Impacts of climate change on rice market and production capacity in the Lower Mekong Basin

The supply of water is affected by climate changes. In addition, high economic growth in the lower Mekong River countries including two large rice exporters is expected to reduce the per capita consumption of rice as incomes grow. Consequently, the need exist to investigate changes in supply and demand using econometric models of rice markets in the countries, where water supplies are expected to change. The objective of this research is to clarify impacts of water supply changes on rice producers and consumers using supply and demand models of rice considering changes in the water supply to aid in producing agricultural policies and plans. The following two simulations were conducted in this assessment: (a) baseline and (b) CC_B2. The simulation of the baseline includes the assumption that the evapotranspiration (ET) of each province after 2000 is the average quantity of ET from 1995 to 1999. The simulation of the CC_B2 includes the assumptions that ET of each province after 2010 accords with the IPCC socioeconomic scenario B2. The simulation results suggest that climate change will depress wet season rice production in Cambodia and Mekong River Delta (MRD) region in Vietnam, and that of dry season rice in the MRD region in Vietnam and northeastern region (Isan) Thailand. The simulation results also indicate that climate change will increase farm prices of rice in Cambodia, Vietnam, and Thailand. The results suggest that climate changes will weigh on the livelihood of rice consumers, especially those of poor rural populations.

     

Impacts of climate change on rice market and production capacity in the Lower Mekong Basin

The supply of water is affected by climate changes. In addition, high economic growth in the lower Mekong River countries including two large rice exporters is expected to reduce the per capita consumption of rice as incomes grow. Consequently, the need exist to investigate changes in supply and demand using econometric models of rice markets in the countries, where water supplies are expected to change. The objective of this research is to clarify impacts of water supply changes on rice producers and consumers using supply and demand models of rice considering changes in the water supply to aid in producing agricultural policies and plans. The following two simulations were conducted in this assessment: (a) baseline and (b) CC_B2. The simulation of the baseline includes the assumption that the evapotranspiration (ET) of each province after 2000 is the average quantity of ET from 1995 to 1999. The simulation of the CC_B2 includes the assumptions that ET of each province after 2010 accords with the IPCC socioeconomic scenario B2. The simulation results suggest that climate change will depress wet season rice production in Cambodia and Mekong River Delta (MRD) region in Vietnam, and that of dry season rice in the MRD region in Vietnam and northeastern region (Isan) Thailand. The simulation results also indicate that climate change will increase farm prices of rice in Cambodia, Vietnam, and Thailand. The results suggest that climate changes will weigh on the livelihood of rice consumers, especially those of poor rural populations.     

2009年中国稻米市场分析及2010年展望

以翔实的资料对2009年中国稻米生产、消费、进出口、供求平衡、库存、价格走势、购销政策和国际稻米供求等情况进行了全面地分析,对影响2010年稻米市场价格走势的各种因素进行了深入研究,并在此基础上对2010年我国稻米市场价格走势进行了预测,结论是我国稻米价格仍呈上行趋势。     

Identification of Nutrients Limiting Rice Growth in Soils of Northeast Thailand under Water-Limiting and Non-Limiting Conditions

Summary

Glasshouse nutrient omission trials are useful in identifying nutrient limitations for plant growth in soils under the same environmental conditions. Soils of low fertility are commonly used for production of rainfed lowland rice (Oryza sativa L.), and the crop often encounters water stress. Nutrient requirements may be modified when standing water disappears from the field. Two experiments with rice seedlings were conducted in a glasshouse at Ubon Rice Research Center, Thailand, to identify the nutrients which limit rice growth in soils of Northeast Thailand, and to determine whether nutrient limitations are affected by water availability. In Experiment 1, rice was grown on two soils (Roi et and Ubon series) under well-watered and water-limiting conditions, and 15 nutrient treatments were imposed. In Experiment 2, six soils from Northeast Thailand were examined using the same 15 nutrient treatments. The nutrients which clearly limited the growth of rice plants in soils of Northeast Thailand were nitrogen (N) and phosphorus (P). In some cases, potassium (K) and sulfur (S) also limited growth, and in one soil zinc (Zn) and boron (B) also limited growth. A shortage of N was the most important limitation for plant growth in all soils except one in which P was more important. The low supply of P decreased plant height and leaf area development during early growth ; low N supply had a greater effect later during growth. The omission of P had a larger detrimental effect on growth when water supply was limited. In the Roi et soil, the omission of S had a large effect on leaf area and total dry matter production only under water stress conditions, but this was not found in the other soils examined. These results from glasshouse studies show that the nutrients limiting rice growth depend on soil type and water availability in soils of Northeast Thailand.     

