玉米流体穴播技术及其装置的研究
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摘要
干旱缺水影响农作物的播种、出苗、以至产量,是制约农业持续发展的重要因素。目前我国47%的地区年均降水量不足400mm,每年受旱农田面积占整个耕地面积的25%～30%,干旱造成的损失超过其它所有自然灾害。作为主要旱作作物的玉米是最重要的粮食和饲料来源,在农业生产和国民经济中占有极其重要地位,由于干旱缺水常无法播种或播种后出苗不全,严重影响其生产。本文结合保水剂的抗旱保水作用、播前浸种、坐水播种以及流体播种的优势,提出了玉米流体穴播方法。通过深入研究流体穴播机理及其关键技术,为流体播种机具的研究及其在旱作农业中的推广应用提供理论依据;为旱作农业解决抗旱、节水、保苗等问题探索一种新途径和新方法,在我国北方长期缺水的现实条件下,具有重要的应用价值和理论意义。
1.本文以玉米种子浸泡后物理机械特性、保水剂胶体溶液粘度的测试研究以及流体播种种液用量和施用浓度的试验研究为基础,通过分析揭示了种子各参数的变化规律和差异,在国内首次提出适于机械化流体播种的玉米种子较为合适浸泡时间为16h～24h,确定了种子浸泡后的各参数值、选用保水剂类型及配制种液的浓度要求;
2.通过二次回归正交旋转组合设计试验,并利用Matlab与Excel软件分析了各因素对玉米出苗和生长性状的影响关系;分别建立了种液用量、种液浓度与土壤含水量数学模型,确定了干旱条件下种液用量和种液浓度的施用条件;
3.通过种子无搅拌条件下的动力学分析,在理论上证实了比重和体积较大的种子在种液中沉降不可避免:深入分析压气搅拌混合机理,首次提出了压气搅拌混合的空气用量的数学模型;分析和试验结果表明,单位容积的种液需要的空气量约为250m~3/m~3·h～330m~3/m~3·h;
4.完成了玉米流体穴播装置结构方案确定,采取压气搅拌混合方式,解决种子沉积和伤种问题;设置稳压控制系统,充分利用压缩空气来维持排液压力,克服播种过程中排种不均问题;利用虹吸原理解决种子沉积堵塞,并利用虹吸排种管中的锤击原理解决排种过程中的堵塞。在利用Solidworks软件进行实体建模和模拟验证基础上,研制了玉米流体穴播排种装置。
5.本研究的创新点在于:
①得出排种阀门开启间隙与开启面积的变化规律;建立了阀门杆关闭的微分方程,求解排种阀门关闭时间和开口面积的变化规律,确定了开口面积的选用原则;
②建立了流体穴播一次排液量与虹吸排种管内径、进出口的垂直距离,种箱内液面高,拨轮半径、拨轮转速,拨轮与阀门杆位置尺寸,阀门杆的结构参数,挡球的质量、直径,弹簧弹性系数以及流量系数的关系的数学模型;利用Matlab软件分析结果表明,可通过更换不同管径的排种管、拨轮转速进行排液量调整;
③建立了排液播种过程中,保证排液稳定的空气用量的数学模型:由此得出单位容积的种液需要的空气量为69.2m~3/m~3·h～149.5 m~3/m~3·h;
④通过对虹吸排种管中的锤击现象的分析,确定了阀门关闭时弹簧拉力数学模型;
6.试验研究结果表明,本研究所研制的流体穴播装置能够实现玉米流体播种,其穴播粒数在2±1之间的穴粒数合格率为75%左右;伤种率为0;空穴率较高,部分试验超过了10%;平均穴距为356.5 mm,穴距合格率为91.67%,穴距稳定性变异系数CV为22.99%;内径20mm排种管的排液量在70～140ml之间可调。
7.经济效益分析结果表明,玉米流体穴播的成本、增产效益、节水效益以及机具开发和应用等方面具有较好的经济性和应用前景。
Water shortage affects the sowing,emergence and yield of crop and it is one of the most important factors which limit the development of agriculture.Maize is one the main dry farming crops which is the most important source of food and forage,and it plays an essential role in agricultural production and natural economy.But it couldn't be sowed or with a low emergence rate for drought.The fluid hilling of maize was put forward in this study which combines the functions of water preserving agent,the watering bed sowing,the properties of the soaked seeds and fluid sowing.The mechanism and key technology of fluid hilling was studied which will contribute to the development and application of fluid sowing machine. The study explored a new way to resist drought,save water and ensure emergence rate.It is especially significant for northern China where lacks of water.
1.According to the study on the physical and mechanical properties of soaked maize seeds, the test on viscosity,quantity and concentration of the mixed liquid of water preserving agent, the varying principle and diference of the parameters of soaked seed were revealed in this study and the suitable soaking time of maize seeds for fluid sowing was put forward for the first time which was16h～24h.And the parameters of soaked maize seeds,the type of water conserving agent utilized and the concentration of the sowing fluid were determined.
2.The quadric orthogonal revolve test was carried out and the effect of the factors on the emergence of maize seed and growth was analyzed with Matlab and Excel.The mathematic model of fluid quantity and soil water content,the fluid concentration and soil water content were set up respectively.The applied fluid quantity and concentration for soil with different water content were determined.
3.Dynamic analysis on the seeds in the fluid without agitation showed that the seeds of larger specific gravity and volume will settle in the fluid.The mechanism of pneumatic agitation and mixing was done and the mathematic model between the air quantity needed and the length,width of the seed chamber,the fluid height in the chamber and the required fluid velocity was put forward for the first time.The analysis and experiment showed that the required air quantity for unit volume of fluid was 250m~3/m~3·h～330m~3/m~3·h;
4.The structure of maize fluid hilling device was determined and air blowing agitation was utilized to reduce the seeds settlement and damage.The pressure control system was set to maintain fluid metering pressure to avoid uneven seed metering caused by the decrease in height and pressure of the fluid in the chamber.Siphon principle was applied to solve the problem of seed settlement and the hammering function in the siphon tube was utilized to avoid seeds blocking during metering.The maize seed fluid metering device was designed based on solid model and simulation verification with Solidworks.
5.The principal innovation of this study are as following:
①The varying law of the opening lash and the area of the metering valve was determined; the differential equation of the close of valve stem was established;the selecting principle for the opening area of the valve was determined by solving the equation of the closing time and opening area.
