Historically, to describe numbers, some cultures used bases much larger than our usual base 10, namely, 20, 40, and 60. There are explanations for 60, there is explanation but 40—used in medieval Russia—remains largely a mystery. In this paper, we provide possible all these three bases, an based on the natural need manage large groups of people. We also speculate why different bases.

Zinc (Zn) fertilizer is not currently recommended for rice grown on clay or clay loam soils in Arkansas. In 2003, eight field sites were established to evaluate the response of rice grown on clay soils to Zn fertilization. Shortly before or after seeding, granular Zn fertilizer was applied to the soil surface at rates of 0, 5, 10, and 20 lb Zn/acre. Tissue Zn concentration 10 to 14 days after f...

To reveal the effect of biochar addition on rice growth and yield under water-saving irrigation, a 2-year field experiment was carried out to clarify variations tiller number, plant height, components, irrigation water use efficiency with different application amounts (0, 20, 40 t/ha) management (flooding irrigation). The results showed that (20 15.53% 24.43% higher than non-biochar paddy field...