限量单次灌溉对套作冬小麦和春玉米产量的影响

A field experiment was conducted during the 2002/2003 cropping season of winter wheat (Triticum aestivum) and spring maize (Zea mays) to evaluate the effect of limited single drip irrigation on the yield and water use of both crops under relay intercropping in a semi-arid area of northwestern China. A controlled 35 mm single irrigation, either early or late, was applied to each crop at a certain growth stage. Soil water, leaf area, final grain yield and yield components such as the thousand-grain weight, length of spike, fertile spikelet number, number of grains per spike, and grain weight per spike were measured, and water use efficiency and leaf area index were calculated for the irrigated and non-irrigated relay intercropping treatments and sole cropping controls. The results showed that yield, yield components, water use efficiency, and leaf area index in the relay intercropping treatments were affected by limited single drip irrigation during various growth stages of wheat and maize. The total yields in the relay intercropping treatment irrigated during the heading stage of wheat and the heading and anthesis stage of maize were the highest among all the treatments, followed by that irrigated during the anthesis stage of wheat and silking stage of maize;so was the water use efficiency. Significant differences occurred in most yield components between the irrigated and non-irrigated relay-intercropping treatments. The dynamics of the leaf area index in the relay-intercropped or solely cropped wheat and maize showed a type of single-peak pattern, whereas that of the relay intercropping treatments showed a type of double-peak pattern. Appropriately, limited single irrigation and controlled soil water content level could result in higher total yield, water use efficiency, and leaf area index, and improved yield components in relay intercropping. This practice saved the amount of water used for irrigation and also increased the yield. Therefore, heading stage of wheat and heading and anthesis stage of maize were suggested to be the optimum limited single irrigation time for relay-intercropped wheat and maize in the semi-arid area.     

秸秆覆盖条件下夏玉米田蒸散、水分利用效率和作物系数研究

Maize （Zea mays L.）, a staple crop grown from June to September during the rainy season on the North China Plain, is usually inter-planted in winter wheat （Triticum aestivum L.） fields about one week before harvesting of the winter wheat. In order to improve irrigation efficiency in this region of serious water shortage, field studies in 1999 and 2001, two dry seasons with less than average seasonal rainfall, were conducted with up to five irrigation applications to determine evapotranspiration, calculate the crop coefficient, and optimize the irrigation schedule with maize under mulch, as well as to establish the effects of irrigation timing and the number of applications on grain yield and water use efficiency （WUE） of maize. Results showed that with grain production at about 8 000 kg ha^-1 the total evapotranspiration and WUE of irrigated maize under mulch were about 380-400 mm and 2.0-2.2 kg m^-3, respectively. Also in 2001 WUE of maize with mulch for the treatment with three irrigations was 11.8% better than that without mulch. In the 1999 and 2001 seasons, maize yield significantly improved （P = 0.05） with four irrigation applications, however, further increases were not significant. At the same time there were no significant differences for WUE with two to four irrigation applications. In the 2001 season mulch lead to a decrease of 50 mm in the total soil evaporation, and the maize crop coefficient under mulch varied between 0.3-1.3 with a seasonal average of 1.0.     

亏缺灌溉对中国西北干旱区棉花生长、水分利用特征和产量的影响

Water shortage is a key constraint to sustainable agricultural production in Xinjiang, Northwest China. To enhance the use efficiency of valuable irrigation water resources, a 2-year experiment(2010–2011) was conducted to quantify the response of cotton(Gossypium hirsutum L.) growth and yield to different degrees of deficit irrigation(DI) regimes; to determine the effects of DI on the characteristics of water use for cotton, seasonal water use, available soil water in the root zone, soil water depletion, evapotranspiration(ET)-based water use efficiency and irrigation-based water use efficiency, and to determine the best DI regime for optimal water-saving and yield output. The plots were irrigated at 100%(100ET), 85%(85ET), 70%(70ET), 55%(55ET) and 45%(45ET) of the regional ET of cotton in northern Xinjiang. The effect of DI irrigation on water use characteristics was evaluated by analyzing available soil water and soil water depletion in the root zone along with water use efficiencies of cotton. The study showed that the growth, water use characteristics and yield of cotton varied with irrigation regime. Seasonal ET and seed cotton yield were linearly correlated with irrigation amount. The second-order polynomial equation best approximated water-yield relationship of cotton in the study area.Cotton yield response factor was 0.65, suggesting limited water conditions were suitable for cotton cultivation. Economic evaluation of DI treatments confirmed that the yield loss was less than 10% under 70 ET and 85 ET, which was acceptable for greater sustainability.The results suggested that proper DI schemes were necessary for sustainable cotton production in the region. While irrigation at 85 ET was safe for high cotton yield, irrigation at 70 ET was a viable alternative under limited irrigation water availability.     

