水稻节水灌溉与雨水利用

通过对降水、调水、弃水以及水稻节水灌溉的分析，论述了充分利用降雨的可行性和重要性，并通过水稻“浅、湿、控”节水灌溉技术试验推广，结合普通淹灌的对比试验，揭示出水稻节水灌溉是充分利用雨水资源，发展节水农业的一条重要途径，对类似地区的节水农业具有重要的参考价值。     

作物产量与全生育期总腾发量之关系的研究

分析了作物产量与全生育期总腾发量之间线性关系产生的原因及其适用条件，给出了基于常规试验数据求解非线性关系的方法，为节水灌溉条件下的最优水管理提供了依据，并进行了实例分析计算。     

基于气温预报的参考作物腾发量预报方法比较

为探索精确预报未来短期ET0的方法,比较了4种基于气温预报ET0预报模型,即Hargreaves-Samani(HS)、Thornthwaite(TH)、简化的Penman-Monteith(PT)及McCloud(MC)模型。收集了西藏林芝站2001年1月1日至2013年12月31日的实测逐日气象数据和2012年6月6日至2013年12月31日逐日对未来7d的气象预报数据,在气温预报精度评价的基础上,采用4种基于温度的参考腾发量计算模型直接进行ET0预报,然后采用率定后的模型进行ET0预报,最后与实测气象数据和FAO-56PM公式计算的ET0值进行比较。结果表明,未率定的4种模型预报误差均较大,其中PT公式精度稍高。经率定后,4种公式的预报精度都有所提高,平均准确率为70%,MAE值HS模型最小,平均为0.57mm/d,其他3个模型为1.27~1.50mm/d;RMSE都在2.0mm/d左右;r值总体仍不高,TH模型平均仅有0.19,其他3种模型在0.6左右。综合来看,PT模型的预报效果稳定性优于其他3个模型。对于林芝地区附近的灌区,无论有无气象观测数据供模型率定,建议采用PT模型进行ET0预报。     

基于气温预报和HS公式的参考作物腾发量预报

为探索精确预报未来短期参考作物腾发量ET0的方法,提出基于气温预报和HargreavesSamani(HS)公式进行ET0预报.收集了南京站2001—2011年逐日气象观测数据和2011年预见期为4 d的逐日天气预报数据,采用FAO-56Penman-Monteith公式计算逐日ET0,用2001—2010年计算的ET0率定HS公式参数;用率定后的公式和2011年的天气预报气温数据进行未来4 d的ET0预报;比较2011年ET0的计算值与预报值、气温观测值与预报值以评价ET0预报精度及误差原因.结果表明:最低气温预报准确率达81.9%,最高气温预报准确率为80.1%;经过参数校正后,HS公式精度较高.ET0预报准确率为85.7%,平均绝对误差为1.01 mm/d,均方根误差为1.42 mm/d,相关系数为0.74;各项预报误差随着预见期的增大而增大.产生误差的主要原因为气温预报误差和HS公式未考虑平均风速和相对湿度的影响.总体而言,基于气温预报和HS公式的ET0预报方法精度较高,可为灌溉预报及决策提供较为准确的ET0预报数据.     

北方农业雨水利用实践与发展前景展望

分析了北方雨水利用的现状,对国内雨水利用技术理论和实践以及国外较成功的经验作了详细的介绍。对雨水的自然利用和集雨农业中的降雨集流技术、雨水贮存净化技术、高效利用技术进行了概述。在北方地区进行集雨灌溉,合理发展集雨农业,既可以缓解灌溉水源紧张的局面,提高农业生产力,又可以减少雨水对土壤的侵蚀和水土流失,有助于北方农业可持续发展,具有广阔的发展前景。     

作物组合种植的需水量研究

对３０余种间作套种组合种植作物的耗水量、产量、产值及其根区土壤含水量进行了分析研究。结果表明：①作物组合种植具有明显的节水增产增收效果;②作物组合种植条件下,处于雨季后期的作物生长,达到了对光、热、水资源的同步利用,明显的提高了雨水资源的利用率。同时分析得出了作物组合种植形式需水规律的特点。     

