There are several factors, which is why that makes agricultural products, such as ground conditions, depressing climate. Water for farming and rice paddies in the epidemic that occurred in a particular range, etc.
There are several factors that cause agricultural production such as low soil conditions, climate conditions for growing rice in the rice and epidemics that occurred during that time and so on.
There are several factors causing agricultural productivity decline, such as the ground, climate condition of water for farming and epidemics in paddy fields occurring in the cuisine. And so on.