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1.
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   

2.
Water and nitrogen (N) nutrition are two key factors affecting nutrient absorption growth and biomass production of vegetables. However, less information is available to the interaction between water utilization and nitrogen use efficiency in vegetable production. In this study, a combination of three water levels and three nitrogen fertilizer rates was applied to optimize water and nitrogen application in field experiments. Plant traits, biomass production, and allocation were determined. The fresh and dry weight of leaf, stem, and root significantly decreased when irrigation water was short. Total aboveground biomass decreased in response to deficit irrigation. Leaf chlorophyll concentrations decreased when nitrogen fertilizer reduced. The leaf area was highest when spinach was grown under 170 kg ha?1 of nitrogen fertilizer and 70–80% of field capacity. These results suggested that spinach could be planted with good growth and quality by implementing effective water and nitrogen managements.  相似文献   

3.
Forage pearl millet (Pennisetum americanum var. Nutrifeed) is a new forage crop in Iran. A field experiment was conducted at the University of Tehran to evaluate the response of pearl millet to four nitrogen (N) levels (0, 75, 150, and 225 kg N ha?1) and four irrigation regimes (40%, 60%, 80%, and 100% of available soil water abbreviated to I40, I60, I80 and I100, respectively) during 2006–2007. Total dry matter production reached a maximum of 24.4 and 23.5 t ha?1at I40 and I60 at N225, respectively. Nitrogen use efficiency decreased by adding more fertilizer and minimum nitrogen use efficiency was recorded at N225 over all irrigation regimes. At N225, water use efficiency reached the maximum of 3.57 and 4.10 kg m?3 in I80 and I100, respectively. Pearl millet forage could be produced in the regions where water is scarce and additional N fertilizer could increase total dry matter and water use efficiency.  相似文献   

4.
为探究适于晋西黄土区果农间作系统滴灌水肥一体化管理制度,以典型的苹果-大豆间作系统为研究对象,设置灌水和施肥两因素,分析不同水肥调控措施对土壤含水量分布、苹果和大豆光合生理特征、大豆生长和产量以及间作系统水分利用等指标的影响。试验在大豆4个关键需水期进行灌水,肥料随灌溉水施入,每次设置不同灌水上限和施肥水平,4个灌水量上限水平分别为:田间持水量(Fc)的60%(W1),70%(W2),80%(W3)和90%(W4),3个施氮水平:纯N 59.40 kg/hm^2(F1),92.00 kg/hm^2(F2),124.32 kg/hm^2(F3),对照处理(CK)整个生育期不灌水不施肥,仅在播种前施入基肥。结果表明:各水肥处理土壤含水量在水平和垂直方向上具有显著差异,灌水量对土壤含水量的影响程度高于施肥量和水肥交互作用。苹果和大豆的净光合速率(Pn)和蒸腾速率(Tr)的日变化特征相似,均为单峰型曲线,最大值均为W3F2处理。各处理大豆株高、茎粗和叶面积指数(LAI)分别较对照组提高了1.3%~32.3%,2.8%~33.9%和3.4%~125.9%,其中最大值均出现在W3F2处理,该处理大豆产量和间作系统水分利用效率(WUE)也最优,较其他处理分别提高了10.9%~99.3%和8.0%~70.0%。在播种至出苗期、幼苗期至分枝期、开花结荚期和鼓粒期可以设置80%Fc的灌水上限,同时在大豆幼苗期至分枝期、结荚期和鼓粒期分别施加92.00 kg/hm^2的氮肥,该水肥管理方式使苹果—大豆间作系统获得较高的作物产量及水分利用效率,可为该地区间作系统滴灌水肥一体化管理提供参考。  相似文献   

5.
ABSTRACT

The effect of deficit irrigation (DI) on wheat crop yield, soil physical parameters and on nitrate nitrogen movement in soil profile was evaluated under application of dairy manure and nitrogen fertilizer. Two levels of DI were taken as I0.6 (60% FC) and I0.8 (80% FC) along with two dairy manure levels (20 and 25 Mg ha?1) and three nitrogen levels (80, 100, and 120 kg ha?1). The grain yield was high under I0.8 than I0.6, whereas the irrigation level has no significant effect on soil organic carbon contents. Dairy manure, irrigation, and nitrogen indicated strong interaction with each other for all yield-related parameters during both years of study, however, results for 2nd year were highly positive. Soil nitrate nitrogen movement was significantly affected under I0.8 with high rate of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1). Results concluded that combined application of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1) under DI level I0.8 resulted in high grain yield. To overcome water scarce conditions, further experiments can be designed by addition of various organic matters in different combination that enhances the yield and soil health.  相似文献   

