Increasing water productivity for paddy irrigation in China

This paper introduces the research on practices to increase water productivity for paddy irrigation in China and summarizes the experience on implementation of the alternate wetting and drying (AWD) irrigation technique. The widespread adoption of the AWD practice on 40% of the rice growing area provides an opportunity for China to produce more food in the water-surplus south where it is wet and the traditional based paddy field agriculture is dominant. Physical and institutional measures leading to increasing water and land productivity in rice-based systems are discussed. Research studies show that AWD practice does not reduce rice yield, but does increase the productivity of water. Water use and thus water charges can be reduced. However, experience shows that demonstrations and training are needed to encourage farmer adoption. Furthermore, there are a range of complementary policies and practices, such as volumetric pricing or farm pond development, which provide incentives for adoption of AWD. Finally, there remain many scientific issues to be addressed. Application of the AWD technique in some regions is still very difficult because of both bio-physical and socio-economic problems. In conclusion, the widespread adoption of AWD is only a first step in the continuing effort to find practices that will increase water productivity for paddy irrigation in China.Dr. Yuanhua Li was a Professor and Dean in Wuhan University of Hydraulic and Electric Engineering from 1996 to 2000. After that, he has been a Professor and Deputy Director General of the National Centre for Irrigation and Drainage Development, Ministry of Water Resources, China. He has been doing research on irrigation principally for paddy since 1982.Dr. Randolph Barker is an agricultural economist and Professor Emeritus Cornell University. From 1966 to 1978 he served as head of the Economics Department, International Rice Research Institute, Los Banos, Philippines and from 1995 to 2004 was principal researcher, International Water Management Institute, Colombo, Sri Lanka.     

21世纪我国节水农业发展趋势及其对策

分析了我国农业用水现状及其发展要求，提出了２１世纪初可能产生突破的几项关键节水技术，分析了农业高效节水技术将对我国２１世纪农业发展可能产生的贡献，最后论述了未来我国在发展节水农业中应采取的一些对策。     

节水农业生产分区技术优化配套的研究

水资源紧缺巳成为全球突出问题之一,国内外对研究节水灌溉都给予高度的重视,但大多数都是从单项内容进行研究,如节水灌溉技术、充分利用雨水、保水农业栽培措施等都取得了一定成效和生产效益。我们认为:节水农业就是充分利用降水和当地水资源,水利措施与农业措施紧密结合以提高水的利用率和水的利用效率。也就是灌溉农业和旱地农业相结合。针对不同的农业生产类型区采取不同的技术措施,从而得出不同的农、水措施优化体系,在中国农科院商丘666.7ha(万亩)节水农业试验区进行了四年的试验与推广,取得了综合节水6％、增产8％的效益。对指导缺水地区生产和宏观控制水、土资源合理开发利用具有现实的意义。     

宁夏土地开发整理应发展的节水灌溉技术

根据宁夏不同灌区水资源及作物种植条件,分析总结出在土地开发整理中应发展的5种节水灌溉技术.这些技术模式在生产中已取得了较好的应用效果,并将在实践中进一步提高和完善,对土地开发整理中应用节水灌溉技术有着重要的技术指导作用.     

Growth and Yield of Six Rice Cultivars under Three Water-saving Cultivations

Abstract

We evaluated the genotypic differences in growth, grain yield, and water productivity of six rice (Oryza sativa L.) cultivars from different agricultural ecotypes under four cultivation conditions: continuously flooded paddy (CF), alternate wetting and drying system (AWD) in paddy field, and aerobic rice systems in which irrigation water was applied when soil moisture tension at 15 cm depth reached ?15 kPa (A15) and ?30 kPa (A30). In three of the sixcultivars, we also measured bleeding rate and predawn leaf water potential (LWP) to determine root activity and plant water status. Soil water potential (SWP) in the root zone averaged ?1.3 kPa at 15 cm in AWD, -5.5 and -6.6 kPa at 15 and 35 cm, respectively, in A15, and ?9.1 and ?7.6 kPa at 15 and 35 cm, respectively, in A30. The improved lowland cultivar, Nipponbare gave the highest yield in CF and AWD. The improved upland cultivar, UPLRi-7, and the traditional upland cultivar, Sensho gave the highest yield in A15 and A30, respectively. The yields of traditional upland cultivars,Sensho and Beodien in A30 were not lower than the yields in CF. However, the yields of the improved lowland cultivars, Koshihikari and Nipponbare, were markedly lower in A15 and A30. Total water input was 2145 mm in CF, 1706 mm in AWD, 804 mm in A15, and 627 mm in A30. The water productivity of upland rice cultivars in aerobic plots was 2.2 to 3.6 times higher than that in CF, while those of lowland cultivars in aerobic plots were lower than those in CF. The bleeding rate of Koshihikari was lower in A15 and A30 than in CF and AWD, and its LWP was significantly lower in A15 and A30 than in CF and AWD, but Sensho and Beodien showed no differences among the four cultivation conditions. We conclude that aerobic rice systems are promising technologies for farmers who lack access to enough water to grow flooded lowland rice. However, lowland cultivars showed severe growth and yield reductions under aerobic soil conditions. This might result from poor root systems and poor root function, which limits water absorption and thus decreases LWP. More research on the morphological and physiological traits under aerobic rice systems is needed.     

