首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 234 毫秒
1.
[目的]为解决内蒙古东部大兴安岭东南地区由于零灌溉所带来的"单产不高,总产不稳"等问题,确定适合于当地的高产高效节水型灌溉制度。[方法]以当地主要作物大豆为供试作物,开展了喷灌条件下的作物产量、水分生产率和经济效益等方面的研究。[结果]当地原有的零灌溉农业种植模式并不能为大豆的种植提供足够的水分,采用喷灌技术追加2次灌溉,大豆可增产20.0%,但是经济效益并没有提高;追加4水灌溉,虽然总收益最高,但是大豆的作物水分生产率却相比3水灌溉小了很多,造成了不必要的水资源浪费。[结论]在开花期、结荚期和鼓粒期分别对大豆增加3次灌水定额为200m3/hm2的灌水,不但可以提高大豆的产量(增产47.8%),而且可以获得最大的经济收益。  相似文献   

2.
Results of studies performed in long-term stationary and short-term experiments on ordinary and leached chernozems in the Central Chernozemic Zone are presented. Agrophysical and physicomechanical parameters are proposed for assessing the degree of physical degradation of chernozemic soils. The scale of chernozem degradation has been improved. After the assessment of the agrophysical fertility parameters of old-arable soils, the limits of chernozem suitability for the minimization of basic tillage have been determined. Minimization of basic tillage is recommended for the nondegraded or slightly degraded soils resistant to compaction, with the soil bulk density of no more than 1.1–1.3 g/cm3, soil penetration resistance of 10–30 kg/cm2, and the content of coarse blocky fraction of no more than 30%.  相似文献   

3.
半干旱地区玉米的水肥空间耦合效应研究   总被引：17，自引：3，他引：17  
在半干旱地区的杨凌,通过对大田夏玉米在拔节期和抽雄期进行灌溉水和氮肥的不同数量和空间耦合处理,研究了不同耦合方式对玉米生理特性和产量的影响及其节水效果,结果表明:在全生育期灌水量为1125m3/hm2和600m3/hm2的水平下,均匀施肥交替灌水、水肥同区交替灌水、水肥异区交替灌水3种水肥空间耦合方式的产量之间不存在显著差异(P<0.05);玉米全生育期灌水量从2250m3/hm2下降到600m3/hm2,玉米产量下降幅度小于15.26%;在相同灌水量下,水肥异区交替灌水和水肥同区交替灌水的根系活力、光合速率、产量和灌溉水利用效率较高;在试验范围内,灌水量越高,水分利用效率越低。以上结果表明,在杨凌地区夏玉米生产中仍有较大的节水潜力;在试验条件下,每次灌水562.5m3/hm2,水肥异区交替灌水和水肥同区交替灌水处理是较好的水肥空间耦合方式  相似文献   

4.
In developing management practices to reduce chemical leaching below the root zone, tillage and irrigation management are important considerations. Two studies were performed to evaluate the movement of bromide in tilled and non-tilled soils under sprinkler versus flood irrigation. In each study, bromide was applied either with an irrigation or presprayed to the soil surface followed by periodic soil sampling to monitor the bromide movement. Tillage was observed to reduce the mean depth of chemical penetration under both irrigation treatments and reduce the spatial variation of bromide concentration under flood irrigation. For example, after 30 days of periodic flood irrigation, 25% of the applied bromide remained in the upper 0.2 m of a tilled soil while in the companion non-tilled soil virtually no bromide remained above this depth. The most rapid bromide movement was observed in non-tilled, flood irrigated soil, particularly when the solute was added with the irrigation. We speculate that the tillage effect of reduced leaching results from the alteration of pore continuity and creation of diffusional sinks and not increased evaporative water loss in the tilled soil. The Root Zone Water Quality Model was calibrated using site-specific hydraulic property measurements and used to predict the solute movement. The model predictions were fairly accurate for the sprinkler irrigated soil but less satisfactory for the flood irrigation studies. In comparing the effect on chemical leaching of the treatments imposed, we found that tillage and the timing of the chemical application had greater impact on reducing leaching than did the method of irrigation.  相似文献   