②The mathematic model of the metering rate of fluid per hill to the diameter and the vertical distance between the inlet and outlet of the siphon metering tube,height of the fluid in the chamber,radius and angular velocity of the push wheel,the position of the push wheel and the valve stem,the parameters of the valve stem,the mass,diameter of the block ball,the elastic coefficient of the spring and the coefficient of the fluid metering rate.The analysis based on Matlab showed that the fluid metering rate could be varied by changing tube with different diameter or changing the revolutions of the push wheel.
③The mathematic model of the increased air quantity needed to maintain stable fluid metering to the metering rate per hill,times of metering and dimension of the chamber was established.The air quantity needed per unit volume of fluid was 69.2m~3/m~3·h～149.5 m~3/m~3·h according to the formula.
④The mathematic of the pull of spring was determined through analysis on the hammering impact in the siphon tube which will help to the design of the spring.
6.The experiments results showed that the fluid metering device could realize maize seed fluid hilling.The percentage of hills with seeds of 2±1was 75%,seeds damage was 0,it had a larger percentage of empty hill,some of it was greater than 10%,the percentage of the permitted hill distance was 91.67%,the variable coefficient of the hill distance was 22.99%. The metering rate of fluid with a metering tube of 20mm can be adjusted between 70 ml～140ml.
7.The economic analysis on the cost of fluid sowing,the increase of yield,the water saving and the development and application of the fluid sowing device showed that the fluid sowing is economical.
1.本文以玉米种子浸泡后物理机械特性、保水剂胶体溶液粘度的测试研究以及流体播种种液用量和施用浓度的试验研究为基础,通过分析揭示了种子各参数的变化规律和差异,在国内首次提出适于机械化流体播种的玉米种子较为合适浸泡时间为16h～24h,确定了种子浸泡后的各参数值、选用保水剂类型及配制种液的浓度要求;
2.通过二次回归正交旋转组合设计试验,并利用Matlab与Excel软件分析了各因素对玉米出苗和生长性状的影响关系;分别建立了种液用量、种液浓度与土壤含水量数学模型,确定了干旱条件下种液用量和种液浓度的施用条件;
3.通过种子无搅拌条件下的动力学分析,在理论上证实了比重和体积较大的种子在种液中沉降不可避免:深入分析压气搅拌混合机理,首次提出了压气搅拌混合的空气用量的数学模型;分析和试验结果表明,单位容积的种液需要的空气量约为250m~3/m~3·h～330m~3/m~3·h;
4.完成了玉米流体穴播装置结构方案确定,采取压气搅拌混合方式,解决种子沉积和伤种问题;设置稳压控制系统,充分利用压缩空气来维持排液压力,克服播种过程中排种不均问题;利用虹吸原理解决种子沉积堵塞,并利用虹吸排种管中的锤击原理解决排种过程中的堵塞。在利用Solidworks软件进行实体建模和模拟验证基础上,研制了玉米流体穴播排种装置。
5.本研究的创新点在于:
①得出排种阀门开启间隙与开启面积的变化规律;建立了阀门杆关闭的微分方程,求解排种阀门关闭时间和开口面积的变化规律,确定了开口面积的选用原则;
②建立了流体穴播一次排液量与虹吸排种管内径、进出口的垂直距离,种箱内液面高,拨轮半径、拨轮转速,拨轮与阀门杆位置尺寸,阀门杆的结构参数,挡球的质量、直径,弹簧弹性系数以及流量系数的关系的数学模型;利用Matlab软件分析结果表明,可通过更换不同管径的排种管、拨轮转速进行排液量调整;
③建立了排液播种过程中,保证排液稳定的空气用量的数学模型:由此得出单位容积的种液需要的空气量为69.2m~3/m~3·h～149.5 m~3/m~3·h;
④通过对虹吸排种管中的锤击现象的分析,确定了阀门关闭时弹簧拉力数学模型;
6.试验研究结果表明,本研究所研制的流体穴播装置能够实现玉米流体播种,其穴播粒数在2±1之间的穴粒数合格率为75%左右;伤种率为0;空穴率较高,部分试验超过了10%;平均穴距为356.5 mm,穴距合格率为91.67%,穴距稳定性变异系数CV为22.99%;内径20mm排种管的排液量在70～140ml之间可调。
7.经济效益分析结果表明,玉米流体穴播的成本、增产效益、节水效益以及机具开发和应用等方面具有较好的经济性和应用前景。
Water shortage affects the sowing,emergence and yield of crop and it is one of the most important factors which limit the development of agriculture.Maize is one the main dry farming crops which is the most important source of food and forage,and it plays an essential role in agricultural production and natural economy.But it couldn't be sowed or with a low emergence rate for drought.The fluid hilling of maize was put forward in this study which combines the functions of water preserving agent,the watering bed sowing,the properties of the soaked seeds and fluid sowing.The mechanism and key technology of fluid hilling was studied which will contribute to the development and application of fluid sowing machine. The study explored a new way to resist drought,save water and ensure emergence rate.It is especially significant for northern China where lacks of water.
1.According to the study on the physical and mechanical properties of soaked maize seeds, the test on viscosity,quantity and concentration of the mixed liquid of water preserving agent, the varying principle and diference of the parameters of soaked seed were revealed in this study and the suitable soaking time of maize seeds for fluid sowing was put forward for the first time which was16h～24h.And the parameters of soaked maize seeds,the type of water conserving agent utilized and the concentration of the sowing fluid were determined.
2.The quadric orthogonal revolve test was carried out and the effect of the factors on the emergence of maize seed and growth was analyzed with Matlab and Excel.The mathematic model of fluid quantity and soil water content,the fluid concentration and soil water content were set up respectively.The applied fluid quantity and concentration for soil with different water content were determined.
3.Dynamic analysis on the seeds in the fluid without agitation showed that the seeds of larger specific gravity and volume will settle in the fluid.The mechanism of pneumatic agitation and mixing was done and the mathematic model between the air quantity needed and the length,width of the seed chamber,the fluid height in the chamber and the required fluid velocity was put forward for the first time.The analysis and experiment showed that the required air quantity for unit volume of fluid was 250m~3/m~3·h～330m~3/m~3·h;
4.The structure of maize fluid hilling device was determined and air blowing agitation was utilized to reduce the seeds settlement and damage.The pressure control system was set to maintain fluid metering pressure to avoid uneven seed metering caused by the decrease in height and pressure of the fluid in the chamber.Siphon principle was applied to solve the problem of seed settlement and the hammering function in the siphon tube was utilized to avoid seeds blocking during metering.The maize seed fluid metering device was designed based on solid model and simulation verification with Solidworks.
