构建湿地中试系统基质剖面微生物活性的研究

对稳定运行的复合垂直流构建湿地中试系统基质进行分层采样,测定微生物数量,生物量氮,酶活性,硝化作用,反硝化作用以及呼吸作用等各项指标.结果表明,上行流和下行流池0～10cm的基质层中好氧微生物数量高出30～55cm的层面1～2个数量级;反硝化细菌除下行流池0～10cm的层面外其他基质层数量都达到10⁷个/g干土以上.0～20cm的基质层中脲酶活性明显高于30～55cm的层面;而0～10cm的层面中脱氢酶活性明显高出10～55cm的层面2～5倍.硝化反硝化作用广泛存在于基质中,硝化作用表现出一定的空间规律,0～10cm的基质硝化作用强度要比40～55cm层面的高出20%;反硝化作用的空间差别很小,其作用率最低也达到85.5%.     

臭氧浓度升高对冬小麦田土壤呼吸、硝化和反硝化作用的影响

为研究臭氧浓度升高对农田土壤呼吸、硝化和反硝化作用的影响,采用开顶箱(OTC)法设置3个臭氧浓度处理,分别为对照CK、T1(100 nL.L-1臭氧)和T2(150 nL.L-1臭氧).以便携式土壤CO2通量观测仪测定不同臭氧浓度处理下的冬小麦田土壤呼吸速率,并采用气压过程分离(BaPS)法测定不同处理的土壤CO2产生速率、硝化速率和反硝化速率.结果表明,在本实验阶段内,CK、T1、T2处理的土壤呼吸速率之间无显著差异(p0.05),其平均土壤呼吸速率分别为(5.36±0.72)、(5.08±0.04)、(4.94±0.18)μmol.(m2.s)-1.CK和T2处理的硝化速率和反硝化速率也均无显著差异(p0.05).不同臭氧浓度处理下的土壤呼吸速率与土壤温度的指数回归关系均达显著水平(p0.05),CK、T1和T2处理的土壤呼吸的Q10值分别为1.72、1.58和1.51.Pearson相关分析结果表明,CK处理中土壤硝化速率与反硝化速率和土壤含水量之间均存在显著相关关系(p0.05),其相关系数分别为0.828和0.890;T2处理中硝化速率与土壤含水量之间存在显著相关关系(p0.05),其相关系数为0.772.本研究表明,臭氧浓度升高未显著改变冬小麦田土壤呼吸、硝化和反硝化速率,但臭氧浓度升高显著降低了土壤呼吸的温度敏感性.     

不同电子受体反硝化过程中C/N对N2O产量的影响

试验采用SBR反应器,分别考察了不同C/N条件下,以硝酸盐和亚硝酸盐为电子受体的反硝化过程中N₂O产生情况.投加乙醇作为反硝化碳源,以硝酸盐为电子受体时调节C/N分别为0、 1.2、 2.4、 3.5、 5.0和20,以亚硝酸盐为电子受体时调节C/N分别为0、 1.8、 2.4、 3.0、 4.3、 5.2、 6.6和20.6.结果发现,以亚硝酸盐为电子受体时,最佳C/N为3.0,此时N₂O产生量为0.044 mg·L^－１;以硝酸盐为电子受体时,最佳C/N为5.0,此时N₂O产生量为0.135 mg·L^－１,是以亚硝酸盐为电子受体时的3倍.电子受体类型不同时,N₂O产生量的变化趋势类似：在碳源严重不足时,反硝化率和N₂O产生量均很低;碳源相对不足时N₂O产生量增加;C/N过大时,虽然反硝化速率很快,但N₂O产量也急剧增大.可见,与全程硝化反硝化工艺相比,短程硝化反硝化工艺可节省40%碳源,且控制C/N=3,其反硝化过程产生的N₂O远少于全程反硝化.     