热带农业生态系统土壤肥力与植物养分综合管理研究进展

The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production.Associated problems include soil erosion,nutrient mining,competition for biomass for multiple uses,limited application of inorganic fertilizers,and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity.Integrated soil fertility management(ISFM) is an approach to improve crop yields,while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers,recycled organic resources,responsive crop varieties,and improved agronomic practices,which minimize nutrient losses and improve the nutrient-use efficiency of crops.Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems.Yield benefits were more apparent when fertilizer application was accompanied by crop rotation,green manuring,or crop residue management.The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%–100%,whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%.Although organic residues are key inputs for soil fertility management,about 85% of these residues is used for livestock feed and energy;thus,there is a need for increasing crop biomass.The main incentive for farmers to adopt ISFM practices is economic benefits.The success of ISFM also depends on research and development institutions to provide technical support,technology adoption,information dissemination,and creation of market incentives for farmers in tropical agro-ecosystems.     

海河流域合理生态用水比例的确定

Winter wheat-maize rotations are dominant cropping systems on the North China Plain, where recently the use of organic manure with grain crops has almost disappeared. This could reduce soil fertility and crop productivity in the long run. A 20-year field experiment was conducted to 1） assess the effect of inorganic and organic nutrient sources on yield and yield trends of both winter wheat and maize, 2） monitor the changes in soil organic matter content under continuous wheat-maize cropping with different soil fertility management schemes, and 3） identify reasons for yield trends observed in Xuzhou City, Jiangsu Province, over a 20-year period. There were eight treatments applied to both wheat and maize seasons： a control treatment （C）; three inorganic fertilizers, that is, nitrogen （N）, nitrogen and phosphorus （NP）, and nitrogen, phosphorus and potassium （NPK）; and addition of farmyard manure （FYM） to these four treatments, that is, M, MN, MNP, and MNPK. At the end of the experiment the MN, MNP, and MNPK treatments had the highest yields, about 7 t wheat ha^-1 and 7.5 t maize ha^-1, with each about 1 t ha^-1 more than the NPK treatments. Over 20 years with FYM soil organic matter increased by 80% compared to only 10% with NPK, which explained yield increases. However, from an environmental and agronomic perspective, manure application was not a superior strategy to NPK fertilizers. If manure was to be applied, though, it would be best applied to the wheat crop, which showed a better response than maize.     

混合施用微咸水和氮肥对甜高粱生物量和产糖量的影响

Soil salinization and non-point source pollution are among the most important and widespread environmental problems in European Mediterranean regions. Sweet sorghum (Sorghum bicolor (L.) Moench var. saccharatum) is a moderate to high salinity tolerant crop with low water and nutrient needs, seen as an alternative to grow in the water scarce regions. A three-year multifactorial study was conducted in southern Portugal to evaluate the combined effects of saline water and nitrogen application on the dry biomass (total, stems, and leaves), sugar content (total reducing sugars and sucrose contents), and sugar yield (here defined as the product of total reducing sugars and stems dry biomass) functions of sweet sorghum. Sorghum dry biomass and sugar yield showed diminishing returns for each incremental change of nitrogen. The use of saline irrigation waters also led to yield reduction. Exception was sucrose content which increased with increasing levels of sodium in the soil. Nitrogen need decreased as the amount of sodium applied increased. Stem dry biomass, sucrose content, and sugar yield progressively increased with progress in the experiment. The effect could be attributed to the increase of the amount of irrigation applied throughout the years, thus increasing the leaching fraction which promoted salt leaching from the root zone, reduced the salinity stress, increased plant transpiration, nitrogen uptake and biomass yield.     

