Features of the AFFRC model for evaluating the relationship between the water cycle and rice production

This paper introduces the Agriculture, Forestry and Fisheries Research Council of Japan (AFFRC) model, an integrated model that predicts future rice production in the Mekong River basin by taking into account the effect of global warming on both the water cycle and the rice economy. The model focuses especially on the water balance of paddy fields for different farmland water use systems. We defined six categories of irrigated paddies and three categories of rain-fed paddies on the basis of their systems of water usage. We included a process-based model to predict future rice production, accounting for daily changes in available water resources such as precipitation. Many models of crop production treat rice in the same way as other crops; the particular characteristics of rice farming are considered in more detail in our model. Our results show that it is possible to estimate future rice production in the Mekong River basin by taking into account changes in available water, and to model the resultant effects on the grain market.     

Traditional ‘maavee’ rice production in Sri Lanka: environmental,economic and social pressures revealed through stakeholder interviews

The Nilwala Ganga Basin of Sri Lanka includes important natural wetlands that are habitat for vulnerable animal and plant species. Flood protection and intensive rice production in the Basin have resulted in degraded acid soils and declining rice yields. However, traditional ‘maavee’ rice production outside the flood protection scheme has continued to generate a high-value rice product. This study reports on interviews conducted with farmers and other stakeholders to document the production practices and the potential environmental and economic benefits associated with maavee rice paddies. The maavee production system has prevailed for at least several decades. Farmers apply no chemicals to their paddies, relying instead on alluvial deposits as a source of nutrients, and on the natural pest and disease resistance of their traditional varieties. The maavee rice product can attain three times the selling price of rice from conventional farms making it more economically viable than conventional rice production. However, much of maavee production is for home consumption and the system is threatened by increasing labour costs, an ageing farming population and pressures to increase rice yields. Non-invasive production practices and the proximity of maavee paddies to regenerating wetlands in the Kirala Kele Sanctuary suggest that traditional paddies may constitute an important habitat for vulnerable wildlife; however, maavee farmers also perceive wetland birds as potentially damaging to rice. Based on a SWOT (strengths, weaknesses, opportunities and threats) analysis, we make recommendations for future research needs and potential management actions to safeguard the environmental and economic sustainability of the maavee system.     

模拟高温季节稻丛基部小气候条件下白背飞虱的生长发育与繁殖

白背飞虱[Sogatella furcifera (Horváth)]是我国最重要的水稻害虫之一。每年6—8月高温是制约该虫在长江流域发生的重要生态因子。白背飞虱多栖息于稻丛基部,其小气候特征常不同于大气。采用变温变湿、恒温恒湿两种方式,通过分别模拟高温期间(日最高温35℃~39℃)水稻拔节后稻丛基部和大气温湿度条件,研究了高温季节稻丛基部与大气温湿度条件对白背飞虱的生长、发育和繁殖的影响。结果表明,稻丛基部温湿度条件下,白背飞虱的生长、发育和繁殖在变温变湿模拟与恒温恒湿模拟间无显著差异,白背飞虱能正常地完成生长发育和繁殖。与之相比,模拟大气条件下,白背飞虱生长、发育和繁殖相关的多数指标均受到显著抑制,其中较为重要的单雌产卵量,大气变温变湿模拟较稻丛基部变温变湿模拟减少了62.1%。可以认为,夏秋高温期间水稻拔节后稻丛基部田间小气候有利于白背飞虱“躲避”高温天气的不利影响。     

稻—小龙虾—泥鳅绿色高效种养技术要点

稻虾鳅绿色高效种养模式能够提高稻田综合生产能力,实现农业增效及农民增收,是水稻种植和水产养殖结合后农业生态系统重建的典范模式.从田间工程改造、清沟消毒、施用基肥、投放有益生物、水稻品种选择、水稻栽培管理、放养苗种、饵料投喂、日常田间管理、水稻和水产品收获等方面介绍了稻虾鳅种养模式的关键技术.     

Pesticide use in rice and rice–fish farms in the Mekong Delta, Vietnam

Pest management practices among rice and rice–fish farmers and their perception of problems related to pests and pesticides were surveyed in the Mekong Delta. A total number of 64 different pesticides were identified during the survey. Approximately 50% were insecticides, 25% were fungicides and 25% were herbicides. The main insecticides used were pyrethroids (42%) carbamates (23%) and cartap (19%). Non-IPM farmers used twice as many pesticides as IPM farmers. Their application frequency and the amount of active ingredient used were 2–3 times higher per crop, as compared to IPM farmers. During the last three years IPM farmers estimated that they had decreased the amount of pesticides used by approximately 65%, while non-IPM farmers said that they had increased the amount of pesticide used by 40%. Also, farmers growing fish in their rice fields used less pesticide than farmers growing only rice, as pesticides adversely affect cultures of fish. Taking a long-term perspective integrated rice–fish farming with IPM practices provides a sustainable alternative to intensive rice mono-cropping, both from an economic as well as an ecological point of view.     

