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1.
为了高效利用天然降雨,缓和农业水资源短缺,该试验在小麦、玉米一年两熟条件下,设置耕作措施和秸秆2个因素,其中耕作措施分为常规耕作、深松耕、耙耕、旋耕、免耕5种,秸秆因素分为玉米秸秆全量还田与不还田,共10个处理,研究了耕作措施与秸秆因素对极端土壤水分和冬小麦产量的效应。结果表明,无论秸秆还田与否,相对于常规耕作,深松耕能提高土壤水分充足期的土壤含水率,增加冬小麦产量,尤其是深松耕秸秆还田,比常规耕作无秸秆还田分别高25.74%和11.45%。秸秆因素在土壤水分充足时影响土壤含水率方面占主导地位,秸秆因素与耕作措施在土壤水分亏缺时影响土壤含水率和冬小麦产量方面均起着重要的作用。免耕、深松耕、耙耕与秸秆还田的交互效应能够增加集雨,提高冬小麦产量。研究结果还表明,冬小麦产量与土壤水分亏缺时土壤含水率相关不显著,而与土壤水分充足期土壤含水率相关显著。  相似文献   

2.
AquaCrop作物模型在松嫩平原春麦区的校正和验证   总被引:2,自引:0,他引:2  
为了研究AquaCrop作物模型在松嫩平原春麦区的适用性,利用实测的土壤水分、春小麦生长和产量数据,结合气象数据,获得AquaCrop模拟土壤水分和春小麦生长的模型参数,并用往年的作物生长数据对模型进行验证。结果表明,春小麦的产量和生物量的实测值与模拟值的绝对平均误差(MAE)为0.058和0.109、均方根误差(RMSE)为0.06和0.11t/hm2、模拟性能指数(EF)为0.795和0.822、残差聚集系数(CRM)为-0.006 96和0.005 87、一致性系数(IoA)为0.959和0.966;对10cm和20cm土壤体积含水率的实测值与模拟值的MAE为5.23和2.53、RMSE为6.47%和7.95%、EF为-0.277和-0.069、CRM为0.097和0.212、IoA为0.585和0.741。说明AquaCrop模型对春小麦的生物量和产量及生育期土壤体积含水率的模拟结果总体较好,对松嫩平原春麦生产有一定的参考意义。  相似文献   

3.
In most parts of Iran, water scarcity has been intensifying and posing a threat to the sustainability of agricultural production. Wheat is the dominant crop and the largest irrigation water user in Iran; hence, understanding of the crop yield-water relations in wheat across the country is essential for a sustainable production. Based on a previously calibrated hydrologic model, we modeled irrigated and rainfed wheat yield (Y) and consumptive water use (ET) with uncertainty analysis at a subbasin level in Iran. Simulated Y and ET were used to calculate crop water productivity (CWP). The model was then used to analyze the impact of several stated policies to improve the agricultural system in Iran. These included: increasing the quantity of cereal production through more efficient use of land and water resources, improving activities related to soil moisture conservation and retention, and optimizing fertilizer application. Our analysis of the ratio of water use to internal renewable water resources revealed that 23 out of 30 provinces were using more than 40% of their water resources for agriculture. Twelve provinces reached a ratio of 100% and even greater, indicating severe water scarcity and groundwater resource depletion. An analysis of Y-CWP relationship showed that one unit increase in rainfed wheat yield resulted in a lesser additional water requirement than irrigated wheat, leading to a larger improvement in CWP. The inference is that a better water management in rainfed wheat, where yield is currently small, will lead to a larger marginal return in the consumed water. An assessment of improvement in soil available water capacity (AWC) showed that 18 out of 30 provinces are more certain to save water while increasing AWC through proper soil management practices. As wheat self-sufficiency is a desired national objective, we estimated the water requirement of the year 2020 (keeping all factors except population constant) to fulfill the wheat demand. The results showed that 88% of the additional wheat production would need to be produced in the water scarce provinces. Therefore, a strategic planning in the national agricultural production and food trade to ensure sustainable water use is needed. This study lays the basis for a systematic analysis of the potentials for improving regional and national water use efficiency. The methodology used in this research, could be applied to other water scarce countries for policy impact analysis and the adoption of a sustainable agricultural strategy.  相似文献   

