中国东南地区两土链土壤中土壤性质和水稻产量的空间变异研究

In the light of an increasing demand for staple food, especially rice, in southeast China, investigations on the specific site potential expressed as the relationship between soil and crop yield parameters gain increasing importance. Soil texture and several soil chemical parameters as well as plant properties such as crop height, biomass and grain yield were investigated along two terraced catenas with contrasting soil textures cropped with wet rice. We were aiming at identifying correlative relationships between soil and crop properties. Data were analyzed both statistically and geostatistically on the basis of semivariograms. Statistical analysis indicated a significant influence of the relief position on the spatial distribution of soil texture, total carbon and total nitrogen contents. Significant correlations were found for the catena located in a sandstone area （Catena A） between rice yield and silt as well as total nitrogen content. Corresponding relationships were not detectable for paddy fields that developed from Quaternary clays （Catena B）. As suggested by the nugget to sill ratio, spatial variability of soil texture, total carbon and nitrogen was mainly controlled by intrinsic factors, which might be attributed to the erosional transport of fine soil constituents, indicating the importance of the relief position and slope in soil development even in landscapes that are terraced. The crop parameters exhibited short ranges of influence and about one third of their variability was unexplained. Comparable ranges Of selected crop and soil parameters, found only for Catena A, are indicative of close spatial interactions between rice yield and soil features. Our findings show that especially in sandstone-dominated areas, a site-specific management can contribute to an environmentally safe rice production increase.     

美国堪萨斯州不同天气事件与土壤类型条件下作物产量预测

Computer simulation was used for predictive analysis of the effects of weather and soil type on crop yield in the U.S.crop insurance program.The Environmental Policy Integrated Climate (EPIC) model was modified to include hail weather events,which completed the modifications necessary to simulate the four most frequent causes of crop yield loss (hail,excessive wet,excessive cold,and excessive dry) associated with soil type in Kansas,USA.At the region level,per hectare yields were simulated for corn,wheat,soybean,and sorghum.We concluded that it was possible to predict crop yields through computer simulation with greater than 93% accuracy.The hail damage model test indicated EPIC could predict hail-soil-induced yield losses reasonably well (R² > 0.6).The investigation of soil type influence on dryland sorghum and wheat production indicated that Wymore silty clay loam soil and Kenoma silt loam produced the highest sorghum yields statistically;Kuma silt loam,Roxbury silt loam,Crete silty clay loam,and Woodson silt soils produced the second highest sorghum yields statistically;and Richfiled silt loam,Wells loam,and Canadian sandy loam produced the lowest sorghum yields.By contrast,wheat production showed less sensitivity to soil type variation.The less sensitive response of wheat yields to the soil type could be largely due to the unconsidered small-scale variability of soil features.     

中国青海湖地区草地蝗虫与土壤的关系

A growth chamber study was conducted to determine the relationships between the supply of soil available nitrogen （N） and sulfur （S） and canola （Brassica napus） and wheat （Triticum aestivum L. ‘Biggar＇） N and S uptake and yield in three Western Canadian soils. The suitability of one-hour burial with an anion exchange membrane （AEM） was assessed for its utility as a quick test of the available N：S balance in the soil. Canola and wheat were grown on a Luvisolic soil low in available S and on Brown and Black Chernozemic soils low in both available N and S, with different rates and combinations of N and S fertilizers applied. AEM burial was used to assess soil available nitrate and sulfate supply rates after fertilization. Dry matter yield and N and S concentrations in plant tissues were determined after 6 weeks of growth. The soil available N：S ratio determined by AEM burial closely reflected the relative supplies of available N and S as revealed in the N：S ratios of plant tissue dry matter. The highest yields were achieved where the available N：S ratio in soil and plant tissue ranged from 5 to 13. Thus, a one-hour burial of an AEM probe in the field may be a useful tool to quickly test if a balanced N and S supply is present in the soil for optimum crop yield.     