5.The principal innovation of this study are as following:
①The varying law of the opening lash and the area of the metering valve was determined; the differential equation of the close of valve stem was established;the selecting principle for the opening area of the valve was determined by solving the equation of the closing time and opening area.
②The mathematic model of the metering rate of fluid per hill to the diameter and the vertical distance between the inlet and outlet of the siphon metering tube,height of the fluid in the chamber,radius and angular velocity of the push wheel,the position of the push wheel and the valve stem,the parameters of the valve stem,the mass,diameter of the block ball,the elastic coefficient of the spring and the coefficient of the fluid metering rate.The analysis based on Matlab showed that the fluid metering rate could be varied by changing tube with different diameter or changing the revolutions of the push wheel.
③The mathematic model of the increased air quantity needed to maintain stable fluid metering to the metering rate per hill,times of metering and dimension of the chamber was established.The air quantity needed per unit volume of fluid was 69.2m~3/m~3·h～149.5 m~3/m~3·h according to the formula.
④The mathematic of the pull of spring was determined through analysis on the hammering impact in the siphon tube which will help to the design of the spring.
6.The experiments results showed that the fluid metering device could realize maize seed fluid hilling.The percentage of hills with seeds of 2±1was 75%,seeds damage was 0,it had a larger percentage of empty hill,some of it was greater than 10%,the percentage of the permitted hill distance was 91.67%,the variable coefficient of the hill distance was 22.99%. The metering rate of fluid with a metering tube of 20mm can be adjusted between 70 ml～140ml.
7.The economic analysis on the cost of fluid sowing,the increase of yield,the water saving and the development and application of the fluid sowing device showed that the fluid sowing is economical.
引文
1.白春晖,宋品玉,于希臣.2007,阜新地区玉米坐水播种保苗效果研究,辽宁农业科学,(5):49-50.
2.B.B.卡法罗夫.1955.液体搅拌.北京:重工业出版社,10-20.
3.蔡典雄,王小彬,Keith Saxton.1999.土壤保水剂对土壤持水特性及作物出苗的影响.土壤肥料,(1):13-16.
4.陈青春,欧志强.2006.节水农业与农业系统工程.农机化研究,(12):16-18.
5.程炳文,买自珍,王勇,罗世武.2006.半干旱地区旱地玉米节水播种技术研究.内蒙古农业科技,(5):40-41.
6.崔奎顺.2002.ZBT-2X玉米催芽滤水穴施肥精播机的试验研究.农机使用与维修,(5):6-7.
7.崔英德,郭建维,阎文峰,易国斌,康正.2003.SA-IP-SPS型保水剂及其对土壤物理性能的影响.农业工程学报,19(1):28-31.
8.戴干策,陈敏恒.2005.化工流体力学(第二版).北京:化学工业出版社.
9.戴干策.1991.化学工程基础(流体流动、传热及传质).北京:化学工业出版社.
10.党秀丽,张玉龙,黄毅.2006.保水剂在农业上的应用与研究进展.土壤通报,37(2):352-355.
11.杜太生,康绍忠,魏华.2000.保水剂在节水农业中的应用研究现状与展望.农业现代化研究,21(5):317-320.
12.冯金超等.1993.土壤保水剂对沙地农作物生长的影响.干旱地区农业研究,11(2):36-40.
13.高宝岩,吕伟,张余良等.1999.几种主要农作物应用保水剂效应的初步研究.天津农林科技,(4):4-6.
14.高照良,冯兴平,彭珂珊.2005.试论我国北方旱地农业与持续发展.生态经济,9:91-94.
15.戈素芬,张素清.2005.节水农业研究动态.水土保持科技情报,(6):33-35.
16.郭维东,夏桂敏,王晓刚,张杰华.2003.坐水播种时土壤临界含水率的确定.灌溉排水学报,22(4):12-13.
17.何俊仕,曹丽娜,逄立辉,刘琳琳,李崇.2005.现代农业节水技术.节水灌溉,(4):36-39.
18.黄占斌,万惠娥,邓西平等.1999.保水剂在改良土壤和作物抗旱节水中的效应.土壤侵蚀与水土保持学报,5(4):52-55.
19.黄占斌.2003.保水剂在农业生产中的应用与发展趋势.干旱地区农业研究,21(3):11-14.
20.黄占斌,张国桢,李秧秧,郝明德等.2002.保水剂特性测定及其在农业中的应用.农业工程学报,18(1):22-26.
21.黄占斌,夏春良.2005.农用保水剂作用原理研究与发展趋势分析.水土保持研究年,12(5):104-106.12.
22.康贵春,李明宇.2007.辽宁省辽西北地区旱作节水农业发展模式.东北水利水电,25(6):10-11.
23.康绍忠,许迪.2001.我国现代农业节水高新技术发展战略的思考.中国农村水利水电,(10):25-29.
24.吉文丽,李卫忠,郝红科,朱清科.2005.喷射绿化技术及其在水土保持中的应用.水土保持研究,12(6):150-152.
25.机械工程手册编辑委员会.1982.机械工程手册(第11卷 第65篇).北京:机械工业出版社,38-59.
26.贾洪雷,马成林,刘昭辰,刘晖.2005.东北垄作蓄水保墒耕作体系与配套机具.农业机械学 报,36(7):32-36.
27.蒋维钧,戴猷元,顾惠君.2002.化工原理(第2版.上册).北京:清华大学出版社:184-192.
28.李宝筏.2003.农业机械学.北京:中国农业出版社,238-239.
29.李宝筏,郭维东,李国臣,张文良.2000.抗旱拌种剂和坐水剂田间试验.中国机械化旱作节水农业国际研讨会论文集.北京:中国农业大学出版社,314-319.
30.李宝筏,杨文革,王勇,邱立春等.2004.东北地区保护性耕作研究进展与建议.农机化研究,(1):9-12.
31.李国强.2005.适于旱作地区使用的播种新技术-液体播种技术.实用技术,(3):15-15.
32.李云开,杨培岭,刘洪禄.2002.保水剂在农业上的应用技术与效应.节水灌溉,(2):12-16.
33.李洪文,高焕文等.2000.旱地玉米保护性耕作经济效益分析.干旱地区农业研究,18(3):44-49.