4.
底墒和磷肥对旱地冬小麦产量及其品质的影响   总被引:1,自引:0,他引:1  
【目的】分析山西省南部旱地小麦产量及品质对底墒和磷肥的响应。【方法】在山西省南部试验设土壤3个播前底墒水平(0~100 cm土层):W1(248 mm)、W2(233 mm)、W3(205 mm),2个施磷水平,P1(75 kg/hm^2)、P2(180 kg/hm^2),研究旱地小麦籽粒产量及其蛋白质量对底墒和磷肥的响应情况。【结果】相同磷肥条件下,W1和W2处理的灌浆持续时间、渐增期持续时间高于W3处理。相同底墒条件下,渐增期和快增期籽粒增加质量和持续时间表现为P2>P1,缓增期的增加质量和持续时间表现为P1>P2,缓增期籽粒增加质量和持续时间变异系数最高,分别达25%和31%。可见,底墒和磷肥提高快增期的持续时间,增加底墒提高灌浆持续时间,增施磷肥减少缓增期持续时间。底墒250mm蛋白质产量最高,相同底墒下,蛋白质产量随磷肥的增加而增加;磷肥对产量的影响大于对蛋白质量的影响。【结论】旱地小麦灌浆过程中增期持续时间对底墒和磷肥响应较好,缓增期变异对籽粒千粒质量影响较大;底墒在250 mm处产量最高。  相似文献   

5.
A field experiment was conducted for 3 years to evaluate the effect of deficit irrigation under different soil management practices on biomass production, grain yield, yield components and water productivity of spring wheat (Triticum estivum L.). Soil management practices consisted of tillage (conventional and deep tillage) and Farmyard manure (0 and 10 t ha?1 FYM). Line source sprinkler laterals were used to generate one full- (ETm) and four deficit irrigation treatments that were 88, 75, 62 and 46 % of ETm, and designated as ETd1, ETd2, ETd3, and ETd4. Deep tillage significantly enhanced grain yield (14–18 %) and water productivity (1.27–1.34 kg m?3) over conventional tillage. Similarly, application of FYM at 10 t ha?1 significantly improved grain yield (10–13 %) and water productivity (1.25–1.31 kg m?3) in comparison with no FYM. Grain yield response to irrigation varied significantly (5,281–2,704 kg ha?1) due to differences in soil water contents. Water productivity varied from 1.05 to 1.34 kg m?3, among the treatments in 3 years. The interactive effect of irrigation × tillage practices and irrigation × FYM on grain yield was significant. Yield performance proved that deficit irrigation (ETd2) subjected to 75 % soil water deficit had the smallest yield decline with significant water saving would be the most appropriate irrigation level for wheat production in arid regions.  相似文献   

6.
非充分灌溉条件下春小麦三水利用效果研究   总被引:1,自引:0,他引:1  
在非充分灌溉条件下,采用不同的灌水次数和不同的灌水定额进行灌溉试验,考虑灌水与无灌水2个因素,对春小麦的水分利用系数及水分生产率进行研究。结果表明,生育期土壤水和灌溉水所产生的效果对于小麦在80%以上,土壤水和降水对春小麦产量的影响是不可忽略的。从而进一步揭示和明确了灌溉水、土壤水、降水的价值,使几种水对作物产生的效果得到客观的评价。在干旱条件下水分利用率高是以牺牲产量为代价,在实际生产中应结合考虑各因素进行优化利用。  相似文献   

7.
小麦节水高产的土壤水分调控标准研究   总被引:1,自引:0,他引:1  
简明阐述了小麦节水高产的土壤水分调控理论依据,系统研究了影响土壤水分调控标准的主要因素的相互作用与特点,总结提出了调控标准与范围以及农水措施相结合的栽培技术,小麦的水分利用效率达到1.61kg/m3,对指导当前节水农业实践具有现实意义  相似文献   