Predicting grain yield and protein content in winter wheat at different N supply levels using canopy reflectance spectra

A field experiment using a split-plot randomized complete block design with three replications was carried out to determine relationships between spectral indices and wheat grain yield （GY）, to compare the performance of four vegetation indices （VIs） for GY prediction, and to study the feasibility of VI to estimate grain protein content （GPC） in winter wheat. Two typical winter wheat （Triticum aestivum L.） cultivars ＇Xuzhou 26＇ （high protein content） and ＇Huaimai 18＇ （low protein content） were used as the main plot treatments and four N rates, i.e., 0, 120, 210, and 300 kg N ha^-1, as the sub-plot treatments. Increasing soil N supply significantly increased GY and GPC （P ≤ 0.05）. For the two cultivars combined, significant and positive correlations were found between four VIs and GY, with the strongest relationship observed when using the green ratio vegetation index （GRVI） at mid-filling. Cumulative VI estimates improved yield predictions substantially, with the best interval being heading to maturity stage. Similar results were found between VI and grain protein yield. However, when using cumulative VI, GPC showed no significant improvement. The strong relationship between leaf N status and GPC （R2 =0.9144 for ＇Xuzhou 26＇ and R2 = 0.8285 for ＇Huaimai 18＇） indicated that canopy spectra could be used to predict GPC. The strong fit between estimated and observed GPC （R2 = 0.7939） indicated that remote sensing techniques were potentially useful predictors of grain protein content and quality in wheat.     

小麦生产管理知识模型系统

A knowledge model with temporal and spatial characteristics for the quantitative design of a cultural pattern in wheat production, using systems analysis and dynamic modeling techniques, was developed for wheat management, as a decision-making tool in digital farming. The fundamental relationships and algorithms of wheat growth indices and management criteria to cultivars, ecological environments, and production levels were derived from the existing literature and research data to establish a knowledge model system for quantitative wheat management using Visual C^＋＋. The system designed a cultural management plan for general management guidelines and crop regulation indices for timecourse control criteria during the wheat-growing period. The cultural management plan module included submodels to determine target grain yield and quality, cultivar choice, sowing date, population density, sowing rate, fertilization strategy, and water management, whereas the crop regulation indices module included submodels for suitable development stages, dynamic growth indices, source-sink indices, and nutrient indices. Ewluation of the knowledge model by design studies on the basis of data sets of different eco-sites, cultiwrs, and soil types indicated a favorable performance of the model system in recommending growth indices and management criteria under diverse conditions. Practical application of the knowledge model system in comparative field experiments produced yield gains of 2.4% to 16.5%. Thus, the presented knowledge model system overcame some of the difficulties of the traditional wheat management patterns and expert systems, and laid a foundation for facilitating the digitization of wheat management.     

Effect of Soil Erosion on Spring Barley Growth in East Anglia,England：Preliminary Results

The effect of soil erosion on spring barley growth was studied on a deep loamy soil in East Anglia,England,in 1992,Soil erosion was simulated by three levels of soil desurfacing,7.5,18and 30cm with three replicates.Significant differences in crop height,ground cover and crop yield were observed between the three levels of desurfacing.Soil desurfacing also has a singnificant effect on soil moisture at the 20cm depth.The interaction between soil removal and crop performance affected soil moisture at the depths of 50 and 100cm,No significant differences were found in runoff and sediment etween the three topsoil removals due to very dry growing season.Regression equations were developed between spring barley yield and soil desurfacing Spring barley grain yield declined by 97.6kg/ha per cm soil desurfacing.     

Assessing Nitrogen Fertilization Strategies in Winter Wheat and Cotton Crops in Northern Greece

The management of fertilizer application is crucial for agricultural production and environmental safety.The objective of this study was to assess the effciency of different fertilization strategies,applying fertilizers with and without nitrification inhibitors(NIs) in split application,in Greece.The assessment criteria used were based on crop yield,soil nitrogen(N)concentrations and economic effciency.For this purpose two crops(winter wheat and cotton)were seffected in order to explore the optimum fertilization strategy for each crop.Three treatments combining fertilizers with NIs were tested compared with conventional fertilization(CF).Slight differences in the quantity and the combination of fertilizers with NIs applied resulted in variable effects on crop yield,soil N and economic return.Split N application of 102 kg ha^-1,with half of the total amount applied at seeding,resulted in higher grain yield of winter wheat,lower NO₃^--N in soil and higher economic return.This result reveals the importance of N application at seeding in wheat crop.Fertilization strategy with 109.5 kg N ha^-1 and split P application resulted in higher cotton yield and higher economic profit.Split P application seemed to increase yield,even though it is not a common practise in the area.     

