Effect of rice straw management on nitrogen balance and residual effect of urea-N in an annual lowland rice cropping sequence

Autor: S. Phongpan, Arvin R. Mosier
Rok vydání: 2002
Předmět:
Zdroj: Biology and Fertility of Soils. 37:102-107
ISSN: 1432-0789
0178-2762
DOI: 10.1007/s00374-002-0566-1
Popis: Two field experiments were conducted in 1999 (wet season) and 2000 (dry season) on a Ustic Endoaquerts in central Thailand to examine the impact of rice straw management practices on rice yield, N uptake and fertilizer-N use efficiency. Treatments included a combination of urea broadcast at a rate of 70 kg N ha−1 with either straw or compost which were incorporated at a rate of 5 Mg ha−1. At maturity of the wet season rice, 15N recovery by the grain was low (11–14%) as well as straw-N derived from labeled N (5–7%). After harvest, 25–29% of applied N still remained in the soil, mainly in the 0 to 5-cm layer. Large amounts of fertilizer-N (53–55%) were lost (unaccounted for) from the soil/plant system during the first crop. Residual fertilizer-N recovery in the second rice crop was less than 3% from the original application. During both fallow seasons NO3 −-N remained the dominant form of mineral N (NO3 − + NH4 +) in the soil but its concentration was low. In the wet season grain yield response to N application was significant (P =0.05). Organic material sources did not significantly change grain yield and N accumulation in rice. In terms of grain yield and N uptake at maturity, there was no significant residual effect of fertilizer-N on the subsequent rice crop. These results indicated that the combined use of organic residues with urea did not decrease total N losses or increase crop yield or uptake of N compared to urea alone.
Databáze: OpenAIRE
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