基于气温预报和神经网络的参考作物腾发量预报

采用反向传播人工神经网络(BP-ANN)逼近气象因子-参考作物腾发量ET0函数关系,以天气预报中的最高和最低气温为输入进行短期ET0预报。收集了南京站实测的2010年7月1日至2013年7月7日逐日气象数据和2012年7月1日至2013年6月30日逐日对未来7d的气象预报数据,以最高、最低气温及相应的日序数为3个输入因子,ET0为输出建立一个包含一个隐含层的3层BP网络,以2010年7月1日至2012年6月30日实测气象数据及通过FAO-56PM公式计算的ET0进行网络,以2012年7月1日至2013年6月30日实测气象数据及通过FAO-56PM公式计算的ET0进行网络验证。将2012年7月1日至2013年6月30日逐日对未来7d的气象预报中的最高、最低气温输入训练及验证后的网络,得到2012年7月1日至2013年6月30日逐日对未来7d的ET0预报值,并与FAO-56PM公式计算的ET0值进行比较以验证预报精度。结果表明,预见期1~7d内,预报的ET0和计算的ET0变化趋势基本一致,预报精度随着预见期的增加而降低;平均准确率(±1.5mm/d以内)达88.08%,相关系数为0.77,均方根误差为1.28mm/d,显示出了较高的预报精度。在局部时间段内出现的ET0,PM和预报ET0的较大差别的原因是该时段内的ET0更多地受到除了日最高和最低气温之外的其他因素的影响。提出的方法 ET0预报,随着气象预报准确度的提高,可实现较为精确的ET0预报。     

白银市旱作农业雨水利用问题的讨论

干旱与贫困是甘肃省白银市干旱地区突出的两大特征,要改变旱作农业生产条件和农民生活条件,水是最大的制约因素。针对白银市干旱缺水地区农业现状和存在的问题,提出了开发雨水资源对策和推广模式。     

旱作物关键灌水期的确定

为了节约灌溉水量,提高水的利用率,必须科学地确定作物全生长期中的各个关键灌水期。为此,根据作物在不同地区、不同生长阶段的缺水状况和作物因缺水造成的可能欠收幅度调查分析,并考虑缺水敏感期,提出了确定作物关键灌水期的原则和方法。     

Alternative cropping strategies for assured and efficient crop production in upland rainfed rice areas of eastern India based on rainfall analysis

The productivity of rice in rainfed upland soils of eastern India is very low (<1 t/ha) and unstable because of erratic monsoon, moisture deficit during dry spells, light textured with less fertile soils and several biological constraints (weeds, pests and diseases). Keeping the urgent need of augmenting the productivity of vast rainfed upland rice ecosystem of eastern India (4.3 million ha), crop diversification technology was generated through on-farm research trials in representative upland rice soils of eastern India after analyzing agro-climatic (rainfall variability, probability and onset of effective monsoon) and edaphic (soil water retention properties) constraints and prospects. Based on rainfall analysis, direct seeded, low water requiring, rice substituted alternative upland crops namely maize, groundnut, pigeonpea, greengram and blackgram (sole or intercropping) was sown in light textured upland rice soils on 24th meteorological weeks (11–17 June) in 3 years 2000–2002 with two to three summer ploughings during pre-monsoon shower (May). Study revealed that in deficit rainfall years (2000 and 2002), when rice yield was affected adversely in light textured upland, higher rice equivalent yield and rain water use efficiency were obtained from groundnut+pigeonpea intercropping followed by sole groundnut and sole pigeonpea. Study also revealed that productivity of rice substituted crops in the same upland did not fluctuate much between rainfall excess (2001) and rainfall deficit years (2002 and 2000). Double cropping in rainfed upland rice soils was also explored through maize–horsegram/sesamum rotation with increased productivity and rainwater use efficiency. The crop diversification technology was found to be very effective for drought mitigation.     

旱地作物机械化移栽关键技术研究现状与发展趋势#br# #br#

机械化移栽技术的发展对农作物生产全程机械化有重要意义。阐明旱地作物机械化移栽主要环节中的关键技术研究现状和发展动态,包括育苗环节、苗盘输送、夹苗取苗、补苗与栽植等环节。阐明育苗质量及幼苗力学特性对移栽质量有显著影响;夹苗取苗机构作为机械化移栽技术的基础和核心,其主要问题是伤苗率高,效率偏低;指出自动补苗和路径规划是提升机械化移栽智能化水平的关键。阐明现有四类移栽机的装备现状,并对比分析其适用性和特点,重点分析吊杯式和钳夹式移栽机的研究进展,阐明其结构特点及优化设计的途径。强调研究人员应利用现代化技术手段如离散元仿真、虚拟技术、机器视觉等为研究服务;机械化移栽技术的重难点有：农机农艺和农业信息技术融合,增加移栽机型的通用性,利用整排式取苗和多行式移栽技术实现高效移栽;自动移栽技术的发展趋势为移栽机器人技术和无人化移栽作业。     