污水生物脱氮过程中N_2O的释放途径和影响因素

为了更好地理解和掌握污水处理过程中N 2O的释放规律,结合近年来已经发表的研究结果,就传统的污水生物脱氮过程(全程硝化反硝化过程)和新型污水生物脱氮过程(同步硝化反硝化、短程硝化反硝化和厌氧氨氧化)中N2O的释放途径以及影响因素进行了综述。通过综述发现,硝化和反硝化过程均有可能导致N2O的释放,且硝化过程更易产生N2O;与传统的脱氮过程相比,同步硝化反硝化等新型脱氮过程产生N2O的概率更大;影响N2O释放的因素主要有DO浓度、NO-2浓度、进水氨氮负荷、SRT和COD/N等运行工况和细菌种类及其活性。最后,展望了该领域的研究方向。     

Nitrous oxide production during nitrogen removal from domestic wastewater in lab-scale sequencing batch reactor

The production of N2O during nitrogen removal from real domestic wastewater was investigated in a lab-scale aerobic-anoxic sequencing batch reactor with a working volume of 14 L. The results showed that the total N2O-N production reached higher than 1.87 mg/L, and up to 4% of removed nitrogen was converted into N20. In addition, N20 led to a much higher greenhouse effect than CO2 during aerobic reaction phase, this proved that N2O production could not be neglected. The N2O-N production during nitrification was 1.85mg/L, whereas, during denitrification, no N2O was produced, nitrification was the main source of N2O production during nitrogen removal. Furthermore, during denitrification, the dissolved N2O at the end of aeration was found to be further reduced to N2. Denitrification thus had the potential of controlling N2O production.     

Long-term impacts of land-use change on dynamics of tropical soil carbon and nitrogen pools

Land-use changes, especially the conversion of native forest vegetation to cropland and plantations in tropical region, can alter soil C and N pools and N availability for plant uptake. Deforestation, followed by shifting cultivation and establishment of rubber tree plantation, is a common land-use change in Xishuangbanna, southwest China. However the influence of this kind of land-use change on soil C and N dynamics in this region remains poorly understood, This study was conducted to assess the effects of land-use change on soil C and N pools. Soil samples were collected on five adjacent plots, which belong to three land-use types including secondary forest-an acuminate banana( Musa itinerans) secondary forest and a male bamboo( Dendrocalamus membranaceae) secondary forest, shifting cultivation, and rubber tree ( Hevea brasiliensis (H. B. K. ) Muell. Arg. ) plantation(one plot is 3-year-old, and another is 7-year-old). We measured soil bulk density (BD), pH value, moisture content and concentrations of soil organic carbon(SOC), total soil nitrogen(TSN), and inorganic N(NO3^- -N and NH4^ -N) at 0--3, 3--20, 20--40 and 40--60cm depths, and calculated C and N pools in 0--20, 20--40, 40--60, and 0--60 cm soil layers. Compared with the adjacent secondary forests, shifting cultivation and establishment of rubber tree plantations resulted in significant decline in concentrations and stocks of SOC and TSN in 0--20 and 0--60cm soil layers, and increase in pH and bulk density at 0--3, 3--20, and 20--40cm depths. Soil moisture content decreased only in 0--20cm surface soils in shifting cultivation and plantations. The dynamics of mineral N was much more complex, which had different trends among depths and ecosystems. Compared with the secondary forests, SOC stocks in 0--20cm surface soils in shifting cultivation and rubber tree plantations(3-year-old plantation and 7-year-old plantation) decreased by 34.0%, 33%, and 23% ; and TSN stocks decreased by 32.2%, 20.4%, and 20.4%, respectively,whereas the decreases of SOC and TSN stocks in 0--60cm soil layers were much less. The results indicated that C and N losses were mainly occurred in 0--20cm surface soil, followed by 20--40cm layer.     

小流域农业面源氮污染时空特征及与土壤呼吸硝化关系分析

土壤呼吸与硝化特性是控制土壤生态系统中氮素转化和面源氮流失的关键因子,也是土壤氮循环的重要组成部分.选取位于巢湖北部的柘皋河流域作为案例研究区,应用BaPS技术测定林地和农田土壤呼吸、硝化和反硝化特性,运用SWAT模型分析农业面源氮污染输出的时空特征,并初步探讨土壤呼吸和硝化特性与农业面源氮污染的相互作用关系.结果表明,由于土地利用和施肥量的变化,1996~2012年间的年均和月均面源氮污染负荷明显大于1980~1995年间的模拟结果,不同月份的面源氮污染输出负荷均存在显著性差异,月均氮负荷受降雨量影响密切.1996~2012年流域面源总氮流失平均负荷为10.40 kg·hm-2,明显大于1980~1995年的8.10 kg·hm-2,方差分析表明两个时期面源总氮流失负荷的空间分布存在一定的差异.林地的呼吸速率远大于农田的呼吸速率.农田较高的总硝化速率和反硝化速率导致土壤氮库中的氮素减少,从而在一定程度上使得面源氮污染的输出负荷减小.农田土壤的总硝化速率大于反硝化速率,导致农田硝态氮的面源污染流失量增加,而有机氮的流失量有所减少.因此,土壤呼吸与硝化特性的研究有利于从土壤生物学角度深入分析土壤氮循环,对农业面源氮污染的防治具有重要的理论和现实意义.     