6.
Camelina (Camelina sativa (L.) Crantz) seed oil has desirable properties for producing advanced biofuels and as a healthy cooking oil. It has been grown for centuries, but basic recommendations for nitrogen (N) fertilizer requirements are still needed to support widespread industrial cultivation across North America. A replicated N-response plot-scale study was conducted on a northern Mollisol soil for two growing seasons to 1) determine seed and oil yield, seed oil content, and vegetative response; 2) determine indices of N use efficiency; and 3) measure post-harvest residual inorganic soil N as an index of environmental risk. Seed and oil yield response to N fertilization was described with a quadratic function, which predicted maximum seed yield (1450 kg ha?1) and oil yield (580 kg ha?1) at about 130 kg N ha?1. However, seed and oil yield did not differ significantly among N-rates above 34 kg N ha?1. Seed oil content averaged 400 g kg?1 among all N rates. Agronomic efficiency declined above 34 kg N ha?1, which coincided with an increase of post-harvest soil nitrate-N plus ammonium-N (residual N). Considering N use efficiency, simple cost analysis, and risk associated with residual N, a rate of 34 kg N ha?1 is recommended.  相似文献   

7.
Abstract

Global warming along with the increasing population and fresh water shortages necessitates a specific fertilization programme under water-scarce conditions. This study was conducted to investigate the effects of different irrigation and nitrogen levels on yield, growth components and water use characteristics of cauliflower (Brassica oleracea L. var. Botrytis cv. Tetris-F1) cultivated in a field for three consecutive years from 2005 to 2007 in the Eastern Mediterranean region of Turkey. Four irrigation (Kcp) levels with a drip irrigation system based on adjustment coefficients (0, 0.75, 1.0 and 1.25) of pan evaporation were used. Nitrogen (N) treatments were consisted of four different nitrogen rates (0, 75, 150 and 225 kg N ha–1). The following yield and quality parameters were determined: curd weight, curd diameters, number of leaves per crop, above ground biomass (AGB) and curd/AGB ratio. Fertilizer use efficiency (FUE) and leaf mineral contents were also determined to clarify the productivity of N treatments. According to the results; the amount of irrigation water and/or total received water affects the plant water consumption, consequently, crop yield in a field grown cauliflower. The highest yield was obtained in Kcp1.0 irrigation level which represents full irrigation treatment. The excess water applications had negative effect on yield and AGB of cauliflower. Highest yield was obtained at 225 kg N ha–1.

The water use efficiency and irrigation water use efficiency values increased with decreasing irrigation rate. However, lower Kcp coefficients resulted in lower total yield. The FUE in irrigation treatments showed linear increases from non irrigation to full irrigation plots. However, excessive irrigation caused a decrease in FUE. It can be recommended that the Kcp1.0 crop-pan coefficient with 225 kg ha–1 nitrogen application can be used to achieve the highest yield for field grown cauliflower in the Eastern Mediterranean coastal region of Turkey.  相似文献   

8.
黄土高原旱地小麦施肥对产量及水肥利用效率的影响   总被引:22,自引:6,他引:16  
在长期定位试验的基础上,研究了黄土高原旱地不同施肥对小麦产量、土壤养分和水分的变化及其利用效率的影响。结果表明,单施有机肥(M)增产效果较好,产量达5265.0 kg/hm2;有机肥和化肥配施(NPM)小麦产量最高,达5898.8 kg/hm2。NPM配施小麦总吸氮量最大,比单施氮肥(N)增加了131.4 kg/hm2;NPM配施的氮肥利用率、氮肥偏生产力、氮肥农学效率、氮肥生理利用率分别为67.0%、49.16 kg/kg、36.97 kg/kg、73.11kg/kg;在不同施肥体系中其变化趋势基本一致,均为:NNPNMNPM,处理间差异显著。土壤养分含量变化看出,单施氮肥土壤全氮、碱解氮与不施肥(CK)的差异不显著;有机肥可显著提高土壤速效钾的含量;NPM配施土壤耗水量最大为558.3 mm,水分利用率最高为31.5 kg/(hm2.mm),随着耗水量增加的同时,土壤出现干燥化趋势。  相似文献   