Estimation irrigation water requirements with derived crop coefficients for upland and paddy crops in ChiaNan Irrigation Association,Taiwan

Field experiments were performed at the HsuehChia Experimental Station from 1993 to 2001 to calculate the reference and actual crop evapotranspiration, derived the crop coefficient, and collected requirements input data for the CROPWAT irrigation management model to estimate the irrigation water requirements of paddy and upland crops at the ChiaNan Irrigation Association, Taiwan. For corn, the estimated crop coefficients were 0.40, 0.78, 0.89 and 0.71 in the initial, crop development, mid-season and late-season stages, respectively. Meanwhile, the estimated crop coefficients for sorghum were 0.44, 0.71, 0.87 and 0.62 in the four stages, respectively. Finally, for soybean, the estimated crop coefficients were 0.45, 0.89, 0.92 and 0.58 in the four stages, respectively. With implementation of REF-ET model and FAO 56 Penman–Monteith method, the annual reference evapotranspiration was 1268 mm for ChiaNan Irrigation Association.In the paddy fields, the irrigation water requirements and deep percolation are 962 and 295 mm, respectively, for the first rice crop, and 1114 and 296 mm for the second rice crop. Regarding the upland crops, the irrigation water requirements for spring and autumn corn are 358 and 273 mm, respectively, compared to 332 and 366 mm for sorghum, and 350 and 264 mm for soybean. For the irrigated scheme with single and double rice cropping patterns in the ChiaNan Irrigation Association, the CROPWAT model simulated results indicate that the annual crop water demands are 507 and 1019 mm, respectively, and the monthly water requirements peaked in October at 126 mm and in January at 192 mm, respectively.     

考虑降雨有效利用的水稻灌溉模式的优化

为充分利用有效降雨挖掘农业节水潜力,以湖北漳河灌区为例,提出一种考虑降雨有效利用的水稻灌溉模式的优化方法,根据长系列历史气象数据对传统淹灌模式进行分阶段优化,改变各生育阶段控制水层深度,寻找最大利用降雨兼顾减少灌水次数的最优水层深度组合并分析节水原因及效果.结果显示,优化后适宜水层下限比优化前低10 mm,降雨后最大蓄...     

雨水集蓄利用技术在广西的实践与认识

1　“九五”广西发展雨水集蓄利用情况简介1.1　发展概况雨水集蓄利用在广西历史较长 ,早在解放前 ,田东、德保一带农民就利用葫芦井解决人畜饮水困难。 70年代在大石山区修建一些大水池 ,但由于缺乏经验 ,选址不当、地下水处理不好及砌筑材料等原因 ,造成不少水池装不了水 ;也有一部分由于管理不善 ,遇到旱季稍长 ,群众饮水仍十分困难。 80年代初在总结了 70年代经验、教训的基础上 ,在凤山县等岩溶地区利用晒坪、屋面集雨建家庭水柜蓄水 ,解决人畜饮水困难取得了成功 ,但由于未及时进行系统的总结研究 ,所以雨水集蓄利用未能得到全面推广…     

两茬收割饲用甜高粱灌溉定额试验研究

为探索饲用甜高粱最佳灌溉定额和节水效果,设置了不同灌溉定额(2 400, 3 000, 3 600, 4 200, 4 800 m³/hm²)对两茬收割饲用甜高粱生长和生物产量的影响的田间试验.结果表明,甜高粱茎粗和株高的峰值分别出现在播后62 d和158 d.随灌溉定额增加甜高粱在形态上表现为株高增加、茎粗减小的趋势.在头茬收割(播后76 d)时,株高日增长率最大,为4.00~4.89 cm/d.两茬收割甜高粱鲜生物学产量为63.9~115.5 t/hm²,干生物学产量为12.7~21.4 t/hm²,全生育期耗水量为326.95~504.24 mm,鲜生物学产量WUE为15.53~24.63 kg/m³,干生物学产量WUE为3.89~4.51 kg/m³.灌溉定额为4 200 m³/hm²时,甜高粱总鲜、干生物量最大,灌溉定额为4 800 m³/hm²时,甜高粱总鲜、干生物量增幅不大.从节水和增加生物量角度而言,畦灌方式下的两茬收割饲用甜高粱全生育期灌水4次,灌水定额为1 050 m³/hm²,灌溉定额为4 200 m³/hm²的灌溉效果最佳.     