Field-scale spatial variability of soil calcium in a semi-arid region: Implications for soil erosion and site-specific management

Excess calcium(Ca) in soils of semi-arid and arid regions has negative effects on soil structure and chemical properties, which limits the crop root growth as well as the availability of soil water and nutrients. Quantifying the spatial variability of soil Ca contents may reveal factors influencing soil erosion and provide a basis for site-specific soil and crop management in semi-arid regions. This study sought to assess the spatial variability of soil Ca in relation to topography, hydraulic attributes, and soil types for precision soil and crop management in a 194-ha production field in the Southern High Plains of Texas,USA. Soils at four depth increments(0–2, 0–15, 15–30, and 30–60 cm) were sampled at 232 points in the spring of 2017. The Ca content of each sample was determined with a DP-6000 Delta Premium portable X-ray fluorescence(PXRF) spectrometer. Elevation data was obtained using a real-time kinematic GPS receiver with centimeter-level accuracy. A digital elevation model(DEM) was derived from the elevation data, and topographic and hydraulic attributes were generated from this DEM. A generalized least-squares model was then developed to assess the relationship between soil Ca contents of the four layers and the topographic and hydraulic attributes. Results showed that topographic attributes, especially slope and elevation, had a significant effect on soil Ca content at different depths(P 0.01). In addition, hydraulic attributes, especially flow length and sediment transport index(STI), had a significant effect on the spatial distribution of soil Ca. Spatial variability of soil Ca and its relationships with topographic and hydraulic attributes and soil types indicated that surface soil loss may occur due to water or wind erosion, especially on susceptible soils with high slopes. Therefore, this study suggests that the application of PXRF in assessing soil Ca content can potentially facilitate a new method for soil erosion evaluation in semi-arid lands. The results of this study provide valuable information for site-specific soil conservation and crop management.     

华北平原土壤质量与农业生产的关系

Sustainable agricultural production is of vital importance to food supply security. This study aimed to investigate crop yield response to spatial variability of soil quality at a county scale in the North China Plain(NCP) and subsequently derive key soil quality indicators. Soil samples were geo-referenced and taken in 2008 from both surface(0–20 cm) and subsurface(20–40 cm) layers in132 fields throughout the Fengqiu County, located in the centre of the NCP, for subsequent soil properties' analyses. Annual crop yields were obtained from the same fields where soil samples were collected. Soil quality was evaluated based on a fuzzy set with 13 soil properties, and its spatial distributions were investigated by integrating geostatistical analysis and geographic information system(GIS) techniques. Soil quality indices were classified into five grades, and their spatial distributions were mapped within the county.The surface soil qualities were about one to two grades higher than the subsurface soil. The quality indices for surface and subsurface soils were positively associated with the annual crop yields, suggesting the importance of both. Soil organic matter, total nitrogen,available P, and available K contributed 50% of the combined weight to the soil quality index and were identified as key indicators of soil quality status in the area in terms of sustainability.     

干旱条件下墨西哥中部高地不同耕作措施和农作物残留物管理对玉米产量和净收益的影响

In the subtropical highlands of Central Mexico, where the main crop is maize （Zea mays）, the conventional practice （CP） involves tillage, monoculture and residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture （CA） has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of crop residues and soil surface cover and use of crop rotation. This study began in 2009 when the highlands of Central Mexico suffered from a prolonged drought during vegetative maize growth in July-August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers＇ management in 2009, the maize yields were 26% higher under CA （6.3 t ha-1） than under CP （5.0 t ha-l）. 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% （6.8 t ha-1 for CA vs. 5.7 t ha-1 for CP）. When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 Mexican Pesos ha-1 （320 $US ha-1） on net return and 1.3 t ha-1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.     

