【作者】 杨有刚；

【导师】 郭康权； 薛少平；

【作者基本信息】 西北农林科技大学 ， 农业机械化工程， 2010， 博士

【摘要】 免耕地施水播种是春旱严重时夏粮抢种保苗的重要手段,对西部旱区农业增产具有积极作用。但是,传统的施水播种灌水后,土壤湿润区的水平方向尺寸是垂直方向的1.5～2.5倍。提高灌水下渗深度,减少水分蒸发,是施水播种技术进一步节水增效的新途径。在保护性耕作条件下,本文首先对施(坐)水播种灌水下渗的影响因素进行了分析,研究了能加速灌水下渗的两种土壤状态,以及切块式和铲式两种土壤松耕方法。然后,探讨了切块式浅松法有利于灌水下渗的土壤结构体形状和大小,在陕西杨凌试验地(塿土)试验分析了切块式和铲式浅松法的松土灌水入渗效果,并与旋耕和免耕土壤施水效果进行了比较;建立了切块式浅松条件下的土壤湿润区数学模型。设计了具有切块式浅松功能、模拟人工挖穴作业的施水播种机,并对其稳定性进行了分析。最后,对结构更简单紧凑,具有铲式浅松和铲式开沟施水功能的施水播种联合作业机进行了田间试验。取得的主要结论如下:1、土壤中孔隙率的增加,是提高施水播种灌水下渗速度和深度的有效途径。因此,首先提出并研究了一种切块式浅松法,该方法产生的土壤结构体互相支撑,形成了有利于灌水下渗的大孔隙,并可以人为控制所切土块的大小,松土效果好,但刀具运动较复杂。其次,根据免耕地土壤较密实的特点,只在玉米种床部位灌水下渗的路径上铲式浅松土壤,增加土壤中的微孔隙,这种方法对应的施水播种联合作业机,结构简单紧凑,在目前的研究水平上,更具应用前景。2、当切块式浅松法产生的土壤结构体,最大尺寸范围为10～40mm时,灌水湿润峰下移速率大,遇水即散,含水率高,干容重小。使用的“Y”型刀具,自洁性好,切下的土块均匀度高,并分布于土层中上部,而碎土则基本位于土层中下部,灌水下渗快,无积水现象,土壤湿润区总体位置比免耕地和旋耕地对应的湿润区位置低13mm,总的水入渗深度比免耕地对应值提高约19.6mm,比旋松土壤对应值提高约24.6mm,灌水水平方向和垂直方向入渗深度的比值由1.27降低到0.8。合适的切土距离为10～30mm。3、针对切块式浅松法,建立了一种求解方便,由代数方程表示的灌水入渗数学模型,通过理论计算结果与试验结果的比较可知,两者湿润区剖面面积的重合度达90%。松耕作业形成的土壤结构体尺寸,种穴或种沟深度等参数,对土壤湿润区宽度的减少,深度的增加有很大影响。4、针对铲式和切块式浅松法,建立并验证了施水播种穴施水量和开沟间歇施水每次施水量的理论计算模型。5、通过对种床下铲式浅松,开沟间歇施水播种机进行的田间试验表明:铲式浅松法松土施水后,水入渗平均深度为76.1mm,比免耕地对应值大4.8mm,比旋松土壤对应值大5.2mm,在地表下50mm处土壤含水率由施水前的6.5%,提高到施水作业后的15.7%,玉米出苗率和苗高等相关指标均合格。机具其他性能参数如:点播距合格率94.7%,变异率4.6%,重播指数1.82%,漏播指数2.19%,种子离水湿润中心距的合格率96%,种水同穴率99.7%等,均满足农艺要求。研究的创新之处:1、提出了通过合理的松耕方法,增加土壤的孔隙率,增加施(坐)水播种灌水下渗速度和深度的方法。2、提出了一种能在土壤中形成大孔隙的切块式浅松法,该松耕方法形成的土壤结构体集中于松土层上部,有利于灌水下渗。3、提出了两侧土壤保持免耕状态下的带状铲式浅松法,增加灌水下渗路径上土壤的微孔隙率,提高灌水下渗速度和深度的方法。更多还原

