HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tripathi, B. P. Articles by Pascua, S. R. Search for Related Content PubMed Articles by Tripathi, B. P. Articles by Pascua, S. R. Agricola Articles by Tripathi, B. P. Articles by Pascua, S. R.

Nitrogen Dynamics and Balance in Intensified Rainfed Lowland Rice-Based Cropping Systems

Soil Microbiology, Soil and Water Sciences Division, International Rice Research Institute (IRRI), P.O. Box 933, Manila, Philippines

J. Timsina

Agronomy, Plant Physiology, and Agroecology Division, IRRI

S. R. Pascua

Rainfed Lowland Rice Research Consortium Site, Mariano Marcos State Univ., Batac, Ilocos Norte, Philippines

*Corresponding author (In%" J.K.LADHA{at}CGNET.COM")

ABSTRACT

Nitrogen dynamics and balances in intensive and diversified lowland rice (Oryza sativa L.)-based cropping systems that receive heavy fertilization, tillage, and irrigation have not been explored. Such information is essential to improve the efficiency of N fertilizer, an input based on a nonrenewable energy resource and whose oxidized products pose hazards to human health and the environment. Field experiments at an experimental farm on an Inceptisol and in two farmers' fields, one with an Inceptisol and one with a Vertisol soil, quantified (i) NO^-₃-N and NH⁺₄-N in different soil layers in relation to water-filled pore spaces (WFPS), (ii) N balance, and (iii) systems-level N efficiencies in several cropping patterns. Nitrate-N and NH⁺₄-N were quantified monthly from July 1993 to June 1994. The WFPS remained <0.80 mL mL^-1 in the beginning of the wet season and throughout the dry season that enhanced nitrification. Ammonium-N in the 100-cm layer was 20 to 40 kg ha^-1 in the wet season and <10 kg ha^-1 in the dry season. Nitrate-N, however, ranged from 27 to 54 and from 67 to 195 kg ha^-1 in the two seasons; it was higher in farmers' fields (192–195 kg ha^-1) than in the experimental farm (67–112 kg ha^-1). Total N loss was 34 to 549 kg ha^-1 across sites, with the largest in rice-sweetpepper (Capsicum annuum L. var. annuum) and rice-tomato (Lycopersicon esculentum Miller). Despite a lack of a consistent trend in N efficiency among the different cropping systems, it was higher with tobacco (Nicotiana tabacum L.) and garlic (Allium sativum L.). There appears an opportunity to grow a NO^-₃ catch crop during the dry-wet transition in rice-sweetpepper and rice-tomato systems to capture and recycle soil NO^-₃-N.

Received for publication August 15, 1995.

This article has been cited by other articles:

				A. M. Briones, S. Okabe, Y. Umemiya, N.-B. Ramsing, W. Reichardt, and H. Okuyama Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice Appl. Envir. Microbiol., June 1, 2002; 68(6): 3067 - 3075. [Abstract] [Full Text] [PDF]

				A. J. Eagle, J. A. Bird, W. R. Horwath, B. A. Linquist, S. M. Brouder, J. E. Hill, and C. van Kessel Rice Yield and Nitrogen Utilization Efficiency under Alternative Straw Management Practices Agron. J., November 1, 2000; 92(6): 1096 - 1103. [Abstract] [Full Text]

				R.K. Shrestha and J.K. Ladha Recycling of Residual Soil Nitrogen in a Lowland Rice-Sweet Pepper Cropping System Soil Sci. Soc. Am. J., September 1, 2000; 64(5): 1689 - 1698. [Abstract] [Full Text]