民勤沙漠绿洲膜下滴灌洋葱灌溉试验研究初探

在民勤沙漠绿洲进行了洋葱膜下滴灌灌溉试验研究,结果表明:膜下滴灌适当减少灌水可以促使洋葱更多的利用土壤底墒,灌水相对较少的处理T2底墒利用率最高,分别比T1、T3、对照CK高10.73%、9.85%和9.92%。膜下滴灌不同灌水处理以灌水最多的T3洋葱产量最高,水分利用效率也最高;灌水最多的常规灌溉CK水分利用效率最低,分别比T1、T2、T3低35.28%、55.21%、58.79%。膜下滴灌条件下适当增加灌水量在一定程度上可增加洋葱产量,当灌水量在一定范围内,洋葱产量和水分利用效率均会显著提高。     

控制性交替灌溉对玉米生长发育的影响

在沈阳地区潮棕壤土上,采用蒸渗仪对不同控制性交替灌溉处理下玉米生长发育、产量和水分生产效率进行分析。结果表明,控制性交替灌溉抑制了玉米地上部分生长,处理2(控制隔沟交替灌水,灌水定额为2/3M)的产量最高,比处理1(均匀灌水,灌水定额为M)增产4.8%,节水13.3%,处理3(控制隔沟交替灌水,灌水定额为1/2M)最节水但产量最低,确定处理2(2/3M)为最优灌溉制度。     

苗期玉米对根区局部供水不同灌水下限的响应

对玉米苗期根系局部供水条件下生长、生理指标对不同灌水下限(占田间持水量60%、65%、70%、75%)的响应进行了研究。结果表明：占田间持水量65%的灌水下限（T₂）处理的株高、茎粗等生长指标明显优于其他处理,与全面灌溉(CK,占田间持水量60%)相比,T₂处理的生物积累总量提高了1.2%,而其他处理的生物积累总量降低;随着灌水下限的不断提高,苗期玉米叶片组织中脯氨酸、可溶性糖和植物组织相对含水量等生理指标不断降低,占田间持水量65%的灌水下限（T₂）处理的脯氨酸和可溶性糖的含量与CK处理结果相近,差异不显著。     

基于RAIGA的PPC模型评价调亏灌溉对东北春玉米生长和产量的影响

为了研究调亏灌溉对东北春玉米生长和产量的综合影响,在移动式遮雨棚下,以东北春玉米为试验材料,采用测筒栽培试验方法,分析了玉米在苗期、拔节期、抽雄期中度调亏灌溉处理后对玉米干物质重、耗水量的影响,并采用实码加速免疫遗传算法进行投影寻踪建模,综合评价灌水方案优劣,结果表明：苗期亏水使玉米具有较强的适应干旱的能力,苗期可中度亏水,即控制土壤水分到田间持水量的50％～60％,且苗期调亏的方案经模型评价要优于其它方案。     

不同灌水水平下少耕地膜覆盖对玉米农田土壤温度和水分利用效率的影响

以大田玉米为研究对象,在少耕地膜覆盖和不同灌水水平下,研究了一膜两年用地膜覆盖、秋免耕春覆膜和传统耕作覆膜对玉米农田土壤温度和水分利用效率(WUE)的影响。结果表明:与传统耕作覆膜和秋免耕春覆膜两种新膜覆盖处理相比,一膜两年用处理在玉米播种到拔节期的增温效果显著低于新膜覆盖,农田0~25 cm土壤平均温度较传统覆膜处理低13.35%,而对玉米拔节期到成熟期的土壤温度无明显影响,且农田0~25 cm土层土壤积温差异也不显著,相同覆膜方式下不同灌水水平间有显著差异,随着灌水水平的降低土壤积温增加;一膜两年用地膜覆盖方式下玉米籽粒产量和WUE与两种新膜覆盖方式相当,中灌水水平下WUE最高,达到17.89kg·mm-1,且在低灌水水平下获得籽粒产量显著高于传统覆膜处理,一膜两年用覆盖、灌溉定额5 700 m3·hm-2较传统耕作覆膜、灌水定额5 700 m3hm-2处理的玉米产量高出16.39%。说明,一膜两年用地膜覆盖在玉米播种到拔节期的增温效应低于新膜覆盖,但并不影响籽粒产量的形成,且在存在水分胁迫的低灌水水平下一膜两年用覆盖模式可减缓干旱胁迫,提高作物籽粒产量,是适于西北绿洲灌区的具有较好经济效益和生态效益的覆膜农田管理新技术。     