不同降水年型施氮量对冬小麦水氮资源利用效率的调控

  【目的】  研究不同降水年型氮肥用量引起的小麦生育期耗水量、植株氮素积累与运转、产量及效率的变化,为黄土高原旱地冬小麦精准施肥提供理论依据。  【方法】  于2017—2020年在山西农业大学闻喜试验示范基地开展大田试验,种植制度为冬小麦后夏休闲,一年一熟。3个试验年降水量分别属于正常、干旱和湿润年型。试验设施氮量 0、120、150、180、210 kg/hm2 5个处理,分析了小麦耗水量、氮素吸收与利用、产量形成及不同降水年型间的差异。  【结果】  不同降水年型旱地小麦生育期总耗水量均以N 180 kg/hm2最高,且丰水年和欠水年耗水变化率以施N 150～180 kg/hm2最高,平水年则以施N 120～150 kg/hm2最高。与其他施氮处理相比,丰水年施N 180 kg/hm2提高了播种—拔节期植株氮素积累量,显著提高了花前叶片和穗轴+颖壳氮素运转量,平水年和欠水年施N 150 kg/hm2提高了播种—拔节期植株氮素积累量及花前叶片和茎秆+叶鞘氮素运转量。不同降水年型花前植株氮素运转量、成熟期的植株氮素积累量变化率均以N 120～150 kg/hm2最高。与其他施氮处理相比,丰水年施N 180 kg/hm2产量显著提高了8.4%～35.6%,平水年施N 150 kg/hm2产量显著提高8.9%～33.7%,欠水年施N 150 kg/hm2产量显著提高13.4%～48.9%;不同降水年型产量变化率以施N 120～150 kg/hm2最高,且施氮量增加到N 180 kg/hm2时在丰水年仍可增产。丰水年施N 150～180 kg/hm2肥效最高,达14.9 kg/kg,平水年和欠水年均施N 120～150 kg/hm2肥效最高,分别达18.0和15.2 kg/kg;丰水年施N 180 kg/hm2、平水年和欠水年施N 150 kg/hm2均可获得较高的水、氮利用效率和氮肥表观利用率。此外,不同降水年型增加施氮量条件下,产量、水分利用效率均与花前植株氮素运转量呈显著相关关系。  【结论】  综合考虑氮肥用量氮肥变化量对耗水量、氮素运转量及产量等变化率的影响,丰水年施N 180 kg/hm2,平水年和欠水年施N 150 kg/hm2可提高产量、水氮利用效率和氮肥表观利用率,该施氮量为该区域的推荐施肥量。     

Crop responses to applied soil compaction and to compaction repair treatments

Crop responses to annual compaction treatments (applied to whole plots) and management treatments to ameliorate compacted soil were determined in a field experiment on a Vertisol. Initially, all treatments except a control were compacted with a 10 Mg axle load on wet soil (26% gravimetric water content compared with a plastic limit of 22%). Annually applied axle loads of 10 and 6 Mg on wet soil (25–32% soil water) tended to reduce seedling emergence, grain yield (wheat, sorghum and maize), soil water storage and crop water use efficiency (WUE). Annual applications of an axle load of 6 Mg on dry soil (<22% soil water) had little effect on crop performance. Mean reductions in the yield of five crops (three wheat, one sorghum and one maize) in comparison with the uncompacted control were 23% or 0.79 Mg ha⁻¹ (10 Mg on wet soil), 13% or 0.44 Mg ha⁻¹ (6 Mg on wet soil) and 1% or 0.03 Mg ha⁻¹ (6 Mg on dry soil). Maize grown in the fifth year of treatment application was most affected by compaction of wet soil, its WUE being reduced from 14.3 to 9.7 kg ha⁻¹ mm⁻¹ in response to an axle load of 10 Mg. Reduced WUE was associated with delayed soil water extraction at depth. A 3-year pasture ley was the most successful amelioration treatment. A wheat and a maize crop grown after the ley outyielded the control by 0.33 and 0.90 Mg ha⁻¹, respectively. So the pasture not only ameliorated the initial compaction damage, with respect to crop performance, but resulted in improvements in two subsequent crops.     

