Study on the physical properties of mixture of fertilizer granules and Coniothyrium Minitans of combined precision seeder for rapeseed

Abstract

<sc>Abstract.</sc> Coniothyrium Minitans is a kind of biological fungicide with high control effect against Sclerotinia sclerotiorum. There is a potential and simplification method to deliver a mixture of compound fertilizer and Coniothyrium Minitans powder into seedbed simultaneously with rape seed by using combined seeder.For this purpose, the special slow-releas fertilizer, common compound fertilizer and Coniothyrium Minitans powder were taken as the research objects and the triaxial size, hygroscopicity, friction coefficient and caking property of the fertilizers and the mixture of the fertilizer and the powder were measured by the determinator for agricultural materials. The results showed that the natural repose angle of special slow-release compound fertilizer, common compound fertilizer and Coniothyrium Minitans powder was 30.45 °, 32.20 ° and 44.88 ° respectively. The static friction coefficient with iron plate was 0.35, 0.41 and 0.70, which was similar with the acrylic plate that was 0.45, 0.57 and 0.70. The moisture absorption ratio of special slow-release compound fertilizer, common compound fertilizer and Coniothyrium Minitans was 0.213%, 0.287% and 0.267% respectively in ten to twenty minutes. While later twenty minutes the ratio beginning to change, the average increment of moisture absorption ratio was 0.006%<monospace>、</monospace>0.287% and 0.015%, respectively. The natural repose angle and static friction coefficient of the mixture increased with the increase of the addition of Coniothyrium Minitans. Although the moisture absorption of the mixture increased gradually with growth over time, it was significantly lower than the bare fertilizer in the first twenty minutes, which indicated that Coniothyrium Minitans could be effectively inhibited the moisture absorption of fertilizer. This study provided a reference for using the fertilizer and powder mixture by employed a combined seeder for rapeseed.