控制中国非点源污染的生物经济学战略

While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.     

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.     

在施钾条件下灌溉水稻的养分吸收和利用效率研究

Potassium is one of the most important nutrients for rice production in many areas of Asia, especially in southeast China where potassium deficiency in soil is a widespread problem. Field experiments were conducted for four consecutive years in Jinhua City, Zhejiang Province, to determine utilization of nutrients (N, P and K) by inbred and hybrid rice and rice grain yields as affected by application of potassium fertilizer under irrigated conditions. Grain yield and nutrient harvest index showed a significant response to the NPK treatment as compared to the NP treatment. This suggested that potassium improved transfer of nitrogen and phosphorus from stems and leaves to panicles in rice plants. N and P use efficiencies of rice were not strongly responsive to potassium, but K use efficiency decreased significantly despite the fact that the amount of total K uptake increased. A significant difference between varieties was also observed with respect to nutrient uptake and use efficiency. Hybrid rice exhibited physiological advantage in N and P uptake and use efficiency over inbred rice. Analysis of annual dynamic change of exchangeable K and non-exchangeable K in the test soil indicated that non-exchangeable K was an important K source for rice. Potassium application caused an annual decrease in the concentration of available K in the soil tested, whereas an increase was observed in non-exchangeable K. It could be concluded that K fertilizer application at the rate of 100 kg ha^-1 per season was not high enough to match K output, and efficient K management for rice must be based on the K input/output balance.     

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.     

SWAT模拟耕作方式与盐分对区域土壤氮运移及作物产量影响

耕作方式与土壤盐渍化是影响河套灌区氮素流失及作物产量的重要因素.明确不同耕作方式与盐渍化水平下硝态氮运移量及作物产量的变化,可为制定合理的灌区耕作措施及盐渍化治理方案提供理论依据,对于揭示灌区氮素流失控制及不同作物增产潜力具有重要意义.该研究基于验证后的SWAT(Soil and Water Assessment To...     

不同降水年型水氮运筹对冬小麦耗水和产量的影响

灌水和施氮是影响农田生态系统粮食生产的2个主要因素,但其增产效应和资源利用效率会受降水年型的影响。该研究基于2011—2014在陕西关中平原进行的3 a冬小麦水氮耦合试验,分析了不同降水年型下水氮管理对土壤含水率、籽粒产量、耗水量(water consumption,ETa)及产量与耗水量关系的影响。结果表明:7—9月总降水量每增加1 mm,小麦播前0~180 cm土壤底墒增加0.47 mm。随着灌水量增加,产量和ETa均增加,但仅在降水较少的2012—2013年增产显著,对水分利用效率(water use efficiency,WUE)的影响不显著;随着施氮量增加,ETa变化不显著,但其增产效果显著,使WUE显著提高,表明施氮增加了作物蒸腾占农田耗水量的比例。根据3 a各处理冬小麦产量和ETa数据,进一步探讨了在一定水分消耗下能达到的最大(边界)产量和WUE,建立了关中平原冬小麦的产量-耗水量边界方程;当ETa超过388 mm时,产量稳定在8 184 kg/hm2,WUE的最大值为2.52 kg/m3。研究可为制订合理的冬小麦水肥管理措施提供科学依据。     