Digital innovation for promoting knowledge of paddy functions

The purpose of this paper is to launch a new platform for advocating three functions of paddies including economics, society and environment through the cross-field integration of the agricultural hydrology, information technology and children’s picture book, which is novel. We translate literatures of paddy agriculture to popular content. Scientific visualization is applied to develop digital value-added content for enhancing effects according to computer graphics technologies. For developing the Internet channel, we take web-based architecture coupled with Java3D and Flash visualization as the main solution for engaging attention of virtual communities. With a web browser, we present paddy knowledge that is based on the above-mentioned popular content related to three functions of rice paddies. Furthermore, for the general public, the tiled display wall is employed to build up a fixed-site channel. In this paper, the demonstration of promoting interest in paddy fields has been established. Through exploring this digital paddy, not only children could be encouraged to learn, but also the public could accumulate the knowledge related to paddy agriculture.     

Factors impacting yields in rain-fed paddies of the lower Mekong River Basin

The Mekong River Basin (MRB) is the biggest basin in Monsoon Asia. About 80% of the agricultural lands, which occupy about 40% of the basin are rain-fed paddy rice area. Therefore, it is assumed that changes in rain-fed paddy rice production affect the total agricultural production to a great degree in the Mekong River Basin. While there are many factors affecting the productivity of rain-fed paddies, such as climate, water use, rice varieties, applications of manure, fertilizer and agro-chemicals, sowing date and other agronomic practices, this paper focuses on the relation between rainfall and yields of rain-fed paddies. Agricultural statistics and rainfall data were collected and analyzed for all 24 provinces in Cambodia for the years 2001 and 2002. Factors such as soil fertility and other natural conditions were removed by comparing the yield and rainfall in one province for different years. Special attention was given to the relation between yields of paddy in the wet season and rainfall, considering factors such as rice varieties, soil fertility, irrigation ratio and the ratio of area damaged by flood, drought, and insect. Although it is not easy to assess those impact factors on yields because they are organically interactive, the following results were obtained: (1) The ratio of high yielding varieties (HYV), soil fertility, and irrigation ratio among many factors that affect yields individually, especially if they are combined, (2) Total rainfall did not have a significant influence on rice yields even for the rain-fed paddies if it was over 700 mm in wet season, and one of the reasons for this would be that there exist supplementary water uses through small ponds and water ponding in local land depressions in and around paddies.     

Both environmental factors and countermeasures affect wild boar damage to rice paddies in Boso Peninsula, Japan

Populations of wild boar (Sus scrofa Linnaeus, 1758) and reports of crop damage by them have increased in Japan. In considering strategies for damage control, it is necessary to quantify both the environmental factors and the countermeasures affecting damage. We surveyed damage by wild boar in 1540 rice paddies on the Boso Peninsula. We obtained environmental factors by GIS: distance from forest edges, rivers and settlements; overground openness; and human population density. We recorded the weeding and fencing practices as countermeasures. We constructed cumulative logit models using Bayesian inference to predict damage and assessed the importance of the simultaneous evaluation of environmental factors and countermeasures by deviance information criteria. The best model incorporated both environmental factors and countermeasures, indicating that both are important for predicting damage. It showed that weeding around rice paddies, electric fencing and corrugated iron fencing were effective at reducing damage by wild boar. The risk of damage increased with lower values of distance from forest edges and rivers, overground openness, and human population density, and with higher values of distance from roads. These environmental factors allowed us to identify high-risk cropland where countermeasures could be introduced to reduce damage.     

Sustainable Management of Rice Insect Pests by Non-Chemical-Insecticide Technologies in China

Chemical pesticides play crucial roles in the management of crop diseases and pests. However, excessive and irrational use of pesticides has become a major concern and obstacle to sustainable agriculture. As a result, the quality and security of agricultural products are reduced, and the ecological and environmental integrities are threatened. Recently, environment-friendly pest management measures have been introduced and adopted to manage rice insect pests and reduce the use of insecticides. This paper reviewed the advancements in development and application of non-chemical technologies for insect pest management during rice production in China.     

