Yields and Nitrogen Dynamics in a Rice–Wheat System Using Green Manure and Inorganic Fertilizer
Milkha S. Aulakha,
Tejinder S. Kheraa,
John W. Doranb,
Kuldip-Singhc and
Bijay-Singha
a Dep. of Soils, Punjab Agricultural Univ., Ludhiana 141004, Punjab, India
b USDA-ARS, East Campus, Univ. of Nebraska, Lincoln, NE 68583 USA
c Farm Advisory Service, Punjab Agricultural University, Kapurthala, Punjab, India
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Fig. 1 Dynamics of (a) NH4–N and (b) NO3–N in three soil layers of no-N control (GM0 FN0–FN0) and fertilizer N (GM0 FN120–FN120) treatment in a rice–wheat cropping system during Year 2 (1993–1994). GM is green manure and FN is fertilizer N; subscripts denote application rates (Mg ha-1 and kg ha-1, respectively). Arrows denote fertilizer N application. * Indicates significant difference (P  0.05) between no-N control and fertilizer N treatment. The periods under fallowing (F), rice, and wheat are marked on the x axis
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Fig. 2 Total amount of (a) NH4–N and (b) NO3–N in the 60-cm soil profile of no-N control (GM0 FN0–FN0) and green manure (GM20 FN0–FN0) treatment in a rice–wheat cropping system during Year 2 (1993–1994). GM is green manure and FN is fertilizer N; subscripts denote application rates (Mg ha-1 and kg ha-1, respectively). *Indicates significant difference (P 0.05) between no-N control and green manure treatment. The periods under fallowing (F), rice, and wheat are marked on the x axis
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Copyright © 2000 by the Soil Science Society of America.