SRT对于污水脱氮过程中N2O产生的影响

试验采用经过长期驯化,控制污泥龄分别为9d和15d的活性污泥,以实际生活污水为研究对象,考察了不同污泥龄(SRT)对污水脱氮过程中N2O的产生量和转化率的影响.结果表明N2O主要产生于污水脱氮的硝化过程中,而反硝化过程的贡献较少.较短的污泥龄有利于脱氮过程中N2O的产生,9d污泥龄的活性污泥系统产生N2O量是15d污泥龄污泥系统的1.2倍,分别为4.62mg·L-1和3.8mg·L-1.不同污泥龄条件下产生N2O的转化率也有所差别,污泥龄较短的活性污泥系统产生N2O的转化率也较高,分别为11.2%和7.8%.系统经长期在较短的污泥龄下运行,并没有影响系统的脱氮效果,两种污泥龄条件下系统的脱氮率都在96%以上.为了减少污水脱氮过程中N20的产生量,应避免污水处理系统过短的污泥龄,造成污水脱氮过程N2O的产量和转化率的大幅升高.     

Effects of long-term amendment of organic manure and nitrogen fertilizer on nitrous oxide emission in a sandy loam soil

To understand the effects of long-term amendment of organic manure and N fertilizer on N2O emission in the North China Plain, a laboratory incubation at different temperatures and soil moistures were carried out using soils treated with organic manure （OM）, half organic manure plus half fertilizer N （HOM）, fertilizer NPK （NPK）, fertilizer NP （NP）, fertilizer NK （NK）, fertilizer PK （NK） and control （CK） since 1989. Cumulative N2O emission in OM soil during the 17 d incubation period was slightly higher than in NPK soil under optimum nitrification conditions （25℃ and 60% water-filled pore space, WFPS）, but more than twice under the optimum denitrification conditions （35℃ and 90% WFPS）. N2O produced by denitrification was 2.1-2.3 times greater than that by nitrification in OM and HOM soils, but only 1.5 times greater in NPK and NP soils. These results implied that the long-term amendment of organic manure could significantly increase the N2O emission via denitrification in OM soil as compared to NPK soil. This is quite different from field measurement between OM soil and NPK soil. Substantial inhibition of the formation of anaerobic environment for denitrification in field might result in no marked difference in N2O emission between OM and NPK soils. This is due in part to more rapid oxygen diffusion in coarse textured soils than consumption by aerobic microbes until WFPS was 75% and to low easily decomposed organic C of organic manure. This finding suggested that addition of organic manure in the tested sandy loam might be a good management option since it seldom caused a burst of N2O emission but sequestered atmospheric C and maintained efficiently applied N in soil.     

管理措施对农田生态系统土壤呼吸的影响

为研究管理措施(氮肥施用和耕翻措施)对农田土壤呼吸的影响,采用静态暗箱-气相色谱法对农田生态系统的土壤呼吸作用进行了5个生长季(2002~2003年小麦,2003年玉米、大豆,2003~2004年小麦,2004年玉米,2004~2005年小麦)的野外观测试验.结果表明,冬小麦基肥(2002-11-09)、返青肥(2003-02-14)和拔节肥(2003-03-26)施用后2周内氮肥施用处理的土壤呼吸速率明显高于对照,但不同施氮水平间的土壤呼吸速率无显著差异.耕翻对土壤呼吸的影响效应受到前茬作物类型的制约.在2003~2004年的冬小麦生长季(其前茬种植的作物为水稻),不耕和浅耕处理的平均土壤呼吸速率之间无显著差异(p>0.05).在2004年玉米生长季浅耕比不耕处理显著增加了土壤呼吸速率(p<0.05),而在后茬的2004~2005年小麦生长季浅耕比不耕又显著降低了土壤呼吸速率(p<0.05).在前茬作物为水稻的麦田(2004~2005年小麦生长季),深耕比不耕处理显著增加了土壤CO2排放量.不同管理措施下,农田土壤呼吸与土壤温度的关系均可用指数方程描述,针对不同管理措施下拟合得到的指数方程求得的Q10值在1...     