34.李小明,王冶,毕勤成,冯全科.2003.气泡在不同液体中上升速度的实验研究.西安交通大学学报,37(9):971-974.
35.李秀芝,梁彩芝.2001.玉米施用抗旱剂的效果研究.耕作与栽培,(6):2-27.
36.李秀君.2002.几种新型抗旱保水剂在玉米上的应用效果.甘肃农业科技,(1):19-20.
37.李云飞,葛克山主编.食品工程原理.北京:中国农业大学出版社.
38.李耀刚.2003.机械化是实施旱作节水农业技术的根本途径.中国农机化,(1):25-26.
39.刘国喜.1990.流体力学及流体机械.吉林科学技术出版社,118-123.
40.刘好.2004.行走式节水灌溉技术在旱作农业中的应用.农业科技与信息,(7):41-41.
41.刘俊渤,华萱.1996.超吸水性树脂在玉米、大豆种植上的应用研究.吉林农业大学学报,18(3):50-52.
42.刘学生,高凤文,赵凤民,罗盛国.2006.保水剂对玉米产量性状和产量的影响.东北农业大学学报,37(2):151-154.
43.刘世亮,寇太记,介晓磊等.2005.保水剂对玉米生长和土壤养分转化供应的影响研究.河南农业大学学报,39(2):146-150.
44.刘胜,杨成渝,王平义.2007.水中气泡运动规律的研究.重庆交通学院学报,26(3):136-139.
45.刘晔.2004.SL—PBJ型水力草种喷播机的研制.农业机械学报,35(2):187-188.
46.刘治先.1998.世界玉米经济的现状和发展趋势.杂粮作物,18(2):7-11.
47.伦世仪.1993.生化工程.北京:中国轻工业出版社,46-83.
48.马英周,魏新田,魏秀山.1995.旱地作物流体播种技术.中国农技推广,(5):29-29.
49.马永忠.2002.玉米播前要浸种.科学种田,(4):13-13.
50.茆诗松,周纪芗,陈颖.试验设计.北京:中国统计出版社.
51.聂俊峰,韩清芳,问亚军,贾志宽,蒋骏.2005.我国北方农业旱灾的危害特点与减灾对策.干旱地区农业研究,23(6):171-178.
52.牛盾.2001.面向二十一世纪的机械化旱作节水农业.北京:中国农业大学出版社.
53.农业部玉米专家指导组.2007.国内外玉米种植密度情况比较.北京农业,(8):23-23.
54.欧阳西荣,官春云,Kenk W.M.Hilhorst.2001.玉米种子发芽和幼苗生长对水分环境的敏感性.湖南农业大学学报(自然科学版),27(1):7-12.
55.裴泽莲,丛福滋,王洪平,张旭东,李宝筏.2005.机械化播种不同坐水量对玉米出苗率的影响.沈阳农业大学学报,36(4):508-510.
56.山仑,邓西平,康绍忠.2002.我国半干旱地区农业用水现状及发展方向.水利学报,(9):27-31.
57.山仑.2002.旱地农业技术发展趋向.中国农业科学,35(7):848-855.
58.石媛媛.2007.外国的旱地节水农业.北京农业实用技术,(1):52-53.
59.隋鹏飞.2000.我国旱作农业发展展望.中国农技推广,(3):39-39.
60.孙本喆等.2003.我国玉米生产现状及发展对策.玉米科学,专刊:32-33.
61.孙骊,吕新民.1996.旱地节水型播种机械研制初探.干旱地区农业研究,14(4):61-66.
62.谭国波等.2005.保水剂对玉米出苗率及土壤水分的影响.吉林农业科学,30(5):26-27.
63.王龙昌,马林,赵惠青,万素梅.2004.国内外旱区农作制度研究进展与趋势.干旱地区农业研究,22(2):189-199.
64.王斌,魏永霞,张忠学,王立敏.2004.坐水种对东北半干旱地区玉米前期生长发育的影响.农业系统科学与研究,20(4):275-280.
65.王忠孝等编著.1998.玉米栽培关键技术问答.北京:中国农业出版社,67-77.
66.江懋华主编.2000.农业机械化工程技术.郑州:河南科学技术出版社,1-79.
67.吴崇友,金诚谦,涂安富等.2004.我国坐水播种机需重点解决的几个技术问题.中国农机化,(6):23-25.
68.魏新田,马英周,魏秀山,冯雁,彭欣.1996.流体播种技术在油菜生产上的应用.河南农业科学,(12):7-9.
69.魏新田,冯俊荣,刘书明.1998.流体播种技术在菠菜上的应用.中国蔬菜,(4):33-34.
70.吴普特,冯浩,牛文全,赵西宁.2007.现代节水农业技术发展趋势与未来研发重点.中国工程科学,9(2):12-18.
71.吴普特,冯浩,赵西宁,牛文全.2006.现代节水农业理念与技术探索.灌溉排水学报,25(4):1-6.
72.吴普特,冯浩.2005.中国节水农业发展战略初探.农业工程学报,21(6):152-157.
73.吴长文,章梦涛,付奇峰.2000.斜坡喷播绿化技术的研究.中国水土保持,(4):24-26.
74.吴德瑜.1995.浅谈流体播种.作物杂志,(1):31-32.
75.吴德瑜.1990.保水剂在全国农林园艺上的应用进展.作物学报,(2):33-37.
76.辛明金,宋玉秋,李宝筏,胡艳清.2007.流体播种技术发展及其关键技术分析.农机化研究,(3)207-209.
77.辛明金,宋玉秋,任文涛,白晓虎,李宝筏.2008.玉米流体穴播关键技术及排种装置研究.农机化研究,(3):165-167.
78.许迪,龚时宏.2005.中国节水农业技术与产品需求分析.灌溉排水学报,24(1):1-7.
79.许迪,吴普特,梅旭荣,康绍忠,钱蕴璧.2003.我国节水农业科技创新成效与进展.农业工程学报,19(3):5-9.
80.许(?),王淑英主编.2005.电器控制与PLC控制技术.北京:机械工业出版社,29-33.
81.萧兵.1985.农业多因素试验设计与统计分析.长沙:湖南科学技术出版社:291-368.
82.杨培岭,张铁军.2004.国外节水农业发展动态.农机科技推广,(2):40-41.
83.杨德编著.2002.试验设计与分析.北京:中国农业出版社.
84.杨同舟主编.2001.食品工程原理.北京:中国农业出版社.
