Shoji Moriizumi

Simulation of greenhouse energy consumption

The energy cost of greenhouses is a major concern in greenhouse management during winter time. Greenhouse energy consumption per day can be reduced by lowering the greenhouse temperature since energy consumption is approximately a linear function of the difference between inside and outside air temperature of the greenhouse. However, lower greenhouse temperature requires longer growth period. Total energy consumption is the product of these two factors, and is not simply calculated. Greenhouse energy consumption is estimated using a model developed in this project.

Simulation of Plant Shoot-Tip Temperature Based on Penman-Monteith Model

Abstract A model that predicts a plant shoot-tip temperature using five environment factors was constructed and simulation study was performed using the developed model to search the most effective environment factor which influences the shoot-tip temperature. The ambient air temperature was found to be the most effective to increase and decrease the shoot-tip temperature compared to changing glazing materials and shortwave radiation coming to the plant canopy.

Studies on the soil displacement by rotary tillage. III. On the relation between tilling pitch and the soil-overturning by down-cut rotary tillage.

As the factors to effect on soil-overturning in rotary tillage, the various factors such as soil texture, tilling pitch and the shape of rotary blade are anticipated. This report deals with the relation between tilling pitch and the soil-overturning in down-cut rotary tillage. The index of soil-overturning was used as the soil displacement ratio which was estimated by means of electrical conductivity method. This experiments were conducted in different five levels of tilling pitch ranging from 20.8mm to 72.8mm.The results were as follows.(1) From the comparison of electrical conductivity Ec between before tillage and after tillage, soil displacement to the backward by rotary tillage was confirmed in the same manner as the previous report.(2) The coefficient of variance of Ec value between the measuring points in which the soil mixing KCl was put in surface layer before tillage became larger according to the increase of tilling pitch. Therefore, it is assumed that the variation of soil displacement by rotary tillage becomes large as the tilling pitch increases.(3) It was proved that the ratio of soil displacement from upper layer to lower layer by rotary tillage decreased with the increase of tilling pitch. On the contrary, the ratio of soil remaining in upper layer after tillage showed the tendency to increase when the tilling pitch increases.(4) The soil displacement ratio of lower and upper layers by the tillage operation showed significant difference among the plots, and it was confirmed that the performance of soil-overturning by rotary tillage deteriorated with the increase of tilling pitch.