8.
Water is the most important limiting factor of wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping systems in the North China Plain (NCP). A two-year experiment with four irrigation levels based on crop growth stages was used to calibrate and validate RZWQM2, a hybrid model that combines the Root Zone Water Quality Model (RZWQM) and DSSAT4.0. The calibrated model was then used to investigate various irrigation strategies for high yield and water use efficiency (WUE) using weather data from 1961 to 1999. The model simulated soil moisture, crop yield, above-ground biomass and WUE in responses to irrigation schedules well, with root mean square errors (RMSEs) of 0.029 cm3 cm−3, 0.59 Mg ha−1, 2.05 Mg ha−1, and 0.19 kg m−3, respectively, for wheat; and 0.027 cm3 cm−3, 0.71 Mg ha−1, 1.51 Mg ha−1 and 0.35 kg m−3, respectively, for maize. WUE increased with the amount of irrigation applied during the dry growing season of 2001-2002, but was less sensitive to irrigation during the wet season of 2002-2003. Long-term simulation using weather data from 1961 to 1999 showed that initial soil water at planting was adequate (at 82% of crop available water) for wheat establishment due to the high rainfall during the previous maize season. Preseason irrigation for wheat commonly practiced by local farmers should be postponed to the most sensitive growth stage (stem extension) for higher yield and WUE in the area. Preseason irrigation for maize is needed in 40% of the years. With limited irrigation available (100, 150, 200, or 250 mm per year), 80% of the water allocated to the critical wheat growth stages and 20% applied at maize planting achieved the highest WUE and the least water drainage overall for the two crops.  相似文献   

9.
Crop production in Mediterranean-type environments is invariably limited by low and erratic rainfall (200-600 mm year−1), and thus soil moisture, and by high evapotranspiration resulting from high temperature. Consequently, a major research challenge is to devise cropping systems that maximize water-use efficiency (WUE). In a long-term trial in northern Syria (1986-1998) we compared the effects of seven wheat-based rotations on soil water dynamics and WUE in both the wheat and non-wheat phase. The cropping systems were durum wheat (Triticum turgidum L.) in rotation with fallow, watermelon (Citrullus vulgaris), lentil (Lens culinaris), chickpea (Cicer arietinum), vetch (Vicia sativa), medic pasture (Medicago spp.), and wheat. Seasonal recharge/discharge were identified using the neutron probe. Depth of wetting varied with seasonal rainfall (233-503 mm). Based on crop yields, WUE was calculated for each cropping option in relation to the durum wheat crop.The greatest limitation to growth was the supply of water and not the soil moisture storage potential. Wheat grain yield was dictated by the extent to which the alternative crops in the rotation dried out the soil profile, in addition to seasonal rainfall and its distribution. Chickpea and medic extracted as much water as continuous wheat. Wheat after these crops was solely dependent on current seasonal rainfall, but fallow, lentil, watermelon, and vetch did not deplete soil moisture to the same extent, leaving some residual soil moisture for the succeeding wheat crop. This difference in soil water resulted in a significant difference in wheat yield and hence WUE, which decreased in the following crop rotation sequence: fallow, medic, lentil, chickpea, and continuous wheat. However, on the system basis, the wheat/lentil or wheat/vetch systems were most efficient at using rainfall, producing 27% more grain than the wheat/fallow, while the wheat/chickpea system was as efficient as wheat/fallow system, with continuous wheat being least efficient. With N added to the cereal phase, system WUE of the system increased, being least for continuous wheat and greatest for wheat/lentil. Wheat-legume rotation systems with additional N input in the wheat phase not only can maintain sustainable production system, but also are more efficient in utilizing limited rainfall.  相似文献   

10.
绿州灌区麦田节水高产适宜土壤水分指标研究   总被引:2,自引:0,他引:2  
土壤水分适宜指标是节水高产栽培的基础。本文采用二次回归旋转设计和回归分析方法,研究了麦田土壤水分的变化特征及其与主要水分生理因子的相关性,认为0~60cm 是影响春小麦生长和产量的主要层次,并与叶水势、蒸腾强度和气孔阻力之间存在极显著的相关关系。在此基础上,研究提出了产量高于12000kg/hm 2 和水分生产率大于12.45kg/m m .hm 2 时不同生育阶段适宜土壤水分下限指标。经示范印证,具有很强的可行性  相似文献   

