Abstracts of Nippon Dojo-Hiryogaku Zasshi 93 - 1

Original Paper

Evaluation of the changes in rice yield and soil chemical properties and estimation of potassium supply mechanism from a paddy-field soil under a 95-year long-term fertilizer experiment in Aichi Prefecture, Japan

Masahiro KASUYA^†, Kaori ANDO, Toshiya OGA, Yoshinori OHASHI and Chikako KUNO

Aichi Agricultural Research Center

^†Present address: Aichi Prefectural Economic Federations of Agricultural Cooperatives

The effects of nitrogen, phosphorus, and potassium deficiency and the continuous application of organic matter on paddy rice yield were examined in relation to the nutrient balance and changes in soil chemistry that were recorded over a period of 95 years, i.e., since 1926. The experiment consisted of the following nine treatment plots: NPK (complete), NF (non-fertilized), -N (non-nitrogen), -P (non-phosphorus), -K (non-potassium), +RSC750 (NPK+rice straw compost, 750 g m⁻²), +RSC2250 (NPK+rice straw compost, 2250 g m⁻²), NPK-Ca (NPK without slaked lime), and NF-Ca (non-fertilized and without slaked lime).

The rice grain yield among various treatment plots was arranged in the following order: (NF-Ca, NF, -P)<-N<(-K, NPK-Ca, NPK)<+RSC750<+RSC2250. The yield ratios of the NF, -P, -N, and -K plots to the NPK plot were 0.27, 0.33, 0.44, and 0.94, respectively. Rice straw compost application increased the grain yield by 1.17 times for +RSC750 and by 1.31 times for +RSC2250 as compared with the NPK plot. Potassium balance was negative in the NF, NF-Ca, -K, NPK, NPK-Ca, and +RSC750 plots. Total soil potassium, exchangeable potassium, and nonexchangeable potassium concentrations were stable for the last 45 years (since 1976), despite the negative potassium balance. Although total potassium concentration in each experimental plot was almost equal, exchangeable potassium and nonexchangeable potassium concentrations differed depending on the treatment, reflecting potassium balance. These findings suggest that potassium dynamics in this paddy field have already reached equilibrium and that weathering of soil minerals is an important source of potassium for crop yield. In addition, potassium fertility in this paddy field is considered to be very persistent because the decrease in yield in the -K plot was lower than that in the NPK plot over 95 years.

Key words: no potassium application, nonexchangeable potassium, NPK element, paddy rice, weathering

(Jpn. J. Soil Sci. Plant Nutr., 93, 1–11, 2022)

Original Paper

Effect of soil acidity amelioration by fly ash application on the priming effect in red-yellow cropland soils of Okinawa, Japan

Hideaki YASUNO¹, Soh SUGIHARA¹, Mayuko SEKI¹, Makoto SHIBATA², Takuya BAN¹ and Haruo TANAKA¹

¹Graduate School of Agriculture, Tokyo University of Agriculture and Technology; ² Graduate School of Global Environmental Studies, Kyoto University

Fly ash is an effective material for ameliorating soil acidity. Soil acidity amelioration has been considered to influence the priming effect by affecting the microbial carbon mineralization activity. However, there is little quantitative information available concerning the relationship between soil acidity amelioration by fly ash application and the priming effect. Thus, this study aimed to investigate the effect of fly ash on soil pH and the priming effect by applying ¹³C-labeled maize residue to red-yellow cropland soil (Acrisol, WRB) from Okinawa, Japan. A 60-day incubation experiment with five treatments (soil only, control [C]; ¹³C-labeled maize residue only, [R]; and ¹³C-labeled maize residue plus 5%, 10%, and 20% (w/w) fly ash [R+ FA5, R+ FA10, and R+ FA20, respectively]) was conducted. During incubation, CO₂ emission, δ¹³C of released CO₂ (to calculate primed carbon), and soil pH were periodically measured. After 60 days, the amount of primed carbon was −31.8, −56.9, −43.9, and 8.4 mg C kg⁻¹ in the R, R+ FA5, R+ FA10, and R+ FA20 plots, respectively. Soil pH after 60 days were 4.5, 4.6, 5.0, 5.3, and 5.9 in the C, R, R+ FA5, R+ FA10, and R+ FA20 plots, respectively. These results indicated that 20% (w/w) fly ash application significantly ameliorated soil pH, led to a positive priming effect, and promoted the decomposition of native soil organic carbon. On the other hand, 5% and 10% (w/w) fly ash applications only slightly, but significantly, ameliorated soil pH ranges from 4.6 to 5.0 and 5.3, respectively, causing a negative priming effect similar to that observed in the R plot.