85.杨敏丽.2000.农业工程技术在旱作农业生产中的应用与发展.抗旱拌种剂和坐水剂田间试验.中国机械化旱作节水农业国际研讨会论文集,381-386.
86.姚玉英主编.2004.化工原理(上册)第二版.天津:天津科学技术出版社,132-147.
87.姚润丰,董峻.2005.关注春旱:我国旱灾发生与损失的特点.新华网,04-0421.杨玉凤.2003.保水剂在农业生产上的应用.四川农业科技,(5):38-38.
88.姚书典.1982.均匀球群的干涉沉降速度.有色金属(选矿部分),(6):30-34.
89.姚书典.1992.重选原理.北京:冶金工业出版社.
90.尹光华,陈温福,刘作新,张旭东,张和喜.2007.中国北方半干旱区机械化坐水种技术研究.农业现代化研究,28(2):238-240.
91.侯玉虹,尹光华,刘作新,刘恩才,侯立白.2007.土壤含水量对玉米出苗率及苗期生长的影响.安徽农学通报,13(1):70-73.
92.张晓梅,吕晶,郭维东.2006.坐水播种技术研究意义浅释.中国科技信息,(7):129-131.
93.张富仓,康绍忠.1999.BP保水剂及其对土壤与作物的效应.农业工程学报,15(2):74-78.
94.赵敏,高会东,崔彦宏.2006.保水剂对夏玉米生长发育和产量的影响.玉米科学,14(6):125-126.
95.张波屏.1997.现代种植机械工程.北京:机械工业出版社,2-22.
96.张爱华.2005.机械化旱作农业节水技术(上).中国教育广播电视报,07-11.
97.张鸿雁,王百田,邹丽玲.2003.半干旱黄土区保水剂使用浓度的研究.北京林业大学学报,25(2):14-17.
98.张林栋,李佐邦,任志宽.1995.高吸水性树脂在农业中的应用试验.精细化工,12(4):64-66.
99.赵立红.1993.IAC-13保水剂在烟草上的应用.中国烟草,(3):40-42.
100.赵学笃,陈元生,张守勤.1987.农业物料学.北京:机械工业出版社,60-67.
101.赵学辉,刘春江,吕晓龙.2007.粘性液体中气泡流体力学特性的模拟研究.天津工业大学学报,26(4):28-31.
102.赵永平.2005.节水灌溉:要节出一条黄河.人民日报,10-10(06).
103.诸林,刘瑾,王兵.2007.化工原理.北京:石油工业出版社,91-123.
104.中国农业机械化科学研究院.1988.农业机械设计手册(上册).北京:机械工业出版社,247-306.
105.中国农用土壤概论编委会.1982.中国农业土壤概论.北京:农业出版社,487-513.
106.郑鑫,李延海,安洪敏.2006.液力喷播技术在北方高速公路护坡植草中的应用.防护林科技,(3):92.
107.Alasdair Barcroff.1984.Super absorbents improve plant survival.World Crops,(1/2):7-10.
108.Al-Harbi A R..1999.Efficiency of a Hydrophilic Polymer Declines with Time in Greenhouse Experiments.Hort Sci.,34(2):223-224.
109.Arthur Wallance,Gam A Wallace.1986.Effects of soil conditioners on emergence and growth of tomato,cotton and lecture seedling.Soil Sic,(141):324-327.Jeff J.Schoenau.2000.Fluid Fertilizers In Direct Seeding Systems.Fluid Journal,1-2.
110.Ben HurM,Keren R.1997.Polymer effects on water infiltration and soil aggregation.Soil Sci.Am.J.,(61):565-570.
111.Bozzano G,Dente M.2001.Shape and terminal velocity of single bubble motion:a novel approach .Computers and Chemical Engineering,(25):571-576
112.BrownL R Halweil B.1998.China's water shortage could shakeworld food security.World Watch, 11 (4): 10-21.
113.Claude Culpin,1986.Farm Machinery (Elevnth Edition) .102-124.
114.Geh ring J M,Lew is A J.1980.Ⅲ Effect of hydrogel on w ilting and moisture stress of bedding plants.JAmer Soc Hortsci, 105 (4): 511-513.
115.1ngram D L.YeagerTH.1987.Effects of irrigation frequency and a water-absorbing polymer amendment on ligustrum growth and moisture retention by a container medium.Journal of Environmental Horticulture, (5): 19-21.
116.Kawai T, Yoshino H, Kawabata Y.2002.Self-regulating characteristics of a cold neutron source with a cylindrical-annulus moderate cell .Physica: B, (311):164-172 .
117.Jeff J.Schoenau.2000.Fluid Fertilizers In Direct Seeding Systems.Fluid Journal,l-2.
118..J.M.Shippen,C.R.Ellin ang C.H.Cloyer.1980.Basic Farm Machinery(Third Edition).161-179.
119.Johnson M S.1984.The Effects of Gel Forming Polyacrylamides on Moisture Storage in Sandy Soils.Sci.Food Agric,(35): 1196-1200.
120..Levin J,et al.1997.Rain energy and soil amendments effect on infiltration and erosion of three different soil types.Aust.J.Soil Res.,(29): 455-465.
121.Mendelson H D.1967.The prediction of bubble terminal velocities from wave theory .AICHE Journal,13(2) :250-252
122.M.J.Hayes, E.D.Williams.1986.Some effect fluid-sowing, pre-germination, irrigation and soil covering on the establishment and growth of seedlings of white clover slot-seeded into permanent pasture Grass arid Forage Science ,41 (2): 151-157.
123.0midian H, Hashemi S A, Sammes P G, et al1998.A Model for the Swelling of Superabsorbent Polymer.Polymer, (26): 6697-6704.
124..P.J.Salter.Fluid Drilling of Pre-germinated Seeds: Progress and Possibilities.SHS Acta Horticulturae 83: Symposium on Seed Problems in Horticulture
125.Raymond F, Rosant J M.2000.A numerical and experimental study of the terminal velocity and shape of bubbles in viscous liquids .Chemical Engineering Science, (55 ):943-955 .
126.Seckler D,Barker R, Amarasinghe U.1999.Water scarcity in the twenty first century.W ater Resources Development, 15( 1-2) :29- 42.
127.Shainberg,Levy G J.1994.0rganic polymers and soil sealing in cultivated soils.Soil Sci,158(4):267-273.