5.
该文系统地对榆林地区农田灌溉和水利资源进行分析,指出该区水地的重点开发区在北六县,灌溉农田可发展到15万hm2,1 hm2产量到6 000 kg,粮田面积为10万hm2,即可产粮达6亿kg。南部丘陵区发展集水补灌农业,修水窖150万孔,可对15万hm2梯田进行补灌,其中10万hm2种粮食,使粮食产量提高到3 750 kg/hm2,可产粮3.75亿kg,全区共产粮9.75亿kg  相似文献   

6.
Efficient crop use of nitrogen (N) fertilizer is critical from economic and environmental viewpoints, especially under irrigated conditions. Cotton yield parameters, fiber quality, water‐ and N‐use efficiency responses to N, and irrigation methods in northern Syria were evaluated. Field trials were conducted for two growing seasons on a Chromoxerertic Rhodoxeralf. Treatments consisted of drip fertigation, furrow irrigation, and five different rates of N fertilizer (50, 100, 150, 200, and 250 kg N /ha). Cotton was irrigated when soil moisture in the specified active root depth was 80% of the field capacity as indicated by the neutron probe.

Seed cotton yield was higher than the national average (3,928 kg/ha) by at least 12% as compared to all treatments. Lint properties were not negatively affected by the irrigation method or N rates. Water savings under drip fertigation ranged between 25 and 50% of irrigation water relative to furrow irrigation. Crop water‐use efficiencies of the drip‐fertigated treatments were in most cases 100% higher than those of the corresponding furrow‐irrigated treatments. The highest water demand was during the fruit‐setting growth stage. It was also concluded that under drip fertigation, 100–150 N kg/ha was adequate and comparable with the highest N rates tested under furrow irrigation regarding lint yield, N uptake, and recovery. Based on cotton seed yield and weight of stems, the overall amount of N removed from the field for the drip‐fertigated treatments ranged between 101 and 118kg and 116 and 188 N/ha for 2001 and 2002, respectively. The N removal ranged between 94 and 113 and 111 and 144 kg N/ha for the furrow‐irrigated treatments for 2001 and 2002, respectively.  相似文献   

7.
有限性灌溉对设施草莓产量及水分利用效率的影响   总被引：1，自引：0，他引：1  
在日光温室环境及盆栽条件下,通过与全灌(FI)比较,研究了亏缺灌溉(DI)及分根交替灌溉(PRD)对草莓产量和灌水利用效率(IWUE)的影响.试验从开花期开始到果实成熟期结束.共分5个处理,全灌(FI);分根灌溉PRD分2个处理水平,即PRD1和PRD2;限制灌溉DI也分两个处理水平,即D11和D12.与F1处理相比,DI1和DI2处理的叶水势和气孔导度明显偏低,单株叶面积、鲜果重、平均单果重也显著低于FI处理.但水分利用效率却比FI处理的高(分别高15.8%和29.3%);PRD1处理的叶水势与FI处理的相当.且高于其它处理,而气孔导度比FI,DI1和D12处理的明显降低,与PRD2处理的相近.PRD1处理的鲜果重、平均单果重与FI处理的相当,比DI1,DI2和PRD2处理的显著提高;与FI处理相比,DI1,DI2,PRD1和PRD2处理分别节水31.5%,50.0%,31.5%和50.0%,水分利用效率分别提高了15.8%,29.3%,44.4%和84.4%,从草莓产量和水分利用效率各指标可以看出,PRD1处理比DI1,DI2和PRD2处理表现出明显的优势,其综合效益最佳.  相似文献   