绿洲灌区地膜利用方式与灌水量对玉米产量形成的协同效应

通过不同地膜利用方式（NT：前茬玉米覆膜收获后免耕,次年直接播种;RT：秋免耕春覆膜;CT：传统耕作覆膜）和不同灌水水平（I1：全生育期灌水450 mm;I2：495 mm;I3:540 mm）下玉米干物质积累和产量构成的响应规律,揭示地膜利用方式和灌溉量调控玉米产量形成的机制,为覆膜种植玉米集成利用免耕和限量灌溉技术提供理论和实践依据。结果表明,NT和RT覆膜免耕处理降低了玉米吐丝期前干物质积累量和群体生长率,分别较传统耕作覆膜处理平均降低32.4%和45.9%,但吐丝期后使干物质积累量和群体生长率分别提高7.4%和32.6%;灌水减量至495 mm未造成干物质累积量和生长率降低。NT和RT覆膜免耕处理使玉米单位面积穗数和百粒重较传统耕作覆膜处理平均分别提高13.4%和6.6%,进而使3 a平均产量提高5.4%;灌水减量至495 mm并未引起减产。通径分析进一步表明,有限灌水条件下覆膜免耕玉米主要通过增加双穗数和增大百粒重来提高籽粒产量。可见,集地膜覆盖和免耕为一体的覆膜免耕技术是干旱地区玉米生产较为理想的种植技术。     

不同深松时期对旱地春玉米水分利用状况及产量的影响

于2010—2012年在晋东南旱平地设置了春季深松、夏季深松和秋季深松3种深松处理试验,以传统翻耕为对照,研究不同处理对春玉米耗水量、干物质积累与分配、产量和水分利用效率的影响。结果表明,秋季深松处理的总耗水量最高,春季深松处理次之,且两者与传统翻耕（对照）差异均显著,表明春季和秋季深松后春玉米的总耗水量增加。夏季深松总耗水量低于对照处理,这是因为夏季深松后,对玉米根系造成一定程度的伤害。在春玉米生育后期,秋季深松和春季深松能有效促进干物质积累,增加春玉米生物干重,提高作物产量。2011年秋季深松处理的产量和水分利用效率最高,且显著高于其它处理,分别比传统深翻（对照）提高13．61％和10．26％,春季深松处理次之,分别比对照提高10．32％和7．62％,夏季深松处理低于传统深翻（对照）,且分别比对照降低3．95％和1．82％,表明秋季深松和春季深松有利于产量的提高和水分的高效利用。     

不同灌水定额处理下基于有效积温玉米生长状况模拟研究

探究不同灌水定额对春玉米生长状况的影响,为优化克拉玛依地区春玉米灌溉制度提供理论依据。于2021年5月～9月,在克拉玛依农业综合开发区开展春玉米田间试验,研究玉米生育期内不同灌水量对株高、叶绿素、叶面积指数以及地上部生物量的影响,建立归一化Logistic模型,探究有效积温与玉米生长及生物量之间的相关关系。灌水定额由W1处理(225m³/hm²)提高至W5处理(525m³/hm²)时更有利于促进玉米生长;随有效积温增加,株高呈不断增长的趋势,叶绿素呈先增后减的趋势,叶面积指数和地上部干物质积累呈慢-快-慢动态变化,玉米叶面积指数拟合值和实际值拟合指数R²>0.9,玉米干物质积累量拟合方程的标准差小于0.06,表明通过Logistic模型建立的拟合方程可以较好模拟春玉米叶面积指数和干物质的变化及积累情况。W5处理(525m³/hm²)相对叶面积指数理想条件下的最大值高于其他处理,玉米地上部干物质积累时间较长,快增期内增长速率最大。...     

内蒙古主要灌区春小麦、春玉米农田优化灌溉指标研究

根据田间试验资料，在系统分析土壤相对有效含水量Ar和耗水量与产量、灌溉量与WUE及需水关键期Ar与WUE关系的基础上，提出适合内蒙古主要灌区春小麦、春玉米不同发育时期农田水分优化灌溉指标，即苗期、孕穗开花期和灌浆期春小麦的灌溉指标分别为Ar60%、70%和55%，春玉米的灌溉指标分别为Ar60%、75%和60%。同时给出了供试作物适宜耗水量、灌水量及WUE最高时的Ar等参数。     