基于水氮管理与种植结构优化的作物丰产高效管理策略

河西走廊农业生产受到水资源短缺与农业资源利用效率低的限制,制约着该地区的种子、粮食生产与农业可持续发展战略。该研究构建了考虑作物水氮需求量、降雨量、土壤初始含氮量的水氮管理制度优化方法,并结合所构建的考虑空间尺度作物产量与水氮利用效率的多目标种植结构优化方法,为河西走廊制种玉米、大田玉米和小麦制定丰产高效的水氮管理与种植结构调整策略,从而实现作物产量和水氮利用效率的协同提升。结果显示：优化的水氮管理制度相比管理现状可减少单位面积灌水量9.1%～27.3%、施氮量26.6%～50.0%;以作物产量和水氮利用效率最大为目标,以种植面积、产量需求和水氮投入量为约束,调整制种玉米、大田玉米和小麦的种植面积与空间分布,优化后制种玉米和小麦种植面积减少、大田玉米种植面积增加,总种植面积减少4 874.8 hm2,且作物种植空间分布较优化前差异明显;水氮管理与种植结构优化协同作用可以在水氮用量分别减少0.29×109 m3和3.36×107 kg的情况下,作物总产量提升0.16×109 kg,区域灌溉水生产力和氮肥利用效率分别提升0.62 kg/m3和18.97 kg/kg。该研究可以为产粮区和缺水区的作物丰产高效和农业可持续发展提供科学指导与决策参考。     

The Effect of Phosphorus,Mucuna, and Nitrogen on the Biomass,Leaf Area Index,and Foliar Nutrient Content of Maize on a Depleted Sandy Loam Soil in Zimbabwe

Sufficient nutrient levels in leaves of crops have substantial effects on plant growth, development, and grain yield, as it is a fundamental constituent of many leaf cell components. The effect of phosphorus (P), mucuna management options, and nitrogen (N) on the biomass, leaf area index (LAI) and leaf nutrient content of maize on a depleted sandy loam soil in Zimbabwe were investigated. The experimental design was a split-split-plot with two P rates, four mucuna management options, and four N treatments (applied to a subsequent maize crop). Biomass, LAI, and foliar N, P, potassium (K), calcium (Ca), and magnesium (Mg) in the subsequent maize crop were determined. A significant three-way interaction (P < 0.05) between mucuna management options, N rates, and time was observed in terms of biomass production and all nutrients in the leaves of the subsequent maize crop.     

Exploring optimal soil mulching to enhance maize yield and water use efficiency in dryland areas in China

Water and nutrient availability significantly limits global crop production, especially for dryland agriculture in arid and semi-arid regions. To explore the optimal soil mulching options for the Loess Plateau in China, a 3-year field study was conducted to investigate the effects of various soil mulching practices on soil temperature and the water use and grain yield of spring maize. The treatments included traditional flat farming (CK), narrow plastic film mulch (NM), wide plastic film mulch (WM) and narrow plastic film mulch?+?maize straw mulch between rows (MS). The results showed that MS treatment increased consistently soil temperature during the initial stages of maize growth, and more importantly, it reduced diurnal temperature variation. MS also increased in soil water storage by 10.1%, leading to the highest water use efficiency (WUE?=?30.9?kg?ha^?1?mm^?1) over CK on 3 year average. MS significantly increased maize yield and net income of farmers by up to 20%, compared to CK. In conclusion, optimisation of soil mulching strategies significantly enhanced crop yield and water productivity in dryland agriculture in China. Our study provides important guidance for exploring better soil management practice for dryland agriculture in the other regions of the world.     

生态集约化养分管理对春玉米产量和氮素利用率的影响

通过两年田间试验,研究了吉林玉米带不同氮素管理措施对春玉米产量、氮素吸收、氮素平衡状况以及经济效益的影响。两年的结果表明:与农民习惯施肥（FP）相比,生态集约化养分管理措施（EI）在减少氮肥用量28%的情况下,并未影响作物的产量和氮素吸收,而其氮素回收率,农学效率,偏生产力和经济效益却分别提高了48.1%、56.9%、43.8%和11.0%; 第一年不施氮肥第二年补施氮肥不会影响第二年春玉米产量和氮肥利用率。在氮素输出项中,EI处理两季作物氮素总表观损失仅为97 kg/hm2,而FP处理高达226 kg/hm2。因此,在考虑高产的基础上兼顾保护环境的要求,基于氮肥农学效率、作物目标产量和作物施肥反应的生态集约化养分管理措施是一种较为理想的氮素管理措施。     

Improving the performance of bread wheat genotypes by managing irrigation and nitrogen under semi-arid conditions