11.
A package of water management practices including pitcher irrigation method and water conserving techniques of manure application and mulching is experimented for sustainable growth and improved production of cucumber crop in Makanya village in North Eastern Tanzania. The increase in total yield due to package of water management practices is 203 per cent and water use efficiency obtained is 12.06 kg m−3. The seasonal water requirement of cucumber crop under package of water management practices ranges from 146.30 to 198.10 mm, which is on an average 4.19 times less as compared to control treatment of can irrigation. The irrigation interval in package of water management practices is 4.9 times higher than the can irrigation method. The water and labour uses are reduced by 75.9 and 73 per cent, respectively in package of water management practices. The results showed that the self-regulative nature of pitchers and moisture retention by water conserving techniques is helpful in mitigating water stress in crop root zone. The moisture retention period in soil is increased assisting reduction of labour hours required in irrigation. In local context, the water management practices included in the package are easy to understand, adopt, operate and maintain.  相似文献   

12.
InfoCrop, a generic crop model, simulates the effects of weather, soils, agronomic management (planting, nitrogen, residues and irrigation) and major pests on crop growth, yield, soil carbon, nitrogen and water, and greenhouse gas emissions. This paper presents results of its evaluation in terms of its validation for rice and wheat crops in contrasting agro-environments of tropics, sensitivity to the key inputs, and also illustrates two typical applications of the model. Eleven diverse field experiments, having treatments of location, seasons, varieties, nitrogen management, organic matter, irrigation, and multiple pest incidences were used for validation. Grain yields in these experiments varied from 2.8 to 7.2 ton ha−1 in rice and from 3.6 to 5.5 ton ha−1 in wheat. The results indicated that the model was generally able to explain the differences in biomass, grain yield, emissions of carbon dioxide, methane and nitrous oxides, and long-term trends in soil organic carbon, in diverse agro-environments. The losses in dry matter and grain yield due to different pests and their populations were also explained satisfactorily. There were some discrepancies in the simulated emission of these gases during first few days after sowing/transplanting possibly because of the absence of tillage effects in the model. The sensitivity of the model to change in ambient temperature, crop duration and pest incidence was similar to the available field knowledge. The application of the model to quantify multiple pests damage through iso-loss curves is demonstrated. Another application illustrated is the use of InfoCrop for analyzing the trade-offs between increasing crop production, agronomic management strategies, and their global warming potential.  相似文献   

13.
This study investigated the impact of using treated wastewater and deficit irrigation on yield, water productivity, dry matter and soil moisture availability. The experiment included six treatments of deficit irrigation with treated wastewater during the 2010 and 2011 seasons and two deficit irrigation treatments combined with 3 organic amendment levels during the 2012 season. The experimental and SALTMED modelling results indicated that regulated deficit irrigation when applied during vegetative growth stage could stimulate root development, increase water and nutrient uptake and subsequently increase the yield. The organic amendment has slightly improved yield under full irrigation but had relatively small effect under stress conditions. The SALTMED model results supported and matched the experimental results and showed similar differences among the different treatments. The model proved its ability to predict soil moisture availability, yield, water productivity and total dry matter for three growing seasons under several deficit irrigation strategies using treated wastewater. The high values of the coefficient of determination R 2 reflected a very good agreement between the model and observed values. The SALTMED model results generally confirm the model’s ability to predict sweet corn growth and productivity under deficit irrigation strategies in the semi-arid region.  相似文献   

14.
Mulching is one of the important agronomic practices in conserving the soil moisture and modifying the soil physical environment. Wheat, the second most important cereal crop in India, is sensitive to soil moisture stress. Field experiments were conducted during winter seasons of 2004-2005 and 2005-2006 in a sandy loam soil to evaluate the soil and plant water status in wheat under synthetic (transparent and black polyethylene) and organic (rice husk) mulches with limited irrigation and compared with adequate irrigation with no mulch (conventional practices by the farmers). Though all the mulch treatments improved the soil moisture status, rice husk was found to be superior in maintaining optimum soil moisture condition for crop use. The residual soil moisture was also minimum, indicating effective utilization of moisture by the crop under RH. The plant water status, as evaluated by relative water content and leaf water potential were favourable under RH. Specific leaf weight, root length density and dry biomass were also greater in this treatment. Optimum soil and canopy thermal environment of wheat with limited fluctuations were observed under RH, even during dry periods. This produced comparable yield with less water use, enhancing the water use efficiency. Therefore, it may be concluded that under limited irrigation condition, RH mulching will be beneficial for wheat as it is able to maintain better soil and plant water status, leading to higher grain yield and enhanced water use efficiency.  相似文献   