Risk analysis of pesticides applied to rice paddies using RICEWQ 1.6.2v and RIVWQ 2.02

Rice is commonly cultivated in Southern Europe in large river basins where the extensive use of herbicides may impact water quality at basin scale level. Consequently, pesticide risk assessment would be more relevant when considering a rice cultivation area as a whole. Accordingly, two watershed-scale scenarios were developed to represent the specific agronomic, water and pesticide management practices of rice cultivation in Greece. These scenarios were utilized for the parameterization of the rice water quality model (RICEWQ) 1.6.2v and the surface water model river water quality (RIVWQ) 2.02. in order to predict the environmental concentrations of pesticides in groundwater (GW) and surface water (SW) systems within a rice area. The annual average pesticide concentrations at 1 m depth, predicted by RICEWQ were used to assess the risk for GW contamination. The predicted exposure concentrations derived through modelling and eco-toxicological endpoints obtained from the literature, were used to calculate acute and long-term toxicity exposure ratios (TERs) for aquatic organisms. Application of these scenarios with RICEWQ and RIVWQ models enabled us to perform a risk assessment exercise for several herbicides registered in Greece for use in rice. Such a risk assessment approach could be further scaled up to represent a whole rice cultivated basin in order to be used for regulatory purposes.     

Potential conflicts for the reuse of rice husk in Thailand

This study aims to investigate the impact of rice-husk power generation on agricultural uses of rice husk and its ash. We conducted case studies at a rice-husk power plant and organic farming groups in northeast Thailand. The case study on a rice-husk power plant showed that rice husk was useful in generating electricity without consuming fossil fuel, while husk ash, the by-product, could be utilized as silicate supplement for farmland soils. The case study on organic farming groups indicated that rice husk was one of the indispensable materials in conducting organic farming with locally available resources. On the basis of these findings, an analytical study on possible husk uses in Thailand was conducted, in which three potential major uses of rice husk were considered: i.e. (1) fuel use inside rice mills followed by husk-ash reuse, (2) fuel use at power plants followed by husk-ash reuse, and (3) direct reuse of husk for compost production. The result indicated that there would be conflicting demands for rice husk among those uses in the future. Therefore, there needs to be a strategy for balancing husk uses among them.     

An index for evaluating the flood-prevention function of paddies

Urbanization is expanding in and around small to medium-sized cities as well as in large cities, and the expansion includes low-lying areas where the flood risk is high. Flood risk in small watersheds has been evaluated using precise mathematical models. However, these models cannot be applied to larger basins due to the complexity of data collection and analysis. As a result, quantitative evaluations of flood risk at macro scales and the flood-prevention function of paddies around urban areas have not been made. This paper proposes a method and an index that can be used to evaluate the flood-prevention function of paddies on a regional scale. In addition, the use of this system for basin-wide management is illustrated by an example for the Kinu and Kokai rivers, which are tributaries of the Tone River of Japan. The applicability of the approach is evaluated using data from a major flood that occurred in the study area.     

Effects of trees planted on levees on rice yields in rain-fed paddy fields of northeast Thailand

Trees are increasingly being planted on the levees of paddy fields of rice (Oryza sativa L.) in northeast Thailand. We investigated and compared the yields of rice grown in rain-fed paddies under and far from canopies of three different tree species: eucalyptus (Eucalyptus spp.), mango (Mangifera indica L.), and the indigenous neem tree (Azadirachta indica A. Juss). Rice yields tended to decrease near trees of all types at five sites, but there was no change in yields at the remaining 11 sites during the 3-year study. The reduced yields likely resulted from lower aboveground biomass, leading to fewer rice panicles and spikelets, particularly near trees with a dense canopy. Extremely low yields were observed near eucalyptus in paddy fields suffering from severe drought. These results, as well as information provided by farmers’, suggest that eucalyptus trees may have detrimental effects on rice and should not be planted on the levees of paddy fields with relatively low productivity.     

Chlorantraniliprole application differentially affects adult emergence of Sympetrum dragonflies in rice paddy fields

Paddy and Water Environment - Rice paddy fields are important habitat for many dragonfly species. In Japan, populations of dragonflies inhabiting rice paddies, in particular Sympetrum (Odonata:...     

UPLC-MS/MS法测定水稻中噁唑酰草胺和氰氟草酯及其代谢物的残留及膳食风险评估

建立了使用分散固相萃取的QuEChERS前处理方法,并通过超高效液相色谱串联质谱（Ultra Performance Liquid Chromatography Tandem Mass Spectrometry,UPLC-MS/MS）对糙米、稻壳和秸秆样品中的噁唑酰草胺和氰氟草酯及其代谢物成功进行了定量测定。结果表明,水稻于2叶1心期施药1次,收获后测定稻谷和糙米中噁唑酰草胺、氰氟草酯及其代谢产物的残留量,均未被检出。通过将国家估算的每日摄入量与可接受的每日摄入量进行比较,评估了这些农药的风险系数（Risk Quotients,RQ）。膳食风险评估的结果显示,在糙米中的噁唑酰草胺和氰氟草酯的RQ分别为0.87%和1.90%,表明在GAP条件下施用噁唑酰草胺和氰氟草酯对消费者的健康风险较低。     