不同绿肥和覆膜措施对渭北旱塬冬小麦产量和土壤水分动态的影响

  【目的】  冬小麦—绿肥轮作在干旱贫水年份易导致冬小麦减产,我们研究了平水年和干旱年旱地绿肥和覆膜措施相结合对小麦产量及水分利用率的影响,为建立科学高效的小麦–绿肥轮作体系奠定基础。  【方法】  田间试验于2017—2019年布设在陕西省永寿县御驾宫乡御中村,试验采用裂区试验设计,以轮作不同绿肥品种(黑麦豆、油菜,夏休闲为对照)为主处理,覆膜措施为副处理,设常规耕作和垄覆沟播两个水平。在冬小麦返青期、开花期、收获期调查小麦苗期生长状况、产量形成、水分利用效率和麦田0—200 cm土壤水分动态变化。  【结果】  1)平水年和干旱年,轮作油菜的冬小麦产量高于轮作黑麦豆,两年间轮作油菜处理比轮作黑麦豆处理的冬小麦产量分别高出 9.3%和43.5% (P<0.05)。2)采用垄覆沟播,轮作绿肥显著降低了冬小麦生育期耗水量,平水年提高了冬小麦的水分利用效率。平水年轮作油菜的水分利用效率最高[14.3 kg/(hm2·mm)],比夏休闲处理增加了7.4%;而干旱年轮作绿肥降低了冬小麦的水分利用效率,与夏休闲相比轮作黑麦豆和油菜处理分别降低58.5%和38.3% (P<0.05)。轮作绿肥与垄覆沟播对提高小麦水分利用效率有显著的交互作用。3)轮作绿肥并垄覆沟播的栽培模式加重了土壤水分的消耗。相比于夏休闲,平水年冬小麦播前0—200 cm土壤贮水量平均降低10.1% (P<0.05),干旱年平均降低15.7% (P<0.05)。  【结论】  我国渭北旱塬地区在平水年采用种植油菜+垄覆沟播新型种植模式,可以在保证不减产的情况下提高冬小麦的水分利用效率,但干旱年小麦产量和水分利用效率均会受到负面影响。     

基于不同降水年型渭北旱塬小麦–土壤系统氮素表观平衡的氮肥用量研究

【目的】 研究渭北旱区不同降水年型氮肥用量对小麦–土壤系统氮素表观平衡的影响规律,以实现作物稳产、平衡土壤氮素携出、避免过多氮肥残留累积为目标,通过3年田间定位试验,探讨渭北旱区冬小麦稳产增效的最佳氮素投入量。 【方法】 2011年7月—2012年6月降水量为710.1 mm,高于年均降水量 23.1%,属于丰水年;2012年7月—2013年6月降水量为391.4 mm,低于年均降水量 32.2%,属于欠水年;2013年7月—2014年6月降水量为603.8 mm,高于年均降水量 4.6%,属于平水年。本研究设置5个氮肥水平 N 0、75、150、225、300 kg/hm2,分别以N0、N75、N150、N225、N300表示,研究不同施氮量对冬小麦产量、吸氮量、氮素表观平衡及收获后土壤硝态氮残留量的影响。通过保证土壤氮素的输入和携出平衡确定氮肥用量,并通过该施氮量下吸氮量、产量及收获后100 cm土层硝态氮累积量加以验证。 【结果】 连续3年的定位试验结果表明,产量随降水量的增加而提高。相同降水量条件下,产量随施氮量增加呈先增加后降低的趋势,3年小麦产量均在N225水平达到最大值,但N225与N150水平之间差异不显著,小麦地上部吸氮量与籽粒产量有相似的规律;小麦收获后0—100 cm土层硝态氮残留量也随施氮量的增加而升高。其中50.8%～75.5%的集中在0—40 cm,并且随着年限的延长逐渐减少,3年平均值分别为63.8%、66.1%和53.6%,而40—100 cm土层硝态氮残留量逐年升高且有向下淋溶的趋势;3种降水年型,土壤氮素盈余量 (土壤氮素输入 – 输出) 为0 kg/hm 2的氮素盈余指标下的氮素投入量有所不同:丰水年、欠水年和平水年施氮量分别为127、54和103 kg/hm2;在考虑到维持作物产量和土壤肥力而允许氮素表观盈余指标为N 40 kg/hm2时,丰水年、欠水年和平水年施氮量分别为170、99和150 kg/hm2。此时的作物吸氮量 (130、59、110 kg/hm2) 和产量 (6267、2309、4502 kg/hm2) 均能保持在较高水平,与理论最高吸氮量和最高产量值接近,而施氮量与理论最高吸氮量和产量时的施氮量相比有不同程度降低,分别减少了4.7%、142%、21.3%和5.3%、120%、30.7%。小麦收获后100 cm土层硝态氮累积量分别为101.4、104.2和113.7 kg/hm2,不仅可以保持土壤氮库的稳定,还能将残留硝态氮基本维持在安全阈值内 (N 90～100 kg/hm2)。 【结论】 综合考虑不同降水年型氮肥用量下冬小麦–土壤系统氮素表观平衡的变化,建议在渭北旱区丰水年、欠水年和平水年施氮量分别为170、99和150 kg/hm2,以保证作物稳产和氮素高效吸收利用。      

