宁夏枸杞园土壤线虫和微生物群落多样性研究

为了揭示宁夏枸杞园土壤质量变化趋势,以宁夏枸杞之乡——中宁县为研究区,选取不同树龄宁夏枸杞园土壤,分析不同季节、土层和树龄条件下土壤线虫和微生物群落特征变化规律。结果表明,随树龄的增加,枸杞园0~20 cm土壤线虫总数先增加后减少,6 a树龄时达最大值。不同树龄表层土壤均为食细菌线虫所占比例最大(夏季和秋季平均分别为57.23%和61.19%),植物寄生线虫次之;亚表层植物寄生线虫比例显著提高。夏季表层土壤总磷脂脂肪酸(PLFA)和细菌PLFA浓度随树龄呈减小-增大-减小的趋势,9 a树龄各菌群PLFA浓度普遍最大。随树龄的增加,夏季0~20 cm土壤线虫多样性和丰富度指数先增大后减小,但土壤微生物多样性指数、均匀度指数都逐渐减小,线虫和微生物群落优势度指数都逐渐增大;20~40 cm土壤线虫和微生物数量、多样性指数和优势度指数变化趋势一致。土壤EC与微生物总PLFA浓度、细菌PLFA浓度达显著负相关;土壤有机质、全氮、速效磷含量与土壤各线虫数量和微生物浓度相关性普遍达显著或极显著水平。土壤线虫总数、食细菌线虫数量与细菌、真菌和放线菌PLFA浓度均显著或极显著相关。总之,季节、土层和树龄对土壤线虫和微生物群落均有不同程度的影响,但树龄对其影响相对最小;季节、土层和树龄对土壤微生物群落的影响比对土壤线虫群落更显著。在相同季节和土层条件下,土壤微环境质量随着树龄的增加呈现出先改善后退化的趋势。     

铅对小白菜根际微生物群落与其生理功能的影响

通过不同铅浓度下小白菜根际土壤微生物数量、硝化和反硝化速率及呼吸速率等特征的研究,揭示铅污染对植物根际微生态系统生态安全性的影响。结果表明,随着铅浓度的增加,细菌、真菌和放线菌数量均呈现先升后降的变化趋势,峰值所对应的铅浓度分别为300、300和600 mg/kg,3种微生物的耐铅能力为真菌放线菌细菌。土壤硝化和反硝化细菌数、硝化和反硝化速率及呼吸速率也随着铅浓度的增加先升后降,各指标峰值所对应的铅浓度均为300 mg/kg;硝化速率与硝化细菌数、反硝化速率与反硝化细菌数及土壤呼吸速率与微生物总数决定系数分别为0.684 7、0.851 1和0.684 3,均显著正相关。研究发现,当土壤铅浓度达到或超过1 200 mg/kg时,小白菜根际微生态系统出现显著的微生物群落结构和功能退化。     

秸秆还田配施氮肥对土壤碳氮含量与玉米生长的影响

为明确宁夏扬黄灌区秸秆还田条件下的适宜施氮量,在玉米秸秆全量还田条件下,设4种纯氮施用水平(0 kg/hm~2(N0)、150 kg/hm~2(N1)、300 kg/hm~2(N2)、450 kg/hm~2(N3)),以秸秆还田不施氮肥(N0)为对照,研究了秸秆还田配施不同纯氮水平对土壤有机碳氮含量、微生物量碳氮含量和酶活性及其对玉米生长的影响。结果表明,秸秆还田配施氮肥有利于耕层土壤有机碳和全氮含量的提高,随施氮量的增加,土壤碳氮比降低,其中以N2和N3处理对提高耕层有机碳氮含量效果最佳。秸秆还田条件下土壤微生物量碳氮比随施氮量的增加而降低,N2处理对微生物量碳含量、N3处理对微生物量氮含量的提高作用最为显著。秸秆还田配施氮肥能显著提高土壤脲酶、过氧化氧酶、碱性磷酸酶和蔗糖酶活性,以N2和N3处理的改善效果较优。秸秆还田配施氮肥对玉米前期生长影响不显著,而N2处理对中后期玉米生长具有显著促进作用。2年玉米籽粒产量以N2处理增产效果最佳,平均较N0处理提高22.0%。通过2年研究结果表明,在宁夏扬黄灌区实施秸秆还田配施氮肥措施可增加土壤有机碳氮含量,调节土壤碳氮比,促进玉米生长,进而提高玉米产量,以秸秆还田配施纯氮300 kg/hm~2效果最佳。     

