不同水分管理方式对水稻生长及产量的影响

通过盆栽试验观测不同水分管理方式对水稻生长的影响.结果表明:深水灌溉产量分别比湿润灌溉、间歇灌溉、受旱灌溉超出22.6％、37.9％、55.8％,湿润灌溉水分利用率分别比间歇灌溉、受旱灌溉高0.29、0.33 kg/m3.湿润灌溉、间歇灌溉有利于水稻生长发育、干物质积累、产量形成,并提高了水分利用率,显著减少了灌水量.受旱灌溉虽节省了灌水量,但显著减产,灌溉水利用率较低.因此,采用湿润灌溉方式既能确保水稻稳产,又能显著减少用水量.     

稻田水分管理方式对水稻光合速率和水分利用效率的影响

以超级杂交稻两优培九和中优6号为材料, 设3个不同水分管理措施,在穗分化期、开花期和花后20 d分别测定叶片光合速率和水分利用率。结果表明:不同水分管理方式影响水稻地上部干物重、叶面积指数、光合速率、蒸腾速率和水分利用效率。水分好气灌溉管理地上部干物重和水分利用效率明显增加;水分低水位管理蒸腾速率、地上部干物重和叶片水分利用效率下降。淹水灌溉地上部干物重、叶面积指数、叶片光合速率和水分利用率较低。因此,水稻好气灌溉有利于光合物质积累,显著增产和提高水分利用效率。试验还表明这3种水分管理对稻米蛋白质含量的影响不显著。     

不同水分管理对杂交水稻产量及其构成的影响

以新两优6号为试验品种,研究了精确定量灌溉、无水层灌溉、常规灌溉、旱作对杂交水稻分蘖动态、生育期、产量及其构成因子的影响.结果表明:过多或过深的水分会抑制分蘖,湿润或无水会促进分蘖,过度干旱会加速后期分蘖消减；不同水分管理对生育进程和全生育期影响不大；无水层灌溉有效穗数、每穗总粒数和结实率较高,产量最高,旱作的有效穗数、每穗总粒数和结实率较低,产量最低,不同水分管理对千粒重影响不大.在水稻生产上以干湿交替的无水层湿润灌溉取代长期上满田水的传统灌溉方式,不仅可以提高产量,还可以节约水资源.     

不同灌溉方式对水稻生长及产量的影响

为建立湘南双季稻区节水灌溉栽培模式提供依据,设置了不同灌溉方式对水稻生长发育的影响试验。试验结果表明：不同灌溉方式在水稻生长、干物质积累、生理特性以及产量上都存在显著差异。4种灌溉方式下水稻生长与产量表现以浅水灌溉最优,受旱灌溉最差,与受旱灌溉比,浅水灌溉株高、分蘖数、光合速率均有提高,结实率提高了41.5%,千粒重增加了1.6 g,产量增加了15.8 g/盆;浅水灌溉下水稻产量、灌溉用水利用率分别比深水灌溉高出7.6 g/盆和0.69 kg/m3。间歇灌溉产量与深水灌溉差异很小,但间歇灌溉水分利用率高出深水灌溉0.44 kg/m3。因此,在湘南双季稻区,针对季节性干旱的特点,采用浅水灌溉方式有利于晚稻高产稳产,间歇灌溉有利于晚稻种植。     

浅谈新宾地区水稻生长与水分的关系

根据新宾县降水特点及水稻生长规律,分析了水稻生长与水分的关系,旱涝灾害对水稻产量的影响,水稻生长过程中各个生育时期对水分的不同要求。由此,提出应根据水稻生长发育的需水规律加强水分管理。     

灌溉方式对水稻产量、品质与抗倒性影响的研究进展

水分管理是调控水稻生长发育的主要农艺措施之一，对水稻产量、品质和抗倒性等具有重要影响。水稻生产中常用的灌溉方式有淹水灌溉、“薄、浅、湿、晒”模式、控制灌溉、半深水灌溉和干湿交替灌溉等。本文阐述了不同灌溉方式对水稻产量、品质和抗倒性的影响研究进展，比较归纳了不同灌溉方式的优劣势，并对未来研究方向进行了展望，以期为水稻高产优质抗倒节水栽培提供理论依据。     