四种农药及其混合使用对广陵香粳籽粒生长的影响

应用粒籽生长模型研究了稻田常用农药单剂、2种、3种及4种农药混合使用对籽粒生长的影响。方差分析表明各处理强势粒饱和生长量（K）、起始生长势（R0）、旺盛生长期干物质累积量（GT）均无显著差异。多重比较表明杀虫双675 g/hm2和4种农药高剂量处理（井冈霉素150 g/hm2+吡虫啉45 g/hm2+杀虫双675 g/hm2+三环唑300 g/hm2）的GT显著大于吡虫啉22.5 g/hm2处理,但与对照相比无显著差异。总体上3种农药单剂低剂量及其混合物对强势粒影响不大,但对弱势粒K值有极显著的影响。对照的K值大于所有处理,其中以4种农药高剂量混合使用K值最小。吡虫啉22.5 g/hm2处理及4种农药高剂量混合使用的GT显著小于对照。4种农药混合使用,特别是高剂量农药混合使用对弱势粒籽粒增重有显著的负效应。     

人工释放赤眼蜂防治水稻稻纵卷叶螟试验

为减少施用化学农药对环境的污染,保持生态平衡,2011年开展了赤眼蜂防治水稻稻纵卷叶螟应用技术研究。结果显示放蜂试验田防效达77%,取得了较好的防治效果。     

水稻种植中减少农业面源污染的几点建议

长期以来,我国水稻种植的环节中存在着化学肥料和农药过量、盲目施用的情况,造成生产成本的增加,形成了农业面源污染,影响了农业生产生活的生态环境安全和农产品质量安全。简要分析当前我国水稻种植中农药化肥的施用、农膜的使用等方面对农业生产环境和农产品安全造成的影响,提出对策建议,以期改善农业生产生态环境,加强农业管理,提升我国农业农村生态环境和保障农产品质量安全水平,促进农业的可持续发展。     

Prediction of the environmental concentration of pesticide in paddy field and surrounding surface water bodies

Pesticides are very important in European rice production. For appropriate environmental protection, it is useful to predict the potential impact of pesticides after application, in paddy fields, in paddy runoff, and in the surrounding water, by calculating predicted environmental concentrations (PECs). In this paper, a joint simulation is described, coupling a field-scale pesticide fate model (RICEWQ) and a transportation model (RIVWQ) to evaluate the potential for predicting environmental concentrations of pesticides in the paddy field and adjacent surface water bodies and comparing the predicted values with the monitoring data. The results demonstrate that the application of the calibrated field-scale RICEWQ model is a conservative method to predict the PEC at the watershed level, overestimating the observed data; the coupled RICEWQ and RIVWQ models could be adequately used to predict PECs in the surrounding water at watershed level and in the higher tier risk assessment procedure.     

中国杂交稻的"超感虫性"研究概况

介绍了高度感虫的中国杂交稻推广带来水稻害虫生态地位发生的变化.褐飞虱和白背飞虱上升为杂交稻上最突出的极易爆发成灾的重要害虫.20世纪70年代以前,白背飞虱只是水稻上的次要害虫,但80年代以来其种群大大增加.由于它从中国南部杂交稻种植区大范围迁飞,白背飞虱也成为中国中部地区粳稻上的重要害虫.由于种植具有抗褐飞虱基因Bph1的杂交稻组合,褐飞虱种群曾得到暂时的控制.然而,抗虫性的杂交稻在中国中部和南部稻飞虱迁飞区推广以后,褐飞虱生物型发生了改变,对抗虫品种产生了适应性.1990年以后,以前表现抗虫的杂交稻变得高感褐飞虱.缺乏抗虫性主基因不是中国杂交稻对稻飞虱超感性的充分理由,杂交稻旺盛生长的杂种优势可能是稻飞虱生殖力提高的部分原因.中国杂交稻对稻飞虱的超感虫性是从不育系遗传而来的.因此,杂交稻抗虫性的提高有赖于不育系的改良.利用持久抗性和多抗性的IR品种如IR64作为恢复系是改善中国杂交稻的超感虫性的一种有效方法.杂交稻上二化螟和三化螟为害也有所增加.与常规稻相比,杂交稻是一种更有利的食料植物且耐虫性更强.进行水稻产量损失的估计,尤其是水稻本身对螟虫为害的补偿能力,以及螟虫和杂交稻之间的生态学关系的研究有助于评价杂交稻对螟虫田间抗性的实际影响.