化肥与有机肥或秸秆配施提高陇东旱塬黑垆土上作物产量的稳定性和可持续性

【目的】明确陇东旱塬长期施肥黑垆土上春玉米–冬小麦轮作系统作物产量和水肥效应与降水年型的响应关系,为该地区不同降水年型的合理施肥提供参考依据。【方法】位于甘肃平凉的长期肥料定位试验始于1979年,试验设6个处理:不施肥 (CK)、单施化学氮肥 (N)、氮磷化肥配施 (NP)、氮磷化肥配施秸秆 (SNP)、单施有机肥 (M) 和氮磷化肥配施有机肥 (MNP)。调查了试验38年玉米和小麦产量,依据降水量将生育年划分为干旱年、平水年和丰水年,分析不同降水年型下春玉米–冬小麦轮作系统长期施肥的产量变化稳定性、可持续性和肥料贡献率,降水利用率特征,探讨不同降水年型下产量、施肥和降水之间的关系。【结果】与N处理相比,NP、SNP、M和MNP处理冬小麦在干旱年、平水年和丰水年分别增产89.8%～151%、108%～174%和52.1%～102%,春玉米分别增产56.3%～99.9%、81.3%～104%和105%～127%。年降水量对冬小麦产量稳定性和可持续性影响较小,对春玉米影响较大。与N处理相比,三种降水年型下NP、SNP、M和MNP处理冬小麦和春玉米的肥料贡献率和降水利用率均显著提高,其中冬小麦在干旱年、丰水年肥料贡献率和降水利用率分别增加166%～198%、520%～654%和100%～164%、53.4%～105%,春玉米分别增加161%～218%、262%～289%和56.0%～99.2%、104%～125%。相同施肥处理下,NP、SNP、M和MNP处理冬小麦平水年和丰水年肥料贡献率分别较干旱年下降9.9%～23.3%和10.6%～23.3%,而春玉米丰水年较干旱年和平水年分别增加6.0%～25.0%和20.4%～27.7%。NP、SNP、M和MNP处理冬小麦平水年和丰水年水分利用率分别较干旱年下降2.2%～26.6%和22.3%～37.7%,而春玉米分别下降了41.9%～49.5%和10.9%～24.4%。回归分析表明,不论年降水量多寡,冬小麦和春玉米产量主要受施肥量和生育期降水影响。【结论】陇东旱塬不论年降水量多寡,氮磷与秸秆或有机肥配施与单施氮肥相比,均可显著提高作物产量、产量稳定性和可持续性,并提高肥料对产量的贡献率及降水利用率。因此,氮磷配合的基础上配合秸秆或有机肥是保障该地区农田生产力可持续的有效措施。同时,不同降水年型应进一步优化施肥策略以获得更高产量。     