δ~(15)N和δ~(18)O指标识别环境中N_2O生成机理

δ15N和δ18O指标在识别环境N2 O生成机理中具有重要的作用。本文主要讨论δ15N指标在识别海洋、土壤和污染水体N2 O生成机理中的作用 ;分析硝化和反硝化作用引起的同位素分馏特征 ;并对δ18O指标的应用进行了探讨。     

Sources of nitrous and nitric oxides in paddy soils：Nitrification and denitrification

Rice-paddies are regarded as one of the main agricultural sources of N 2O and NO emissions. To date, however, specific N2O and NO production pathways are poorly understood in paddy soils. ^15N-tracing experiments were carded out to investigate the processes responsible for N2O and NO production in two paddy soils with substantially different soil properties. Laboratory incubation experiments were carried out under aerobic conditions at moisture contents corresponding to 60% of water holding capacity. The relative importance of nitrification and denitrification to the flux of NaO was quantified by periodically measuring and comparing the enrichments of the N2O, NH~-N and NO3-N pools. The results showed that both N2O and NO emission rates in an alkaline paddy soil with clayey texture were substantially higher than those in a neutral paddy soil with silty loamy texture. In accordance with most published results, the ammonium N pool was the main source of N2O emission across the soil profiles of the two paddy soils, being responsible for 59.7% to 97.7% of total N2O emissions. The NO3-N pool of N2O emission was relatively less important under the given aerobic conditions. The rates of N2O emission from nitrification （N2On） among different soil layers were significantly different, which could be attributed to both the differences in gross N nitrification rates and to the ratios of nitrified N emitted as NzO among soil layers. Furthermore, NO fluxes were positively correlated with the changes in gross nitrification rates and the ratios of NO/N2O in the two paddy soils were always greater than one （from 1.26 to 6.47）. We therefore deduce that, similar to N2O, nitrification was also the dominant source of NO in the tested paddy soils at water contents below 60% water holding capacity.     

冻融对内蒙古温带贝加尔针茅草甸草原N2O通量的影响

本研究以内蒙古呼伦贝尔草甸草原为研究对象,通过室内模拟实验与野外观测实验相结合,分析不同土层、放牧与封育、长期与短期冻融、不同冻融频率与冻融温差强度对草地土壤N2O产生与排放的影响.结果表明:冻融期间,从地表到下层15cm土壤N2O的产生速率随深度的增加而逐渐减少,N2O的产生主要来源于0~9cm的表层土壤;冻融期间温差相同的情况下,冻融次数越多,N2O的产生速率越小;N2O的产生速率随着温差的变小而减少;冻融期间封育样地的N2O排放量大于放牧样地,且封育样地的N2O排放量占全年排放总量的25.09%,大于放牧样地(12.38%),但从观测年排放总量看,放牧却促进了草地N2O源的功能;草地春融期间的N2O排放量是整个冻融期N2O排放量的最大贡献者.     

不同污水生物脱氮工艺中N2O释放量及影响因素

微生物的硝化及反硝化过程为污水处理过程中N2O的主要产生源.从微生物学和生物化学反应的角度,阐述了硝化及反硝化过程中N2O的生成机理以及与N2O产生相关的关键酶的基本特性,同时给出了几种典型硝化及反硝化菌的N2O产生与释放情况.通过对实际污水处理厂、不同污水处理工艺,尤其是新工艺过程中N2O释放量及产因的分析,指出污水生物处理过程中N2O的释放量与污水水质、污水处理工艺、工艺的运行工况及微生物的种群结构有关,并对底物浓度、DO浓度、SRT等关键性因素进行了重点论述.在综合分析N2O产生机理及影响因素的基础上,从工艺运行工况及微生物种群优化2个角度,初步提出了控制污水生物处理过程中N2O释放的策略.     

