TITLE:
Suitable Soil Conditions for Tomato Cultivation under an Organic Farming System
AUTHORS:
Dinesh Adhikari, Yuya Kobashi, Takamitsu Kai, Taiki Kawagoe, Kenzo Kubota, Kiwako S. Araki, Motoki Kubo
KEYWORDS:
Tomato, Bacterial Biomass, Nitrogen Circulation Activity, Phosphorus Circulation Activity, SOFIX
JOURNAL NAME:
Journal of Agricultural Chemistry and Environment,
Vol.7 No.3,
August
1,
2018
ABSTRACT: This study was conducted to determine the suitable
soil conditions for tomato cultivation under an organic farming system.
Tomatoes were cultivated in chemically and organically fertilized experimental
fields from 2013 to 2015 in Moriyama City, Shiga prefecture, Japan. Organically
and chemically fertilized soils had different total carbon (TC) and total
nitrogen (TN) contents, and different carbon-to-nitrogen ratios (C/N ratios).
The tomato yields varied from 1290 to 5960 kg/0.1ha in the organically
fertilized fields. The organic soil conditions for the highest tomato yield
showed a TC content of ~33,000 mg/kg, TN content of ~1600 mg/kg, and a C/N
ratio of ~21. The yield was reproducible in the organic fields under similar
values of TC, TN, and C/N ratio in the soil. Significantly higher nitrogen and
phosphorus circulation activities were observed in the high-yielding fields.
Appropriate control of TC, TN, and C/N ratio is necessary for the enhancement
of both microbial activity and tomato yield. Values of the important tomato
quality parameters (lycopene, glutamic acid,
and acid content) were also increased in the high- yielding tomato fields. We therefore suggest that a suitable soil condition for improving both the yield and quality of
tomatoes in an organic farming system is TC of 30,000 - 36,000 mg/kg, TN of 1600 - 1900 mg/kg, and a C/N
ratio of 18 - 21.