海河平原小麦-玉米不同种植制度节水特性分析

试验于2014—2016年在河北省景县进行。试验处理为冬小麦-夏玉米一年两熟（CK）、春玉米→冬小麦-夏玉米两年三熟(A1)、春玉米-夏玉米一年两熟(A2)、春玉米一年一熟(A3)、夏玉米一年一熟(A4) 5种种植制度,系统分析了各处理作物产量、周年土壤水分动态和水分利用效率。结果表明：5种种植制度中,CK产量最高,2个种植周期的总产量为38 574.24 kg·hm^-2,A1、A2、A3、A4总产量分别比CK减少23.7%、23.8%、51.2%和39.6%;CK的总耗水量最高,为1 851.45 mm,A1、A2、A3、A4 相对CK耗水量分别减少了504.3、452.3、753.5 mm和712.8 mm;各处理间水分利用效率没有显著差异,A1较高为21.84 kg·mm^-1·hm^-2。A1和A2相对CK总产量有所降低,但周年总耗水量分别比CK减少504.25 mm和452.30 mm,水分利用效率分别提高了4.8%和0.8%。这2种种植制度可作为当前小麦-玉米两熟的重要补充,加强周年土壤水分管理是本区域粮食生产和水分可持续利用的重要措施。     

东北地区玉米大豆水分利用效率研究

利用大安和朝阳玉米研究站点、呼玛和锦州大豆研究站点近20 a作物产量、发育期及土壤水分实测资料,同时结合分期播种试验资料,研究了玉米大豆产量水分利用效率(WUE_g)对降水、温度的响应特征,分析了两种作物产量水分利用效率与群落水平水分利用效率(WUE_b)的关系。结果表明:大安和朝阳站点玉米WUE_g分别为1.75±0.47 kg·m~(-3)和1.98±0.72 kg·m~(-3),呼玛和锦州站点大豆WUE_g分别为0.63±0.35 kg·m~(-3)和0.55±0.18kg·m~(-3);玉米站点WUE_g与播种—成熟期间的降水量和ET均呈显著的二次曲线关系(P0.05),WUE_g与温度关系不明显;大豆WUE_g与播种至成熟期间的降水量呈现显著的负相关关系;历史资料分析结果表明,随着生育期期间平均气温的增加,大豆WUE_g升高;在大安和朝阳站点,取得高水分利用效率与获得高产所消耗的水量(即ET)并不一致,表明对于存在干旱胁迫的半干旱和半湿润区,有效的利用水(Effective use of water,EUW)而不是一味追求水分利用效率(WUE)是提高产量的有效途径,植物消耗的水量(ET)往往是决定作物产量的重要因素。     

土地资源配置过程中违规问题分析

研究目的:探讨杜绝土地资源配置违规与合理可行的方法措施。研究方法:文献资料法、因果分析法、理论指导法。研究结果:土地资源配置的违法环节:农地转变为农村集体建设用地、农村集体土地转变为城市国有土地、政府划拨土地转变为城市商业用地;违规者有地方政府、村集体和个人;土地用途、使用权转变政策漏洞的巨大套利空间是其动力。研究结论:改革健全现行土地管理中政府划拨、商业与非商业用地间的悬殊价格差异,是杜绝土地违规交易的根本办法。     

Long-term cultivation and landscape position effects on aggregate size and organic carbon fractionation on surface soil properties in semi-arid region of Iran

This study was carried out to investigate the effects of long-term cultivation and landscape position on organic carbon content and soil aggregation. Sampling sites were determined based upon land use at the end of 50 years soil use and management, cultivated/annual wheat cropping and grazed pasture, and landscape position in Chaharmahal-va-Bakhtiary province, southwest Iran. Soil samples were collected from the 0–5 cm and 5–15 cm depths in two adjacent fields that have the same slope and aspect. The soil was silty clay at the summit and footslope positions, and was a silty clay loam at the backslope. Wet-sieving analysis and aggregate-size fractionation methods were used to separate the samples into three aggregate fractions (i.e., 2–4.75, 0.25–2, and 0.053–0.25 mm). The treatments were arranged in a factorial design. Land use significantly affected the water-stable aggregate fractions, so that the wet soil stability of the macroaggregates (i.e., 2–4.75 mm) was higher in the pasture, whereas it was greater for the meso-aggregates (i.e., 0.25–2 mm) in the cultivated soils. Cultivation decreased both the wet-aggregate stability and percent of macroaggregates whereas long-term pasture enhanced aggregation. Soil organic carbon (SOC) content within aggregates and primary particles was also significantly influenced by landscape position, land use, and the depth of sampling. The SOC content was higher in clay than those in silt and sand contents. The SOC content decreased as depth increased in all fractions. In general, the highest and lowest wet-stable aggregates were observed on the footslope and backslope positions, respectively.     

