Abstract:
Applied fertilizer N is not supposed to be 100 per cent utilized by crops but supplemented by soil native organic and inorganic forms during the growing season which is influenced, mainly by soil, water and plant inter-relationship. A study was conducted at the National Agricultural Research Centre, Islamabad to find out quantitatively (i) the uptake of native as well as applied nitrogen by wheat under different application methods, (ii) to select effective source of N fertilizer and (iii) to know the residual effects of N sources applied in different ways and on the following sorghum crop. Soil samples of the experimental field were analysed upto 150 cm depth before wheat sowing and 90 cm depth after harvest during 1989. Ammonical, nitrate and urea forms of N including check were applied as broadcast, dibbled with and without poultry manure 10 cm deep at the rate of 100kg N per hectare. Phosphorus @ 90 kg P205 and K @ 60 kg K20 per hectare were applied as basal dose. Dibbling ammonical 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 per cent NUE from 60 to 75cm depth. Residual effect of fertilizer resulted in increased accumulation of ammonical nitrogen in soil. Leaching of nitrogen beyond 60cm deep was negligible from ammonical nitrogen and broadcast method of placement. Maximum fodder yield was obtained from dibbling alongwith pm and correlated with residual soil nitrogen.
Page(s):
72-76
DOI:
DOI not available
Published:
Journal: Pakistan journal of soil science, Volume: 11, Issue: 1--2, Year: 1996