15.
春小麦免储水灌全膜覆盖穴播与保水剂配合节水技术研究   总被引:1,自引:0,他引:1  
通过对甘肃河西地区春小麦免储水灌全膜覆盖穴播与保水剂配合节水技术的试验研究,测定了春小麦地土壤水分变化规律、小麦耗水规律及产量效应,分析配套施用保水剂对春小麦地土壤水分的影响。研究结果表明,在河西地区,小麦采用免储水灌全膜覆盖施用保水剂穴播技术能有效地减少农田在休闲期的土壤蒸发量,提高农田的水分利用效率,可减少首次灌水量30mm,全生育期耗水量减少80.0mm,节水16.60%,增产4.37%,水分利用效率提高21.70%。  相似文献   

16.
High evaporative demand and limited precipitation restrict the yield of winter wheat (Triticum aestivum L.) grown in the Loess Plateau of China under semiarid climatic conditions. Grain yield can be improved by effective water management practices. A 13-year field experiment was conducted at the CERN Changwu Agro-ecological Experimental Station of the Loess Plateau to determine optimal irrigation strategies under limited water supply and to develop relationships among grain yield (Y), seasonal evapotranspiration (SET) and water-use efficiency (WUE). The experiment consisted of five irrigation treatments and three blocks. Measurements included grain yield, soil water content at various depth intervals in the 0–3,000 mm layer, irrigation amount, and precipitation. Results showed that winter wheat grown in this area experienced serious water stress during critical growth stages for the no-irrigation treatment. The amount and timing of irrigation had an important effect on grain yield, but significant differences in yield were not observed between the three-irrigation and the four-irrigation treatments. Grain yield was linearly related (R2=0.66) to SET, but differences in WUE were not significant for any of the treatments. The relationship between WUE and Y was best represented by a second order polynomial (R2=0.65) consisting of a nearly linear portion between 1.5 and 5.0 Mg ha–1. Optimum water management of winter wheat in the Loess Plateau should consist of three 87.5 mm irrigations applied at stem elongation, booting, and anthesis.Communicated by J.E. Ayars  相似文献   

17.
Evapotranspiration (ET) is an important component of the water cycle at field, regional and global scales. This study used measured data from a 30-year irrigation experiment (1979-2009) in the North China Plain (NCP) on winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) to analyze the impacts of climatic factors and crop yield on ET. The results showed that grass reference evapotranspiration (ETo, calculated by FAO Penmen-Monteith method) was relatively constant from 1979 to 2009. However, the actual seasonal ET of winter wheat and maize under well-watered condition gradually increased from the 1980s to the 2000s. The mean seasonal ET was 401.4 mm, 417.3 mm and 458.6 mm for winter wheat, and 375.7 mm, 381.1 mm and 396.2 mm for maize in 1980s, 1990s and 2000s, respectively. The crop coefficient (Kc) was not constant and changed with the yield of the crops. The seasonal average Kc of winter wheat was 0.75 in the 1980s, 0.81 in the 1990s and 0.85 in the 2000s, and the corresponding average grain yield (GY) was 4790 kg ha−1, 5501 kg ha−1 and 6685 kg ha−1. The average Kc of maize was 0.88 in the 1980s, 0.88 in the 1990s and 0.94 in the 2000s, with a GY of 5054 kg ha−1, 7041 kg ha−1 and 7874 kg ha−1, respectively, for the three decades. The increase in ET was not in proportion to the increase in GY, resulting improved water use efficiency (WUE). The increase in ET was possibly related to the increase in leaf stomatal conductance with renewing in cultivars. The less increase in water use with more increase in grain production could be partly attributed to the significant increase in harvest index. The results showed that with new cultivars and improved management practices it was possible to further increase grain production without much increase in water use.  相似文献   