128.Siberbush M ,Adar E,De Malach Y.1993.Use of an hydrophilicpolymer to improve water storage and availability to cropsgrown in sand dunes.A gricultural Water Management,(23):303-313.
129.Sojka R E, et al.1998.Water and erosion management with multip leapp lication of polyacrylamide in furrow irrigation.Soil Sci.SocAm.J., (62): 1672-1680.
130.Suhas R.Ghate.a new seeder for fluid sowing germinated seeds.ISHS Acta Horticulturae 187: I International Symposium on Mechanization of Vegetable Production 131.Taylor K C,HalfacreRG.1986.The effect of hydrophilic polymer on media water.retention and nutrition availability to Ligustrumlucidum.HorticulturalScience,21(5):l 159-1161.
132.Woodhouse J,M.S.Johnson.1991.Effect of super-absorbent polymers on survival and growth of crop seedings.Agricultural Water Management, (20): 63-70.
133.Wallance A.1986.A polysaccharide (GUAR ) as a soil conditioner .Soil Sci, (14)1:371-376.
2.B.B.卡法罗夫.1955.液体搅拌.北京:重工业出版社,10-20.
3.蔡典雄,王小彬,Keith Saxton.1999.土壤保水剂对土壤持水特性及作物出苗的影响.土壤肥料,(1):13-16.
4.陈青春,欧志强.2006.节水农业与农业系统工程.农机化研究,(12):16-18.
5.程炳文,买自珍,王勇,罗世武.2006.半干旱地区旱地玉米节水播种技术研究.内蒙古农业科技,(5):40-41.
6.崔奎顺.2002.ZBT-2X玉米催芽滤水穴施肥精播机的试验研究.农机使用与维修,(5):6-7.
7.崔英德,郭建维,阎文峰,易国斌,康正.2003.SA-IP-SPS型保水剂及其对土壤物理性能的影响.农业工程学报,19(1):28-31.
8.戴干策,陈敏恒.2005.化工流体力学(第二版).北京:化学工业出版社.
9.戴干策.1991.化学工程基础(流体流动、传热及传质).北京:化学工业出版社.
10.党秀丽,张玉龙,黄毅.2006.保水剂在农业上的应用与研究进展.土壤通报,37(2):352-355.
11.杜太生,康绍忠,魏华.2000.保水剂在节水农业中的应用研究现状与展望.农业现代化研究,21(5):317-320.
12.冯金超等.1993.土壤保水剂对沙地农作物生长的影响.干旱地区农业研究,11(2):36-40.
13.高宝岩,吕伟,张余良等.1999.几种主要农作物应用保水剂效应的初步研究.天津农林科技,(4):4-6.
14.高照良,冯兴平,彭珂珊.2005.试论我国北方旱地农业与持续发展.生态经济,9:91-94.
15.戈素芬,张素清.2005.节水农业研究动态.水土保持科技情报,(6):33-35.
16.郭维东,夏桂敏,王晓刚,张杰华.2003.坐水播种时土壤临界含水率的确定.灌溉排水学报,22(4):12-13.
17.何俊仕,曹丽娜,逄立辉,刘琳琳,李崇.2005.现代农业节水技术.节水灌溉,(4):36-39.
18.黄占斌,万惠娥,邓西平等.1999.保水剂在改良土壤和作物抗旱节水中的效应.土壤侵蚀与水土保持学报,5(4):52-55.
19.黄占斌.2003.保水剂在农业生产中的应用与发展趋势.干旱地区农业研究,21(3):11-14.
20.黄占斌,张国桢,李秧秧,郝明德等.2002.保水剂特性测定及其在农业中的应用.农业工程学报,18(1):22-26.
21.黄占斌,夏春良.2005.农用保水剂作用原理研究与发展趋势分析.水土保持研究年,12(5):104-106.12.
22.康贵春,李明宇.2007.辽宁省辽西北地区旱作节水农业发展模式.东北水利水电,25(6):10-11.
23.康绍忠,许迪.2001.我国现代农业节水高新技术发展战略的思考.中国农村水利水电,(10):25-29.
24.吉文丽,李卫忠,郝红科,朱清科.2005.喷射绿化技术及其在水土保持中的应用.水土保持研究,12(6):150-152.
25.机械工程手册编辑委员会.1982.机械工程手册(第11卷 第65篇).北京:机械工业出版社,38-59.
26.贾洪雷,马成林,刘昭辰,刘晖.2005.东北垄作蓄水保墒耕作体系与配套机具.农业机械学 报,36(7):32-36.
27.蒋维钧,戴猷元,顾惠君.2002.化工原理(第2版.上册).北京:清华大学出版社:184-192.
28.李宝筏.2003.农业机械学.北京:中国农业出版社,238-239.
29.李宝筏,郭维东,李国臣,张文良.2000.抗旱拌种剂和坐水剂田间试验.中国机械化旱作节水农业国际研讨会论文集.北京:中国农业大学出版社,314-319.
30.李宝筏,杨文革,王勇,邱立春等.2004.东北地区保护性耕作研究进展与建议.农机化研究,(1):9-12.
31.李国强.2005.适于旱作地区使用的播种新技术-液体播种技术.实用技术,(3):15-15.
32.李云开,杨培岭,刘洪禄.2002.保水剂在农业上的应用技术与效应.节水灌溉,(2):12-16.
33.李洪文,高焕文等.2000.旱地玉米保护性耕作经济效益分析.干旱地区农业研究,18(3):44-49.
34.李小明,王冶,毕勤成,冯全科.2003.气泡在不同液体中上升速度的实验研究.西安交通大学学报,37(9):971-974.
35.李秀芝,梁彩芝.2001.玉米施用抗旱剂的效果研究.耕作与栽培,(6):2-27.
36.李秀君.2002.几种新型抗旱保水剂在玉米上的应用效果.甘肃农业科技,(1):19-20.
37.李云飞,葛克山主编.食品工程原理.北京:中国农业大学出版社.
38.李耀刚.2003.机械化是实施旱作节水农业技术的根本途径.中国农机化,(1):25-26.
39.刘国喜.1990.流体力学及流体机械.吉林科学技术出版社,118-123.
40.刘好.2004.行走式节水灌溉技术在旱作农业中的应用.农业科技与信息,(7):41-41.
41.刘俊渤,华萱.1996.超吸水性树脂在玉米、大豆种植上的应用研究.吉林农业大学学报,18(3):50-52.
