I= PROFILE DISTRIBUTION AND AVAILABILITY OF NITROGEN IN BENCHMARK SOILS OF POTHWAR
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Title of Thesis
PROFILE DISTRIBUTION AND AVAILABILITY OF NITROGEN IN BENCHMARK SOILS OF POTHWAR

Author(s)
Fazli Qayyum Khan
Institute/University/Department Details
Department of Biological Sciences/ Quaid-i-Azam University, Islamabad
Session
1992
Subject
Biological Sciences
Number of Pages
136
Keywords (Extracted from title, table of contents and abstract of thesis)
nitrogen, pothwar, ammoniacal soil, balkassar, dibbling nitrate, soil nitrogen

Abstract
Studies on the profile distribution and availability of nitrogen on benchmark soils of Pothwar were carried out in order to (1) evaluate soil profile nitrogen, (2) predict the role of residual soil nitrogen, (3) economize the use of N fertilizers and (4) compare sources and N fertilizer placement methods for maximum efficiency. Soil samples were collected from four soil series in Pothwar area to a depth of 150 cm. Soil samples of the experimental field were analyzed upto 0-150 cm depth before wheat sowing and 0-90 cm depth after harvest.

Reduction in Soil nitrate nitrogen content was obtained with increase in soil depth in general. Accumulation of nitrates in most soils had taken place at depth ranging from 45 to 75 cm. Nitrate content of soil was found more in September than in March. Fluctuating amounts of ammoniacal soil nitrogen were found at various soil depths. The amounts of ammoniacal nitrogen were greater in soils collected in March than that September. The losses of ammoniacal nitrogen were greater in Missa, Rajar and lower depths in Balkassar soils due to high calcium carbonate contents than the gains in nitrate nitrogen caused due to increase in seasonal temperature. Organic matter and organic nitrogen decreased with increase in soil depths. With the exception of Guliana and lower depth (60-150 cm) of Missa soil, the ratios of organic matter to nitrogen decreased in September than in March.

Dibbling ammoniacal and urea fertilizers alone or with poultry manure proved equally better than dibbling nitrate source for producing grain and straw yield of wheat. Uptake of nitrogen by wheat was maximum from dibbling fertilizer with poultry manure and crop N requirements were met with in 64.27 to 75.28% NUE. Residual effect of fertilizer resulted in increased accumulation of ammoniacal nitrogen in soil. Leaching of nitrogen beyond 60 cm deep was negligible from ammoniacal nitrogen and broadcast method of placement. pH of soil was slightly reduced with ammonium and increased with urea application. Fodder sorghum yield correlated with residual nitrogen was maximum from treatments of dibbling with poultry manure. Grain protein was maximum from treatments of dibbling with poultry manure. Grain protein was increased by 7.76 and 6.67% by ammoniacal and urea nitrogen respectively as compared to nitrate source and by 20.11 and 22.77% respectively by dibbling alone and alongwith poultry manure over broadcasting, giving 66.67% more protein over check treatments (463.17 kg/ha).

Organic nitrogen in plant tissue was positively correlated with grain yield at all growth stages. Dibbling fertilizer with poultry manure increased tissue N concentration over other methods and decreased with growth stage. Tissue nitrate concentration was found more at 120 days after germination than that at 60 days. Dibbling fertilizer with poultry manure and urea application affected maximum tissue nitrate concentration.

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
117.47 KB
2 1 Introduction 1
71.54 KB
3 2 Review Of Literature 8
211.9 KB
4 3 Materials And Methods 27
90.29 KB
5 4 Results And Discussion 35
652.98 KB
  4.L Distribution Of Nitrogen In Pothwar Soils 35
  4.2 Crop Response To Fertilizer- N 51
  4.3 Effect Of Applied Fertilizer Nitrogen On Residual Soil Nitrogen After Wheat Harvest 58
  4.4 Comparison Of Available Models 69
  4.5 Effect Of Sources And Methods Of Nitrogen Fertilizer Application On Grain Protein 80
  4.6 Organic Nitrogen In Plant 82
  4.7 Nitrate Nitrogen In Plant 84
6 5 Summery 87
61.78 KB
7 6 Conclusions And Recommendations 92
24.04 KB
  6.1 Conclusions 92
  6.2 Recommendations 93
8 7 References 94
145.64 KB
9 8 Appendices 108
105.52 KB