Based on the experiment studies , the study on water and solute transport in sandy soil under reclaimed water irrigation was made , the result can give some reference for the effect on soil solute transport and soil environment under micro - contaminated water irrigation 摘要以宁夏回族自治区大武口市森林公园的含砾砂土为研究对象,通过室内试验,对中水灌溉条件下砂砾质土壤在不同灌水量、多次连续灌水、降雨淋洗等不同来水条件下水分、污染物运移的规律进行了初步的研究,为微污染水用于绿化灌溉对砂砾质土壤中污染物运移及累积的研究提供科学依据。
This dissertation describes the studying of the whole construction of water - saving irrigation expert control system , the realization of hardware and software and low - cost soil - moisture sensor which is needed for water - saving irrigation . the distributed control system based on bus . according to real - time data of soil - moisture , water - level of sump , pressure of tube , etc . and irrigation knowledge in expert knowledge bases , it can make decisions such as when to irrigation , the water quantity to irrigation and the cost and benefit of the irrigation 本文对节水灌溉专家控制系统的总体结构、软硬件实现以及节水灌溉急需的低成本土壤水分传感器进行了研究,系统采用了基于总线的分布式控制结构,根据实时检测的土壤水分、水槽水位、管道压力等实时参数,知识库的作物灌溉知识,分析决策灌水时间、灌水量、灌溉成本及灌溉效益。
Water and nitrogen are two important factors which strongly affect vegetable growth . there were no significant differences in marketable yield between irrigation at rate of 250mm and 350mm and among n use more than 135kg / hm2 , which means that much water and nitrogen fertilizer could be saved using irrigation treat 250mm and nitrogenous fertilizer with 135kg / hm2to obtain higher yield 另外油菜的生物量在低施氮量下,过量的灌水可使油菜有减产的趋势,水分利用效率下降;芫荽的生物量随着施氮量和灌水量的增加而增加,但是当施氮量超过一定的值后,随着施氮量的增加其增加幅度呈降低的趋势。
In field study , the expenment on nitrogen transport and transformation in soils with different irrigation ( with both ground water and sewage effluent ) and fertilization levels has been conducted . with considenng the n - uptake , nitrification and demtrification processes , a model for describing no2 - - n transport and transformation in unsaturated soil has been applied . results show that , the n03 + - n accumulating in soil is contributed more by fertilization but lees by irrigation with sewage effluent , and the model can be used to simulate no3 - - n transport in soils 在室外进行了不同清污水灌水量与施肥条件下氮素迁移转化试验,同时进行了考虑根系吸收,硝化和反硝化的田间非饱和no _ 3 ~ - ? n迁移转化模型的数值模拟,研究结果表明与施肥相比,污水灌溉对土壤中no _ 3 ~ - ? n累积的贡献较小,所建立模型可用于模拟no _ 3 ~ - ? n在土壤中的迁移。
The horizontal wetting front in big discharge rate is wider than that of small discharge rate , and the vertical wetting front in big discharge rate is shallower than that of small discharge rate . the horizontal wetting front of 5 . 3l / h is wider 17 percent than 2 l / h , and the vertical wetting front of 5 . 3 l / h is shallower 20 percent than 2 l / h 对滴头流量在2 5 . 3l h范围内的微源入渗分析表明,对应于同一灌水量,流量为5 . 3l h的水平湿润锋比2l h的大17而垂向湿润锋则比之小20 。
Results showed : ( 1 ) if the proportion of water in the soil is lower than wilting coefficient , and if irrigating water is very little , ( irrigating water is spreading horizontally and vertically ) the relationship between the horizontal width ( x ) and the ? rtical depth ( y ) is remarkable . the equation is y - 0 . 02 12x2 + l . 8546x - 17 . 88 . the related coefficient is r = 0 . 9350 结果表明: ( 1 )在土壤含水量低于萎蔫系数的干燥条件下,进行微量穴滴灌,滴灌点土壤湿润面直径x与最大垂直面渗透深度y呈显著相关,数学模型为: y = - 0 . 0212x ~ 2 + 1 . 8546x - 17 . 88 ,相关系数r = 0 . 9350 ( 2 )在微量补水灌溉情况下,只有灌水量大于4000ml /穴,才能使滴灌水渗透到20cm以下土层,达到作物根系集中层,否则水分很难被作物吸收,造成滴灌水的浪费。
In general , the wetted soil volume is a semi - elliptic cone . the relationship between horizontal and vertical wetting front and infiltration time is remarkable power function . the relationship between wetted soil volume and infiltration time is remarkable stright line , and in case of certain volume of applied water , the wetted soil volume is not influenced by discharge rate 微源入渗的水平和垂向湿润锋与入渗时间存在极显著的幂函数关系;土壤湿润体体积与入渗时间之间存在显著的线性关系,直线斜率和供水强度有关;土壤湿润体体积和灌水量之间存在显著的线性关系,在灌水量一定的条件下,滴头流量对湿润体体积影响很小,在滴头流量为2 5 . 3l h的范围内,对于同一灌水量湿润体体积的差异保持在5以内。
Nitrate content of rape and coriander increased with higher nitrogenous fertilizer application and lower water supply . nitrogen leaching in the soil increased with higher nitrogenous fertilizer application and water supply in column and micro - plot experiments , especially on higher irrigation and higher nitrogenous fertilizer . there was little nitrogen leaching when n application was below 135 kg / hm2 , but n use at a rate of 270 kg / hm2 increased nitrogen leaching in the soil 在一定的施氮量下,硝态氮的积累峰值随着灌水量的增加而下移, 150mm灌水量下田区试验和模拟土柱试验0 100cm土体内硝态氮的积累峰值分别出现在0 30cm和50 70cm ; 250mm灌水量下分别出现在40 60cm和60 80cm ; 350mm灌水量下田区试验中0 100cm土体硝态氮没有出现峰值,而模拟土柱试验在80 100cm则有明显的积累。
Under the situation of total irrigation water use decreasing greatly and it is essential to irrigate saline soil ( saline soil and salt soil area constitutes 65 % of the whole infield ) , a saving irrigation experiment study was carried out in hetao irrigation area , and crop response to water and salt stress was studied by way of pot and field experiment 本文在河套灌区总灌水量减少又要解决盐渍化土地(占总耕地面积65 % )灌溉问题的前提下,针对主要作物油葵,采用苗期盆栽和田间试验相结合的方法进行作物水盐胁迫响应研究。
But , when the total water quantity is reduced 30 % of present average amount in the 2010 , the total salinity of groundwater will have significant increase in the different period ( pre - summer irrigation , post - summer irrigation , pre - autumn irrigation and pre - freezing up of soil four periods ) . the water quality will be likely to deteriorate ; in addition , the prediction models of soil moisture and saline concentration are established 通过试区土壤水分、盐分的bp与rbf模型的模拟与检验,预测了2005年、 2010年夏灌前、夏灌后、秋浇前与封冻前的土壤水盐状况,得出上壤水分随着灌水量的减少呈下降趋势,而土壤盐分在浅层与中层呈现出不同的结果: oa