县域土地利用/土地覆被时空转换研究--以杜尔伯特蒙古族自治县为例

在遥感和GIS支持下 ,利用TM、MSS、地形图及相关资料 ,研究了 1 95 4 - 2 0 0 1年杜尔伯特蒙古族自治县土地利用时空转换形式 ,运用稳定性的概念来解释土地利用变化趋向稳定与否的。结果表明水域和与人类活动关系密切的城镇及居民用地 ,耕地最为稳定 ,其次稳定的是盐碱地和其他难利用土地 ,湿地 ,林地 ,草地稳定性较差。这充分说明了人类在土地利用中一旦开垦耕地一般就不会放弃耕种 ,水域和湿地不能轻易改为它用 ,土地退化了的盐碱地因改良难而较稳定 ,湿地和草地因受降水量的影响 ,较不稳定。     

Water,land, and energy use efficiencies and financial evaluation of air conditioner cooled greenhouses based on field experiments

High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m² for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m² in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.     

不同保护性耕作方式对冬小麦叶片水平水分利用效率的影响

比较河西灌区传统耕作方式和4种保护性耕作方式对冬小麦抽穗期旗叶叶片水平水分利用效率以及与之相关生理生态因子的影响,探索高产节水、保护耕地的冬小麦栽培措施。结果表明:秸秆翻压(TIS)、免耕(NT)和免耕覆盖(NTS)的耕作方式使冬小麦的叶片水分利用效率(WUEl)日变幅缩小,而免耕立茬耕作方式(NTSS)使冬小麦WUEl日变幅加大;NT、NTS和TIS的日光合量均明显高于传统耕作,但由于它们的日蒸腾量也明显高于传统耕作(T),使得这三种耕作方式的日累积水分利用效率和日平均水分利用效率都低于T。NTSS和T耕作方式的叶片水平水分利用效率在11∶00~13∶00的高峰区有可能就是Pn和Tr达到优化组合的一种状态。免耕覆盖可以减少棵间蒸发,缓慢释放CO2,使植株间的CO2浓度升高,从而提高作物的水分利用效率;RHin是冬小麦水分利用效率(WUE)变化的一个重要值,在生产实践中采用各种提高RHin的生产措施,都能有效地提高作物叶片水平WUE。     

基于功能性状评价7种核桃砧木幼苗水分利用效率

为筛选高效用水核桃砧木,测定了干旱条件下7种核桃砧木幼苗的长期水分利用效率(WUEL)及其水分利用相关功能性状,分析WUEL与各功能性状的相关性,采用隶属函数法、主成分分析法和聚类分析法对7种核桃砧木幼苗的水分利用效率进行综合评价.结果表明:7种核桃砧木幼苗的WUEL存在显著的种间差异(P<0.001),其中鸡爪绵和香...     

Effects of water salinity and N application rate on water- and N-use efficiency of cotton under drip irrigation

In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficien     

不同水肥条件对间作花生和谷子水分养分利用的影响

采用水、氮、磷"3414"试验设计,研究了花生和谷子间作不同水肥条件对作物水分、养分利用的影响。结果表明:当氮素和磷素均处于丰富水平,随着土壤水分的提高,花生叶片水分利用效率呈下降趋势,谷子呈先升高后下降的趋势;在水分和其中一种肥料因素处于丰富水平时,花生和谷子叶片水分利用效率均随着另一肥料因素的增加呈先升高后下降趋势。花生氮素积累量与施氮量,花生磷素积累量与施磷量,谷子氮素、磷素和钾素积累量与土壤水分含量具有明显相关性。花生氮积累量与钾积累量、磷积累量与钾积累量之间具有较高相关性;谷子氮积累量、磷积累量和钾积累量,三者中两因素之间均具有较高相关性;花生氮积累量与谷子钾积累量和磷积累量、花生磷积累量与谷子磷积累量、花生钾积累量与谷子钾积累量和磷积累量具有较高的协同相关性。在其他两因素处于丰富水平,随着土壤水分的提高,花生和谷子氮素、磷素和钾素利用效率均呈先升高后下降趋势;随着施氮量的增加,花生和谷子氮素和钾素利用效率呈先升高后降低的趋势,谷子磷素利用效率呈增高趋势;随着磷素水平的不断提高,花生和谷子氮素、磷素和钾素利用效率均呈先升高后降低趋势。     

基于RS 与GIS 的石家庄市区土地利用／土地覆被变化研究

以1993年TM和2000年ETM＋图像为信息源,分析了石家庄市区1993～2000年的土地利用变化情况,结果表明,土地利用类型以居民点和耕地为主;7年间,研究区土地利用程度加强,土地利用程度指数增加了5.49%;耕地、林地和园地减少,耕地减少最多,耕地和园地主要转为居民点,林地转为居民点和未利用土地。