18.
The predictive quality of CERES-wheat was tested under contrasting nitrogen management and temperate-maritime climate conditions of North-Germany. Field data from 9 years of observations were used in this study. The magnitudes of the genetic parameters of the local wheat cultivar “Orestis” were strongly influenced by seasonal weather fluctuations. For predicted yield and harvest biomass, the root mean square error was 2.2 t/ha and 3.2 t/ha, respectively. These errors were too large to permit a practical application of the CERES-wheat model for optimizing fertilizer management under the production conditions of North-Germany. The results of this study suggest that the model needs to be considerably improved with respect to the simulation of soil and plant water-relations, as well as the interaction between water and nitrogen uptake which were found to be inconsistent.  相似文献   

19.
Water productivity (WP) expresses the value or benefit derived from the use of water, and includes essential aspects of water management such as production for arid and semi-arid regions. A profound WP analysis was carried out at five selected farmer fields (two for wheat–rice and three for wheat–cotton) in Sirsa district, India during the agricultural year 2001–02. The ecohydrological soil–water–atmosphere–plant (SWAP) model, including detailed crop simulations in combination with field observations, was used to determine the required hydrological variables such as transpiration, evapotranspiration and percolation, and biophysical variables such as dry matter or grain yields. The use of observed soil moisture and salinity profiles was found successful to determine indirectly the soil hydraulic parameters through inverse modelling.Considerable spatial variation in WP values was observed not only for different crops but also for the same crop. For instance, the WPET, expressed in terms of crop grain (or seed) yield per unit amount of evapotranspiration, varied from 1.22 to 1.56 kg m−3 for wheat among different farmer fields. The corresponding value for cotton varied from 0.09 to 0.31 kg m−3. This indicates a considerable variation and scope for improvements in water productivity. The average WPET (kg m−3) was 1.39 for wheat, 0.94 for rice and 0.23 for cotton, and corresponds to average values for the climatic and growing conditions in Northwest India. Including percolation in the analysis, i.e. crop grain (or seed) yield per unit amount of evapotranspiration plus percolation, resulted in average WPETQ (kg m−3) values of 1.04 for wheat, 0.84 for rice and 0.21 for cotton. Factors responsible for low WP include the relative high amount of evaporation into evapotranspiration especially for rice, and percolation from field irrigations. Improving agronomic practices such as aerobic rice cultivation and soil mulching will reduce this non-beneficial loss of water through evaporation, and subsequently will improve the WPET at field scale. For wheat, the simulated water and salt limited yields were 20–60% higher than measured yields, and suggest substantial nutrition, pest, disease and/or weed stresses. Improved crop management in terms of timely sowing, optimum nutrient supply, and better pest, disease and weed control for wheat will multiply its WPET by a factor of 1.5! Moreover, severe water stress was observed on cotton (relative transpiration < 0.65) during the kharif (summer) season, which resulted in 1.4–3.3 times lower water and salt limited yields compared with simulated potential yields. Benefits in terms of increased cotton yields and improved water productivity will be gained by ensuring irrigation supply at cotton fields, especially during the dry years.  相似文献   

20.
为提高冬小麦水肥利用效率,旨在探索滴灌冬小麦最佳水肥运筹模式,为滴灌条件下冬小麦优质高产的水肥高效管理提供科学依据。本研究选择两块不同土壤基础肥力的田块,进行冬小麦不同生育阶段的水氮组合处理对比试验研究,通过对冬小麦生长、产量和品质等指标的测定,分析不同土壤肥力条件、不同水氮运筹方案对滴灌冬小麦产量及品质的影响。结果表明:土壤基础肥力对滴灌冬小麦株高的影响显著,再适当增加返青-拔节期灌水量,对滴灌冬小麦株高有更好的调控效应;增施基肥能提高冬小麦光合产物从而提高冬小麦产量。土壤基础肥力提高对滴灌冬小麦籽粒容重、蛋白质含量、维生素B1、氨基酸含量和吸水率具有负效应。推荐高肥力田滴灌冬小麦水肥运筹方式为W2N2即灌浆期水分调控和氮肥后移的组合方式,低肥力田滴灌冬小麦水肥运筹方式为W1N3即返青-拔节期水肥调控的组合方式为宜。  相似文献   

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