title: Tropical legume crop rotation and nitrogen fertilizer effects on agronomic and nitrogen efficiency of rice.
abstract: Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m(-2) preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m(-2). No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m(-2) achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13-23% higher grain yield than rice after fallow rotation with 8 g N m(-2). The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m(-2) can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m(-2). The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.
authors: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Motior M
authors: MM
authors: Rahman
authors: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Aminul M
authors: AM
authors: Islam
authors: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Sofian M
authors: SM
authors: Azirun
authors: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Amru N
authors: AN
authors: Boyce
mesh_terms: D000383:Agriculture; D018533:Biomass; D018556:Crops, Agricultural; D007887:Fabaceae / Q000502:physiology*; D005308:Fertilizers; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D009586:Nitrogen Fixation; D012275:Oryza / Q000502:physiology*
chemical_list: D005308:Fertilizers; D009584:Nitrogen