42.刘学生,高凤文,赵凤民,罗盛国.2006.保水剂对玉米产量性状和产量的影响.东北农业大学学报,37(2):151-154.
43.刘世亮,寇太记,介晓磊等.2005.保水剂对玉米生长和土壤养分转化供应的影响研究.河南农业大学学报,39(2):146-150.
44.刘胜,杨成渝,王平义.2007.水中气泡运动规律的研究.重庆交通学院学报,26(3):136-139.
45.刘晔.2004.SL—PBJ型水力草种喷播机的研制.农业机械学报,35(2):187-188.
46.刘治先.1998.世界玉米经济的现状和发展趋势.杂粮作物,18(2):7-11.
47.伦世仪.1993.生化工程.北京:中国轻工业出版社,46-83.
48.马英周,魏新田,魏秀山.1995.旱地作物流体播种技术.中国农技推广,(5):29-29.
49.马永忠.2002.玉米播前要浸种.科学种田,(4):13-13.
50.茆诗松,周纪芗,陈颖.试验设计.北京:中国统计出版社.
51.聂俊峰,韩清芳,问亚军,贾志宽,蒋骏.2005.我国北方农业旱灾的危害特点与减灾对策.干旱地区农业研究,23(6):171-178.
52.牛盾.2001.面向二十一世纪的机械化旱作节水农业.北京:中国农业大学出版社.
53.农业部玉米专家指导组.2007.国内外玉米种植密度情况比较.北京农业,(8):23-23.
54.欧阳西荣,官春云,Kenk W.M.Hilhorst.2001.玉米种子发芽和幼苗生长对水分环境的敏感性.湖南农业大学学报(自然科学版),27(1):7-12.
55.裴泽莲,丛福滋,王洪平,张旭东,李宝筏.2005.机械化播种不同坐水量对玉米出苗率的影响.沈阳农业大学学报,36(4):508-510.
56.山仑,邓西平,康绍忠.2002.我国半干旱地区农业用水现状及发展方向.水利学报,(9):27-31.
57.山仑.2002.旱地农业技术发展趋向.中国农业科学,35(7):848-855.
58.石媛媛.2007.外国的旱地节水农业.北京农业实用技术,(1):52-53.
59.隋鹏飞.2000.我国旱作农业发展展望.中国农技推广,(3):39-39.
60.孙本喆等.2003.我国玉米生产现状及发展对策.玉米科学,专刊:32-33.
61.孙骊,吕新民.1996.旱地节水型播种机械研制初探.干旱地区农业研究,14(4):61-66.
62.谭国波等.2005.保水剂对玉米出苗率及土壤水分的影响.吉林农业科学,30(5):26-27.
63.王龙昌,马林,赵惠青,万素梅.2004.国内外旱区农作制度研究进展与趋势.干旱地区农业研究,22(2):189-199.
64.王斌,魏永霞,张忠学,王立敏.2004.坐水种对东北半干旱地区玉米前期生长发育的影响.农业系统科学与研究,20(4):275-280.
65.王忠孝等编著.1998.玉米栽培关键技术问答.北京:中国农业出版社,67-77.
66.江懋华主编.2000.农业机械化工程技术.郑州:河南科学技术出版社,1-79.
67.吴崇友,金诚谦,涂安富等.2004.我国坐水播种机需重点解决的几个技术问题.中国农机化,(6):23-25.
68.魏新田,马英周,魏秀山,冯雁,彭欣.1996.流体播种技术在油菜生产上的应用.河南农业科学,(12):7-9.
69.魏新田,冯俊荣,刘书明.1998.流体播种技术在菠菜上的应用.中国蔬菜,(4):33-34.
70.吴普特,冯浩,牛文全,赵西宁.2007.现代节水农业技术发展趋势与未来研发重点.中国工程科学,9(2):12-18.
71.吴普特,冯浩,赵西宁,牛文全.2006.现代节水农业理念与技术探索.灌溉排水学报,25(4):1-6.
72.吴普特,冯浩.2005.中国节水农业发展战略初探.农业工程学报,21(6):152-157.
73.吴长文,章梦涛,付奇峰.2000.斜坡喷播绿化技术的研究.中国水土保持,(4):24-26.
74.吴德瑜.1995.浅谈流体播种.作物杂志,(1):31-32.
75.吴德瑜.1990.保水剂在全国农林园艺上的应用进展.作物学报,(2):33-37.
76.辛明金,宋玉秋,李宝筏,胡艳清.2007.流体播种技术发展及其关键技术分析.农机化研究,(3)207-209.
77.辛明金,宋玉秋,任文涛,白晓虎,李宝筏.2008.玉米流体穴播关键技术及排种装置研究.农机化研究,(3):165-167.
78.许迪,龚时宏.2005.中国节水农业技术与产品需求分析.灌溉排水学报,24(1):1-7.
79.许迪,吴普特,梅旭荣,康绍忠,钱蕴璧.2003.我国节水农业科技创新成效与进展.农业工程学报,19(3):5-9.
80.许(?),王淑英主编.2005.电器控制与PLC控制技术.北京:机械工业出版社,29-33.
81.萧兵.1985.农业多因素试验设计与统计分析.长沙:湖南科学技术出版社:291-368.
82.杨培岭,张铁军.2004.国外节水农业发展动态.农机科技推广,(2):40-41.
83.杨德编著.2002.试验设计与分析.北京:中国农业出版社.
84.杨同舟主编.2001.食品工程原理.北京:中国农业出版社.
85.杨敏丽.2000.农业工程技术在旱作农业生产中的应用与发展.抗旱拌种剂和坐水剂田间试验.中国机械化旱作节水农业国际研讨会论文集,381-386.
86.姚玉英主编.2004.化工原理(上册)第二版.天津:天津科学技术出版社,132-147.
87.姚润丰,董峻.2005.关注春旱:我国旱灾发生与损失的特点.新华网,04-0421.杨玉凤.2003.保水剂在农业生产上的应用.四川农业科技,(5):38-38.
88.姚书典.1982.均匀球群的干涉沉降速度.有色金属(选矿部分),(6):30-34.
89.姚书典.1992.重选原理.北京:冶金工业出版社.
90.尹光华,陈温福,刘作新,张旭东,张和喜.2007.中国北方半干旱区机械化坐水种技术研究.农业现代化研究,28(2):238-240.
91.侯玉虹,尹光华,刘作新,刘恩才,侯立白.2007.土壤含水量对玉米出苗率及苗期生长的影响.安徽农学通报,13(1):70-73.
