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Simulation of Water Productivity and Soil Desiccation of Dryland Apple Orchard on Semi-humid and Prone Drought Areas of the Loess Plateau

Author: WangYaLi
Tutor: LiJun
School: Northwest University of Science and Technology
Course: Crop Cultivation and Farming System
Keywords: Loess Plateau Drylands in semi Apple Orchard EPIC model Water productivity Soil desiccation
CLC: S714
Type: Master's thesis
Year: 2011
Downloads: 27
Quote: 0
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Located in the middle of the Loess Plateau drylands in semi apple production base is rapidly expanding emerging. However, due to natural precipitation is low and the Apple growth of water consumption strongly, leading rainfed orchard soil desiccation phenomenon began to appear and gradually intensified, a serious threat to the sustainable development of the apple production. Different growth years of the study on the Loess Plateau drylands in semi Xifeng and Yan'an the Apple Orchard deep soil moisture determined, comparison and analysis of rainfed and irrigated Apple Orchard soil dry layer formation law, and stubble soil desiccation intensity contrast, reveals a different land use types and under different management, soil desiccation Occurrence. In the formation of the Loess Plateau semi-humid the Arid Regions Xifeng and Yan'an region sequence of daily meteorological elements, typical soil profile physicochemical traits, crop growth parameters database on the basis of, application WinEPIC model simulation study from 1960 to 1999, the Xifeng Yan'an water productivity changes dynamically and soil desiccation effects reveal the the orchard soil dry layer formation law and soil desiccation of the long-term effects of orchard productivity, determining reasonable to adapt to the different regions orchard planting years for Apple Orchard in the Loess Plateau sustainable use of soil moisture and apple production base to provide a scientific basis for health stable development. The main progress achieved as follows: 1. The Xifeng area measured in the field study results show that: (1) orchard soil desiccation intensity was significantly higher than the wheat stubble ground. 0 ~ 1300 cm stubble ground soil storage capacity of 2065 mm, above 12 age, age 18 and 26 age orchards average (2014 mm); water overuse was 119 mm, significantly less than the 12 Age 18 Age the 26 Age orchard water overuse the average (249 mm). The stubble ground dry layer depth of 440 cm, the significantly shallower the age of 12, age 18 and 26 age dry layer depth average of 880 cm. (0 ~ 1300 cm 2) age 26 to irrigate the orchards soil average soil moisture of 11.7%, higher than the 18 age orchards (11.12%); their dry layer up to 1040 cm, the age of 18 orchards (1082 cm); soil desiccation intensity (mild desiccation) lighter than the age of 18 orchards (moderate desiccation). Yan'an area of ??field survey results show that: (1) in the same planting density, rainfed orchard with the prolongation of planting years, 0 ~ 1000 cm soil moisture content decreased gradually, year after year to deepen thickened dry layer, and 12 age and 20 Age orchard dry layer up to 800 cm and 1000 cm, soil desiccation intensity from mild desiccation (age 12) - the moderate dry (18 age). (2) The spacing of 3 m × 4 m 16 Age orchard soil desiccation strength is higher than the spacing of 4 m × 5 m 12 Age 20 Age orchard. 16 age 0 ~ 840 cm soil layer storage capacity of 1290 mm, below the age of 12 and 20 age orchard average (to 1389 mm); water overuse 400 mm, significantly more than the 12 age and 20 age orchard water The over-consumption of the average (237 mm). Model simulation results show that: (1) from 1960 to 1999 during the simulation of, Xifeng and Yan'an fruit trees, production in the 10-year-old reached the highest value was significant fluctuations in a downward trend, the two trees, respectively, in the age of 22 and 23 age after more than 70% of the fruit trees yield reached low-yielding orchards yield value, yield and with changes in precipitation unstable fluctuations, the average of of 16.53 t/hm2 and 16.31 t / hm ~~ 2, respectively. (2) the Xifeng and Yan'an 1 to 10 age and 11 to 23 age Apple Corner year average water consumption is higher than the same period in precipitation, soil desiccation rate of 94 mm / a and 22.6 mm / a and 114 mm / a and 23.9 mm / a, so that the soil layer of 0 ~ 10 m to 23 age Apple Orchard effective water content was significantly lower trend; 24 to 40 age Apple Orchard is roughly equal to the average annual water consumption over the same period of precipitation, during which the two soil effective water content, respectively, in the 70 ~ 240 mm and 281.7 ~ 319.2 mm range with changes in growing season precipitation stabilize fluctuations. (3) from 1960 to 1999 during the simulation of the Xifeng Yan'an Apple Orchard in 0 ~ 200 cm soil layer, soil moisture fluctuations significantly reduced year by year; 2 ~ 10 m soil average soil moisture, dry layer every year to deepen and thicken 12 age orchards dry layer has reached 10 m; Since then, the old soil humidity in the two regions is becoming more and more stable wilting humidity at age 24 and 21 age. Soil desiccation intensity of the Xifeng area by no desiccation (age 1 to 6) - slightly desiccated (age 7) - moderate desiccation (age 8 to 9) - severe desiccation (age 10 to 11) - strongly desiccated (12 age) and the gradual strengthening of the formation of a stable and strong drying state even after 24 age. Yan'an areas dry soil strength by desiccation (age 1 to 6) - mild desiccation (age 7 to 9) - moderate desiccation (age 10 to 11) - severe desiccation (12 age) gradually strengthen as well as the formation of a stable and strong drying state after 21 age. (4) In view of the strength of the analysis of the stability of yield and soil desiccation, the Xifeng and Yan'an rainfed Apple Orchard soil moisture reasonable duration of use were 22 to 24 years and 21 to 23 years.

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