Study on the Relationships between Utilization Ratios and Conversion Rates of Nitrogen, Phosphorus and Potassium for Maize.

This paper studied the relationships between utilization ratios and conversion rates of nitrogen, phosphorus and potassium for maize by data mining method based on data of "3414 fertilizer field trials" of maize by published papers from national soil testing and recommendation since 2005. The results and conclusions were as follows: <D the conceptual model of fertilizer utilization ratio of maize for plot was that, YΝ =a + b x optimum yield, YΡ = a + b x optimum yield - c x optimum nitrogen application amount - d x optimum potassium application amount, YΚ = a - b x optimum nitrogen application amount - c x temperature in growth season -d x rainfall in growth season, respectively. (ID Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships. No significant relationships: 22, of which 16 were soil nutrients and 5 were environmental factors, the results showed that soil nutrients and environmental factors had little effect on nutrient conversion rate and fertilizer utilization ratio; consistent significant relationships: 14, illustrating that conversion rate and utilization ratio of maize were consistent in most cases, and it was because that maize was planted for a long term, and its fertilizer absorption law was basically stable; contrary significant relationships: 0, illustrating that there was no reverse relationship between conversion rate and utilization ratio of maize; complementary significant relationships: 18, the cause of the complementary phenomenon was that the fertilizer utilization ratio was the measuring index of fertilizer efficiency in one season, while the nutrient conversion rate was the measuring index of fertilizer efficiency in more seasons. It showed that the fertilizer utilization ratio was significantly correlated, or the nutrient conversion rate was significantly correlated. [ABSTRACT FROM AUTHOR]