Dissertation > Excellent graduate degree dissertation topics show

Study on Farmland Water-Nitrogen Distribution Characteristics and Water Consumption Law of Maize under Film Hole Irrigation

Author: JiaLiHua
Tutor: FeiLiangJun
School: Xi'an University of Technology
Course: Agricultural Soil and Water Engineering
Keywords: Film hole irrigation Corn Distribution of soil water and nitrogen Water law Irrigation system
CLC: S513
Type: Master's thesis
Year: 2008
Downloads: 155
Quote: 3
Read: Download Dissertation

Abstract

Evapotranspiration of corn and farmland nitrogen study film hole irrigation with water-saving agricultural development needs and of groundwater environmental pollution problems caused due to the application of nitrogen fertilizer is increasingly prominent, distribution characteristics has important scientific value and production of practical significance. At present, the domestic scholars focused on the film hole irrigation infiltration characteristics, flow characteristics of the field surface irrigation technology elements and irrigation quality evaluation conducted a series of studies, these studies did not involve Farmland nitrogen distribution of film hole irrigation and crop consumption water law issues. The papers on the basis of the inspection and summarizes domestic and foreign film hole irrigation and soil nitrogen transport and other related literature, and the National Natural Science Foundation of film hole of farmland nitrogen transport characteristics irrigation quality evaluation method research \the outdoor plot experiment and theoretical study of the combination of technology to test the main route farmland corn film hole irrigation of farmland water and nitrogen distribution characteristics and water law, the key findings are as follows: (1) film hole irrigation irrigation system water and nitrogen distribution characteristics were studied. The results show that: the soil water and nitrogen of farmland irrigation system in the 0 ~ 60cm soil seasonal dynamic change, soil nitrate in the growth period of the vertical profile of the center of the membrane pore existence of a centralized distribution area, the distance from the the film hole center level farther, the smaller the distribution concentration peaks. Vertical soil profile nitrate nitrogen the seasonal content by irrigation frequency of irrigation quota, far fertilization point less affected in nearly fertilization. Irrigation times, more irrigation quota soil surface nitrate seasonal decreases faster, more soil nitrate reduced deep, deep 80 ~ 100cm nitrate accumulation in the larger, irrigation quota on its The influence of irrigation frequency. This article under the test conditions, the corn growth stages to irrigation four times the irrigation quota 524.7m ~ 3/hm ~ 2 for the best. (2) study the film hole irrigation farmland soil water and nitrogen distribution and nitrogen transformation characteristics. The results show that: the film hole with good soil moisture characteristics, slowed by coating the the traditional border irrigation soil surface moisture abrupt change with the seasons, about 20.0% compared to border irrigation water saving. Film hole irrigation eliminates border irrigation soil intense evaporation of urea hydrolysis and nitrification film hole irrigation urea hydrolysis rate uniform flat farmland soil test conditions herein urea hydrolysis and nitrification of ammonium nitrogen basic in 20 days completed. Film hole irrigation with soil nitrate distribution in the vicinity of the film hole, the film hole center vertical soil profile nitrate distribution is more uniform soil nitrate content was first increases and then decreases the distribution shape; the border irrigation distribution is more concentrated vertical profile of soil nitrate content in nearly fertilization, far fertilization point small. Under the test conditions of this article, the film hole irrigation than basin irrigation compared to 80 to 100cm deep nitrate leaching losses reduced by 27.0%. (3) research the Corn film hole irrigation water law and water production efficiency. The results show that: the film hole irrigation corn growth period, the greater the irrigation quota of irrigation times more maize growing larger water consumption. Water consumption by irrigation times, the effect size is mainly reflected in the increase of irrigation times, the effect of irrigation quota than large irrigation times; fixed in irrigation and irrigation times, under the conditions of the maize growing water consumption and water consumption intensity are a linear function of the relationship between irrigation amount and frequency; reveals the accumulated water consumption and water consumption of maize growing strength of the growth period the number of days between the film hole irrigation corn production meet the logarithmic function and a quadratic function relationship; satisfy a quadratic function of the relationship between soil moisture production efficiency and water consumption. This paper under the test conditions, the film hole irrigation than basin irrigation compared to water production efficiency of 23.3%, an increase of 15.9%. (4) corn film hole irrigation system. The results show that: the irrigation frequency and irrigation quota on corn biological indicators in less irrigation times, small irrigation quota impact significant increase in seedling irrigation on corn plant height and diameter, corn lodging resistance reduced. Corn entering the heading stage reproductive growth essentially stopped after harvest corn plant height, leaf area and heading basically the same; established at heading stage corn plant height with the same period the cumulative water consumption between a quadratic function relationship; calculated by theoretical analysis obtained efficient water irrigation quota of corn under the test conditions herein 2111.97m ~ 3/hm ~ 2 true by considering the test from the water-saving and high-yielding, best corn irrigation system: irrigation quota 2098.95m ~ 3/hm ~ 2, irrigation 4 times, respectively, at the jointing stage irrigation 2 1, heading irrigation, irrigation at grain filling stage 1, the irrigation quota to 524.7m ~ 3/hm 2.

Study on Farmland Water-Nitrogen Distribution Characteristics and Water Consumption Law of Maize under Film Hole Irrigation

Abstract

Related Dissertations