寒地水稻高产栽培技术

结合黑龙江省青冈县水稻生产实际,从品种选择、种子处理、苗床地选择及做床、秧本田管理等方面总结了适合当地的寒地水稻高产栽培技术,其中按浸种量大小提出了不同的种子催芽方式,在秧田管理部分重点介绍了水分及温度管理,并明确了本田整地、施肥、灌溉等方面的本田管理技术要求。     

水分胁迫对节水抗旱稻产量形成和根系形态生理特性的影响

[目的]探究节水抗旱稻组合旱优73在不同灌溉条件下产量形成特点及其根系形态生理的变化情况.[方法]以节水抗旱稻旱优73和高产水稻H优518为材料,通过根管试验设置三种水分处理(常规灌溉、轻度水分胁迫、重度水分胁迫),调查株高、分蘖、根系形态特征和生理特性以及产量构成因素,分析性状之间的关系,探究不同程度水分胁迫对旱优7...     

宁夏稻作区水分胁迫对水稻分蘖动态及产量的影响

研究了不同灌溉方式对水稻分蘖能力及产量的影响。结果表明,灌溉条件越好,水稻分蘖能力越强,收获穗数越多,产量越高;全生育期间歇灌溉和胁迫灌溉对水稻分蘖能力以及产量均有较大影响。在宁夏水资源紧缺的条件下,应通过调整种植业结构、增加轮作面积、延长轮作周期等措施压减控制水稻种植面积,保证有限的水资源能够充分灌溉一定面积的水稻,并通过完善改进水利设施,达到减少渗漏浪费、提高水资源利用效率的目的。     

水分管理对免耕抛秧水稻根系生长及产量的影响

研究了水分管理对免耕水稻根系生长和产量的影响。结果表明,干湿交替灌溉对根系的伸长、生长、生理及分布具有较大影响,水稻各生育期干湿交替灌溉处理水稻单株根干质量、单株生物量、根半径、根表面积、总根数、根系活力、超氧化物歧化酶活性均显著高于淹水淹灌。干湿交替灌溉处理实收产量显著高于淹水淹灌,增产主要因子是有效穗数、每穗粒数和结实率。灌浆盛期干湿交替灌溉处理单株生物量、根半径、根表面积、总根数、超氧化物歧化酶活性均显著高于湿润淹灌,水稻产量差异则不显著。     

Transferring water from irrigation to higher valued uses: a case study of the Zhanghe irrigation system in China

The Zhanghe irrigation system (ZIS) is located in the Yangtze River Basin approximately 200 km west of Wuhan in Hubei Province. The reservoir was designed for multiple uses—irrigation, flood control, domestic water supply, industrial use, aquaculture, and hydropower. Over a period of more than 30 years a steadily increasing amount of water has been transferred from irrigation to other uses. Activities on the part of government, irrigation system managers, and farmers made this transfer possible with only modest decline in rice production. Most important factor was the steady increase in rice yields. The water pricing system provided an incentive for ZIS to reduce irrigation releases. With the steady decline in releases, farmers were forced to find ways to save water. Farmers improved existing ponds and built new ones to store water (improved infrastructure). Access to pond water on demand facilitated the adoption of alternate wetting and drying (technology) particularly in dry years. The establishment of volumetric pricing (price policy) and water user associations (institutions) may also have provided incentives for adoption of AWD, but more research is needed to establish their impact. These activities taken together can be seen as potentially complementary measures. Farmers received no direct compensation for the transfer of water, but recently farm taxes have been reduced or altogether abolished. Further reduction in water releases from the ZIS reservoir could adversely affect rice production in normal or dry years.     