农作物优化组合需水规律试验研究

根据“水稻－玉米”、“西瓜－水稻”、“烤烟－水稻”三种优化组合模式,与“早稻－晚稻”浅灌中蓄灌溉为对照,通过试验对灌溉用水量、产量、产值和纯收入等进行了对比分析,提出了不同组合方式的需水指标和经济效益指标。并建立了农作物优化组合决策模型,对湖南省缺水地区（水稻区“干旱死角”田）进行了优化计算。结果表明,采用农作物优化组合种植模式,可节水４１．３％～４４．１％。增加产值５９．９％～１３２．８％,提高纯收入１６１．１％～３９９．９５％,节水高产效果十分显著。试验研究的定量数据和优化决策成果,为组织高产优质高效农业,合理利用缺水地区的水土资源提供了科学依据。     

降雨入渗对微生物注浆加固边坡的稳定性影响研究

利用微生物注浆加固边坡,分析降雨入渗作用下微生物注浆加固土体的非饱和土-水特征参数,并采用Van Genuchten公式进行拟合,获得微生物注浆土体渗透函数的特征参数.利用MIDAS/GTS分析降雨入渗条件下,坡面加固边坡的非饱和土体,在流固耦合作用下的暂态孔隙水压力,并用于考虑基质吸力影响的边坡稳定性计算.根据设定的...     

Water productivity analysis of irrigated crops in Sirsa district,India

Water productivity (WP) expresses the value or benefit derived from the use of water, and includes essential aspects of water management such as production for arid and semi-arid regions. A profound WP analysis was carried out at five selected farmer fields (two for wheat–rice and three for wheat–cotton) in Sirsa district, India during the agricultural year 2001–02. The ecohydrological soil–water–atmosphere–plant (SWAP) model, including detailed crop simulations in combination with field observations, was used to determine the required hydrological variables such as transpiration, evapotranspiration and percolation, and biophysical variables such as dry matter or grain yields. The use of observed soil moisture and salinity profiles was found successful to determine indirectly the soil hydraulic parameters through inverse modelling.Considerable spatial variation in WP values was observed not only for different crops but also for the same crop. For instance, the WP_ET, expressed in terms of crop grain (or seed) yield per unit amount of evapotranspiration, varied from 1.22 to 1.56 kg m⁻³ for wheat among different farmer fields. The corresponding value for cotton varied from 0.09 to 0.31 kg m⁻³. This indicates a considerable variation and scope for improvements in water productivity. The average WP_ET (kg m⁻³) was 1.39 for wheat, 0.94 for rice and 0.23 for cotton, and corresponds to average values for the climatic and growing conditions in Northwest India. Including percolation in the analysis, i.e. crop grain (or seed) yield per unit amount of evapotranspiration plus percolation, resulted in average WP_ETQ (kg m⁻³) values of 1.04 for wheat, 0.84 for rice and 0.21 for cotton. Factors responsible for low WP include the relative high amount of evaporation into evapotranspiration especially for rice, and percolation from field irrigations. Improving agronomic practices such as aerobic rice cultivation and soil mulching will reduce this non-beneficial loss of water through evaporation, and subsequently will improve the WP_ET at field scale. For wheat, the simulated water and salt limited yields were 20–60% higher than measured yields, and suggest substantial nutrition, pest, disease and/or weed stresses. Improved crop management in terms of timely sowing, optimum nutrient supply, and better pest, disease and weed control for wheat will multiply its WP_ET by a factor of 1.5! Moreover, severe water stress was observed on cotton (relative transpiration < 0.65) during the kharif (summer) season, which resulted in 1.4–3.3 times lower water and salt limited yields compared with simulated potential yields. Benefits in terms of increased cotton yields and improved water productivity will be gained by ensuring irrigation supply at cotton fields, especially during the dry years.     

Irrigation for crops in a sub-humid environment

Summary The water use of two soybean cultivars (Bragg and Ruse) was measured for three seasons for a range of irrigation treatments. The seasonal totals of plant and soil evaporation ranged from 450 to 750 mm or from 36 to 64% of class A pan evaporation for the same period. Both cultivars extracted approximately 60% of the total extractable soil water in the top 1.2 m of soil before actual evaporation (Ea) dropped below potential evaporation (Eo). Up to this point the ratio between Ea and class A pan evaporation averaged 0.8. Ruse used water at a faster rate than Bragg but Ruse was not as effective in extracting the deep (below 1.0 m) soil water as Bragg. Water use efficiency (kg seed ha^–1 mm^–1 water) showed a small but general increase with decreasing irrigation water application. Runoff losses varied from zero for non-irrigated Ruse in 1977/78 to 352 mm for frequently-irrigated Bragg in 1976/77, generally increasing with the number of irrigations.