秸秆还田配施氮肥对土壤碳氮含量及玉米生长的影响

为明确宁夏扬黄灌区秸秆还田条件下的适宜施氮量,在玉米秸秆全量还田条件下,设4种纯氮施用水平[0 kg/hm~2(N0)、150 kg/hm~2(N1)、300 kg/hm~2(N2)、450 kg/hm~2(N3)],以秸秆还田不施氮肥(N0)为对照,研究了秸秆还田配施不同纯氮水平对土壤有机碳氮、微生物量碳氮含量和酶活性及其对玉米生长的影响。结果表明,秸秆还田配施氮肥有利于耕层土壤有机碳和全氮含量的提高,随施氮量的增加,土壤碳氮比降低,其中以N2和N3处理对提高耕层有机碳氮含量效果最佳。秸秆还田条件下土壤微生物量碳氮比随施氮量的增加而降低,N2处理对微生物量碳含量、N3处理微生物量氮含量的提高作用最为显著。秸秆还田配施氮肥能显著提高土壤脲酶、过氧化氧酶、碱性磷酸酶和蔗糖酶活性,以N2和N3处理的改善效果较优。秸秆还田配施氮肥对玉米前期生长影响不显著,而N2处理对中后期玉米生长具有显著的促进作用。两年玉米籽粒产量以N2处理增产效果最佳,平均较N0处理提高22.0%。通过两年研究结果表明,在宁夏扬黄灌区实施秸秆还田配施氮肥措施可增加土壤有机碳氮含量,调节土壤碳氮比,促进玉米的生长,进而提高玉米产量,以秸秆还田配施纯氮300 kg/hm2效果最佳。     

节水灌溉下秸秆还田形式对黑土区稻田N2O排放与产量的影响

为探寻不同灌溉模式下秸秆还田形式对黑土区稻田N2O排放与产量的影响,于2023年进行大田试验,设置常规灌溉（F）与控制灌溉（C）两种灌溉模式,同时设置秸秆还田（S）、秸秆炭化为生物炭还田（B）、秸秆过牛腹为有机肥还田（O）3种还田形式,以及秸秆不还田（N）作为对照组,共计8个处理。分析不同灌溉模式下秸秆还田形式对稻田N2O排放通量与水稻产量的影响,测定了水稻各生育期稻田土壤铵态氮含量、硝态氮含量、微生物氮含量、pH值,并分析了N2O排放总量和水稻产量与土壤环境因子之间的关系。结果表明：除返青期外,与秸秆不还田处理相比,秸秆还田与有机肥还田处理土壤铵态氮含量、硝态氮含量、微生物氮含量均表现为增加。相同秸秆还田形式下,控制灌溉模式下各处理生育期内土壤平均铵态氮含量、硝态氮含量较常规灌溉模式高36.23%~60.82%、14.16%~19.61%。同时,秸秆还田与生物炭还田能提高稻田土壤pH值。相同灌溉模式下,与秸秆不还田处理相比较,秸秆还田与有机肥还田处理N2O排放总量分别增加14.44%~24.09%、8.22%~14.44%,生物炭还田处理N2O排放总量降低14.31%~23.90%。生物炭还田与有机肥还田各处理水稻产量提高3.28%~13.07%,其中控制灌溉模式下生物炭还田处理产量最高。综上所述,控制灌溉下生物炭还田可以实现节水、增产、减排的目的。     

秸秆不同还田方式对土壤理化性质及玉米产量的影响研究

为了探索秸秆不同还田方式在土壤改良、土壤培肥及作物产量方面的作用,通过大田小区试验,研究土壤在分别施用秸秆生物炭和秸秆后,土壤含水率、土壤温度、土壤pH值及电导率,土壤有机质和速效养分在玉米整个生育期的变化规律并比较玉米产量情况。结果表明,施用生物炭提高耕层土壤含水率,相比对照,土壤含水率在三叶期和成熟期差异显著;秸秆还田在三叶期、拔节期和抽雄期提高耕层土壤含水率且高于生物炭处理,与对照相比三叶期土壤含水率增幅最大,0~10和10~20cm土壤深度增幅分别为:12.24%和14.17%,在灌浆期和成熟期,秸秆还田降低耕层土壤含水率,其中,0~10和10~20cm土壤深度土壤含水率最大降幅分别为:-12.27%和-9.35%;生物炭和秸秆还田,在三叶期对土壤温度影响较小,没有明显的规律,在后面的生育期表现为不同的规律,生物炭在拔节期提高土壤温度,其余玉米生育期均表现为降低作用,秸秆还田在以后的生育期均表现为升温作用;生物炭和秸秆还田降低耕层土壤pH值增大耕层土壤电导率,各处理在玉米不同生育期土壤pH值从大到小依次为:B0、B15、BJ,电导率从大到小依次为:B15、BJ、B0;两种秸秆还田方式提高耕层土壤有机质和速效养分含量,各处理耕层土壤碱解氮、速效钾、有机质和有效磷含量在三叶期和拔节期,从大到小均为:BJ、B15、B0,在抽雄期、灌浆期和成熟期,从大到小均为:B15、BJ、B0;相比对照,生物炭和秸秆还田显著提高玉米产量,分别增产:19.27%和8.1%,生物炭处理相比秸秆还田增幅达到10.3%,差异显著。综上所述,生物炭和秸秆还田能够改善土壤,培肥土壤,增加作物产量,为秸秆及生物炭广泛推广并利用提供理论基础,秸秆还田可在玉米生育后期适量追肥灌水,以达到产量最大化。     

