KINOSHITA Rintaro Assistant Professor

ThemeBuilding crop production systems suited to the soil environmental conditions

My DreamUnravel soil functions to improve agricultural productivity
  • Laboratory of Environmental Soil Science

Belongs

Research Center for Global Agromedicine/Department of Agriculture and Animal ScienceResearch Department/Department of Agro-environmental Science/Division of Plant Production Science/Section of Plant Production Science
Field Soil science, Environmental information science
Keyword Soil fertility, Phosphorus, Rapid soil assessment, Remote sensing, GIS, Clay minerals, Soil formation

Introduction

In order to achieve high crop yield while minimizing environmental impact in agricultural production, it is fundamental to understand the soils capacity to retain nutrients and water, and manage the crop according to the soil conditions. Yield potential of a crop is primarily determined by weather conditions and genetic potentials but soil’s ability to supply water and nutrients determine how much of the potential is achieved (Fig. 1). Currently, only 20-30% of the yield potential is achieved in many of crop growing areas across the world. Even in Hokkaido, depending on environmental conditions and growers management strategies, the degree of yield potential achieved is highly variable.

The characteristics of agricultural soils are variable depending on the parent materials (rocks, volcanic ash, plant residue…), climate conditions and other factors. In order for a grower to properly manage their crop, we need to understand the inherent characteristics of the soil. In our laboratory, we conduct soil profile assessment in various places in the world (Fig. 2). We incorporate the knowledge of geology to evaluate the soils in field. We also use laboratory assessment in combination with the field survey to understand the characteristics of the soil.

After understanding the inherent characteristics of the soil, we need to evaluate soil conditions of each field and within field. I have been conducting soil survey at a regional scale from various grower fields to understand the soil physical and chemical conditions. I have been assessing farm field soils at regional scale when I lived in United States where maize and soybeans are mainly grown. In my current research, I have been conducting soil survey in Kenya in East Africa (Fig. 3). In these regions, soil testing has not been incorporated in their agricultural practices. I have been working on building models to use infrared spectroscopy techniques as a rapid and low-cost soil testing method. In Tokachi Hokkaido, farm fields are getting larger and we have been finding high spatial variation of soil properties even at within-field scale. Therefore, some of my work is on the use of satellite and drone images to estimate soil properties at within-field scale (Fig. 4).

Also, we have been conducting field trials to grow potatoes at grower’s fields (Fig. 5). I have been trying to combine the knowledge of soil information that can be gained from various technologies and field trial information to derive crop production systems that is suited to particular soil environmental conditions.

Fig. 1 Factors determining yield potential and yield reducing factors
Fig. 2 Soil profiles
Fig. 3 Conducting field survey in Kiambu county, Kenya
Fig. 4 Use of drone technology for assessing soil characteristics
Fig. 5 Conducting crop growth trials in Biei town, Hokkaido

List of current research topics

  • Evaluation of within-field variable soil phosphorus fertility and soil water holding capacity using satellite and drone information
  • Use of infrared spectroscopy for soil evaluation
  • Development of phosphate fertilizer application guidelines for improving yield and quality of potatoes in Kenya
  • Influence of traditional slash-and-burn agriculture on carbon accumulation and soil fertility in Sabah, Malaysia
  • Effects of various fertilizers and soil conditioners on crop growth in various soil types
  • Effects of Chinese yam cultivation on soil fertility and ways for improvements
  • Influence of land use change on soil physical, chemical, and biological characteristics
Related industries Agricultural production, Remote sensing technologies, Fertilizer industry
Affiliated academic society Japanese Society of Soil Science and Plant Nutrition, Soil Science Society of America, Japanese Society of Pedology
エディター Pedologist: 2018-Current
Academic degree Ph.D. (Soil Science)
Self introduction

I am from Yokohama and have lived in Wales, Costa Rica, and the United States in the past 10 years before coming to Obihiro University. During that time, I not only learnt how to speak English and Spanish but also took courses in agronomy and soil science in undergraduate and post graduate courses. My main focus was the use of infrared spectroscopy techniques in soil evaluation and now I am using this expertise in estimating various soil properties using satellite and drone images. My other interests are the improvement of crop productivity worldwide through appropriate soil evaluation and soil fertility management. Much of my work focuses in Hokkaido but also I go overseas frequently for research visits. My hobby is salsa dancing that I started when I was in Costa Rica and the United States.

Room addressGeneral Research Building II
Room number202
Mail address rintaro atmark obihiro.ac.jp