辽宁稻区渠道防渗技术科技成果转化研究

以渠道防渗技术为例,在辽宁稻区通过对其节水科技成果应用的调查分析,进一步整理出辽宁节水农业管理体系的建立。应用统计学研究方法,比较渠道防渗技术科技成果应用前后对辽宁稻区农业节水及产量的变化,分析节水农业应用的价值和潜力。渠道防渗技术的应用为辽宁稻区节水农业科技成果转化的管理提供了新的思路,为整个节水农业科技成果转化管理体系的建立打下了坚实的基础。     

基于CROPWAT-DSSAT关中地区冬小麦需水规律及灌溉制度研究

明确关中地区作物需水规律可为合理制定灌溉制度提供理论前提,从而为合理开发和高效利用农业水资源提供帮助。该文基于CROPWAT-DSSAT模型模拟分析了关中地区近30年来冬小麦生长季期间的有效降水量、作物需水量等季节变化特征,并模拟不同降水年型不同灌溉制度下作物产量的变化趋势,分析了多次灌水对产量及经济效益的影响,以确定不同降水年型下的最优灌溉方案。结果表明:关中地区冬小麦生长季期间有效降水量不足其需水量的50%,不同降水年型的季节特征有所不同,总体表现为越冬及返青拔节期缺水较为严重。冬小麦生长期间,越冬水、返青水、拔节水及灌浆水4水中以返青水最为关键,其次为拔节水,灌浆水对产量的贡献作用最小;丰水年、平水年、枯水年冬小麦最佳灌溉定额分别为75 mm、125 mm及150 mm;枯水年需在越冬期、返青期和拔节期分别灌水25 mm、75 mm和50 mm,此时冬小麦产量和经济收益均最高;平水年需在越冬期、返青期、拔节期分别灌水50 mm、50 mm和25 mm,此时冬小麦产量最高,越冬水灌溉量减半后经济效益最高;丰水年则需在越冬期、返青期和拔节期均灌溉25 mm为宜,此时冬小麦产量和经济效益均最高。     

水稻节水控制灌溉技术研究

几年来,通过对水稻节水控制灌溉技术的试验研究,探讨在控制灌溉基础上寻求确保水稻高产、提优的水稻生产新途径。试验证明:控灌区比常规灌溉区平均增产7.8%,节灌区比常规灌溉区平均增产5.5%,水稻节水控制灌溉对水稻生长发育、抗倒伏、抗病、提高产量和品质起到了重要作用,应大面积推广应用。     

宁夏引黄灌区畦种膜上灌水下水肥耦合对玉米生长发育和产量的影响

[目的]针对宁夏引黄灌区灌溉水资源日益缺乏与作物需水矛盾的问题,研究玉米节水灌溉最佳灌水定额与最佳肥料种类配比。[方法]采用畦种膜上灌溉,肥料用常规肥、玉米配方肥和玉米专用肥,灌溉定额为600、750、900m^3／hm^2,研究不同处理对玉米生物性状及产量的影响。[结果]施用配方肥条件下,玉米株高、叶面积、干物质和产量均高于施用专用肥和常规肥,且差异显著;灌水量为900m^3／hm^2时玉米的生物性状及产量均高于600、750m^3／hm^2灌水量处理,但灌水定额间无显著差异。[结论]玉米畦种膜上节水灌溉最佳肥水组合为玉米配方肥＋600m^/hm^3灌水量,该结果可为宁夏灌区玉米节水生产提供合理灌溉与施肥依据。     

不同栽培方式下节水抗旱稻“旱优3号”的产量及经济效益分析

为推广节水抗旱稻以提高水稻的水分利用效率,2008-2009年在上海市奉贤区庄行镇对节水抗旱稻旱优3号进行5种栽培方式的试验,并对其产量和经济效益进行了分析。结果表明:机插秧栽培方式产量最高;免耕栽培方式经济效益最好,并能改善土壤理化性质;传统栽培方式生产投入最大,收益最低。