【Abstract】 The no-tillage farmland is an important measure for rush planting and protecting young plants in summer during the severe spring drought. It has a positive role in agricultural production in the arid western region . However, after the traditional Bed-irrigating sowing irrigation , the horizontal direction size of the soil moist areas is the 1.5 to 2.5 times of the vertical size. How to improve the depth of irrigation infiltration, and reduce evaporation, water seeding technique is to take the key to further water-saving efficiency of Bed-irrigating sowing.In conservation tillage, this article first applied Bed-irrigating sowing, influencing factors were analyzed to study the two soil status which can accelerate the infiltration of irrigation and two loose soil farming methods of cut and shovel .Then, the shape and size of the soil structure element which is beneficial to improve the depth of irrigation infiltration in the shallow digging of cut type were discussed. an experiment was carried out in Yangling, Shaanxi to test the effect of irrigation infiltration effect of the shallow digging of cut type and shovel type and compared the effect of irrigation with rotary tillage and no-tillage soil. established a mathematical model of cut-type light loose soil moist area. Designed an irrigating-sowing machine with a shallow cut loose type function, and simulation of artificial digging operations and analysised its stability.Finally an experiment was carried out in the farmland to test the combine irrigating-sower Which with spade and shovel loose shallow operations. The main conclusions obtained are as follows:1、The increase of soil porosity is the effective way to improve the water infiltration rate depth of irrigating-sowing. So, firstly proposed and studied a dicing style of topsoil cultivation method, which produces soil structure support each other, forming a favorable irrigation infiltration of large pores, and can be artificially control the cutting the size of clods, loose soil effect, but more complex tool movement. Secondly, according to a more dense soil characteristics of no-tillage farmland, shovel loose soil only on the path of irrigation infiltration shallow of the maize seed-bed parts, increase soil micro-pores, the corresponding irrigating-sowing joint operation machine has simple and compact structure, at the present research level, has more application prospect. 2. When the soil structure produced by shallow digging of cut type, which the largest size ranges of 10 ~ 40mm, the irrigation wetting peak moves down quickly, goes off when encountering the water, high moisture content, dry bulk density small. Using of the "Y"-type tools, the self-cleaning is good, the cut clods has a high degree of homogeneity, and distributed in the upper soil layers, while the pulverizer is basically located in the lower part of soil, irrigation infiltration fast, no water phenomenon , the overall position of humid regions is 13mm lower than in soil-free and spin-cultivated land area corresponding to the position of humid, the total depth of water infiltration is more than the corresponding values for free land increased by about 19.6mm, loosen the soil than the corresponding value increase of about 24.6mm, the ratio of irrigation horizontal and vertical infiltration depth decreases from the 1.27 to 0.8. The suitable soil-cut distance is 10 ~ 30mm.3. Aiming at the method of loosening the soil by cutting up clod on the surface, an easy solved mathematical model was set up. It gives a description of watering and penetrating through the soil.By contrasting the results of theoretical computation with the results of the experiments, it showed the two areas of cross-section of the humid region coincided up to 90%. The parameters of the depth of the seed hole, the depth of furrow depth and the measurement of soil particle formed in the loosening cultivation played an important role in reducing the width of the humid region and increasing its depth.4. Aiming at the method of shovel-like topsoil cultivation and the method of loosening the soil by cutting up clod on the surface, a theoretical calculation model was set up. It certified the water supply of irrigation per hole and per water supply of intermittent watering in the process of ditching.5. Through the field experiments on the shove-like surface tillage ditching and intermittent watering sowing machine, it shows: after scarification and watering by using the method of shovel-like topsoil cultivation, the average depth of the water seeping into the soil was 76.1mm. It is 4.8mm deeper than that of the no-tillage farmland and 5.2mm deeper than that of the rotary tilling soil. Under the earth surface about 50mm, the moisture content of the soil increased from 6.5% to 15.7%. Targets about the emergence rate, the seeding height of the corn and so on were all up to standard.The other performance parameters machinery such as: the yield of hill-seeding distance is 94.7%, the variation rate is 4.6%, the Index of reseeds is 1.82% , the index of leakage sowing is 2.19% ,the yield of seeds from water moist center distance is 96%, the rate of water and seeds in the same hole is 99.7% and so on, and those can meet the agricultural requirements. The innovation of the research:1. Put forward by increasing the micro porosity and the big porosity, to improve (by) water infiltration rate and depth of sowing irrigation methods. Corresponding to the two soils situation, separately studied two methods which can increase the soil porosity:(1) Propose and study a shallow digging of cut type method, which produces the basic focus of soil structure loose soil on top, and mutual support, Led to the formation of large pores which is in favor of irrigation infiltration. An irrigating-sowing machine for plant corn which can sow and irrigation for each hole was Designed with slider crank reciprocating motion, driving the cutter to loose soil and dig.(2) Took use of no-tillage farmland more compact, we proposed shallow shovel loose ribbon, with a direction perpendicular to keep the farmland no-till soil condition, and the method of increase the micro-porosity which on the path of irrigation soil infiltration. Studied and tested an irrigating-sowing machine which with shallow digging of shovel type to loose soil and ditch.2. Established a convenient for solving mathematical model of infiltration in irrigation.3. Established a theoretical model of Water supply for each hole in the Bed-irrigating sowing and Water supply of irrigation in the Ditching intermittence.更多还原