9.
Flat transplanting with flooded irrigation is commonly used for growing rice, but it results in ineffective use of applied fertilizer and water. The objective of this study was to compare nitrogen use efficiency and water saving of rice transplanted on beds and on flat ground. This field experiment was performed in randomized complete design for three continuous years and all treatments were repeated three times. Results showed that transplanting of four lines of rice nursery on bed and one line in furrow and nitrogen application at 150 kg ha?1 recorded 16.06, 21.81, 16.0 and 20.21% higher paddy yield, nitrogen (N) uptake in paddy, N use efficiency and N agronomic efficiency than traditional flat method at same N level. Without loss in yield, about 25 kg ha ?1 of N fertilizer and 24% of water can be saved with bed transplanting of rice as compared to flat method.  相似文献   

10.
A field experiment was conducted to assess the effect of sulfur (S) fertilization on distribution of S in soil and use efficiency on blackgram in subtropical Inceptisol of acidic soil of Assam, India. Five levels of S were applied (0, 10, 20, 30 and 40 kg S ha?1) along with recommended dose of nitrogen, phosphorus and potassium. Available S content gradually decreased with the advancement of crop growth stages and lowest value was observed at 60 DAS. Different S fractions were found to increase with increasing levels of S application and 40 kg S ha?1 resulted the highest content for all S fractions. The grain and stover yield of blackgram increased significantly up to 20 kg S ha?1 which was 95.69% higher over control. Agronomic efficiency, apparent S recovery and recovery efficiency of S were higher at 10 kg S ha?1and found decreased with increase in level of S.  相似文献   

11.
Evaluation of any crop response to different nitrogen amounts is important for determining the amount that can be considered as optimum from economical and environmental point of view. This study was conducted to (1) evaluate the growth and yield of pumpkin (Cucurbita pepo L.) under different nitrogen rates and (2) determine the nitrogen use efficiency (NUE) of pumpkin in two growing seasons (2013 and 2014). In both growing seasons, nitrogen fertilizer (at three rates including 50, 150, and 250 kg ha?1) was band-dressed on the planted side of each furrow, coinciding with 4–6 leaves stage and flowering. Crop performance over 2 years was evaluated by measuring shoot dry matter, crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), intercepted PAR (PARi), radiation use efficiency (RUE), shoot nitrogen uptake, water use efficiency (WUE), NUE, and fruit and seed yield. The results showed that in both growing seasons, the highest growth and yield of pumpkin were obtained by applying 250 kg N ha?1 (using urea fertilizer containing 46% nitrogen). Increased nitrogen rate from 50 to 250 kg ha?1 resulted in 87.3%, 27.0%, 62.1%, 87.5%, and 84.5% increase in shoot dry weight, RUE, WUE, fruit yield, and seed yield of pumpkin, respectively, across both growing seasons. However, higher application nitrogen rate decreased the NUE of pumpkin, i.e., the NUE decreased by 62.5% when the nitrogen rate increased from 50 to 250 kg ha?1. The effect of nitrogen applied in 2014 growing season on growth and yield of pumpkin was higher than that in 2013 growing season, which might be due to more suitable weather condition. In conclusion, the nitrogen rate of 250 kg ha?1 produced the highest amount of fruit and seed yield in pumpkin.  相似文献   

12.
Abstract

Salinity is a negative abiotic stress that produces drastic disorders on soils and plants causing a critical reduction in plant growth and yield parameters, particularly maize plant, which considers a moderately sensitive plant to soil and water salinity. Although proline and nitrogen are well known to protect plants and improve their tolerance against various abiotic stresses including salinity, the interaction between proline and nitrogen fertilizer under saline conditions remained unclear. Two field experiments were conducted, on a clay saline soil in a split-plot design with four replicates. The main plots were arranged to study the effect of exogenous of proline applications at 0, 50 and 100?mM during seedling and vegetative stages, and mineral of nitrogen fertilization rates were 0, 140, 280, and 420?kg N ha?1 occupied the subplots. A significant response to fertilizer N was observed at 420?kg ha?1, while the optimum N rate of 50?mM of proline was 410.3?kg ha?1 and the economic optimum dose was 403.43?kg ha?1. Therefore, we recommend using 403.43?kg N ha?1 to get an optimum economic yield of maize, especially in saline soil, when used 50?mM exogenous of proline at seedling and vegetative stages.  相似文献   