不同种植模式对冬小麦土壤养分及水肥利用效率的影响

为缓解关中地区水资源短缺与小麦生产高耗水的特征性矛盾,通过田间试验,设置垄沟覆膜还田(FMSR)、垄沟不覆膜还田(FNSR)、垄沟覆膜不还田(FMSN)、垄沟不覆膜不还田(CK)4种不同种植模式,分析了不同处理对小麦土壤养分及水肥利用效率的变化影响.结果表明,较于对照处理,覆膜秸秆还田各指标均显著提高(p<0.05),其中土壤含水率提升了2.73％～29.01％,土壤养分提升了38.41％～40.23％,作物茎干物质量提高了30.6％,水分利用效率提高了24.49％,氮肥偏生产力显著(p<0.05)增加了21.7％.综合土壤养分和水肥利用效率考虑,秸秆还田垄沟覆膜种植方式能够有效促进冬小麦的生长,综合考虑节水、增产的目的,在关中地区推荐垄沟覆膜秸秆还田种植模式为较优的种植模式.     

保护性耕作下棉花-春玉米轮作对玉米田土壤性状及水分利用效率的影响

为探索棉花-春玉米轮作下,棉花秸秆还田配合耕作措施对土壤性状和玉米水分利用效率的影响,通过4 a大田定位试验,以试验处理前土壤理化性质为参照,研究了翻耕秸秆还田(PT+SR)、旋耕秸秆还田(RT+SR)、翻耕秸秆不还田(PT+NSR)、旋耕秸秆不还田(RT+NSR)、免耕秸秆还田(NT+SR)、免耕秸秆不还田(NT+NSR)对土壤容重、水分、养分、微生物等的影响;不同处理方式对玉米产量、产量构成因素、水分利用效率的影响。结果表明,秸秆还田配合耕作措施可有效降低0～20 cm和20～40 cm土层土壤容重,以PT+SR处理效果最优,与处理前相比,降幅达9.87%和7%。PT+SR处理在玉米生长中后期具有较好的蓄水保墒效应,玉米产量和水分利用效率最高,2 a平均玉米籽粒产量和水分利用效率分别达到了1.29万kg/hm²和2.42 kg/m³。秸秆还田配合耕作措施可有效提高耕层土壤有机碳、全氮、碱解氮、有效磷和速效钾含量以及真菌、细菌和放线菌数量,其中以PT+SR处理效果最优,分别较试验处理前提高了11.9%、40.5%、32.8%、23.1%、2...     

油菜整秸秆还田机械化技术

秸秆富含提高土壤肥力所需的N、P、K等多种营养元素,它能增加土壤有机质含量,促进土壤微生物繁衍,促使土壤松软,改善土壤团粒结构,所以推行秸秆还田对建立生态农业,实行可持续发展战略具有十分重要意义。 然而,传统的秸秆还田靠人工将秸秆铡短,经旋耕机旋耕后还田。因在农忙季节,费工费时,劳动强度大,且埋草效果差,耕作质量不理想,不够符合插种要求,所以     

温室秸秆还田土壤多源信息实时分析技术研发

针对秸秆腐化还田环境下“土壤—秸秆—环境”关系复杂,环境干扰因素导致土壤信息时空变异大,在线实时检测效率低、不准确、过程繁琐等问题,为满足准确高效采集土壤质量信息的需求,文章提出了通过基于光电和波谱特性的光谱仪器与相应田间作业装备分析不同秸秆腐化还田土壤参数下的光谱特征变化,实时准确获取秸秆腐化深还田土壤pH值、湿度与含氮量的参数信息,可以为秸秆可控还田与环境调控提供实时决策。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。