Impacts of water cycle changes on the rice market in Cambodia: stochastic supply and demand model analysis

A supply and demand model for rice in Cambodia, which includes among other factors evapotranspiration as a water supply variable impacting regional yields and planted areas, is developed to aid in the design of agricultural policies and planning. Impacts are determined stochastically by drawing on water cycle distributions and evaluating the resulting variation in production and price bands for local rice markets. The results of the baseline analyses indicate that production of wet and dry season rice steadily increases and the consumption per capita slightly decreases due to the negative income elasticity. Results of a partial stochastic analyses show that the production of rice in regions where elevations are high and the land vulnerable to flooding are the most sensitive to increased fluctuations in water supply. The changes also affect the rice market through equilibrium price changes. The upper price band, which is the width between average and 90th percentile, is larger than the lower band, which is the width between average and tenth percentile, suggesting that the situation of low income consumers could grow worse under an unstable environment with relatively larger upward price spikes. The results imply that development of irrigation facilities and water management systems maybe required for Cambodian provinces which rely heavily on agriculture, particularly rice production, under increasing climatic variation.     

More Rice,Less Water—Integrated Approaches for Increasing Water Productivity in Irrigated Rice-Based Systems in Asia

Abstract

The water crisis is threatening the sustainability of the irrigated rice system and food security in Asia. Our challenge is to develop novel technologies and production systems that allow rice production to be maintained or increased in the face of declining water availability. This paper introduces principles that govern technologies and systems for reducing water inputs and increasing water productivity, and assesses the opportunities of such technologies and systems at spatial scale levels from plant to field, to irrigation system, and to agro-ecological zones. We concluded that, while increasing the productivity of irrigated rice with transpired water may require breakthroughs in breeding, many technologies can reduce water inputs at the field level and increase field-level water productivity with respect to irrigation and total water inputs. Most of them, however, come at the cost of decreased yield. More rice with less water can only be achieved when water management is integrated with (i) germplasm selection and other crop and resource management practices to increase yield, and (ii) system-level management such that the water saved at the field level is used more effectively to irrigate previously un-irrigated or low-productivity lands. The amount of water that can be saved at the system level could be far less than assumed from computations of field-level water savings because there is already a high degree of recycling and conjunctive use of water in many rice areas. The impact of reducing water inputs for rice production on weeds, nutrients, sustainability, and environmental services of rice ecosystems warrants further investigation.     

水稻节水栽培研究进展

总结了国内外水稻耐旱品种选育、水稻节水灌溉技术、覆盖旱作技术以及稻田土壤耕作技术等主要水稻节水栽培技术,并对水稻节水栽培技术的研究方向进行了展望。     

移栽水稻高产高效节水灌溉技术的生理生化机理研究进展

水资源匮乏威胁水稻生产的可持续发展和粮食安全。为了应对水资源紧缺和增加粮食产量,农业科学家开发了各种节水灌溉技术和生产体系。本文综述了当前移栽水稻生产上主要应用的节水灌溉技术并从水稻生长、激素、蔗糖-淀粉代谢途径关键酶活性等方面阐述了其生理生化机制,提出水稻高产高效节水灌溉技术存在的问题与研究展望。     

Chlorophyll meter-based nitrogen management of rice grown under alternate wetting and drying irrigation