8.
ABSTRACT

There is a growing concern about excessive use of nitrogen (N) and water in agricultural system with unscientific management in Indian and developing countries of the world. Field experiments were conducted on the lateritic sandy loam soils of Kharagpur, West Bengal, India, during spring–summer (February-June) seasons for three years (2015–2017) to evaluate okra crop response under subsurface drip and conventional furrow irrigation with varying amount of nitrogen treatments. Irrigation treatments had three levels of soil water depletion from field capacity (i.e., 20%, 35%, and 50%) under subsurface drip system. There was no soil water depletion under conventional furrow irrigation system. There were four levels of nitrogen fertilizer treatments (i.e., 0, 80, 100, and 120 kg ha?1). This was supplied using urea as a nitrogenous fertilizer. The yield response of okra crop under subsurface drip was found to be 56.4% higher than that of the furrow irrigation treatment. Best yield response and maximum water use efficiency and nitrogen use efficiency were recorded under 20% soil water depletion with 100 kg ha?1 of nitrogen fertigation. Among the various soil moisture depletions, subsurface drip at 20% soil water depletion treatment responded least quantity of water lost through deep drainage and nitrogen loss beyond the root zone as compared to other irrigation treatments. The water loss through subsurface drainage was observed as 33.11 mm lesser under subsurface drip as compared to that of the furrow irrigation, and this may due to low-volume and frequent irrigation water application with subsurface drip. Hence, irrigation through subsurface drip should be used for improving water and nitrogen fertilizer use efficiency of okra crop cultivation.  相似文献   

9.
This is an experiment to study the effect of water supply on the quality of the must produced by grapevines, and to determine the water use efficiency (WUE) of different irrigation strategies to give farmers a tool to optimize irrigation, reducing water use with the least negative effect on production. WUE was based on the ratio between a given parameter (yield, different must solubes) and the water used by plant transpiration plus evaporation from soil. The experiment was a completely randomized design with six irrigation treatments (non-irrigated, irrigated from flowering to veraison at rates of 4 and 8 mm day?1, irrigated from veraison to commercial maturation at rates of 4 and 8 mm day?1, and irrigated from flowering to commercial maturation at a rate of 8 mm day?1) in three replications over three seasons (2004–2006). Irrigation significantly increased grapevine yield and, because the plants produced larger berries, there was a dilution of colour, aroma and soluble solids that corresponded to a lower quality of the must. The higher WUE was achieved with no irrigation but yield was very low, albeit with an outstanding quality, that might not be profitable. The best strategy is to balance the water stress of the vines that best combines yield and berry quality and this was achieved by irrigating from flowering to veraison at a rate of ～50% of the potential evapotranspiration. This strategy might conserve water, an increasingly scarce resource that we are pressed to use with the utmost efficiency.  相似文献   

10.
塔里木灌区膜下滴灌的棉花需水量及节水效益   总被引：2，自引：0，他引：2  
为了确定适宜的灌溉制度,2008年通过田间灌溉试验,采用水量平衡法研究了塔里木灌区膜下滴灌棉花需水和耗水规律。以田间试验数据为基础,拟合了棉花的水分生产函数模型,分析评价了膜下滴灌棉花的节水效益。结果表明:塔里木灌区膜下滴灌棉花需水量为543 mm,其中苗期252 mm,蕾期186 mm,花铃期316 mm,吐絮期139 mm。随滴灌量减小,耗水量减小。滴灌量影响棉花各生育阶段的耗水量及产量,并不影响耗水比例。相应于灌溉水利用效率最高点的滴灌量要低于产量最高点的,因此节水与增产产生矛盾,仅从节水角度考虑,滴灌量为3 091 m3/hm2时,可以达到最大灌溉水利用效率,要获得最大产量,滴灌量应满足3 464 m3/hm2。与漫灌相比,膜下滴灌节水增产效益明显。在同一灌溉量下,膜下滴灌增产30.2%,灌溉水利用效率提高30.2%,在同一产量水平下,节水29.3%,灌溉水利用效率提高41.5%。  相似文献   

