| Autor: |
H.U. Neue, Gloria Umali, Joyotee Smith |
| Rok vydání: |
1987 |
| Předmět: |
|
| Zdroj: |
Agricultural Systems. 24:165-181 |
| ISSN: |
0308-521X |
| Popis: |
Fertilizer response declines as soil nitrogen levels increase. Nitrogen fertilizer recommendations should therefore be tailored to the soil's nitrogen supplying capacity. A major methodological problem is the estimation of the quantity of nitrogen available from the soil. This paper uses recent advances made by soil chemists in the quantification of soil N-uptake to estimate a Total Nutrient model and derive farm specific nitrogen fertilizer recommendations for irrigated rice production in the Philippines. The analysis extends earlier work of this nature by Smith & Umali (1984) (Journal of Agricultural Economics), by using a more sophisticated formulation of soil N and a biologically more realistic fertilizer response function. Results show that farm incomes and production could increase substantially and foreign exchange requirements decline significantly if tailored recommendations replaced the current practice of making uniform fertilizer recommendations. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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