92.张晓梅,吕晶,郭维东.2006.坐水播种技术研究意义浅释.中国科技信息,(7):129-131.
93.张富仓,康绍忠.1999.BP保水剂及其对土壤与作物的效应.农业工程学报,15(2):74-78.
94.赵敏,高会东,崔彦宏.2006.保水剂对夏玉米生长发育和产量的影响.玉米科学,14(6):125-126.
95.张波屏.1997.现代种植机械工程.北京:机械工业出版社,2-22.
96.张爱华.2005.机械化旱作农业节水技术(上).中国教育广播电视报,07-11.
97.张鸿雁,王百田,邹丽玲.2003.半干旱黄土区保水剂使用浓度的研究.北京林业大学学报,25(2):14-17.
98.张林栋,李佐邦,任志宽.1995.高吸水性树脂在农业中的应用试验.精细化工,12(4):64-66.
99.赵立红.1993.IAC-13保水剂在烟草上的应用.中国烟草,(3):40-42.
100.赵学笃,陈元生,张守勤.1987.农业物料学.北京:机械工业出版社,60-67.
101.赵学辉,刘春江,吕晓龙.2007.粘性液体中气泡流体力学特性的模拟研究.天津工业大学学报,26(4):28-31.
102.赵永平.2005.节水灌溉:要节出一条黄河.人民日报,10-10(06).
103.诸林,刘瑾,王兵.2007.化工原理.北京:石油工业出版社,91-123.
104.中国农业机械化科学研究院.1988.农业机械设计手册(上册).北京:机械工业出版社,247-306.
105.中国农用土壤概论编委会.1982.中国农业土壤概论.北京:农业出版社,487-513.
106.郑鑫,李延海,安洪敏.2006.液力喷播技术在北方高速公路护坡植草中的应用.防护林科技,(3):92.
107.Alasdair Barcroff.1984.Super absorbents improve plant survival.World Crops,(1/2):7-10.
108.Al-Harbi A R..1999.Efficiency of a Hydrophilic Polymer Declines with Time in Greenhouse Experiments.Hort Sci.,34(2):223-224.
109.Arthur Wallance,Gam A Wallace.1986.Effects of soil conditioners on emergence and growth of tomato,cotton and lecture seedling.Soil Sic,(141):324-327.Jeff J.Schoenau.2000.Fluid Fertilizers In Direct Seeding Systems.Fluid Journal,1-2.
110.Ben HurM,Keren R.1997.Polymer effects on water infiltration and soil aggregation.Soil Sci.Am.J.,(61):565-570.
111.Bozzano G,Dente M.2001.Shape and terminal velocity of single bubble motion:a novel approach .Computers and Chemical Engineering,(25):571-576
112.BrownL R Halweil B.1998.China's water shortage could shakeworld food security.World Watch, 11 (4): 10-21.
113.Claude Culpin,1986.Farm Machinery (Elevnth Edition) .102-124.
114.Geh ring J M,Lew is A J.1980.Ⅲ Effect of hydrogel on w ilting and moisture stress of bedding plants.JAmer Soc Hortsci, 105 (4): 511-513.
115.1ngram D L.YeagerTH.1987.Effects of irrigation frequency and a water-absorbing polymer amendment on ligustrum growth and moisture retention by a container medium.Journal of Environmental Horticulture, (5): 19-21.
116.Kawai T, Yoshino H, Kawabata Y.2002.Self-regulating characteristics of a cold neutron source with a cylindrical-annulus moderate cell .Physica: B, (311):164-172 .
117.Jeff J.Schoenau.2000.Fluid Fertilizers In Direct Seeding Systems.Fluid Journal,l-2.
118..J.M.Shippen,C.R.Ellin ang C.H.Cloyer.1980.Basic Farm Machinery(Third Edition).161-179.
119.Johnson M S.1984.The Effects of Gel Forming Polyacrylamides on Moisture Storage in Sandy Soils.Sci.Food Agric,(35): 1196-1200.
120..Levin J,et al.1997.Rain energy and soil amendments effect on infiltration and erosion of three different soil types.Aust.J.Soil Res.,(29): 455-465.
121.Mendelson H D.1967.The prediction of bubble terminal velocities from wave theory .AICHE Journal,13(2) :250-252
122.M.J.Hayes, E.D.Williams.1986.Some effect fluid-sowing, pre-germination, irrigation and soil covering on the establishment and growth of seedlings of white clover slot-seeded into permanent pasture Grass arid Forage Science ,41 (2): 151-157.
123.0midian H, Hashemi S A, Sammes P G, et al1998.A Model for the Swelling of Superabsorbent Polymer.Polymer, (26): 6697-6704.
124..P.J.Salter.Fluid Drilling of Pre-germinated Seeds: Progress and Possibilities.SHS Acta Horticulturae 83: Symposium on Seed Problems in Horticulture
125.Raymond F, Rosant J M.2000.A numerical and experimental study of the terminal velocity and shape of bubbles in viscous liquids .Chemical Engineering Science, (55 ):943-955 .
126.Seckler D,Barker R, Amarasinghe U.1999.Water scarcity in the twenty first century.W ater Resources Development, 15( 1-2) :29- 42.
127.Shainberg,Levy G J.1994.0rganic polymers and soil sealing in cultivated soils.Soil Sci,158(4):267-273.
128.Siberbush M ,Adar E,De Malach Y.1993.Use of an hydrophilicpolymer to improve water storage and availability to cropsgrown in sand dunes.A gricultural Water Management,(23):303-313.
129.Sojka R E, et al.1998.Water and erosion management with multip leapp lication of polyacrylamide in furrow irrigation.Soil Sci.SocAm.J., (62): 1672-1680.
130.Suhas R.Ghate.a new seeder for fluid sowing germinated seeds.ISHS Acta Horticulturae 187: I International Symposium on Mechanization of Vegetable Production 131.Taylor K C,HalfacreRG.1986.The effect of hydrophilic polymer on media water.retention and nutrition availability to Ligustrumlucidum.HorticulturalScience,21(5):l 159-1161.
132.Woodhouse J,M.S.Johnson.1991.Effect of super-absorbent polymers on survival and growth of crop seedings.Agricultural Water Management, (20): 63-70.
133.Wallance A.1986.A polysaccharide (GUAR ) as a soil conditioner .Soil Sci, (14)1:371-376.