11.
研发和推广应用高效节水技术是提升扬黄灌区制种玉米产量、支撑制种玉米产业增效和持续发展的重要途径。为了给建立制种玉米水肥一体化技术模式下的科学高效灌溉制度提供科学依据。在甘肃扬黄灌区滴灌水肥一体化条件下,研究了不同灌溉定额和灌水次数下制种玉米的产量表现和水分利用效果。结果表明,灌溉定额从2 250 m3/hm2增加到3 000 m3/hm2时,制种玉米增产幅度达33.84%,但灌溉定额高于3 000 m3/hm2并继续增大时增产效果不明显,生育期耗水量增加,水分利用效率降低明显。灌水次数从10次增加至20次时,制种玉米产量及水分利用效率均呈降低趋势,灌水次数多于15次并继续增加时,制种玉米减产显著。灌水次数和灌溉定额之间不存在互作效应。在灌溉定额偏低条件下,增加灌水次数会造成制种玉米严重减产。当生育期灌溉定额为3 000 m3/hm2、灌水次数为10次时,折合产量较高,为7 386.9 kg/hm2,较其余处理增产-2.77%～93.58%;水分利用效率最高,为17.83 kg/(mm·hm2),较其余处理提高5.32%～78.30%;种植纯收益较高,为29 683.6元/hm2,较其余处理增加-511.8～20 675.4元/hm2;产投比最高,为3.03,较其余处理增加0.07～1.38。可见,灌水10次、灌溉定额为3 000 m3/hm2时灌溉水利用效果相对优化。  相似文献   

12.
To calculate the soil loss tolerance for chernozems of the central chernozemic region, a linear modification of Skidmore’s equation was used. The soil loss tolerance values were obtained with due account for the soil type, the degree of erodibility, and the crop rotation pattern. The maximum possible value (10 t/ha per year) was obtained for a typical noneroded chernozem in all the crop rotations. Close values were obtained for noneroded leached and typical chernozems (9.6–9.9 t/ha per year depending on the crop rotation pattern). The soil loss tolerance for the noneroded podzolized chernozem was somewhat lower: 9.1 t/ha per year in the grain-herb-intertilled crop rotation and 6.3 t/ha/year in the grain-intertilled crop rotation. With an increase in the degree of the soil erosion, the soil loss tolerance decreased in all the variants of the experiment with an especially abrupt decrease in the grain-intertilled crop rotation (from 9.9–10.0 to 0.3–2.0 t/ha per year in the, respectively, noneroded and slightly eroded ordinary and typical chernozems). In the grain-herb-intertilled crop rotation, these differences were much smaller: in the slightly eroded typical chernozem the soil loss tolerance was estimated at 9.7 t/ha per year, while, in the slightly eroded typical chernozem, at 8.1 t/ha per year. The moderately eroded chernozems without the addition of manure could only be used in the grain-herb-intertilled crop rotation; the soil loss tolerance was estimated at 9.0 t/ha per year for the typical chernozem and 4.3 t/ha per year for the ordinary chernozem.  相似文献   

13.
Development of alternative sources through wastewater reuse is important to meet water demands in arid regions. However, effects of wastewater irrigation on soil properties and crop performance must be evaluated before advocating its widespread use. Objectives of this study were to evaluate: (i) effects of prior evaporative disposal of saline‐sodic blowdown water (BW) on soil (fine‐loamy, mixed, and thermic Typic Calciorthods) properties in the disposal area, and (ii) effects of flood irrigation with three water qualities (control, BW 1X, and BW 2X) on soil salinity and alfalfa performance using a greenhouse soil column study (soil collected from same study area as objective (i)). Results indicated that although prior land disposal of BW had increased salinity and sodicity of soil, they were within the tolerance limits of the intended crop, alfalfa. Mass balance calculations indicated measured (15·6 Mg ha−1) and calculated (13·2 Mg ha−1) salt accumulation at the test site used for evaporative disposal were similar. Alfalfa grown using BW under greenhouse conditions produced prime quality hay and biomass yield similar to the control treatment (8·3 g column−1 vs. 10·5 g column−1 in control). Although 3·6 years equivalent of flood irrigation with BW 1X did not result in saline soil (BW 1X irrigated soils EC ranged from 2·2 to 3·5 dS m−1), BW 2X irrigation resulted in saline soils. Sodicities of irrigated soils were greater in fine textured deep soils than coarse textured surface soils (e.g., SAR of 6·1 at 0–5 cm vs. 19·5 mmol1/2 L−1/2 at 30–60 cm in BW 1X), indicating the need for high solubility Ca amendments for long‐term irrigation with BW on fine texture soils within the soil profile. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