2012年中国稻米市场分析及2013年展望

2012年,我国稻谷供给量和需求量进一步增长,总量和各品种均供需平衡有余;在政策与供求等因素的共同作用下,全年稻米价格呈现出先涨后落的走势,年末稻谷收购价格低迷。展望2013年国内稻米市场,由于上年稻谷继续丰收,产需平衡结余较多,供给压力加大,但在稻谷最低收购价上调的作用下,稻米市场价格仍有上升动力,价格涨跌空间都有限,总体上呈稳中有升态势。     

江苏水稻生产现状和新形势下绿色可持续发展的技术对策

水稻是江苏省第一大粮食作物,也是最主要的口粮作物。新形势下江苏水稻生产出现增产不增收、资源过度消耗、生态环境受损、供给矛盾凸显等一些新问题、新情况,严重影响水稻绿色可持续发展。本文按照"提质增效转方式、稳粮增收可持续"的思路方向与"藏粮于技"的战略要求,总结阐述了江苏水稻生产现状,分析指出了生产上存在的主要问题,研究提出了绿色可持续发展的技术对策,以促进水稻产能稳定、产出高效、产品安全,实现绿色可持续发展。     

浅谈稻米行业发展趋势

稻米行业中稻谷总产连年增加,常规籼稻供大于求,粳稻供需仍存缺口,北方优质稻谷货源、质量稳定。稻米市场方面,常规籼稻市场平静,优质稻谷稳步上扬;消费市场出现分化,国有民营平分天下;国内需求疲软,微利时代到来。稻谷生产要适应WTO、供求关系、生态环境与可持续发展原则,根据市场需求生产。     

我国稻米价格的历史变化及影响与今后调控对策的探讨

本文分五个时期概述了建国以来我国稻米价格体系发展的历程,对影响较大的三次稻米价格变动事件进行了概述和研究,并分析了导致稻米价格上涨的主要原因,包括供求关系和货币影响等;对近期国内外稻米价格变化亦进行了比较分析,指出近期可能出现的变化趋势;最后探讨了今后国内稻米价格的调控政策。     

Crop and water productivity as influenced by rice cultivation methods under organic and inorganic sources of nutrient supply

A field experiment was conducted during the wet seasons of 2010 and 2011 at New Delhi, India to study the influence of organic, inorganic, and integrated sources of nutrient supply under three methods of rice cultivation on rice yield and water productivity. The experiments were laid out in FRBD with nine treatment combinations. Treatment combinations included three sources of nutrient supply viz., organic, integrated nutrient management, and inorganic nutrition and three rice production systems viz., conventional transplanting, system of rice intensification (SRI) and aerobic rice system. Results indicated that the conventional and SRI showed at par grain and straw yields but their yields were significantly higher than aerobic rice. Grain yield under organic, inorganic and integrated sources of nutrient supply was at par since the base nutrient dose was same. Plant growth parameters like plant height, tillers, and dry matter accumulation at harvest stage were almost same under conventional and SRI but superior than aerobic rice system. Root knot nematode infestation was significantly higher in aerobic rice as compared to SRI and conventional rice. However, organic, inorganic and integrated sources of nutrient supply did not affect nematode infestation. There was significant advantage in term of water productivity under SRI over conventional transplanted (CT) rice and less quantity of water was utilized in SRI for production of each unit of grain. A water saving of 34.5–36.0 % in SRI and 28.9–32.1 % in aerobic rice was recorded as compared to CT rice.     

2010年中国稻米市场形势分析及2011年展望

2010年我国稻谷供给总体增加,粳稻供给略有减少;稻米消费基本稳定,粳米消费增长较快;稻谷整体上供大于需,但粳稻供给紧张的矛盾比较突出;稻米价格全面上升,粳稻米价格涨幅较大;国家调控措施出台较多,政策对稻米市场走势产生了较大影响。展望2011年稻米市场,稻谷整体上仍然产大于消,由于粳稻增产较多,粳稻米供给紧张的矛盾将有所缓和,但"稻强米弱"和"粳紧籼多"的矛盾仍会存在;影响稻米市场价格上升和下跌的因素都有,形势较往年复杂,相互作用的结果将使全年价格整体呈小幅上升走势,国家政策调控仍将成为影响全年稻米市场价格走势的重要因素。     

Simulation model of rainfed rice production on sloping land in northeast Thailand

In northeast Thailand, the rapid expansion of rainfed paddy fields has decreased the stability of rice production. This paper describes a model that computes rice production on the basis of the hydrologic conditions of rainfed paddy fields on hill slopes. The model well expressed the hydrologic processes, rice yield, and production at the study site. We simulated rice production as uphill paddy plots are abandoned, increasing catchment area, under various rainfall conditions. The simulation showed that rice yield and stability increase as uphill plots are abandoned, although the total rice production decreases. Thus, the effect of catchment size on rice production in each plot was quantified. The model proved to be useful for analyzing rainfed rice production under various land and water conditions.     