Wheat (Triticum aestivum L.) productivity is generally affected by water limitation and inadequate nitrogen supply especially under semi-arid environment. The current study was conducted to determine whether the crop yield and irrigation water use efficiency (IWUE) could be manipulated through alteration of nitrogen and irrigation application. To meet the desired objectives, a two-year field study was carried out in 2013–2014 and 2014–2015, in a split-split plot arrangement with three factors i) irrigation in main plots, ii) nitrogen in sub-plots, and iii) twenty genotypes in sub-sub plots on a sandy loam soil. The analysis of variance revealed that the wheat performance was affected by genotypes and alteration of irrigation and nitrogen application with respect to IWUE and final grain yield. IWUE under water stress conditions was observed 56% higher than normal irrigated. Much higher values of IWUE under water stress indicated that the existing optimum water requirements of the crop needs to be revaluated. The regression model indicated that addition of nitrogen and irrigation patterns along with morphological traits cannot explain variation in yield related traits more than 65% under semi-arid conditions. Therefore, for better crop yields in semi-arid environment, more physiological parameters should be considered in evaluation of yield.     

长期施肥下我国灌淤土粮食产量和土壤养分的变化

【目的】 灌淤土是我国西北地区重要的粮食和经济作物土壤。了解灌淤土上作物产量的变化,及其对长期施肥的响应,以及灌淤土生产力的变化与其氮磷钾含量的关系,为西北地区作物增产和灌淤土培肥与可持续利用提供理论依据。 【方法】 1988到2004年间,在宁夏银川市、吴忠市、石嘴山市和新疆和田市典型灌淤土区域陆续建立了7个国家耕地质量监测点。2016年,利用时间趋势分析法,探讨了作物产量随时间的变化趋势,分析了长期不施肥和常规施肥条件下,玉米、小麦和水稻产量、产量变异系数、可持续性指数、增产率及地力贡献指数的变化特征,并进一步探讨了增产率与土壤养分的关系。 【结果】 灌淤土上小麦产量随时间呈现递增的趋势,在2004年达到最高 (7.58 t/hm2),之后保持稳定,2016年约为初始年产量的3倍;玉米产量随时间一直呈递增趋势,2016年平均产量为9.8 t/hm2,约为初始年的两倍;水稻产量近年来变化不大。与不施肥相比,常规施肥下小麦、玉米 (28年间) 和水稻 (8年间) 分别平均增产3.43倍、3.20倍和1.21倍,产量可持续性指数分别提高了18.8%、148%和13.9%。监测以来,小麦和玉米农田的地力贡献指数略有下降,但变化不显著。水田的地力贡献指数以每年0.0125的速率增加。28年间,常规施肥使土壤全氮含量从0.4 g/kg提高到1.1 g/kg,有效磷和速效钾含量变化不大。小麦与玉米的增产率与土壤全氮含量呈显著直线正相关关系,小麦、玉米和水稻的平均氮肥农学效率分别为9.8、16.8和27.4 kg/kg。 【结论】 灌淤土上常规施肥 (主要是氮肥)有效提高了玉米、小麦和水稻的产量。土壤全氮含量呈增加趋势,有效磷和有效钾含量基本平稳。土壤肥力对玉米和小麦产量的贡献呈下降趋势,对水稻产量的贡献高且平稳。因此,灌淤土应在合理施用氮肥的同时,注重采取提升地力,实现作物的高产和高效。      

中国科学院栾城农业生态系统试验站农田节水研究过去、现在和未来

本文回顾了中国科学院栾城农业生态系统试验站(以下简称栾城试验站)建站初期20 世纪80 年代以来在农田节水方面开展的研究。20 世纪80 年代以作物优化灌溉制度为研究重点, 解决生产实际问题; 20 世纪90 年代围绕土壤-植物-大气系统水分传输和界面调控开展了系统研究, 为农田节水措施的形成提供理论基础和技术途径; 近10 年来进一步深化了农田节水生理生态研究, 并根据多年研究积累, 形成了综合节水技术模式, 进行推广应用。未来栾城试验站农田节水工作将更加突出多学科渗透交叉, 以提高农田水分利用效率和效益为目标, 加强基础研究和节水技术的示范应用。