14.
Modification of plant population density and irrigation regime may impact seed cotton and lint yield, fiber quality, photosynthesis, and nitrogen uptake, especially in areas with severe water shortages and limited water resources. Furthermore, it reduces seeds and other agricultural practices costs without sacrificing yield. Field experiments examining the impact of plant population and irrigation regime on cotton growth, cotton yield parameters, fiber quality, leaf area, and chlorophyll content of cotton leaves were conducted in the city of Aleppo, northern Syria, in 2004 and 2005. Plant populations of 74,000, 57,000, 48,000, 41,000, and 33,500 plants ha?1 and two drip irrigation regimes [one planting row/one irrigation line (one/one) and two planting rows/one irrigation line (two/one)] were tested. Cotton was planted in April 2004 and 2005 at the Agricultural Research Center in northern Syria on a Chromoxerertic Rhodoxeralf soil. Cotton was irrigated when soil moisture in the specified active root depth was 80% of the field capacity as indicated by the neutron probe. Before all plots were hand-picked each year, a 20-lint sample was collected per plot and sent to the Cotton Research Administration Laboratory for fiber quality analysis. Seed cotton yields were lowest with populations of 33,500 plants ha?1 compared to the other tested population densities. However, the other plant densities did not much influence seed cotton yield, fiber quality, leaf area, and leaf chlorophyll content. Water savings for different plant densities grown under the one/one irrigation regime ranged between 11.2 and 38.3% of irrigation water relative to two/one irrigation regime. Reducing population densities up to 41,000 plants ha?1 and adapting a one/one irrigation regime appear to be viable cost-saving options.  相似文献   

15.
A system for the diagnostics of chernozemic soils of the Tambov Lowland based on concretions is proposed for agricultural and reclamation purposes. The relationships between the structure and composition of the carbonate concretions, the long-term water regime of the soils, and the productivity of the crops have been established. The dense concretions in the typical chernozem testify to the depth of the seasonal wetting; the angular-rounded concretions in the deeply gleyed chernozem-like soil, to the upper boundary of the capillary fringe; and the angular concretions with sharp edges and cavities in the gleyic chernozem-like soils, to the groundwater table. In the chernozem-like soils that were waterlogged with bicarbonate-sodium water, the black angular concretions were formed in the solonetzic horizons, while the weakly compacted light-colored ones, in the zone of the capillary fringe. Humic acids were responsible for the color of the dark neoformations, and fulvic acids predominated in the light-colored ones. The appearance of black fine nodules indicated periodic surface water stagnation. Manganese predominantly accumulates in these nodules. The structure of the Mn-Fe concretions in the plow horizon observed at a magnification of 40–50 times has a diagnostic importance. The short-term (2–3 weeks) water stagnation leads to the formation of fine-stratified concretions, and the long-term (up to 1.5 months) stagnation promotes the formation of uniform porous ones. The solonetzic process induced by the bicarbonate-sodium water results in the appearance of mottled concretions.  相似文献   

16.
Abstract

Yield, water storage, and water use efficiency of irrigated cowpea (Vigna unguiculata L. Walp) were evaluated under four tillage systems and five irrigation regimens. The tillage systems are conventional tillage, reduced tillage, zero tillage, and manual tillage, and the irrigation regimens were created by using a line source sprinkler system. Reduced and conventional tillage produced higher yield and water use efficiency than zero and manual tillage (p<0.05). Reduced tillage produced the highest yield of 1.88 t/ha and had slightly higher yields than conventional tillage in the first four irrigation levels because of higher water storage and lower percolation than conventional tillage. Although manual tillage had high water storage and low percolation, the water was not beneficially used probably because of high evaporation leading to significantly (p<0.05) high soil moisture tension before irrigation. Zero tillage, on the other hand, resulted in significantly (p<0.05) lower application efficiency due to higher runoff. Therefore, irrigated land requires some forms of mechanical tillage or water conservation measures for manually tilled land for improved water use efficiency.  相似文献   