冬季轮茬作物养分还田特征及其对水稻产量和稻田水环境的影响

采用大田小区试验研究了不同冬季轮茬种植模式下作物养分还田特征,及其对水稻产量和稻田表水环境主要参数的影响,并对各轮茬种植模式下的经济效益进行了分析。结果表明,不同冬季轮茬作物产量差异较大,且其养分含量差异亦较大,导致各轮茬种植模式下养分还田量差异显著。“红花草-水稻”模式下,N、P素还田量均最高。从短期效应来看,冬季作物轮茬对后茬水稻株高、产量及肥料利用率的影响均不显著。然而,从环境效应角度考量,不管何种轮茬种植模式,均应充分考虑水稻季基肥到分蘖肥期间的稻田水环境效应,监测发现,稻田表水总磷（TP）、可溶性总磷（DP）平均含量几乎都超过了易引发水体富营养化的临界水平（溶解磷0.05 mg/L和总磷0.1 mg/L）。同时,从周年经济效益角度考量,“青饲小麦-水稻”和“蚕豆-水稻”种植模式具有较高收益,可进一步推广应用。     

重庆马铃薯产业经济调研情况分析与建议

在调研重庆马铃薯概况、加工情况、批发市场、产地价及均价、销售量、农户信息(包括总耕地面积、马铃薯栽培面积、生产类型、栽培品种、家庭年消费量、技术需求)等指标的基础上,对种植马铃薯的收益、物质与服务费用、人工成本等情况进行了分析,认为重庆马铃薯产业呈现面积单产齐增加的局面,但加工业发展水平滞后,商品薯产地价和批发价较低,农户种植马铃薯纯收益较低,应从5个方面进行建设,促进重庆马铃薯产业的健康发展。     

Growth Responses of Drought Resistant Rice Cultivars to Soil Compaction under Irrigated and Succeeding Non-irrigated Conditions during the Vegetative Stage

Abstract

We investigated whether drought resistant rice cultivars exhibit higher dry-matter production under wet and dry compacted soil conditions in the vegetative stage and determined the dominant factors governing resistance to soil compaction. Three rice cultivars, a drought-sensitive Nipponbare, and drought-resistant Senshou and Dular, were grown in pots at four soil bulk densities (SBD) ranging from 1300 to 1600 dry soil kg m^?3. Root and shoot dry matter productions was slightly smaller in Nipponbare over the 29 days after sowing under irrigated conditions than in the other cultivars at all SBDs. Senshou and Dular also maintained a higher dry matter production, both in relative and absolute values, than Nipponbare under the condition of withheld irrigation from days 29 — 39 after sowing. The higher stomatal conductance and leaf water potential of these two cultivars were supported by a larger root system which was mostly accompanied by lower top-root ratios in the irrigated and compacted soils. The higher plant growth rate under the non-irrigated condition might have been a result of both the higher water absorption rate and water use efficiency, which in turn were supported by the larger root biomass. We conclude that the ability of rice to rapidly develop a root system in the early vegetative phase under compacted soils facilitates plant production under subsequent soil desiccated conditions.     

稻鳖共作模式中的土壤养分动态变化及产量形成

为探明稻鳖共作模式中的土壤养分变化及产量形成规律,选取湖南地区常用的两个水稻品种黄华占(H)及Y两优800(Y),设置稻鳖共作模式(T)及常规单作模式(N),以头季稻+再生稻(R)两季种植的方式,通过定时测定土壤中的养分含量变化情况及产量,进行了对比试验.结果表明:T模式中全氮、全磷含量呈"峰"型变化,N模式全程为缓慢下降趋势,相对平均差值为全氮15.3%、全磷16.35%;碱解氮、有效磷及有机质等指标在不同模式间变化趋势相似,相对平均差值为碱解氮5.3%、有效磷6.97%;T模式中有机质含量长期保持较高水平,相对平均差值为6.7%.T模式头季稻平均增产9.75%,再生稻平均增产10.05%.     