人工快速渗滤池微生物活性的研究

基于微生物活性测定方法,研究了人工快速渗滤池中各层中微生物数量、酶活性、硝化作用、反硝化作用和呼吸作用强度.结果表明,好氧细菌在数量上占绝对优势;各种微生物大都呈现出从表层到底层数量逐渐减少的规律;0～20cm砂层的脲酶、脱氢酶和磷酸酶活性明显高于其他层;在快渗池内,氮转化以硝化作用为主,反硝化作用比较弱;渗滤池上部呼吸作用明显强于中下部,与微生物的分布呈正相关.     

Effects of elevated atmospheric CO2 concentration and temperature on the soil profile methane distribution and diffusion in rice–wheat rotation system

The aim of this experiment was to determine the impacts of climate change on soil profile concentrations and diffusion effluxes of methane in a rice–wheat annual rotation ecosystem in Southeastern China. We initiated a field experiment with four treatments: ambient conditions (CKs), CO₂ concentration elevated to ~ 500 μmol/mol (FACE), temperature elevated by ca. 2°C (T) and combined elevation of CO₂ concentration and temperature (FACE + T). A multilevel sampling probe was designed to collect the soil gas at four different depths, namely, 7 cm, 15 cm, 30 cm and 50 cm. Methane concentrations were higher during the rice season and decreased with depth, while lower during the wheat season and increased with depth. Compared to CK, mean methane concentration was increased by 42%, 57% and 71% under the FACE, FACE + T and T treatments, respectively, at the 7 cm depth during the rice season (p < 0.05). Mean methane diffusion effluxes to the 7 cm depth were positive in the rice season and negative in the wheat season, resulting in the paddy field being a source and weak sink, respectively. Moreover, mean methane diffusion effluxes in the rice season were 0.94, 1.19 and 1.42 mg C/(m²·hr) in the FACE, FACE + T and T treatments, respectively, being clearly higher than that in the CK. The results indicated that elevated atmospheric CO₂ concentration and temperature could significantly increase soil profile methane concentrations and their effluxes from a rice–wheat field annual rotation ecosystem (p < 0.05).     

季节性冻融期沼泽湿地CO2、CH4和N2O排放动态

三江平原季节性冻-融时间长达7～8个月,对沼泽湿地温室气体排放有重要影响.采用静态箱/气相色谱法研究了三江平原冻、融期沼泽湿地温室气体排放特征,表明三江平原不同类型沼泽湿地冬季都有明显的CH₄和CO₂排放,且冬季沼泽湿地CH₄排放量在全年CH₄排放中占有重要份额.融冻期沼泽湿地出现明显的CH₄和CO₂排放峰值,季节性积水沼泽化草甸CH₄和CO₂排放量大于常年积水沼泽湿地,而冬季常年积水沼泽湿地CH₄排放通量大于季节性积水沼泽化草甸.融冻期CO₂排放通量与土壤温度(5cm)呈指数相关关系(R²=0.912,p<0.001),沼泽湿地CO₂排放通量与CH₄通量间也呈显著正相关关系(R²=0.751,p<0.001).冬季三江平原沼泽湿地是N₂O的汇,融冻期随着土壤温度升高逐渐成为N₂O的源,且在5月份沼泽湿地表层土壤(0～20cm)融冻期间N₂O排放通量明显增大.三江平原土壤冻、融期间沼泽湿地温室气体的排放特征,反映了冬季微生物活性的存在及融冻作用对土壤碳矿化和氮硝化、反硝化作用有重要影响.     

旱地土壤反硝化厌氧甲烷氧化菌的垂向分布特性与活性分析

在厌氧条件下,以亚硝酸盐作为电子受体将甲烷氧化的反硝化厌氧甲烷氧化反应(nitrite-dependent anaerobic methane-oxidizing,n-damo)的发现,彻底颠覆了人们对甲烷循环的传统理解.通过分子生物学方法及13C和15N稳定同位素示踪技术,对河北省北澧河附近的旱地农田土壤(0~1 m)中n-damo菌的群落结构、丰度和活性进行了研究,深入探究了n-damo菌的亚硝酸盐底物来源.结果显示,n-damo菌更多存在于旱地浅层土壤中,并且随季节变化分布在不同深度的土壤中.针对其pmo A基因的系统发育分析显示,旱地土壤中n-damo菌的群落结构具有明显的空间异质性,来自土壤0~20 cm和40~60 cm土层的序列完全分开,处于系统发育树不同分枝.针对其16S rRNA基因的实时荧光定量PCR结果显示,n-damo菌丰度随土壤深度的增加而降低,夏季丰度(1.44×10~4~1.02×10~5copies·g~(-1))低于冬季(3.66×104~2.67×105copies·g-1).在浅层土壤(0~20 cm)中,硝化反应和反硝化反应共同为n-damo菌提供亚硝酸盐底物来源;而在深层土壤(60~80 cm)中,亚硝酸盐底物主要来源于硝化反应.n-damo菌的活性(0.18 nmol·g~(-1)·d~(-1),以CO_2计)只能在夏季表层土壤(0~20 cm)中检测到,其余深度均未检测到其活性.在旱地农田土壤中,反硝化厌氧甲烷氧化菌对农田碳循环的影响可能不大.     

