Dissertation > Excellent graduate degree dissertation topics show

Nutrient Balance Estimates and Environmental Impact in Typical Red Soil Region in Qiyang County

Author: ALaTengXiHuRi
Tutor: ZengXiBai
School: Chinese Academy of Agricultural Sciences
Course: Soil
Keywords: red soil spatial variability nutrient balance environment impact
CLC: S158
Type: Master's thesis
Year: 2010
Downloads: 72
Quote: 0
Read: Download Dissertation

Abstract


Red soil region in southern China is an important agricultural production base, with land area only of 1/5, but raising 40% of the population. With the increase of modern agricultural inputs, the influence of non-point source pollution in the environment caused by agricultural production and rural life has become increasingly prominent. In Qiyang County, Hunan Province, we investigated farmland field area and collected related information, and collected a large number of soil samples by using GPS. Compared with the results of long-term fertilization experiment, we discussed the temporal- spatial variability of soil nutrient, nutrient balance and estimated the nutrient loss to provide a scientific basis for the prevention and control of agricultural non-point source pollution. The main conclusions of this paper were as follows:1) Compared with the results of the Second Soil Census, almost all nutrients contents including OM, TN, available N and available P have increased in different levels, in which paddy field increased by 9.6%, 17.4%, 23.4% and 46.5%, respectively, and upland field increased by 13.6%, 8.3%, 6.1% and 49.4%,respectively. Available K decreased sharply by 18.4% in paddy field and by 24.1% in upland field. In different soil profile, contents of OM and TN increased in all layers of paddy soil and upland soil; TP decreased in all layers of paddy and upland soil; TK decreased in cultivated horizon and plow pan in paddy field, and decreased in cultivated horizon and illuvial horizon in upland field. TK increased significantly in gley horizon of paddy field and parent material horizon of upland field. From thickness of soil layers, the depth of cultivated horizon and plow pan decreased 9cm and 8cm in paddy field, respectively, and in upland field, the depth of cultivated horizon decreased 5cm and illuvial horizon increased 4 cm .2) N and P were in surplus and K had a deficit in Qiyang county agroecosystem. Surplus amount of N was 194.63 kg·hm-2·a-1 ~243.44 kg·hm-2·a-1, and the average annual rate of profit is 89.20% in paddy soil. Surplus amount of N was 50.96 kg·hm-2·a-1 ~150.84 kg·hm-2·a-1 in upland field, and the rate of profit is 50.88%. Surplus amount of P was 2.86 kg·hm-2·a-1 ~32.35 kg·hm-2·a-1 and 26.63 kg·hm-2·a-1 ~39.98 kg·hm-2·a-1 in paddy soil and upland field,with the average annual rate of profit of 13.96% in paddy soil and 27.75% in upland soil, respectively. The deficit of K was 69.07 kg·hm-2·a-1 ~137.52 kg·hm-2·a-1 and10.32 kg·hm-2·a-1 ~164.69 kg·hm-2·a-1 in paddy soil and upland field,and the average annual rate of deficit is 34.55% and 29.07%, respectively.3) Through long-term different fertilization treatment test located in Qiyang County, we studied the effect of different fertilization treatment on the soil balance. In CK treatment, the supplying amount of N, P and K were 21.43 kg·hm-2·a-1, 10.72 kg·hm-2·a-1, 31.71 kg·hm-2·a-1, respectively. The amount of nutrients absorption declined year by year, and N, P and K nutrients in soils were depleted greatly. With inorganic chemical treatment, soil nutrition balance had increased, and surplus amount of N was 211.88 kg·hm-2·a-1 ~254.17 kg·hm-2·a-1. With NPKM treatment, the contents of soil TN, TP and TK in plough layer improved, and the amount of nutrients absorption increased and soil nutrients kept balance on the whole as an ideal fertilizer treatment.4) The amount of N loss in farmland at Qiyang County was 26933.10t,including leaching amount of 362.72t, ammonia volatilization of 26141.6t, and nitrification-denitrification loss of 428.78t. The amount of P loss was 3.30t, including leaching amount of 2.64t, and runoff amount of 0.66t. The amount of K loss was 507.81t, including leaching amount of 422.08t, and runoff amount of 85.73 t. The loss of these nutrients was not only a serious waste of limited resources, but also increased the production cost of agriculture, and reduced the overall efficiency of agriculture, which may be a major reason to non-point source pollution.From the above, we should reduce the use of chemical fertilizers,and increase the amount of organic manure fertilizer application to improve soil fertility and nutrient storage capacity, reducing the loss of Nitrogen and Phosphorus in the environment for building high-yield crops and resource-saving environment-friendly agricultural development mode.

Related Dissertations

  1. Study on Rice-Frog and Melon-Frog-fish Ecological Cultivation and Breeding Mode and the Nutrient Balance,S-0
  2. Risk Analysis and Mitigation Experiment of Heavy Metal Pollution in Croplands in Vicinity of Pollution Sources,X820.4
  3. Subarea Management of Tobacco Soil Nutrients and Adequate Fertilization Research by Micro Scale,S158
  4. Spatial Variability and Quality Evaluation of Soil Nutrient in the Small Watershed of Red Eroded Soil Area,S158
  5. Study on Spatial Variability and Assessments of Soil Nutrients and Heavy Metals in Intertidal Zones,S158
  6. Study on Methane and Nitrous Oxide Emission in Double-Crop Rice Fields at Red Paddy Soil under Long-Term Different Fertilizer Systems,S511
  7. The Heavy Metals Distribution Characteristics and Risky Evaluations of Farmland Soils-Crops Around Different Types of Chemical Industrial Park,X833
  8. Distribution and Spatial Variability Characteristics Analysis of Saline Soil at Settlement No.1 of Huanghua in Irrigated Areas in Gansu Shule,S153.6
  9. Spatial Variability of Water Quality Parameters in Rivers,X824
  10. Nutrient Balance and Fertilization for Wheat/ Maize Rotation System in Western Guanzhong,S513
  11. Lan Ling Tea Creek watershed slope nutrient distribution characteristics and spatial heterogeneity,S158
  12. Study on the Erosion Treatment Effectiveness and Implementation Model of Red Soils Developed from Two Parent Materials in Hilly Region,S157
  13. Spatio-temporal Variability of Red Soil Fertility and Utilization Potential Evaluation in Low Hill Region of Longyou County,S158
  14. Analysis on Spatial Variability of Soil Heavy Mentals and Evaluation on Their Pollution Status in Urban Verge Zone,X820
  15. Study on the Influence of Changqing Areas Exploitation to the Yellow River’s Hydraulic Works and Environment,X820.3
  16. Effect of Near-Surface Soil Hydrological Conditions on Soil Erosion and Nutrient Losses at Hillslopes,S157.1
  17. Variation of Soil Nutrients and Coupling of Soil Water-Nutrients in Typical Red Soil with Long-Term Fertilization,S158
  18. Study on Spatial Variability of Soil Water and Salinity in Hetao District in Inner Mongolia, China,S153
  19. Study on the Improvement Measures of Haizhou Open-cut Coal Mine Dump Soil,S156
  20. Spatial Variability and Condition Evaluation of Soil Nutrients in Heyang,S158.9

CLC: > Agricultural Sciences > Agriculture as the foundation of science > Soil > Soil fertility (soil fertility )
© 2012 www.DissertationTopic.Net  Mobile