13.
Nitrogen fertilization management under water limited conditions needs to be refined to save environmental ecosystems and increase economic returns. Two-year field studies in a split-plot design were conducted to investigate the response of maize to different nitrogen rates (N100 = 100, N130 = 130, and N160 = 160?kg N ha?1) under two irrigation levels (100 or 75% of water requirements). Under deficit irrigation, water and N were used more efficiently than normal water supply. N-fertilization of drip irrigated maize grown under deficit irrigation with N160 increased the uptake of N, P and K by 35, 29 and 70% compared with N100. Fertilization of maize grown under deficit irrigation with N160 increased the grain, straw and biological yield and water use efficiency by 50, 14, 22 and 33% compared with N100. Based on the obtained results, 160?kg of N ha?1 is the optimum rate of N for maize irrigated by 75% of water requirements.  相似文献   

14.
Traditional irrigation and nitrogen (N) fertilization in North China may elevate water drainage and nitrate concentrations in soil and groundwater. A field experiment was conducted in an intensively irrigated vegetable (cauliflower, amaranth, and spinach) field for three consecutive years (1999–2002). The main objective was to test to what extent an improved water and fertilizer management, based on the maintenance of field capacity a defined range of the water content in the 0–50 cm soil layer and an N expert system, could reduce drainage and nitrate leaching without impairing vegetable yield. Rates of water drainage and related nitrate leaching were calculated based on measurements of soil water potential and soil‐water nitrate concentrations. Soil water potential was monitored with tensiometers at depths of 75 cm and 105 cm. Nitrate concentrations were analyzed in soil leachates collected at 90 cm soil depth using ceramic suction cups. The results revealed that the average annual drainage related to the cultivation season for cauliflower, amaranth, and spinach was reduced from 275 mm in the traditional system to 29 mm with improved management practice. The average annual cumulative nitrate leaching during the vegetable‐growing period amounted to 301 kg ha–1 and 13 kg ha–1 in the traditional and improved management practices, respectively. Vegetable yields were not significantly different under the traditional and improved management practices.  相似文献   

15.
Field experiments were conducted for two years to find out the appropriate sowing configuration and rate of nitrogen (N) for sustained yield and improved water use efficiency of hybrid Bt cotton irrigated through surface drip irrigation. Drip irrigation under normal sowing, in which equal quantities of water and N were applied as check-basin irrigation, resulted in an increase of 389 and 155 kg ha?1 in seed cotton yield compared with check-basin irrigation during the first and second year, respectively. Normal paired row sowing under a drip irrigation system, in which only 50% of irrigation water was applied compared with normal sowing, produced a yield similar to normal sowing under drip irrigation during both years, resulting in 22% higher water use efficiency. Dense paired row sowing under drip irrigation, in which only 75% irrigation water was applied compared with normal sowing, increased the mean seed cotton yield by 5% and water use efficiency by 19%. Decrease in the rate of nitrogen application (from 150 to 75 kg N ha?1) caused a decline in seed cotton yield and water use efficiency under all the methods of sowing, but the reverse was true for agronomic efficiency of N.  相似文献   

16.
ABSTRACT

The effects of deficit irrigation and fertilizer use under drip irrigation (DI), on vegetative growth of mature cherry trees were studied in two field experiments. Treatments for the assessment of deficit irrigation consisted of two drip line arrays: double drip lines (T1) and loop (T2) as main treatments. Three irrigation levels: irrigation at 100% of crop evapotranspiration (ETc or I1), 75% ETc or I2, and 50% ETc or I3, constituted the sub-treatments. To assess soil fertility practices, the main treatments consisted of T1 and single drip line (T3) arrays; sub-treatments were two fertilizer regimes: basic fertilizer recommendation plus 0.5 m3 sheep manure per tree (F1) and basic fertilizer recommendation plus 1300 g potassium sulfate, 350 g of zinc (Zn), 140 g of iron (Fe), and 600 g ammonium phosphate (F2). Total irrigation amount, which was applied routinely in control treatment (7466.7 m3ha? 1), was less than the crop water requirement (8764.5 m3 ha? 1). A significant correlation between both the length of young branches and canopy volume with annual applied irrigation water was observed. Mean canopy volume under T1 was 26.0 m3 tree? 1, which was significantly less than 28.6 m3 tree? 1 under T2. Water use efficiency (kg m? 3) was increased by water stress, but there was no significant yield reduction from I1 to I2. Concentration of Fe, phosphorus (P), potassium (K), and magnesium (Mg) in leaf samples increased with the use of double drip lines array compared to use of single drip line array and it was higher under F2 fertilizer level. The concentration of calcium (Ca) in leaf samples was higher than critical level in all treatments. We conclude that I2 irrigation level and F2 fertilizer management was the most efficient practice for cherry trees in the study area.  相似文献   

