以适应时代发展。基于学习产出的OBE教育理念,始终强调学生的中心地位及学习成果,这一理论对于弥补传统工科院校人才培养的缺陷具有重要意义。对OBE理论的含义和OBE理论下工科院校在人才培养方面存在的主要问题进行分析,从变革人才培养目标、建设“双师双能”型师资队伍、提高实践课比重、丰富教学形式等方面探究了工科院校人才培养的路径,以期为我国培育更多优秀的工程人才。

Effects of plastic film mulching on soil greenhouse gases(CO2,CH4 and N2O) concentration within soil profiles in maize fields on the Loess Plateau,China

To better understand the effects of plastic film mulching on soil greenhouse gases(GHGs) emissions,we compared seasonal and vertical variations of GHG concentrations at seven soil depths in maize(Zea mays L.) fields at Changwu station in Shaanxi,a semi-humid region,between 2012 and 2013.Gas samples were taken simultaneously every one week from non-mulched(BP) and plastic film-mulched(FM) field plots.The results showed that the concentration of GHGs varied distinctly at the soil-atmosphere interface and in the soil profile during the maize growing season(MS).Both carbon dioxide(CO_2) and nitrous oxide(N_2O) concentrations increased with increasement of soil depth,while the methane(CH_4)concentrations decreased with increasement of soil depth.A strong seasonal variation pattern was found for CO_2 and N_2O concentrations,as compared to an inconspicuous seasonal variation of CH_4 concentrations.The mean CO_2 and N_2O concentrations were higher,but the mean CH_4 concentration in the soil profiles was lower in the FM plots than in the BP plots.The results of this study suggested that plastic film mulching significantly increased the potential emissions of CO_2and N_2O from the soil,and promoted CH_4 absorption by the soil,particularly during the MS.

Soil Organic Nitrogen and Its Contribution to Crop Production

Plant growth and crop production depend to a large extent on soil N supplying capacity(SNSC):The higher the SNSC,the higher the dependence of crops on soil and the lower the N fertilizer recovery.Of the SNSC,soil organic N(ON)played a key role in supplying N nutrient to crop production and still does in many subsistence and low-input farming systems.In this paper,soil ON contents,types,chemical components and its contribution to plant production are reviewed up to date in details,the characteristics of ON in dryland soils discussed together with its chemical components,and the mineralization and availability to plants of some important chemical components are emphasized at the last part for practical considerations.

Soil mulching can mitigate soil water defi ciency impacts on rainfed maize production in semiarid environments

Temporally irregular rainfall distribution and inefficient rainwater management create severe constraints on crop production in rainfed semiarid areas. Gravel and plastic film mulching are effective methods for improving agricultural productivity and water utilization. However, the effects of these mulching practices on soil water supply and plant water use associated with crop yield are not well understood. A 3-yr study was conducted to analyze the occurrence and distribution of dry spells in a semiarid region of Northwest China and to evaluate the effects of non-mulching(CK), gravel mulching(GM) and plastic film mulching(FM) on the soil water supply, plant water use and maize(Zea mays L.) grain yield. Rainfall analysis showed that dry spells of ≥5 days occurred frequen tly in each of 3 yr, accounting for 59.9–69.2% of the maize growing periods. T he >15-d dry spells during the jointing stage would expose maize plants to particularly severe water stress. Compared with the CK treatment, both the GM and FM treatments markedly increased soil water storage during the early growing season. In general, the total evapotranspiration(ET) was not significantly different among the three treatments, but the mulched treatments significantly increased the ratio of pre- to post-silking ET, which was closely associated with yield improvement. As a result, the grain yield significantly increased by 17.1, 70.3 and 16.7% for the GM treatment and by 28.3, 87.6 and 38.2% for the FM treatment in 2010, 2011 and 2012, respectively, compared with the CK treatment. It's concluded that both GM and FM are effective strategies for mitigating the impacts of water deficit and improving maize production in semiarid areas. However, FM is more effective than GM.

Gully Impact on Soil Moisture in the Gully Bank

In order to preliminarily look at rules for soil moisture changes in the bank of the gully and to provide some recommendations for vegetative restoration in gully bank regions in the Loess Plateau, changes of soil moisture with depth and distance to the gully edge and their dynamic changes with time were observed to study the soil water characteristics in the bank of the gully. The results showed that soil water content increased with increasing distance from the gully edge, whereas for the same time period, the closer the distance to the gully wall, the greater the water loss; and that the influential distance of side evaporation decreased as depth increased.

Effects of Soluble Organic N on Evaluating Soil N-Supplying Capacity

It is important to study the soluble organic N (SON) extracted during water-logged incubation for evaluating soil N-supplying capacity. Soil initial SON and mineral N (Nmin), cumulative soluble organic N and NH4+-N in leachates duringwater-logged incubation, mineralization potentials of both easily decomposable N (ND) and resistant N (NR), and theirrelationships with N uptake by crop in pot experiment were investigated by using 10 kinds of farmland soils with widelydifferent physical and chemical properties on the Loess Plateau, China, and the effects of SON on evaluating soil N-supplying capacity were studied. The results showed that the average content of initial SON (23.9 mg kg-1) of 10 soils was28.8% of initial total soluble N and 2.4% of soil total N. The percentage of cumulative SON in leaching total soluble N(118.1 mg kg-1) was 46.4%, higher than the percentage of initial SON (28.8%), and almost close to the percentage ofcumulative NH4+-N in the leachates. ND had close correlation with total N, and the correlation coefficients were 0.92(P < 0.01, excluding SON in estimating ND) and 0.88 (P < 0.01, including SON in estimating ND), respectively. Nmineralization potential and mineralization rate constant were different with the soil types. ND of Los-Orthic Entisolsand Ust-Sandiic Entisols were lower than that of Eum-Orthrosols. Mineralization rate constant for the fastdecomposable N-fraction (kD) decreased and the mineralization rate constant of resistant materials (kR) increasedwhen SON was taken into account. Cumulative NH4+-N was a better evaluation index of soil N-supplying capacity, andit is not only suitable for the first season crops but also for two successive season crops. Cumulative SON alone wasnot a satisfactory index for the potential of mineralizable N. But it would be more accurate for ND in revealing thepotential mineralizable N when SON was taken into account. Cumulative TSN, to some extent, could also be taken asan index for the potential mineralizable N. Cumulative NH4+-N, total soluble N, and ND were good indexes for estimatingsoil potential mineralizable N, especially for soils of two successive season crops. And cumulative total soluble N andND in evaluating the permanence of soil N-supply is of greater significance when SON was included.