Farmers have adopted alternate wetting and drying (AWD) irrigation to cope with water scarcity in rice production. This practice shifts rice land away from being continuously anaerobic to being partly aerobic, thus affecting nutrient availability to the rice plant, and requiring some adjustment in nutrient management. The use of a chlorophyll meter (also known as a SPAD meter) has been proven effective in increasing nitrogen-use efficiency (NUE) in continuously flooded (CF) rice, but its use has not been investigated under AWD irrigation. This study aimed at testing the hypotheses that (i) SPAD-based N management can be applied to AWD in the same way it is used in CF rice, and (ii) combining chlorophyll meter-based nitrogen management and AWD can enhance NUE, save water, and maintain high rice yield. Experiments were conducted in a split-plot design with four replications in the 2004 and 2005 dry seasons (DS) at IRRI. The main plots were three water treatments: CF, AWD that involved irrigation application when the soil dried to soil water potential at 15-cm depth of −20 kPa (AWD₋₂₀) and −80 kPa (AWD₋₈₀) in 2004, and AWD₋₁₀ and AWD₋₅₀ were used in 2005. The subplots were five N management treatments: zero N (N₀), 180 kg N ha⁻¹ in four splits (N₁₈₀), and three SPAD-based N-management treatments in which N was applied when the SPAD reading of the youngest fully extended leaf was less than or equaled 35 (N_SPAD35), 38 (N_SPAD38), and 41 (N_SPAD41). In 2005, N_SPAD32 was tested instead of N_SPAD41. A good correlation between leaf N content per unit leaf area and the SPAD reading was observed for all water treatments, suggesting that the SPAD reading can be used to estimate leaf N of rice grown under AWD in a way similar to that under CF. SPAD readings and leaf color chart (LCC) values also showed a good correlation. There were no water × nitrogen interactive effects on rice yield, water input, water productivity, and N-use efficiency. Rice yield in AWD₋₁₀ was similar to those of CF; yields of other AWD treatments were significantly lower than those of CF. AWD₋₁₀ reduced irrigation water input by 20% and significantly increased water productivity compared with CF. The apparent nitrogen recovery and agronomic N-use efficiency (ANUE) of AWD₋₁₀ and AWD₋₂₀ were similar to those of CF. The ANUE of N_SPAD38 and N_SPAD35 was consistently higher than that of N₁₈₀ in all water treatments. N_SPAD38 consistently gave yield similar to that of N₁₈₀ in all water treatments, while yield of N_SPAD35 about 90% of that of CF. We conclude that a combination of AWD₋₁₀ and SPAD-based N management, using critical value 38, can save irrigation water and N fertilizer while maintaining high yield as in CF conditions with fixed time and rate of nitrogen application of 180 kg ha⁻¹. Treatments AWD₋₂₀ and N_SPAD35 may be accepted by farmers when water and N fertilizer are scarce and costly. The findings also suggested LCC can also be a practical tool for N-fertilizer management of rice grown under AWD, but this needs further field validation.     

Modeling of water and nitrogen balance in the ponded water of rice fields

A water and nitrogen balance model for the surface ponded water compartment of rice fields was developed. The model estimates the daily ponded water depth and the daily losses and the uses of NH₄–N and NO₃–N in their transformation processes. The model was applied with data obtained from two rice fields during 2005 at Thessaloniki plain in northern Greece. Significant amounts of applied irrigation water were lost with the surface runoff and deep percolation to groundwater. The gaseous losses of nitrogen (volatilization and denitrification) and nitrogen uptake by algae were the main processes of nitrogen reduction in the ponded water of rice fields. The study showed that the system of a rice field is a natural system where an important amount of influent nitrogen applied by irrigation water can be reduced. These processes decrease the possibilities of water resources contamination.     

Differences in rice water consumption and yield under four irrigation schedules in central Jilin Province,China

The center of Jilin Province is one of the major rice-producing areas of Northeast China; however, rice production consumes large amounts of water, which is incompatible with the increasingly limited water supply. Rice yield and water consumption are the two most important considerations in the rice production process, and they may vary under different irrigation schedules. In this study, conducted in 2011 and 2012, differences in water consumption and rice yield were observed and analyzed under four different irrigation schedules—flooding irrigation (FI), shallow-wet irrigation (SWI), intermittent irrigation (II), and controlled irrigation (CI)—in a typical rice-growing area of central Jilin. The results showed that, under the four irrigation schedules, water consumption rates were (from highest to lowest) FI (1137.9 mm), SWI (984.0 mm), II (804.3 mm), and CI (678.5 mm), and rice yield rates were (from highest to lowest) SWI (9777.5 kg/ha), FI (9006.1 kg/ha), II (8936.3 kg/ha), and CI (8843.7 kg/ha), respectively. This indicated that, in central Jilin Province, the application of an advanced irrigation schedule not only saved a large amount of water for irrigation, but also that rice yields were not greatly reduced, and even increased in SWI. Therefore, we hope that in this and other similar rice cultivation areas, a universal high-yield and water-saving irrigation schedule can effectively reduce the problem of agricultural water use.