17.
The wastewater from swine production facilities has been typically managed by treatment in anaerobic lagoons followed by land application. However, there have been considerable advances in superior treatment technologies. Wastewater from one of these technologies was effective for subsurface drip irrigation of bermudagrass. The objectives of this experiment were to assess accumulation of soil nitrogen and carbon along with grain yield, dry-matter accumulation, and plant nitrogen accumulation of soybean [Glycine max (L) Merr., cv.] and wheat [Triticum aestivum (L), cv.] when supplementally irrigated with treated swine effluent via subsurface drip irrigation (SDI). The soil series was Autryville loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudults). Its low unsaturated hydraulic conductivity of 0.0017 ± 0.0023 mm h?1 caused problems with water movement to either the soil surface or laterally to adjoining soybean and wheat roots. This condition contributed to complete crop failure in soybean in 2 years and generally poor yields of wheat. In a good rainfall year, the soybean yield was somewhat satisfactory and benefited from the supplemental irrigation. In that year, nonirrigated and irrigated soybean mean yields were 1.55 versus 1.98 Mg ha?1, respectively. The mean yield of wheat was only 1.06 Mg ha?1, and it was not affected by irrigation. The means for soil nitrogen and carbon in the 0- to 15-cm depth were 414 and 5,679 mg kg?1, respectively, and they were not affected by the water treatments. Thus, neither soil conditions nor soybean/wheat production were greatly enhanced by the SDI system.  相似文献   

18.
The reasons for the deterioration of the irrigation water quality and the alkaline degradation of chernozems in the Danube-Dnestr and Azov irrigation systems on the East-European Plain were studied. The water of the accumulation reservoirs in these systems is alkaline (pH up to 8.6), contains 1.5–2.5 g/l total dissolved salts, and is characterized by an increased content of magnesium (35% of the total cations). The irrigation of chernozems with such water results in the alkalinization of the soils and a decrease in the content of exchangeable calcium from 85–90 to 55–65% of the total exchangeable cations. The content of exchangeable magnesium increases to 30–40% and that of sodium to 3–5% of the total exchangeable cations. Problems of soil reclamation that have arisen during the functioning of irrigation systems without solving the main task (the improvement of the irrigation water’s quality) have been considered. Recommendations are given for the conservation of chernozems and the preservation of the quality of the irrigation water from the Kuban and Don rivers during its transportation to the irrigated fields.  相似文献   

19.
河套灌区井渠结合膜下滴灌土壤盐分演化规律   总被引：4，自引：3，他引：1  
针对内蒙古河套灌区井渠结合的问题,基于SaltMod模型建立井灌区和渠灌区水盐均衡模型,并引入含水层侧向交换量对模型进行改进,利用隆胜井渠结合试验区15 a水盐观测资料对改进的模型进行率定和验证,采用验证后的模型分析了隆胜井渠结合区在现状条件下以及在井渠结合膜下滴灌推广实施后区域的土壤盐分演化规律。结果表明,现状条件下隆胜井渠结合区土壤盐分基本稳定,尤其是渠灌区根系层盐分基本稳定,保持在较低水平,可以在长时期内满足作物生长的需求。当推广井渠结合膜下滴灌后,井灌区的生育期灌溉定额和地下水埋深对其灌溉用地根系层土壤盐分积累的影响较小,而地下水矿化度与秋浇频率的影响较大。对于井灌区,建议采用黄河水2年1次进行秋浇压盐,可以长期将土壤全盐维持在3 g/kg以下,以满足作物生长需求。  相似文献   

20.
The effects of 15N-labeled ammonium nitrate on yield, uptake of nitrogen (N) by sorghum (Sorghum sudanense, Piper), and on N remaining in the soil were studied in a field experiment with different N rates (0, 50, and 100 kg N ha?1) and with two irrigation water qualities, well water (WW) and treated wastewater (TWW). Treated wastewater irrigation increased dry matter and N yield compared to WW. At equal N rates, recovery of 15N-labeled fertilizer by plants increased with TWW irrigation compared to WW (36% versus 23%). Neither fertilizer rate nor water quality had an effect on the 15N-labeled fertilizer remaining in the 0- to 60-cm layer of soil. On average 41% in the TWW treatment (49–33%) and 38% in WW treatment was mostly present in the surface 20-cm layer. Losses of 15N-labeled fertilizer were unaffected by irrigation water quality (35%) and increased with N application rate in TWW (4% versus 31%).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号