Key words:¹³C-labeled plant residue, fly ash, priming effect, soil organic carbon

(Jpn. J. Soil Sci. Plant Nutr., 93, 12–19, 2022)

Original Paper

Effects of landform, land improvement, and land-use changes on soil profile morphology of paddy soil

Takashi KANDA^1,†, Yusuke TAKATA¹, Yuta ISE¹, Kunihiko TAKEHISA², Hiroyuki HASUKAWA^{2, ‡} and Yuji MAEJIMA¹

¹Institute for Agro-Environmental Sciences, NARO² Agricultural Technology Promotion Center of Shiga Prefecture

^†Present address: Tropical Agriculture Research Front, Japan International Research Center for Agricultural Sciences

^‡Present address: Shiga Prefecture Government

To predict present-day soil distribution in Japan, it is necessary to clarify the effects of landform, land improvement, and land-use changes on soil class because many agricultural fields have experienced anthropogenic activities since the original agricultural soil maps were created. For this purpose, we compared the previous soil profiles of a paddy field in Shiga prefecture with the results of a present-day simple soil profile survey. The results of this survey revealed that Gley lowland soils were distributed in a valley bottom plain, regardless of soil class, before land improvement and associated soil movement due to normal water addition from a nearby forested area. Although there was no relationship between soil classes in the delta landform, the soil class changed after the introduction of a drainage system and subsequent land-use changes. Gley lowland soils that occurred in the delta before land improvement were subsequently altered to other soil classes. Some soils provided good drainage in the delta before the land became a lowland-paddy soil area by paddy soil-forming processes over more than 50 years. In conclusion, although land improvement and land-use changes had a significant impact on the agricultural field surveyed, we are still able to predict modern soil distribution by considering current landforms and past soil conditions.

Key words:comprehensive soil classification system of Japan first approximation, landform, land improvement, land-use changes, simple soil profile survey

(Jpn. J. Soil Sci. Plant Nutr., 93, 20–28, 2022)

Note

Simple and rapid analysis of available nitrogen content in non-volcanic agricultural soil in Aichi Prefecture by absorbance measurement of 80°C-16 h hot water extraction

Yoshitaka NAKAMURA, Chikako KUNO, Yoshinori OHASHI, Kaori ANDO and Toshiya OTAKE

Aichi Agricultural Research Center

(Jpn. J. Soil Sci. Plant Nutr., 93, 29–33, 2022)

Lecture

Pathways and dynamics of phosphorus supply to plants through organic substances⁶. The quest for function and dynamics of soil organic phosphorus with respect to phytic acid

Yusuke UNNO

Institute for Environmental Sciences

(Jpn. J. Soil Sci. Plant Nutr., 93, 34–39, 2022)

Miscellaneous

The surveys on poor growth of asparagus in major production region

Miyuki ISHIKAWA^1,†, Shigeru YAMADA¹, Yuzo KIOKA¹, Katsunori NOGUCHI¹ and Yasufumi URASHIMA²

¹Tsukuba Research Institute, Katakura & Co-op Agri Corporation² Central Region Agricultural Research Center (Kanto, Tokai and Hokuriku Regions), NARO

^†Present address: Ibaraki Prefecture Government

(Jpn. J. Soil Sci. Plant Nutr., 93, 40–45, 2022)

Miscellaneous

Ten years after the Fukushima nuclear power plant accident: The past, present, and future of agriculture

Hirofumi TSUKADA¹, Yusuke TAKATA², Yuji MAEJIMA², Kazunori KOHYAMA², Takashi SAITO³, Noriko YAMAGUCHI², Atsushi NAKAO⁴, Shigeto FUJIMURA⁵, Naoto NIHEI⁶, Jun FURUKAWA⁷ and Takuro SHINANO8

¹Institute of Environmental Radioactivity, Fukushima University² Institute for Agro-Environmental Sciences, NARO³ Hama Agricultural Regeneration Research Centre, Fukushima Agricultural Technology Centre⁴Graduate School of Life and Environmental Sciences, Kyoto Prefectural University⁵Agricultural Radiation Research Center, Tohoku Agricultural Research Center, NARO⁶Faculty of Food and Agricultural Sciences, Fukushima University⁷Center for Research in Isotopes and Environmental Dynamics, Tsukuba University⁸Graduate School of Agriculture, Hokkaido University

(Jpn. J. Soil Sci. Plant Nutr., 93, 46–61, 2022)

Miscellaneous

Ten years after the nuclear power plant accident: The past, present, and future of agriculture

Atsushi NAKAO¹ and Takuro SHINANO²

¹ Kyoto Prefectural University² Hokkaido University, Research Faculty of Agriculture

(Jpn. J. Soil Sci. Plant Nutr., 93, 62, 2022)

Miscellaneous

Regional trends: Hokkaido

Takuji NAKAMURA

Hokkaido Agricultural Research Center, NARO (HARC/NARO)

(Jpn. J. Soil Sci. Plant Nutr., 93, 63, 2022)

Disclosure statement

No potential conflict of interest was reported by the author(s).