地理信息系统技术在水稻产量时空变化研究中的应用

将地理信息系统引入浙江省的水稻产量的时空分布特征研究,它能定量、直观地表达水稻产量空间变化。1987年与1977年相比,浙江省有87％的县市增产;而1997年与1987年相比,有76％的县市减产,而且减产幅度大。1977～1987年水稻总产增加以单产为主要驱动力,而1987～1997水稻总产减少以面积为主要驱动力。近十年来水稻总产呈下降趋势,未来浙江省水稻面积将进一步减少,总产也随之减少。浙江省水稻单产和趋势产量呈上升趋势,气象产量的年际变化呈剧烈波动特征,水稻播种面积变化呈抛物线型。在单产的年际变化中,技术水平和社会因素对水稻、 早稻及早中稻、 晚稻及迟中稻的影响不足30％,气象条件的影响70％以上,即在水稻单产的年际变化中,气象因素的影响比技术水平和社会因素都要大。     

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.     

Climate change impacts on agriculture and irrigation in the Lower Mekong Basin

According to hydrological simulations by the Mekong River Commission, average annual flow of the Mekong will not change significantly despite climate change. However, they projected increased variability in wet and dry season flows, which will tend to increase the flood and drought risks to crops. To learn the implications of climate change for rice farming in the Lower Mekong Basin (LMB), a lower part of the Basin from China-Lao PDR border to the South China Sea, climate and hydrological figures related to rice production were compared in between the baseline in 1985–2000 and the climate change scenario in 2010–2050. Special attention was given to their 10 and 90 % exceedance values, which are rough equivalence of 10 and 90 % cumulative probabilities, to see changes in the frequency and extent of extreme weather events. Major findings of this study include the followings: (1) evapo-transpirations will increase in both average and 90 % cumulative probability values, raising irrigation demand. (2) Deviation of the annual rainfall will become larger, causing water shortage in reservoirs more frequently in the future. (3) The transplanting date of rain-fed rice will be delayed more likely due to insufficient precipitation in the early wet season, which may result in decreasing rice production. (4) Longer dry spells will be observed during the wet season, raising the drought risk to rain-fed rice. (5) These changes will be generally observed across the LMB, while the extent of the changes varies among regions.

     

Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity

References

Genetic improvement in water uptake ability and/or water use efficiency (WUE) of rice cultivars is one option to enhance productivity under water-limited conditions. We examined the genotypic variation in biomass production among 70 rice cultivars (69 cultivars of NIAS global rice core collection and Azucena) under different soil moisture conditions, and to identify whether water uptake ability or WUE is responsible for the variation, if any. Two-week-old seedlings were transplanted into pots and grown for three weeks in an environmentally-regulated growth chamber under three soil moisture regimes: flooded (?0.02 MPa soil water potential) and two unflooded (?0.10 and ?0.52 MPa) conditions. Substantial genotypic variations in total dry weight (TDW) were observed under all three regimes. Among all the cultivars tested, TDW was significantly correlated with water uptake ability, but not with WUE. However, several cultivars exhibited comparably higher WUE while showing superior biomass production under the ?0.52 MPa regime. The amount of water uptake was significantly correlated with root dry weight among cultivars regardless of moisture regimes, while substantial genotypic difference in the amount of water uptake per unit root dry weight was observed. These results indicate that a marked genotypic difference exists in biomass production at the early vegetative growth under water-deficient conditions, and that this difference appears to be ascribed primarily to greater water uptake capacity, and additionally to higher WUE in drought-tolerant cultivars.     

Climate change impacts on agriculture and irrigation in the Lower Mekong Basin

According to hydrological simulations by the Mekong River Commission, average annual flow of the Mekong will not change significantly despite climate change. However, they projected increased variability in wet and dry season flows, which will tend to increase the flood and drought risks to crops. To learn the implications of climate change for rice farming in the Lower Mekong Basin (LMB), a lower part of the Basin from China-Lao PDR border to the South China Sea, climate and hydrological figures related to rice production were compared in between the baseline in 1985–2000 and the climate change scenario in 2010–2050. Special attention was given to their 10 and 90 % exceedance values, which are rough equivalence of 10 and 90 % cumulative probabilities, to see changes in the frequency and extent of extreme weather events. Major findings of this study include the followings: (1) evapo-transpirations will increase in both average and 90 % cumulative probability values, raising irrigation demand. (2) Deviation of the annual rainfall will become larger, causing water shortage in reservoirs more frequently in the future. (3) The transplanting date of rain-fed rice will be delayed more likely due to insufficient precipitation in the early wet season, which may result in decreasing rice production. (4) Longer dry spells will be observed during the wet season, raising the drought risk to rain-fed rice. (5) These changes will be generally observed across the LMB, while the extent of the changes varies among regions.