增温对农田土壤碳氮循环关键过程的影响

为研究模拟增温对农田土壤碳氮循环关键过程的影响,设置了包含增温和对照两个处理的随机区组试验.采用气压过程分离技术(BaPS)测定土壤CO2产生速率、硝化速率、反硝化速率,并测定了根生物量、水溶性有机碳(DOC)、亚硝酸根、硫酸根、硝酸根等指标.结果表明,在冬小麦-大豆轮作生长季,增温和对照处理的平均土壤CO2产生速率分别为(149.7±19.6)和(114.5±11.6) μg/(kg·h),增温和对照处理的平均土壤硝化速率分别为(563.6±119.56),(399.9±98.2)μg/(kg·h),增温和对照处理的平均土壤反硝化速率分别为(319.7±94.6), (216.2±44.7) μg/(kg·h).研究表明,无论是在冬小麦生长季还是在大豆生长季, 模拟增温均促进了土壤CO2产生速率,增温对大豆田土壤CO2产生速率的促进作用高于冬小麦田,并且这种促进作用主要体现在作物生长后期.模拟增温显著促进了冬小麦–大豆田的土壤硝化、反硝化速率,夏季增温对土壤硝化、反硝化速率的促进作用最明显.模拟增温对土壤中根生物量、DOC、亚硝酸根、硫酸根、硝酸根含量无显著影响.     

秸秆还田配施化肥对土壤养分及冬小麦产量的影响

为探究关中地区秸秆还田配施化肥对土壤养分和冬小麦产量的影响,研究采用裂区试验设计,主区为：秸秆不还田（S₀）和秸秆还田（S）;副区为：不施肥（WF）、氮肥（NF）和氮磷肥（NPF）.应用生态化学计量的方法,探究秸秆还田配施化肥下土壤碳氮磷含量变化及其和产量的关系.结果表明,秸秆和施肥互作对表层（0~20 cm）土壤有机碳、全氮和全磷含量均产生显著影响（P<0.05）.与S₀WF处理相比,SNPF处理显著提高表层（0~20 cm）土壤有机碳和全氮含量（P<0.05）.秸秆和年份互作对表层（0~20 cm）土壤全氮含量产生显著影响（P<0.05）,随着秸秆还田时间的增加,在2021年SWF处理下表层（0~20 cm）土壤全氮含量显著高于S₀WF （P<0.05）.秸秆和施肥及其互作对20~40 cm土层有机碳和全氮含量无显著影响（P>0.05）,但对20~40 cm土壤全磷含量产生显著影响（P<0.05）,与SWF处理相比,SNPF处理显著增加了20~40 cm土层全磷含量（P<0.05）.秸秆还田配施化肥对土壤化学计量特征也产生显著影响.与S₀WF处理相比,S₀NPF处理能够降低表层（0~20 cm）土壤C：N,提高表层（0~20 cm）土壤C：P和N：P.与SWF处理相比,SNF处理能够降低表层（0~20 cm）土壤C：N.秸秆还田配施化肥对冬小麦产量也产生显著影响,2020年和2021年SNPF处理与S₀WF处理相比分别增产24.23%和28.9%.相关性分析表明,产量与C：N （P<0.05）和C：P （P<0.01）呈显著正相关关系.全氮和N：P与处理年份呈极显著正相关关系（P<0.001）.综上所述,在关中地区秸秆还田配施氮磷肥处理（SNPF）会改善土壤养分,改变土壤化学计量特征,同时提高产量.因此,本研究结果表明秸秆还田配施氮磷肥（SNPF）是优化区域农田养分管理,提高粮食生产能力的有效途径.