I= NITROGEN NUTRITION MANAGEMENT AND FERTILIZER USE EFFICIENCY IN WHEAT UNDER DIFFERENT SOIL CONDITIONS
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Title of Thesis
NITROGEN NUTRITION MANAGEMENT AND FERTILIZER USE EFFICIENCY IN WHEAT UNDER DIFFERENT SOIL CONDITIONS

Author(s)
Muhammad Arshad
Institute/University/Department Details
Department of Biological Sciences/ Quaid-i-Azam University, Islamabad
Session
1999
Subject
Biological Sciences
Number of Pages
167
Keywords (Extracted from title, table of contents and abstract of thesis)
nitrogen nutrition management, fertilizer, wheat, wheat production, dicyandiamide, calcium ammonium nitrate, rainfed

Abstract
Nitrogen fertilizers are the major input being used for crop production especially for wheat in Pakistan. However, wheat yields are low, almost stagnant and nitrogen use efficiency is poor. Efforts are underway to improve wheat production and enhance nitrogen use efficiency. In this connection, different studies were carried out. In one study in which the effect of mixed NH4+ - N and NO3- -N nutrition was investigated, it was found that wheat yield and nitrogen utilization efficiency significantly improved when mixed NH4+ - N and NO3- -N in 50:50 ratio was used as compared to when these sources were used alone. It was further observed that balanced nitrogen nutrition was helpful to overcome the adverse effect of drought and salt stress. In another study on the effect of nitrogen carrier and dicyandiamide (DCD), it was found that nitrogen sources significantly affected the wheat yield and nitrogen use efficiency. Calcium ammonium nitrate (CAN) was found to be the most efficient nitrogen source followed by ammonium sulphate and urea. Use of DCD with CAN improved wheat yield by 29 per cent and plant nitrogen recovery by 34 per cent. This is because DCD inhibited nitrification process and maintained an ideal NH4+ - N :NO3- -N ratio in the soil where CAN was used. However, DCD was not helpful to improve efficiency of urea and ammonium sulphate, because of inhibition of nitrification process with the result ammoniacal nitrogen dominated in the soil when these fertilizers were used. Dominant. presence of this nitrogen form disturbed the ideal balance of NH4+ - N and NO3- -N ratio of 50:50. Therefore, no improvement in wheat yield and nitrogen use efficiency was registered. As regard the effect of gypsum and nitrogen sources on wheat yield and nitrogen utilization it was observed that the use of gypsum improved wheat yield from 30 per cent to 46 per cent and plant nitrogen recovery from 25 per cent to 39 per cent. Improved nitrogen use efficiency was attributed to reduction in soil pH and ammonia volatilization losses. In another study potassium helped to improve efficiency of nitrogen fertilizers for wheat production due to its role in nitrogen metabolism and other multifarious functions. On the whole findings of these research studies are of great practical significance, because if adopted at farm level can save chemical fertilizers worth several billions through improved nitrogen use efficiency and will enhance wheat production in the country, a step towards food self-sufficiency

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19916.82 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
861.34 KB
2 1 Introduction 1
1000.77 KB
3 2 Review Of Literature 3
6259.69 KB
  2.1 Behaviour Of Nitrogen Fertilizers In Soil 9
  2.2 Nitrogen Transformation In The Soil 10
  2.3 Fertilizer Use Efficiency For Crop Production 25
4 3 Materials And Methods 53
2026.22 KB
  3.1 Effect Of Salinity And Mixed NH 4 + - N and NO 3 - -N Nutrition On Wheat 53
  3.2 Effect Of Mixed NH 4 + - N and NO 3 - -N Nutrition On Wheat Under Different Moisture Regimes 55
  3.3 Effect Of Nitrogen Sources And Dicyandiamide (DCD) On Wheat 56
  3.4 Effect Of Gypsum On Ammonia Volatilization Losses And Efficiency Of Different Nitrogen Fertilizer For Wheat 58
  3.5 Effect Of Potassium Fertilization On The Efficiency Of Different Nitrogen Fertilizer For Rainfed Wheat 61
  3.6 Soil Analyses 62
  3.7 Plant Analysis 67
5 4 Results 71
6428.48 KB
  4.1 Effect Of Salinity And Mixed NH 4 + - N and NO 3 - -N Nutrition On Wheat 71
  4.2 Effect Of Mixed NH 4 + - N and NO 3 - -N Nutrition On Wheat Under Different Moisture Regimes 78
  4.3 Effect Of Nitrogen Sources And Dicyandiamide (DCD) On Wheat 85
  4.4 Effect Of Gypsum On Ammonia Volatilization Losses And Efficiency Of Different Nitrogen Fertilizer For Wheat 101
  4.5 Effect Of Potassium Fertilization On The Efficiency Of Different Nitrogen Fertilizer For Rainfed Wheat 117
6 5 General Discussion 125
3532.86 KB
  5.1 References 132