Abstract

In order to improve a soil test-based fertilization model for nitrogen, the Mitscherlich-Baule-Spillman equation modified by Bray and his coworkers was introduced and tested for its possibility of application. The coefficients $C_1$ and $C_2$ in the equation A were calculated by applying 10 pot experimental results done by the National Institute of Agricultural Sciences and Technology. Then, a regression(B) between C_1 and x, the fertilizer level was estimated. log(Ymax-Y) = logYmax-$C_1x-C_2b$ (A) where Ymax : maximum yield. Y : yield without or with a limited amount of fertilizer applied, x : application level of fertilizer, b : content of a nutrient in soil, $C_1$ and $C_2$ : coefficients of x and b, respectively. log(0.05)=$-C_1x-C_2b$ (B) Fertilizer requirement calculated by the equation B was significantly correlated with the real level of fertilizer applied for 95 percentage of the maximum yield. A more extensive and precise study on $C_1$ and $C_2$ in the equation A in expected to improve significantly the fitness of soil analysis to the fertilizer recommendation.

토양검정의 적중율을 높이기 위하여 농업과학기술원에서 실시한 10개의 pot시험 결과를 Bray등이 개정한 Mitscherlich-Baule-Spillman식(A)에 넣어 토양질소와 시비질소의 이용계수 $C_2$와 $C_1$을 계산하고, 적정 수량을 생산하는데 소요되는 시비량(x) 산출식(B)을 유도하였다. log(Ymax-Y) = logYmax-$C_1x-C_2b$ (A) Ymax : 최고수량, Y: 무비구 또는 일정량의 시비구 수량 b: 토양의 $NO_3{^-}-N(mg\;kg^{-1})$, x:시비량 log(0.05))=$-C_1x-C_2b$ =-C_1x-C_2b (B) 실제 시비량에 대한 식 B로 계산되는 비료 소요량과 는 유의한 정의 상관 관계를 보였다. 식 A와 B의 $C_1$과 $C_2$값에 관한 정밀한 연구는 토양검정의 실용성을 높일 수 있다.

Keywords

• Soil nitrogen;
• Fertilizer recommendation;
• Soil test