耕作方式和氮肥用量对旱地小麦产量、水分利用效率和种植效益的影响

为探索旱地小麦增产增效增收协同的耕作方式及其配套施氮技术。2016—2017(欠水年)和2017—2018(丰水年)年度,在豫西典型旱区洛宁县设置夏闲期深松(ST,麦收后2周左右隔年进行)和翻耕(PT,传统的7月或底8月初连年进行)2种耕作方式为主区,设置4个氮肥用量为副区(播前基施纯氮0(N0),120(N120),180(N180),240 (N240) kg/hm~2)的田间定位试验,分析了土壤水分以及小麦产量、水分利用效率和种植效益。结果表明:与翻耕相比,深松提高了休闲效率,播前、开花期和成熟期0—200 cm土壤蓄水量分别提高6.5%～11.7%,5.0%～8.5%,4.7%～8.2%,使欠水年的千粒重、丰水年的穗数和穗粒数显著提高(P0.05),从而使欠水年的产量和经济效益分别提高7.1%～17.8%和5.5%～30.2%,丰水年施氮处理的产量、水分利用效率和经济效益分别提高10.2%～22.0%,3.0%～13.0%,16.1%～35.1%。增加氮肥用量有利于提高休闲效率,使播前土壤蓄水量翻耕下得到恢复、深松下显著提高(P0.05),小麦产量、水分利用效率和经济效益翻耕下N180最优,较其他处理分别提高6.5%～43.9%,8.1%～36.1%,12.4%～61.3%;深松下欠水年以N180较优,丰水年以N240最优,且较其他处理分别提高3.9%～67.9%,1.0%～54.1%,3.6%～95.8%。因此,麦收后2周左右隔年深松有利于提高土壤含水量,进而提高产量、水分利用效率和种植效益,且在欠水年配施纯氮180 kg/hm~2、丰水年配施纯氮240 kg/hm~2效果最优。研究结果可为提高旱地小麦产量、效率和效益提供理论依据和技术参考。     

江苏沿海垦区暗管排水对冬小麦产量的影响模拟

江苏沿海垦区农田地下水位埋深较浅,冬小麦生长易受到渍害的影响;为探究不同暗管排水条件影响下冬小麦产量的变化,该研究根据在江苏东台试验站实测的气象、土壤、地下水埋深等数据,联合运用田间水文模型DRAINMOD和作物模型AquaCrop模拟不同暗管排水条件对冬小麦产量的影响.结果显示:DRAINMOD模型可准确模拟研究区地...     

灌区蓝绿水资源与作物生产水足迹多时空分布量化分析

作物生产水足迹度量作物生产过程对不同类型水资源的消耗,为实现农业水资源管理与评价提供了更全面的新视角。该研究通过耦合土壤水分动态平衡模块,考虑输配水损失,构建灌区蓝、绿水资源与作物生产水足迹多时间尺度分布式量化模型;以宝鸡峡灌区为例,定量评价不同典型年灌区蓝绿水资源与作物生产水足迹多时间尺度演变规律。结果表明:宝鸡峡灌区蓝绿水资源总量在2008-2017年呈上升趋势。各作物对绿水资源利用效率均持续上升,而小麦蓝水资源利用效率呈下降趋势;玉米、小麦生产总水足迹整体呈上升趋势,多年平均值分别为573和779 m3/t;作物生产绿水足迹在拔节-灌浆期占比较高,成熟期占比较低;作物生产水足迹在日尺度波动幅度最大;平水年、丰水年灌区用水存在不合理现象,枯水年作物生产单产水平最高,总水足迹最低,水资源利用效率最高。该研究所构建模型可移植适用于无排水渠系灌区水文模拟,准确量化灌区农业生产耗水,解析日-月尺度作物生产水足迹演变特征,有助于明确灌区作物耗水规律,进而高效利用绿水资源,合理配置蓝水资源,提高作物产量,实现高效生产。