Development of a nitrogen soil test for fertilizer requirements for corn and wheat production in Que...

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" Development of a nitrogen soil test for fertilizer requirements for corn and wheat production in Quebec "
M. R. Miransari Mahabadi A. F. Mackenzie

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1113265
Doc. No	:	TLpq304267707
Main Entry	:	A. F. Mackenzie
	:	M. R. Miransari Mahabadi
Title & Author	:	Development of a nitrogen soil test for fertilizer requirements for corn and wheat production in Quebec\ M. R. Miransari MahabadiA. F. Mackenzie
College	:	McGill University (Canada)
Date	:	1995
student score	:	1995
Degree	:	M.Sc.
Page No	:	127
Abstract	:	One must consider the effects of both soil N and fertilizer N, if rates of N-fertilizer application are to be optimized and NO3\sp- leaching into groundwater be controlled. Objectives were (1) to determine soil usd\rm NO\sb3\sp-usd-N and NH4\sp+-N, soil total N, and N fertilizer levels and corn and wheat yields; and, (2) to determine soil sampling times and depths for N analyses that correlated with yields and fertilizer N response. Soil samples taken at seeding and postseeding were analyzed for NH4\sp+-N and NO3\sp--N, and for total N in 29 wheat sites and 44 corn sites fertilized with four rates of N. N-Trak (quick test) and laboratory methods were employed to measure soil NO3\sp--N. A significant correlation was found between N-Trak and laboratory methods (R2 = 0.61 for corn and 0.89 for wheat). Compared to the laboratory method, N-Trak overestimated soil NO3\sp--N. Soil NO3\sp--N levels increased upon drying. In some cases soils showed an increase in soil NO3\sp--N from seeding to postseeding. Wheat yields and wheat grain N uptake were better correlated with soil NO3\sp--N at seeding than at postseeding. For corn, yields and grain uptake showed a higher correlation with soil NO3\sp--N at postseeding. Corn regression models predicted 180 to 240 kg ha of N fertilizer to obtain optimum economic yields and 0 to 40 kg ha N for wheat. Soil total N was not correlated with corn yields as highly as soil NO3\sp--N. Soil NO3\sp--N can be used as an indicator of fertilizer N requirements for corn and wheat in Quebec.
Subject	:	Agronomy
	:	Biological sciences
	:	Soil sciences
	:	Soil sciences