17.
在宁夏银北盐碱地区,以'Cave-in-rock'柳枝稷为材料,采用随机区组试验设计,研究了水氮耦合对柳枝稷生物质产量、品质及水肥利用效率的影响,利用模糊相似优先比法分析了不同水氮处理下柳枝稷产量、品质及水肥利用效率的变化特征.结果表明,在盐碱地条件下,充足的灌水和适量的氮肥投入是柳枝稷高产和水肥高效利用的保证.在相同...  相似文献   

18.
A field experiment was conducted over two years to evaluate the gas exchange, water relations, and water use efficiency (WUE) of wheat under different water stress and nitrogen management practices at Crop Physiology Research Area, University of Agriculture, Faisalabad, Pakistan. Four irrigation regimes and four nitrogen levels, i.e., 0, 50, 100, and 150 kg N ha?1 were applied in this study. The photosynthetic gas exchange parameters [net carbon dioxide (CO2) assimilation rate, transpiration rate and stomatal conductance] are remarkably improved by water application and nitrogen (N) nutrition. Plants grown under four irrigation treatments as compared with those grown under one irrigation treatment average stomatal conductance increased from 0.15 to 0.46 μ mol m?2s?1mol during 2002–2003 and 0.18 to 0.33 μ mol m?2s?1mol during the year 2003–2004 and photosynthetic rate from 9.33 to 13.03 μmol CO2 m?2 s?1 and 3.99 to 7.75 μmol CO2 m?2 s?1 during the year 2002–2003 and 2003–2004, respectively. The exposure of plants to water and nitrogen stress lead to noticeable decrease in leaf water potential, osmotic potential and relative water content. Relative water content (RWC) of stressed plants dropped from 98 to 75% with the decrease in number of irrigation and nitrogen nutrition. The higher leaf water potential, and relative water contents were associated with higher photosynthetic rate. Water use efficiency (WUE) reduced with increasing number of irrigations and increased with increasing applied nitrogen at all irrigation levels.  相似文献   

19.
为探究设施农业中不同灌溉量与施肥模式对土壤理化特性、作物产量、品质、水分利用效率(water use efficiency,WUE)及氮肥偏生产力(nitrogen partial productivity,NPP)的影响。该研究通过对温室黄瓜设置充分(W1)与亏缺(W2)灌溉下不同比例减氮(N1:275 kg/hm2、N2:220 kg/hm2、N3:165 kg/hm2)配施腐熟羊粪有机肥(O1:12 t/hm2、O2:8 t/hm2)处理试验,分析充分与亏缺灌溉下不同减氮配施有机肥处理对土壤理化特性、黄瓜品质、产量、WUE及NPP的影响。结果表明,在相同灌溉条件下,减施氮肥和配施有机肥均能有效改善土壤结构,O1N3处理较其他处理土壤容重平均降低5.8%,孔隙度平均增加7.7%,三相组成优化,大粒径水稳性团聚体含量平均提高25.4%,0~30 cm土层土壤硝态氮含量平均降低21.8%。同时,配施有机肥能提高温室黄瓜WUE和NPP,在相同灌溉和氮肥条件下,O1较O2水平黄瓜WUE和NPP分别平均提高14.5%和15.7%。综合对比分析不同指标得出W1O2N2处理表现最佳,黄瓜可溶性葡萄糖、可溶性固形物、维生素C(VC)含量及产量较W1O1N1处理无显著差异(P>0.05),同时能有效改善土壤环境,减少肥料用量,保证生产经济效益。研究结果对于设施农业科学水肥管理及绿色高效生产具有重要的参考意义。  相似文献   

20.
Different methods of fertilizer application-drip fertigation and conventional fertilizer application under drip, surface irrigation, and rainfed conditions were evaluated during 2009–2012 at Krishi Vigyan Kendra, Shimla, India. The experiment was arranged in randomized block design (RBD), replicated thrice. Results suggest that fertigation significantly increased growth parameters over conventional methods. Fruit yield was significantly higher under fertigation (13.7 t ha?1) over conventional fertilizer application with drip (11.6 t ha?1), surface irrigation (10.6 t ha?1), and under rainfed (8.6 t ha?1). Fruit quality parameters were also superior under fertigation. Fertigation maintained higher available nitrogen (N) and potassium (K) content in 0-30 cm soil layers. Available phosphorus (P) was higher in 0-20 cm soil depths in all the treatments. Fertigation with 80 and 100 percent recommended NPK dose registered statistically comparable results. In addition to higher productivity, fertigation resulted in 20 percent fertilizer savings over drip irrigation and 20 percent fertilizer besides 40 percent water savings over surface irrigation.  相似文献   

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